From pata at ieee.org  Mon Nov  1 03:29:13 2010
From: pata at ieee.org (pata at ieee.org)
Date: Mon, 01 Nov 2010 11:29:13 +0900
Subject: [sdiy] SSM2020 Dual VCAs needed
In-Reply-To: <4CCDCAD6.4050903@sbcglobal.net>
References: <4CCDCAD6.4050903@sbcglobal.net>
Message-ID: <4CCE25F9.9040306@ieee.org>

"Ubanmusic", Japan, says they have some SSM chips.

http://www.urbanmusic.com/frame_top.html

(2010/11/01 5:00), klosmon wrote:
> ...to help maintain some rev 2 Prophet 5s for some people.
> Anybody have any spares, let me know.
> Thanks.
>
> ~GMM

-- 
=========================================
KATAYAMA, Takuya
Muse Music Synthesizer Laboratory, Japan


From ic1 at bell.net  Mon Nov  1 09:03:35 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Mon, 1 Nov 2010 04:03:35 -0400
Subject: [sdiy] Alesis Midiverb eprom images
Message-ID: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>

Hi list,

I think I messed up the 27C256, U51, eprom when I read it in my trusty old eprom programmer.
I discovered that to my horror it wasn't properly seated in it's ISA slot.
I looked at the bins and could see only a partial read was succesful, i.e. lower 512 are all FF's.
Now the unit behaves erratically and distorts and overloads.
I also read the 2764 operating system, and it also partially read.
I took the normal static precautions and used a ground strap.

I am devastated and am pleading with anybody who might have a copy of the images they'd be willing to share.
I can trade for some other machines eprom images.

This is the original 12 bit DAC/SAR Midiverb.

U51 27C256 label reads "MVOBJ 2-6-86" ( effects programs)
U54 2764 label reads "MVOP 4-7-86" (operating system for the 80C31)

Appreciate any help with this, in the meantime I have contacted Alesis in a last ditch effort.

Tony Kalomiris




From rw at firstpr.com.au  Mon Nov  1 09:50:28 2010
From: rw at firstpr.com.au (Robin Whittle)
Date: Mon, 01 Nov 2010 19:50:28 +1100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
Message-ID: <4CCE7F54.7070800@firstpr.com.au>

Hi Tony,

Here are the raw binary images of the EPROM which drives the DSP
section, for the MIDIVerb in its two incarnations - a reverb device
and an effects device (delay etc. if I recall correctly):

  http://www.firstpr.com.au/temp/MIDIVERB/MVERBREV
  http://www.firstpr.com.au/temp/MIDIVERB/MVERBFEX

I took these and used them in the mid-80s, but haven't used them
since.  It is possible to make a dual mode device, with a toggleswitch
to select between two EPROMs, or to control the highest address bit of
a 27C512.

I think the MIDIVerb DSP section is remarkable - just an EPROM,
standard logic chips, RAM and a DAC, with a bit of analogue circuitry.
 It performs A to D, stereo D to A and then all the effects.  I recall
staring at the circuit for a long time and still not being able to
figure out how it works.

  Cheers

    - Robin         http://www.firstpr.com.au/rwi/dfish/

> Hi list,
> 
> I think I messed up the 27C256, U51, eprom when I read it in my trusty old eprom programmer.
> I discovered that to my horror it wasn't properly seated in it's ISA slot.
> I looked at the bins and could see only a partial read was succesful, i.e. lower 512 are all FF's.
> Now the unit behaves erratically and distorts and overloads.
> I also read the 2764 operating system, and it also partially read.
> I took the normal static precautions and used a ground strap.
> 
> I am devastated and am pleading with anybody who might have a copy of the images they'd be willing to share.
> I can trade for some other machines eprom images.
> 
> This is the original 12 bit DAC/SAR Midiverb.
> 
> U51 27C256 label reads "MVOBJ 2-6-86" ( effects programs)
> U54 2764 label reads "MVOP 4-7-86" (operating system for the 80C31)
> 
> Appreciate any help with this, in the meantime I have contacted Alesis in a last ditch effort.
> 
> Tony Kalomiris


From aym-htnys at teaser.fr  Mon Nov  1 11:33:42 2010
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Mon, 1 Nov 2010 11:33:42 +0100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <4CCE7F54.7070800@firstpr.com.au>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
Message-ID: <20101101103342.GA4201@aym.net2.nerim.net>

On 2010-11-01 19:50 +1100, Robin Whittle wrote:

> Here are the raw binary images of the EPROM which drives the DSP
> section, for the MIDIVerb in its two incarnations - a reverb device
> and an effects device (delay etc. if I recall correctly):

There were two versions of the Midiverb ?

> I think the MIDIVerb DSP section is remarkable - just an EPROM,
> standard logic chips, RAM and a DAC, with a bit of analogue circuitry.
>  It performs A to D, stereo D to A and then all the effects.  I recall
> staring at the circuit for a long time and still not being able to
> figure out how it works.

http://valhalladsp.wordpress.com/2010/08/25/rip-keith-barr/

"The DRAM required 2 addressing cycles, ROW and COLUMN, each 7
bits wide. I developed a system that fetched 2 bytes from the
EEPROM and used the lower 7 bits of each as row and column
addresses, after passing them through an 8 bit adder which
summed the last values of ROW and COL with the new ones. This
eliminated an address counter, as the code simply expressed the
next address relative to the previous address."

-- 
Andr? Majorel http://www.teaser.fr/~amajorel/


From ic1 at bell.net  Mon Nov  1 13:55:48 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Mon, 1 Nov 2010 08:55:48 -0400
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <4CCE7F54.7070800@firstpr.com.au>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
Message-ID: <BLU0-SMTP324349015393F4F843DE2A97480@phx.gbl>

Hi Robin,

Thanks so much for this , I really appreciate it.
One question can I can append the FEX to the VERB and burn into a 27C256 as per the original eprom ?
The images you so generously provided are 16 K each.
Could the MVERBFEX be from a MIDIFEX unit and not a MIDIVERB ? Apparently the only difference was one eprom - the hardware was identical.
In fact there was a guy from Ontario who offered a mod that had one half VERB and one half FEX programs, for the best of both worlds.
I know 1986 is a long time ago ;- )

I hate to sound greedy here but you wouldn't happen to also have the 2764 eprom image for the 80C31 ? 
I'm still worried I might have damaged that one , but I doubt it, it's a NMOS part - but you never know.


Tony Kalomiris


On 2010-11-01, at 4:50 AM, Robin Whittle wrote:

> Hi Tony,
> 
> Here are the raw binary images of the EPROM which drives the DSP
> section, for the MIDIVerb in its two incarnations - a reverb device
> and an effects device (delay etc. if I recall correctly):
> 
>  http://www.firstpr.com.au/temp/MIDIVERB/MVERBREV
>  http://www.firstpr.com.au/temp/MIDIVERB/MVERBFEX
> 
> I took these and used them in the mid-80s, but haven't used them
> since.  It is possible to make a dual mode device, with a toggleswitch
> to select between two EPROMs, or to control the highest address bit of
> a 27C512.
> 
> I think the MIDIVerb DSP section is remarkable - just an EPROM,
> standard logic chips, RAM and a DAC, with a bit of analogue circuitry.
> It performs A to D, stereo D to A and then all the effects.  I recall
> staring at the circuit for a long time and still not being able to
> figure out how it works.
> 
>  Cheers
> 
>    - Robin         http://www.firstpr.com.au/rwi/dfish/
> 
>> Hi list,
>> 
>> I think I messed up the 27C256, U51, eprom when I read it in my trusty old eprom programmer.
>> I discovered that to my horror it wasn't properly seated in it's ISA slot.
>> I looked at the bins and could see only a partial read was succesful, i.e. lower 512 are all FF's.
>> Now the unit behaves erratically and distorts and overloads.
>> I also read the 2764 operating system, and it also partially read.
>> I took the normal static precautions and used a ground strap.
>> 
>> I am devastated and am pleading with anybody who might have a copy of the images they'd be willing to share.
>> I can trade for some other machines eprom images.
>> 
>> This is the original 12 bit DAC/SAR Midiverb.
>> 
>> U51 27C256 label reads "MVOBJ 2-6-86" ( effects programs)
>> U54 2764 label reads "MVOP 4-7-86" (operating system for the 80C31)
>> 
>> Appreciate any help with this, in the meantime I have contacted Alesis in a last ditch effort.
>> 
>> Tony Kalomiris
> 



From ic1 at bell.net  Mon Nov  1 14:19:57 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Mon, 1 Nov 2010 09:19:57 -0400
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <4CCE7F54.7070800@firstpr.com.au>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
Message-ID: <BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>

Morning Robin and list memebers,

Ok I re-read your message, and think I understand now.
The MIDIVERB and MIDIFEX units only use one half of the 27C256 eprom.
That's why I got one half unprogammed for the first 16 K (not 256 as originally reported) - all FF's.
Ok the programs start at $4000.
The MVERBREV image is from the MIDIVERB and the MVERBFEX is from the MIDFEX unit, I'm guessing.
So  I would need to load these into a 27C256 and toggle the high order address bit, not a 27C512.
Sound about right ?

Tony Kalomiris



From m.bareille at free.fr  Mon Nov  1 15:08:31 2010
From: m.bareille at free.fr (m.bareille at free.fr)
Date: Mon, 01 Nov 2010 15:08:31 +0100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
	<BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>
Message-ID: <1288620511.4ccec9dfea6fd@imp.free.fr>

Hello,

I did this 'mod' many times and all my Midiverb/fex are tweaked like this :)

MidiVerb and Midifex share  the same hardware exactly, the difference is only
into the 'object' eprom who contain effects algorithms ( or IR models may be ? )
The reverb structure look like a  discrete TTL/CMOS logic DSP , with a 12 bits
DAC.

You can put Midiverb and Midifex datas all into a 27C512 eprom, add a switch on
the panel  to swap the MSB adress of the eprom to selec 'verb'or 'fex' area and
then you get a two in one effect box with 127 preset instead of 63 :)

It is very easy to do , it work really fine :)

Just take  care to use a fast eprom with 70nsec latency . I you use a 100nsec or
slower  eprom it make very ugly noise ( digital bugs ) because the eprom cannot
provide datas fast enough

Cheers,

Marc B.

Papareil Synth Labs
http://m.bareille.free.fr





Selon Tony Kalomiris <ic1 at bell.net>:

> Morning Robin and list memebers,
>
> Ok I re-read your message, and think I understand now.
> The MIDIVERB and MIDIFEX units only use one half of the 27C256 eprom.
> That's why I got one half unprogammed for the first 16 K (not 256 as
> originally reported) - all FF's.
> Ok the programs start at $4000.
> The MVERBREV image is from the MIDIVERB and the MVERBFEX is from the MIDFEX
> unit, I'm guessing.
> So  I would need to load these into a 27C256 and toggle the high order
> address bit, not a 27C512.
> Sound about right ?
>
> Tony Kalomiris
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From m.bareille at free.fr  Mon Nov  1 17:00:33 2010
From: m.bareille at free.fr (m.bareille at free.fr)
Date: Mon, 01 Nov 2010 17:00:33 +0100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
	<BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>
Message-ID: <1288627233.4ccee421116ad@imp.free.fr>


I have quickly setup a web page with pictures i had on my drives about the
Midiverb / Midifex eprmos mods and other minor tweaks i did on it ...

It is here now :

http://m.bareille.free.fr/goodies/midiverb/midiverb.htm


Cheers,

Marc B.






From loscha at gmail.com  Mon Nov  1 22:22:31 2010
From: loscha at gmail.com (Loscha)
Date: Tue, 2 Nov 2010 08:22:31 +1100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <1288627233.4ccee421116ad@imp.free.fr>
References: <BLU0-SMTP3378BCED91112B9F78EC1B97480@phx.gbl>
	<4CCE7F54.7070800@firstpr.com.au>
	<BLU0-SMTP8946243793F05A81700D2497480@phx.gbl>
	<1288627233.4ccee421116ad@imp.free.fr>
Message-ID: <AANLkTikEK8PTBwCsTJzdaTqqKhNJtP1Uq-DKegfcy83Z@mail.gmail.com>

Thanks very much for this stuff Marc and Robin.

I have had one of these for a few good many years now, and I did a few
minor changes to mine as well.

I replaced the RCA plugs on the back with real jack plugs. This was
quite easy. I had small enough jack sockets that I just bolted them in
and ran an inch of wire to the board. The back of the case sits about
1mm shy of closing, but that was because I didn't file out the arch a
bit - I think the sockets were ones salvaged from a broken Yamaha Rx5
drum machine - they are mostly black, but with some red plastic on one
side.

I replaced some of the LEDs with modern LEDs, but because they have
different voltage drops, the way their circuit works didn't agree with
it too much. I wouldn't recommend this unless you had the proper
schematic so you can calculate changes in all the resistors (not just
the current limiting resistor - it seems more complicated than that).

Paul Perry has (or at least had in Feb of 07 when I took this photo)
one that was modded to be a double-tasked unit
http://www.loscha.com/images/PP-Verb-Chips.jpg
http://www.loscha.com/images/PP-Verb-Front.jpg  (Mmark, please feel
free to copy these images to your site or link to them).

The audio has a slight compressing quality as it goes into the unit as
well, which also adds to the uniqueness of the sound, I think.

Again, no idea what's going on there, but would love to see a schematic.

/Edward

On Tue, Nov 2, 2010 at 3:00 AM,  <m.bareille at free.fr> wrote:
>
> I have quickly setup a web page with pictures i had on my drives about the
> Midiverb / Midifex eprmos mods and other minor tweaks i did on it ...
>
> It is here now :
>
> http://m.bareille.free.fr/goodies/midiverb/midiverb.htm
>
>
> Cheers,
>
> Marc B.
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



-- 
www.loscha.com


From grant at musictechnologiesgroup.com  Mon Nov  1 23:42:02 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Mon, 01 Nov 2010 15:42:02 -0700
Subject: [sdiy] Alesis Midiverb eprom images
Message-ID: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>

Judging from the photos I think you are correct. Pin 27 is A14 and it's
pulled up to Vcc using the resistor you see. The switch probably just
grounds A14 in one position and leaves it to be pulled high to Vcc by
the resistor in the other position. This seems to indicate that the code
is 27128 size or smaller, but they just used 27256's for cost or
convenience.  So basically you have two "pages" (or banks) of 128kbits
or 32kbytes.

GB


> -------- Original Message --------
> Subject: Re: [sdiy] Alesis Midiverb eprom images
> From: Tony Kalomiris <ic1 at bell.net>
> Date: Mon, November 01, 2010 6:19 am
> To: Robin Whittle <rw at firstpr.com.au>
> Cc: synth diy <synth-diy at dropmix.xs4all.nl>
> 
> 
> Morning Robin and list memebers,
> 
> Ok I re-read your message, and think I understand now.
> The MIDIVERB and MIDIFEX units only use one half of the 27C256 eprom.
> That's why I got one half unprogammed for the first 16 K (not 256 as originally reported) - all FF's.
> Ok the programs start at $4000.
> The MVERBREV image is from the MIDIVERB and the MVERBFEX is from the MIDFEX unit, I'm guessing.
> So  I would need to load these into a 27C256 and toggle the high order address bit, not a 27C512.
> Sound about right ?
> 
> Tony Kalomiris
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From grant at musictechnologiesgroup.com  Tue Nov  2 00:06:25 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Mon, 01 Nov 2010 16:06:25 -0700
Subject: [sdiy] Alesis Midiverb eprom images
Message-ID: <20101101160625.c16e921f9c8655b42ea149fc1daa3492.e0fa966782.wbe@email04.secureserver.net>

> convenience.  So basically you have two "pages" (or banks) of 128kbits
> or 32kbytes.

Argh. Two pages of 16kbytes.  :-)



From m.bareille at free.fr  Tue Nov  2 00:13:05 2010
From: m.bareille at free.fr (m.bareille at free.fr)
Date: Tue, 02 Nov 2010 00:13:05 +0100
Subject: [sdiy] Alesis Midiverb eprom images
In-Reply-To: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
Message-ID: <1288653185.4ccf49816116c@imp.free.fr>

ooops sorry for the mistake in previous email ...

The eprom is a 27C256 !

Cheers,

Marc B.


Selon grant at musictechnologiesgroup.com:

> Judging from the photos I think you are correct. Pin 27 is A14 and it's
> pulled up to Vcc using the resistor you see. The switch probably just
> grounds A14 in one position and leaves it to be pulled high to Vcc by
> the resistor in the other position. This seems to indicate that the code
> is 27128 size or smaller, but they just used 27256's for cost or
> convenience.  So basically you have two "pages" (or banks) of 128kbits
> or 32kbytes.
>
> GB
>
>
> > -------- Original Message --------
> > Subject: Re: [sdiy] Alesis Midiverb eprom images
> > From: Tony Kalomiris <ic1 at bell.net>
> > Date: Mon, November 01, 2010 6:19 am
> > To: Robin Whittle <rw at firstpr.com.au>
> > Cc: synth diy <synth-diy at dropmix.xs4all.nl>
> >
> >
> > Morning Robin and list memebers,
> >
> > Ok I re-read your message, and think I understand now.
> > The MIDIVERB and MIDIFEX units only use one half of the 27C256 eprom.
> > That's why I got one half unprogammed for the first 16 K (not 256 as
> originally reported) - all FF's.
> > Ok the programs start at $4000.
> > The MVERBREV image is from the MIDIVERB and the MVERBFEX is from the MIDFEX
> unit, I'm guessing.
> > So  I would need to load these into a 27C256 and toggle the high order
> address bit, not a 27C512.
> > Sound about right ?
> >
> > Tony Kalomiris
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From thx1138 at earthlink.net  Tue Nov  2 03:40:57 2010
From: thx1138 at earthlink.net (thx1138)
Date: Mon, 01 Nov 2010 19:40:57 -0700
Subject: [sdiy] Wersi Organ Contact springs
Message-ID: <C8F4C849.20D9C%thx1138@earthlink.net>

Hi Guys,

I am restoring a PPG PRK and am in need of some Wersi Organ Contact springs.

Anyone seen these Organ DIT guys around anymore?

Regards,

Terry



From tom at electricdruid.net  Tue Nov  2 13:11:21 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 2 Nov 2010 12:11:21 +0000
Subject: [sdiy] CMOS Switches
Message-ID: <E68FED5C-F7A4-4B7F-B461-8706A9D4DF93@electricdruid.net>

Hi there,

Does anyone know of a CMOS switch IC (either original 4000 series or DG) that is arranged as a dual 4x1 switch? There are quite a few that *claim* to be this arrangement, but in fact they share the two address pins, which means the two switches can't be set to different inputs. I need something where either switch can be set to any of the four inputs.

If not, I guess I have to do it with two quad SPST chips. At least that's versatile!

Thanks
Tom



From paul at fitvideo.co.uk  Tue Nov  2 13:17:16 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Tue, 2 Nov 2010 12:17:16 -0000
Subject: [sdiy] Moog
Message-ID: <000501cb7a87$e47b4a90$ad71dfb0$@co.uk>

This just dropped in my inbox here in the UK..

http://www.nytimes.com/2010/11/02/arts/music/02moog.html?_r=1&nl=nyregion&em
c=urb3

Regards

Paul Burns



From cheater00 at gmail.com  Tue Nov  2 14:49:38 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 2 Nov 2010 14:49:38 +0100
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
Message-ID: <AANLkTinSjkdTPTKJ9YsA1BZvXF7sMAsORmOkXRSNHGKn@mail.gmail.com>

Hi Tom!
Thanks a lot for the link, it was very helpful to figure out how this
is supposed to work :) I wonder what sort of problems it could cause
to other devices in the adjacent signal chain (i.e. the effect units
connected to the input of our stomp box)

On 28/10/2010, Tom Wiltshire <tom at electricdruid.net> wrote:
> Fair enough - words are not exactly the best way to transmit this type of
> information. It's amazing we get as much across on this forum as we do
> manage.
>
> This page has the whole lot on stompbox power, with diagrams:
>
> http://www.beavisaudio.com/techpages/PedalPower/
>
> FWIW, I disagree with Don and Harry. Whilst it might send the power through
> lots of connections and so forth, it's a simple method, is cheap to do (and
> cheap to repair), and uses the most basic, easily available parts. That
> makes it a good fit for a box that spends its life getting stamped on on
> that beer-soaked floor Harry mentioned.
>
> T.
>
>
> On 28 Oct 2010, at 17:22, cheater cheater wrote:
>
>>
>> Tom,
>>> That's often done using a normal stereo jack with no 'break' or 'make'
>>> connections at all. Instead when a normal mono jack is inserted into
>>> a stereo socket, the ground and the ring are connected together by
>>> the jack. When there's no jack, the circuit has no ground connection
>>> and is switched off.
>>
>> How does that work? I'm sorry, I'm having a bit of a hard time visualizing
>> :-)
>>
>> Thanks,
>> D.
>
>


From neil.johnson97 at ntlworld.com  Tue Nov  2 15:22:42 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 2 Nov 2010 14:22:42 +0000
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
Message-ID: <AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>

Hi,

Tom Wiltshire wrote:
> FWIW, I disagree with Don and Harry. Whilst it might send the power through lots of
> connections and so forth, it's a simple method, is cheap to do (and cheap to repair), and
> uses the most basic, easily available parts. That makes it a good fit for a box that spends
> its life getting stamped on on that beer-soaked floor Harry mentioned.

Why not use a p-channel MOSFET to switch the power, with its gate
pulled low by the mono-in-stereo ground ring switch?

Cost increment is pretty small (one transistor, one resistor) and it
minimises the current through the jack plug.

Neil
-- 
http://www.njohnson.co.uk


From cheater00 at gmail.com  Tue Nov  2 16:40:30 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 2 Nov 2010 16:40:30 +0100
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
	<AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
Message-ID: <AANLkTi=dbm4M9hc+XnsYL+_CaVAFZ-A5Cei-qZEFUcO+@mail.gmail.com>

I am guessing one more way would be to have some form of "current
detection" circuit in the signal path... which would detect if there's
a closed circuit (hence, signal coming in and so, current
happening)... and you could use that MOSFET you talk about, I guess?

Cheers,
D.

On Tue, Nov 2, 2010 at 15:22, Neil Johnson <neil.johnson97 at ntlworld.com> wrote:
> Hi,
>
> Tom Wiltshire wrote:
>> FWIW, I disagree with Don and Harry. Whilst it might send the power through lots of
>> connections and so forth, it's a simple method, is cheap to do (and cheap to repair), and
>> uses the most basic, easily available parts. That makes it a good fit for a box that spends
>> its life getting stamped on on that beer-soaked floor Harry mentioned.
>
> Why not use a p-channel MOSFET to switch the power, with its gate
> pulled low by the mono-in-stereo ground ring switch?
>
> Cost increment is pretty small (one transistor, one resistor) and it
> minimises the current through the jack plug.
>
> Neil
> --
> http://www.njohnson.co.uk
>


From neil.johnson97 at ntlworld.com  Tue Nov  2 16:52:29 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 2 Nov 2010 15:52:29 +0000
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <AANLkTi=dbm4M9hc+XnsYL+_CaVAFZ-A5Cei-qZEFUcO+@mail.gmail.com>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
	<AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
	<AANLkTi=dbm4M9hc+XnsYL+_CaVAFZ-A5Cei-qZEFUcO+@mail.gmail.com>
Message-ID: <AANLkTinm52bVFO14o5B26O9bTNtmLWe_BbUw33ZxaXEH@mail.gmail.com>

Hi,

On 2 November 2010 15:40, cheater cheater <cheater00 at gmail.com> wrote:
> I am guessing one more way would be to have some form of "current
> detection" circuit in the signal path... which would detect if there's
> a closed circuit (hence, signal coming in and so, current
> happening)... and you could use that MOSFET you talk about, I guess?

Nah, you're just overcomplicating things for no additional benefit.
Also, what to do about quiet moments (i.e. what is the signal
detection threshold?) - do you want the popping sounds as the supply
switches on/off?  Probably not.

keep it simple.

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From harrybissell at wowway.com  Tue Nov  2 17:19:41 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 2 Nov 2010 12:19:41 -0400 (EDT)
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <AANLkTinm52bVFO14o5B26O9bTNtmLWe_BbUw33ZxaXEH@mail.gmail.com>
Message-ID: <779087799.73879.1288714781364.JavaMail.root@md01.wow.synacor.com>

LOL 

I was going to suggest an "auto-off" circuit that would power the
stompbox down (let's say) five minutes after your last 'power chord'


(wouldn't that just p!ss you off :^)

H^) harry


----- Original Message -----
From: Neil Johnson <neil.johnson97 at ntlworld.com>
To: cheater cheater <cheater00 at gmail.com>
Cc: Synth DIY <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 02 Nov 2010 11:52:29 -0400 (EDT)
Subject: Re: [sdiy] Stompbox power (was Re: Socket schematic symbol question)

Hi,

On 2 November 2010 15:40, cheater cheater <cheater00 at gmail.com> wrote:
> I am guessing one more way would be to have some form of "current
> detection" circuit in the signal path... which would detect if there's
> a closed circuit (hence, signal coming in and so, current
> happening)... and you could use that MOSFET you talk about, I guess?

Nah, you're just overcomplicating things for no additional benefit.
Also, what to do about quiet moments (i.e. what is the signal
detection threshold?) - do you want the popping sounds as the supply
switches on/off?  Probably not.

keep it simple.

Cheers,
Neil
-- 
http://www.njohnson.co.uk
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From tom at electricdruid.net  Tue Nov  2 17:20:39 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 2 Nov 2010 16:20:39 +0000
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
	<AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
Message-ID: <EFC8556F-E979-4843-9DF3-738A0E0EBBE1@electricdruid.net>


On 2 Nov 2010, at 14:22, Neil Johnson wrote:

> Hi,
> 
> Tom Wiltshire wrote:
>> FWIW, I disagree with Don and Harry. Whilst it might send the power through lots of
>> connections and so forth, it's a simple method, is cheap to do (and cheap to repair), and
>> uses the most basic, easily available parts. That makes it a good fit for a box that spends
>> its life getting stamped on on that beer-soaked floor Harry mentioned.
> 
> Why not use a p-channel MOSFET to switch the power, with its gate
> pulled low by the mono-in-stereo ground ring switch?
> 
> Cost increment is pretty small (one transistor, one resistor) and it
> minimises the current through the jack plug.

Ok, but what's the advantage? I don't get it (but it's been a long grey day...).

Tom



From neil.johnson97 at ntlworld.com  Tue Nov  2 17:39:28 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 2 Nov 2010 16:39:28 +0000
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <EFC8556F-E979-4843-9DF3-738A0E0EBBE1@electricdruid.net>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
	<AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
	<EFC8556F-E979-4843-9DF3-738A0E0EBBE1@electricdruid.net>
Message-ID: <AANLkTintCH02YkcTUbp+ROhucS8LJDCZfW3TThauWQ94@mail.gmail.com>

Hi,

Tom Wiltshire wrote:
> Neil Johnson wrote:
>> Why not use a p-channel MOSFET to switch the power, with its gate
>> pulled low by the mono-in-stereo ground ring switch?
>>
>> Cost increment is pretty small (one transistor, one resistor) and it
>> minimises the current through the jack plug.
>
> Ok, but what's the advantage? I don't get it (but it's been a long grey day...).

You don't put the battery across the input jack as it is pushed in?  I
dunno, I guess it depends on personal preference, and how cheap and
crackly you want to be.

Neil
-- 
http://www.njohnson.co.uk


From tom at electricdruid.net  Tue Nov  2 18:41:42 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 2 Nov 2010 17:41:42 +0000
Subject: [sdiy] Stompbox power (was Re: Socket schematic symbol question)
In-Reply-To: <AANLkTintCH02YkcTUbp+ROhucS8LJDCZfW3TThauWQ94@mail.gmail.com>
References: <4cc9790a.04f6d80a.3983.3017@mx.google.com>
	<11C43BD5-351E-4D84-BA6A-30AC174F3D38@till.com>
	<4CC99CF8.5080108@eventualdecline.com>
	<AANLkTimMRkhA_3UZtJEUJWLeY2hYhib95770wMHUkBN8@mail.gmail.com>
	<3A2575A5-325A-4F6C-AE84-DAA34299E40D@electricdruid.net>
	<AANLkTimFMZOtUqXBiAHUAptrB78FRNNUBgLWUd2oGkTO@mail.gmail.com>
	<EFC8556F-E979-4843-9DF3-738A0E0EBBE1@electricdruid.net>
	<AANLkTintCH02YkcTUbp+ROhucS8LJDCZfW3TThauWQ94@mail.gmail.com>
Message-ID: <5AFCB91D-644B-4B17-9A18-B447A6DAA8C1@electricdruid.net>


On 2 Nov 2010, at 16:39, Neil Johnson wrote:
> Tom Wiltshire wrote:
>> Neil Johnson wrote:
>>> Why not use a p-channel MOSFET to switch the power, with its gate
>>> pulled low by the mono-in-stereo ground ring switch?
>>> 
>>> Cost increment is pretty small (one transistor, one resistor) and it
>>> minimises the current through the jack plug.
>> 
>> Ok, but what's the advantage? I don't get it (but it's been a long grey day...).
> 
> You don't put the battery across the input jack as it is pushed in?  I
> dunno, I guess it depends on personal preference, and how cheap and
> crackly you want to be.

It's only the battery -ve terminal, so it's not like you're feeding 9V back up the jack lead.

Do I want to be cheap and crackly? Dunno. It's funny how these things go around though. When I was younger, the Boss pedals were highly regarded because they featured 'noiseless switching' (done with a couple of FETs and discrete flip-flop attached to the footswitch). Nowadays everyone wants 'true bypass' and people are modding the old Boss pedals to remove the noiseless switching!

T.




From cheater00 at gmail.com  Tue Nov  2 20:01:22 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 2 Nov 2010 20:01:22 +0100
Subject: [sdiy] Wersi Organ Contact springs
In-Reply-To: <C8F4C849.20D9C%thx1138@earthlink.net>
References: <C8F4C849.20D9C%thx1138@earthlink.net>
Message-ID: <AANLkTi=WnsmfLvkHyYrdvt8mSukUQqu5uM4Bxe0i0n19@mail.gmail.com>

Hi Terry,
have you tried talking to Wersi directly? Or service centers?
There are those guys:
http://www.wersi-orgelstudio.de/

There's also a fairly comprehensive list of service centers here:
http://www.wersi.net/service.html

the page does say that it's only for the "newer" organs, but I think
at least some of those guys should be able to handle issues with the
older kinds as well.

Cheers,
D.

On Tue, Nov 2, 2010 at 03:40, thx1138 <thx1138 at earthlink.net> wrote:
> Hi Guys,
>
> I am restoring a PPG PRK and am in need of some Wersi Organ Contact springs.
>
> Anyone seen these Organ DIT guys around anymore?
>
> Regards,
>
> Terry
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From gsn10 at hotmail.com  Wed Nov  3 17:18:10 2010
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Wed, 3 Nov 2010 12:18:10 -0400
Subject: [sdiy] Wersi Organ Contact springs
In-Reply-To: <AANLkTi=WnsmfLvkHyYrdvt8mSukUQqu5uM4Bxe0i0n19@mail.gmail.com>
References: <C8F4C849.20D9C%thx1138@earthlink.net>,
	<AANLkTi=WnsmfLvkHyYrdvt8mSukUQqu5uM4Bxe0i0n19@mail.gmail.com>
Message-ID: <SNT104-W373CDE82A09731431C5375B44A0@phx.gbl>


Here's the problem with finding older Wersi parts: they went through 
several bankruptcies and changes of ownership in the 90's, and after 
numerous liquidations, all old parts are very likely long gone.? On 
top of that they are known for decades of poor support and many 
who would be of assistance refuse to deal with them.

It took me years to find an MK1/EX20 user manual, but I finally 
found one...

----------------------------------------
> Date: Tue, 2 Nov 2010 20:01:22 +0100
> From: cheater00 at gmail.com
> To: thx1138 at earthlink.net
> CC: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Wersi Organ Contact springs
>
> Hi Terry,
> have you tried talking to Wersi directly? Or service centers?
> There are those guys:
> http://www.wersi-orgelstudio.de/
>
> There's also a fairly comprehensive list of service centers here:
> http://www.wersi.net/service.html
>
> the page does say that it's only for the "newer" organs, but I think
> at least some of those guys should be able to handle issues with the
> older kinds as well.
>
> Cheers,
> D.
>
> On Tue, Nov 2, 2010 at 03:40, thx1138  wrote:
> > Hi Guys,
> >
> > I am restoring a PPG PRK and am in need of some Wersi Organ Contact springs.
> >
> > Anyone seen these Organ DIT guys around anymore?
> >
> > Regards,
> >
> > Terry
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
 		 	   		  

From cheater00 at gmail.com  Wed Nov  3 17:57:38 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Wed, 3 Nov 2010 17:57:38 +0100
Subject: [sdiy] Wersi Organ Contact springs
In-Reply-To: <SNT104-W373CDE82A09731431C5375B44A0@phx.gbl>
References: <C8F4C849.20D9C%thx1138@earthlink.net>
	<AANLkTi=WnsmfLvkHyYrdvt8mSukUQqu5uM4Bxe0i0n19@mail.gmail.com>
	<SNT104-W373CDE82A09731431C5375B44A0@phx.gbl>
Message-ID: <AANLkTin6Evi0cXE0vUPBz63w9SYe1ycZs6qVkt6bSPXs@mail.gmail.com>

You didn't end up digitizing it by chance, did you? :)

Cheers,
D.

On Wed, Nov 3, 2010 at 17:18, Scott Nordlund <gsn10 at hotmail.com> wrote:
>
> Here's the problem with finding older Wersi parts: they went through
> several bankruptcies and changes of ownership in the 90's, and after
> numerous liquidations, all old parts are very likely long gone.? On
> top of that they are known for decades of poor support and many
> who would be of assistance refuse to deal with them.
>
> It took me years to find an MK1/EX20 user manual, but I finally
> found one...
>
> ----------------------------------------
>> Date: Tue, 2 Nov 2010 20:01:22 +0100
>> From: cheater00 at gmail.com
>> To: thx1138 at earthlink.net
>> CC: synth-diy at dropmix.xs4all.nl
>> Subject: Re: [sdiy] Wersi Organ Contact springs
>>
>> Hi Terry,
>> have you tried talking to Wersi directly? Or service centers?
>> There are those guys:
>> http://www.wersi-orgelstudio.de/
>>
>> There's also a fairly comprehensive list of service centers here:
>> http://www.wersi.net/service.html
>>
>> the page does say that it's only for the "newer" organs, but I think
>> at least some of those guys should be able to handle issues with the
>> older kinds as well.
>>
>> Cheers,
>> D.
>>
>> On Tue, Nov 2, 2010 at 03:40, thx1138 ?wrote:
>> > Hi Guys,
>> >
>> > I am restoring a PPG PRK and am in need of some Wersi Organ Contact springs.
>> >
>> > Anyone seen these Organ DIT guys around anymore?
>> >
>> > Regards,
>> >
>> > Terry
>> >
>> > _______________________________________________
>> > Synth-diy mailing list
>> > Synth-diy at dropmix.xs4all.nl
>> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> >
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From eric at ericframpton.com  Wed Nov  3 18:29:44 2010
From: eric at ericframpton.com (Eric Frampton)
Date: Wed, 3 Nov 2010 13:29:44 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
Message-ID: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>

Hi all -

I'm trying to troubleshoot a failed Korg DW-8000 power supply. Disconnected from any load it pops fuses as soon as it's powered up. I started with the bridge rectifier, it's fine; while it was removed I checked the xformer, it's fine. There doesn't appear to be anything irregular (trace damage, burns, blown bits, etc.) on the board.

Do you guys have any techniques you can share for where I might start with this thing, since I can't power it up at all? It's not like there's just one rail down and I can fire up the rest of it to test.

And yes, I realize I'm dealing with potentially lethal voltages and I won't hold any of you accountable if I screw up my own handiwork.

Thanks,
Eric



From harrybissell at wowway.com  Wed Nov  3 18:43:32 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 3 Nov 2010 13:43:32 -0400 (EDT)
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
Message-ID: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>

ohmmeter across the power supply outputs... look for short circuits.

Suspect failed electrolytic caps...

I assume that with the transformer disconnected, you got reasonable AC
voltages, and that you checked the bridge rectifier (ohms) out of the circuit.
With the bridge rectifier out, you could easily meter any shorts...

H^) harry





----- Original Message -----
From: Eric Frampton <eric at ericframpton.com>
To: SDIY <Synth-diy at dropmix.xs4all.nl>
Sent: Wed, 03 Nov 2010 13:29:44 -0400 (EDT)
Subject: [sdiy] Korg DW-8000 power supply help?

Hi all -

I'm trying to troubleshoot a failed Korg DW-8000 power supply. Disconnected from any load it pops fuses as soon as it's powered up. I started with the bridge rectifier, it's fine; while it was removed I checked the xformer, it's fine. There doesn't appear to be anything irregular (trace damage, burns, blown bits, etc.) on the board.

Do you guys have any techniques you can share for where I might start with this thing, since I can't power it up at all? It's not like there's just one rail down and I can fire up the rest of it to test.

And yes, I realize I'm dealing with potentially lethal voltages and I won't hold any of you accountable if I screw up my own handiwork.

Thanks,
Eric

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From ic1 at bell.net  Wed Nov  3 19:01:33 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Wed, 3 Nov 2010 14:01:33 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
Message-ID: <BLU0-SMTP1002040D02D375DCD37980C974A0@phx.gbl>

Check IC2 and IC3 , both of those 7805 regulatos were defective in an EX-8000 - rack version of the DW-8000 - I serviced recently.


Tony Kalomiris


On 2010-11-03, at 1:43 PM, Harry Bissell wrote:

> ohmmeter across the power supply outputs... look for short circuits.
> 
> Suspect failed electrolytic caps...
> 
> I assume that with the transformer disconnected, you got reasonable AC
> voltages, and that you checked the bridge rectifier (ohms) out of the circuit.
> With the bridge rectifier out, you could easily meter any shorts...
> 
> H^) harry
> 
> 
> 
> 
> 
> ----- Original Message -----
> From: Eric Frampton <eric at ericframpton.com>
> To: SDIY <Synth-diy at dropmix.xs4all.nl>
> Sent: Wed, 03 Nov 2010 13:29:44 -0400 (EDT)
> Subject: [sdiy] Korg DW-8000 power supply help?
> 
> Hi all -
> 
> I'm trying to troubleshoot a failed Korg DW-8000 power supply. Disconnected from any load it pops fuses as soon as it's powered up. I started with the bridge rectifier, it's fine; while it was removed I checked the xformer, it's fine. There doesn't appear to be anything irregular (trace damage, burns, blown bits, etc.) on the board.
> 
> Do you guys have any techniques you can share for where I might start with this thing, since I can't power it up at all? It's not like there's just one rail down and I can fire up the rest of it to test.
> 
> And yes, I realize I'm dealing with potentially lethal voltages and I won't hold any of you accountable if I screw up my own handiwork.
> 
> Thanks,
> Eric
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> -- 
> Harry Bissell & Nora Abdullah 4eva
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From tim.parkhurst at gmail.com  Wed Nov  3 19:30:16 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Wed, 3 Nov 2010 11:30:16 -0700
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
References: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
	<227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTinwSjQjwPGGzUpGgEbRqMYzfcyKuhRXSCftPGEC@mail.gmail.com>

On Wed, Nov 3, 2010 at 10:43 AM, Harry Bissell <harrybissell at wowway.com> wrote:
> ohmmeter across the power supply outputs... look for short circuits.
>

Ohmmeter across the power supply outputs WITH THE POWER SUPPLY OFF.


Tim (just making sure my Caps Lock key works) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From harrybissell at wowway.com  Wed Nov  3 19:32:49 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 3 Nov 2010 14:32:49 -0400 (EDT)
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <AANLkTinwSjQjwPGGzUpGgEbRqMYzfcyKuhRXSCftPGEC@mail.gmail.com>
Message-ID: <856257312.108133.1288809169124.JavaMail.root@md01.wow.synacor.com>

Spank acknowledged...  ;^)

H^) harry


----- Original Message -----
From: Tim Parkhurst <tim.parkhurst at gmail.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: Eric Frampton <eric at ericframpton.com>, SDIY <Synth-diy at dropmix.xs4all.nl>
Sent: Wed, 03 Nov 2010 14:30:16 -0400 (EDT)
Subject: Re: [sdiy] Korg DW-8000 power supply help?

On Wed, Nov 3, 2010 at 10:43 AM, Harry Bissell <harrybissell at wowway.com> wrote:
> ohmmeter across the power supply outputs... look for short circuits.
>

Ohmmeter across the power supply outputs WITH THE POWER SUPPLY OFF.


Tim (just making sure my Caps Lock key works) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings

-- 
Harry Bissell & Nora Abdullah 4eva


From kokoon at gmail.com  Wed Nov  3 19:45:32 2010
From: kokoon at gmail.com (jure zitnik)
Date: Wed, 3 Nov 2010 19:45:32 +0100
Subject: [sdiy] RFZ gear - negative voltage power supply?
Message-ID: <AANLkTim1V0Ertay9QJYjJH8T5JZpUwOfR268g1SBYoLd@mail.gmail.com>

Greetings, list!

I'm sitting here in front of three ancient RFZ console modules, trying
to wrap my head around this.
I want to put them in a single enclosure and power them all from a single PSU.

the modules are:
1x W735/1 (a two channel 7-band EQ)
2x V740/1c (a mono preamp)

I have some vague info on the pinout and it says they take just a
single -24V line for power...

Now how exactly does that work? Can I just take a normal AC-DC 24V
supply, hook the +24V to the module's ground and the supply's ground
to module's -24V input?
Does anybody know these specific modules? I read somewhere they don't
even need regulated voltage... any ideas?

Thanks a bunch,
jure


From gsn10 at hotmail.com  Wed Nov  3 19:52:12 2010
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Wed, 3 Nov 2010 14:52:12 -0400
Subject: [sdiy] Wersi Organ Contact springs
In-Reply-To: <AANLkTin6Evi0cXE0vUPBz63w9SYe1ycZs6qVkt6bSPXs@mail.gmail.com>
References: <C8F4C849.20D9C%thx1138@earthlink.net>,
	<AANLkTi=WnsmfLvkHyYrdvt8mSukUQqu5uM4Bxe0i0n19@mail.gmail.com>,
	<SNT104-W373CDE82A09731431C5375B44A0@phx.gbl>,
	<AANLkTin6Evi0cXE0vUPBz63w9SYe1ycZs6qVkt6bSPXs@mail.gmail.com>
Message-ID: <SNT104-W637C73D1BF2B76EDB7D452B44A0@phx.gbl>


> You didn't end up digitizing it by chance, did you? :)
>
> Cheers,
> D.

I'm working on a writeup with info and demos and everything, I'll 
try to get the documentation scanned at some point too.

...the English manual leaves out most of the programming info anyway.


> On Wed, Nov 3, 2010 at 17:18, Scott Nordlund  wrote:
> >
> > Here's the problem with finding older Wersi parts: they went through
> > several bankruptcies and changes of ownership in the 90's, and after
> > numerous liquidations, all old parts are very likely long gone.  On
> > top of that they are known for decades of poor support and many
> > who would be of assistance refuse to deal with them.
> >
> > It took me years to find an MK1/EX20 user manual, but I finally
> > found one...
> >
> > ----------------------------------------
> >> Date: Tue, 2 Nov 2010 20:01:22 +0100
> >> From: cheater00 at gmail.com
> >> To: thx1138 at earthlink.net
> >> CC: synth-diy at dropmix.xs4all.nl
> >> Subject: Re: [sdiy] Wersi Organ Contact springs
> >>
> >> Hi Terry,
> >> have you tried talking to Wersi directly? Or service centers?
> >> There are those guys:
> >> http://www.wersi-orgelstudio.de/
> >>
> >> There's also a fairly comprehensive list of service centers here:
> >> http://www.wersi.net/service.html
> >>
> >> the page does say that it's only for the "newer" organs, but I think
> >> at least some of those guys should be able to handle issues with the
> >> older kinds as well.
> >>
> >> Cheers,
> >> D.
> >>
> >> On Tue, Nov 2, 2010 at 03:40, thx1138  wrote:
> >> > Hi Guys,
> >> >
> >> > I am restoring a PPG PRK and am in need of some Wersi Organ Contact springs.
> >> >
> >> > Anyone seen these Organ DIT guys around anymore?
> >> >
> >> > Regards,
> >> >
> >> > Terry
> >> >
> >> > _______________________________________________
> >> > Synth-diy mailing list
> >> > Synth-diy at dropmix.xs4all.nl
> >> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >> >
> >> _______________________________________________
> >> Synth-diy mailing list
> >> Synth-diy at dropmix.xs4all.nl
> >> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
 		 	   		  

From dancemachine at gmail.com  Wed Nov  3 20:38:42 2010
From: dancemachine at gmail.com (dancemachine)
Date: Wed, 3 Nov 2010 15:38:42 -0400
Subject: [sdiy] RFZ gear - negative voltage power supply?
In-Reply-To: <AANLkTim1V0Ertay9QJYjJH8T5JZpUwOfR268g1SBYoLd@mail.gmail.com>
References: <AANLkTim1V0Ertay9QJYjJH8T5JZpUwOfR268g1SBYoLd@mail.gmail.com>
Message-ID: <AANLkTimi=T23h1puV5RpYfUst=1QXnvY-fy5st4Grre5@mail.gmail.com>

really needs "-24V"? or maybe there is just a confusing dash in front of "24V"

I am just speculating though

On Wed, Nov 3, 2010 at 2:45 PM, jure zitnik <kokoon at gmail.com> wrote:
> Greetings, list!
>
> I'm sitting here in front of three ancient RFZ console modules, trying
> to wrap my head around this.
> I want to put them in a single enclosure and power them all from a single PSU.
>
> the modules are:
> 1x W735/1 (a two channel 7-band EQ)
> 2x V740/1c (a mono preamp)
>
> I have some vague info on the pinout and it says they take just a
> single -24V line for power...
>
> Now how exactly does that work? Can I just take a normal AC-DC 24V
> supply, hook the +24V to the module's ground and the supply's ground
> to module's -24V input?
> Does anybody know these specific modules? I read somewhere they don't
> even need regulated voltage... any ideas?
>
> Thanks a bunch,
> jure
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From profpep at hotmail.com  Wed Nov  3 21:06:22 2010
From: profpep at hotmail.com (Mike Pepper)
Date: Wed, 3 Nov 2010 20:06:22 -0000
Subject: [sdiy] Korg DW-8000 power supply help?
References: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
Message-ID: <004501cb7b92$9752d1a0$c800a8c0@desk>

> I'm trying to troubleshoot a failed Korg DW-8000 power supply.
Disconnected from any load it pops fuses as soon as it's powered up. I
started with the bridge rectifier, it's fine; while it was removed I checked
the xformer, it's fine. There doesn't appear to be anything irregular (trace
damage, burns, blown bits, etc.) on the board.
>
> Do you guys have any techniques you can share for where I might start with
this thing, since I can't power it up at all? It's not like there's just one
rail down and I can fire up the rest of it to test.
>
> And yes, I realize I'm dealing with potentially lethal voltages and I
won't hold any of you accountable if I screw up my own handiwork.
>

I'd more likely supect a blown chopper transistor on the primary. At least
if the fuse is blowing, the ground resistor in the chopper is probably OK,
(choppers can be bipolar or MOSFET, and often have a current sensing
resistor in the 'ground side' lead).

Remember to put some kind of dummy load(s) on the output, a lot of switch
modes don't like working into an open circuit.

The Old TV engineer's trick of putting a standard light bulb in series with
the mains live can save a lot of blown parts. If the bulb lights up, you
still have a short, if it just blinks, and the supply fires up, you can
remove it. I still somewhere have a box with a bulb holder, mains lead and
socket, big bright 'Power On' neons and a bypass switch. Harry is right
about shorted electrolytics. Prime suspect is the big high voltage one in
the primary circuit. Make yourself a discharger resistor, or solder some
on - those caps can stay charged for hours, and deliver a nasty bite if you
touch them.

||\/||ike










From gatkins at blueyonder.co.uk  Wed Nov  3 21:15:07 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Wed, 3 Nov 2010 20:15:07 +0000
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <004501cb7b92$9752d1a0$c800a8c0@desk>
References: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
	<004501cb7b92$9752d1a0$c800a8c0@desk>
Message-ID: <E7DF9087-4314-4050-85AB-11E8D0AE61E7@blueyonder.co.uk>

Hold on, we were talking linear power supplies just, not switched mode.

Graham

On 3 Nov 2010, at 20:06, Mike Pepper wrote:

>> I'm trying to troubleshoot a failed Korg DW-8000 power supply.
> Disconnected from any load it pops fuses as soon as it's powered up. I
> started with the bridge rectifier, it's fine; while it was removed I  
> checked
> the xformer, it's fine. There doesn't appear to be anything  
> irregular (trace
> damage, burns, blown bits, etc.) on the board.
>>
>> Do you guys have any techniques you can share for where I might  
>> start with
> this thing, since I can't power it up at all? It's not like there's  
> just one
> rail down and I can fire up the rest of it to test.
>>
>> And yes, I realize I'm dealing with potentially lethal voltages and I
> won't hold any of you accountable if I screw up my own handiwork.
>>
>
> I'd more likely supect a blown chopper transistor on the primary. At  
> least
> if the fuse is blowing, the ground resistor in the chopper is  
> probably OK,
> (choppers can be bipolar or MOSFET, and often have a current sensing
> resistor in the 'ground side' lead).
>
> Remember to put some kind of dummy load(s) on the output, a lot of  
> switch
> modes don't like working into an open circuit.
>
> The Old TV engineer's trick of putting a standard light bulb in  
> series with
> the mains live can save a lot of blown parts. If the bulb lights up,  
> you
> still have a short, if it just blinks, and the supply fires up, you  
> can
> remove it. I still somewhere have a box with a bulb holder, mains  
> lead and
> socket, big bright 'Power On' neons and a bypass switch. Harry is  
> right
> about shorted electrolytics. Prime suspect is the big high voltage  
> one in
> the primary circuit. Make yourself a discharger resistor, or solder  
> some
> on - those caps can stay charged for hours, and deliver a nasty bite  
> if you
> touch them.
>
> ||\/||ike
>
>
>
>
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From profpep at hotmail.com  Wed Nov  3 22:08:03 2010
From: profpep at hotmail.com (Mike Pepper)
Date: Wed, 3 Nov 2010 21:08:03 -0000
Subject: [sdiy] Korg DW-8000 power supply help?
References: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
	<004501cb7b92$9752d1a0$c800a8c0@desk>
	<E7DF9087-4314-4050-85AB-11E8D0AE61E7@blueyonder.co.uk>
Message-ID: <006901cb7b9b$349999a0$c800a8c0@desk>

> Hold on, we were talking linear power supplies just, not switched mode.
>
> Graham
>

Just realised. Doh!

I think it was the fact that I've been working on them recently, cued by the
statement "I started with the bridge rectifier". I'd have started with the
transformer, diconnecting the bridge, then checking for a reasonable output
before replacing the bridge. Disconnect the load side, check for damaged
regs, then for load side shorts. If any tantalum caps, suspect them at once.

A minor note: some 79xx series regs need a load or they won't work properly.
Forgot that myself a few months back and swapped out a reg in one of the
boards I'd built until I remembered.

||\/||ike



> On 3 Nov 2010, at 20:06, Mike Pepper wrote:
>
> >> I'm trying to troubleshoot a failed Korg DW-8000 power supply.
> > Disconnected from any load it pops fuses as soon as it's powered up. I
> > started with the bridge rectifier, it's fine; while it was removed I
> > checked
> > the xformer, it's fine. There doesn't appear to be anything
> > irregular (trace
> > damage, burns, blown bits, etc.) on the board.
> >>
> >> Do you guys have any techniques you can share for where I might
> >> start with
> > this thing, since I can't power it up at all? It's not like there's
> > just one
> > rail down and I can fire up the rest of it to test.
> >>
> >> And yes, I realize I'm dealing with potentially lethal voltages and I
> > won't hold any of you accountable if I screw up my own handiwork.
> >>
> >
> > I'd more likely supect a blown chopper transistor on the primary. At
> > least
> > if the fuse is blowing, the ground resistor in the chopper is
> > probably OK,
> > (choppers can be bipolar or MOSFET, and often have a current sensing
> > resistor in the 'ground side' lead).
> >
> > Remember to put some kind of dummy load(s) on the output, a lot of
> > switch
> > modes don't like working into an open circuit.
> >
> > The Old TV engineer's trick of putting a standard light bulb in
> > series with
> > the mains live can save a lot of blown parts. If the bulb lights up,
> > you
> > still have a short, if it just blinks, and the supply fires up, you
> > can
> > remove it. I still somewhere have a box with a bulb holder, mains
> > lead and
> > socket, big bright 'Power On' neons and a bypass switch. Harry is
> > right
> > about shorted electrolytics. Prime suspect is the big high voltage
> > one in
> > the primary circuit. Make yourself a discharger resistor, or solder
> > some
> > on - those caps can stay charged for hours, and deliver a nasty bite
> > if you
> > touch them.
> >
> > ||\/||ike
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>





From kokoon at gmail.com  Wed Nov  3 23:05:14 2010
From: kokoon at gmail.com (jure zitnik)
Date: Wed, 3 Nov 2010 23:05:14 +0100
Subject: [sdiy] RFZ gear - negative voltage power supply?
In-Reply-To: <AANLkTimi=T23h1puV5RpYfUst=1QXnvY-fy5st4Grre5@mail.gmail.com>
References: <AANLkTim1V0Ertay9QJYjJH8T5JZpUwOfR268g1SBYoLd@mail.gmail.com>
	<AANLkTimi=T23h1puV5RpYfUst=1QXnvY-fy5st4Grre5@mail.gmail.com>
Message-ID: <AANLkTi=bEtnwSO1miTJc0bUhk=HWTpkHLL8C-zsj_opT@mail.gmail.com>

no, it's definitely -24V... it's obviously a common german thing from
the old school broadcast consoles.
i've read some about it, also, here's a pinout for one of them:
http://german-modules.de-blog.jp/photos/uncategorized/2009/09/06/w735_1_pinout.jpg

there's been some discussing of the subject on the prodigy-pro forums,
but i haven't been able to find a definite answer.


On Wed, Nov 3, 2010 at 8:38 PM, dancemachine <dancemachine at gmail.com> wrote:
> really needs "-24V"? or maybe there is just a confusing dash in front of "24V"
>
> I am just speculating though
>
> On Wed, Nov 3, 2010 at 2:45 PM, jure zitnik <kokoon at gmail.com> wrote:
>> Greetings, list!
>>
>> I'm sitting here in front of three ancient RFZ console modules, trying
>> to wrap my head around this.
>> I want to put them in a single enclosure and power them all from a single PSU.
>>
>> the modules are:
>> 1x W735/1 (a two channel 7-band EQ)
>> 2x V740/1c (a mono preamp)
>>
>> I have some vague info on the pinout and it says they take just a
>> single -24V line for power...
>>
>> Now how exactly does that work? Can I just take a normal AC-DC 24V
>> supply, hook the +24V to the module's ground and the supply's ground
>> to module's -24V input?
>> Does anybody know these specific modules? I read somewhere they don't
>> even need regulated voltage... any ideas?
>>
>> Thanks a bunch,
>> jure
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>


From dancemachine at gmail.com  Wed Nov  3 23:21:44 2010
From: dancemachine at gmail.com (dancemachine)
Date: Wed, 3 Nov 2010 18:21:44 -0400
Subject: [sdiy] RFZ gear - negative voltage power supply?
In-Reply-To: <AANLkTi=bEtnwSO1miTJc0bUhk=HWTpkHLL8C-zsj_opT@mail.gmail.com>
References: <AANLkTim1V0Ertay9QJYjJH8T5JZpUwOfR268g1SBYoLd@mail.gmail.com>
	<AANLkTimi=T23h1puV5RpYfUst=1QXnvY-fy5st4Grre5@mail.gmail.com>
	<AANLkTi=bEtnwSO1miTJc0bUhk=HWTpkHLL8C-zsj_opT@mail.gmail.com>
Message-ID: <AANLkTi=mHiX7E9cf+aSY+xuSG55gyp9KW6H+EVnn1Yfv@mail.gmail.com>

yeah y'know i have heard of this before now that you mention it,
something about "reverse ground" or something like that.  connecting a
power supply in reverse like you mention should work just fine but I
have not tried it myself.  If I were faced with the challenge, I would
definitely do exactly that.


On Wed, Nov 3, 2010 at 6:05 PM, jure zitnik <kokoon at gmail.com> wrote:
> no, it's definitely -24V... it's obviously a common german thing from
> the old school broadcast consoles.
> i've read some about it, also, here's a pinout for one of them:
> http://german-modules.de-blog.jp/photos/uncategorized/2009/09/06/w735_1_pinout.jpg
>
> there's been some discussing of the subject on the prodigy-pro forums,
> but i haven't been able to find a definite answer.
>
>
> On Wed, Nov 3, 2010 at 8:38 PM, dancemachine <dancemachine at gmail.com> wrote:
>> really needs "-24V"? or maybe there is just a confusing dash in front of "24V"
>>
>> I am just speculating though
>>
>> On Wed, Nov 3, 2010 at 2:45 PM, jure zitnik <kokoon at gmail.com> wrote:
>>> Greetings, list!
>>>
>>> I'm sitting here in front of three ancient RFZ console modules, trying
>>> to wrap my head around this.
>>> I want to put them in a single enclosure and power them all from a single PSU.
>>>
>>> the modules are:
>>> 1x W735/1 (a two channel 7-band EQ)
>>> 2x V740/1c (a mono preamp)
>>>
>>> I have some vague info on the pinout and it says they take just a
>>> single -24V line for power...
>>>
>>> Now how exactly does that work? Can I just take a normal AC-DC 24V
>>> supply, hook the +24V to the module's ground and the supply's ground
>>> to module's -24V input?
>>> Does anybody know these specific modules? I read somewhere they don't
>>> even need regulated voltage... any ideas?
>>>
>>> Thanks a bunch,
>>> jure
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>
>


From eric at ericframpton.com  Thu Nov  4 09:25:53 2010
From: eric at ericframpton.com (Eric Frampton)
Date: Thu, 4 Nov 2010 04:25:53 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
Message-ID: <C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>

Resolved!

On Nov 3, 2010, at 1:43 PM, Harry Bissell wrote:

> ohmmeter across the power supply outputs... look for short circuits.
> 
> Suspect failed electrolytic caps...

then Andy Jury wrote:

> This PSU has two bridge rectifiers. One block device and another composing
> D8/9/11/12, so check these. Other suspects are IC1 and C11. Looks for dead

Bingo. It was C11, the electrolytic that comes right after the block bridge rectifier.

Interesting, I replaced that one cap and every rail came right back up. Re-connected the CPU board to the PSU, and one 5V supply immediately dropped to about 3.5V. Then, over the course of letting the machine sit for about a half hour, it kept rising until it finally settled at about 4.95V and remained there ever since. Might that be a result of bypass caps on that CPU board re-forming, or...? That was a new thing for me.

Thanks for the help, y'all.

Eric



From rainer at buchty.net  Thu Nov  4 10:47:19 2010
From: rainer at buchty.net (Rainer Buchty)
Date: Thu, 4 Nov 2010 10:47:19 +0100 (CET)
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <AANLkTinwSjQjwPGGzUpGgEbRqMYzfcyKuhRXSCftPGEC@mail.gmail.com>
References: <5CFB9C3C-3F1C-48B5-A72C-7ACBAFD8FF24@ericframpton.com>
	<227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinwSjQjwPGGzUpGgEbRqMYzfcyKuhRXSCftPGEC@mail.gmail.com>
Message-ID: <alpine.DEB.1.10.1011041047020.6568@athlon>

On Wed, 3 Nov 2010, Tim Parkhurst wrote:

> Ohmmeter across the power supply outputs WITH THE POWER SUPPLY OFF.

Sheesh, why does nobody trust in Darwin anymore these days :)

Rainer



From ic1 at bell.net  Thu Nov  4 10:47:38 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Thu, 4 Nov 2010 05:47:38 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
Message-ID: <BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>

Nice job Eric,

Are you saying C11 was shorted ? Or did you just find it by substitution ?
I've seen tantalums short but don't recall this happening with electrolytics.
That's the longest time constant I've ever seen - half an hour !
I'd change that regulator and re-test.

Tony Kalomiris


On 2010-11-04, at 4:25 AM, Eric Frampton wrote:

> Resolved!
> 
> On Nov 3, 2010, at 1:43 PM, Harry Bissell wrote:
> 
>> ohmmeter across the power supply outputs... look for short circuits.
>> 
>> Suspect failed electrolytic caps...
> 
> then Andy Jury wrote:
> 
>> This PSU has two bridge rectifiers. One block device and another composing
>> D8/9/11/12, so check these. Other suspects are IC1 and C11. Looks for dead
> 
> Bingo. It was C11, the electrolytic that comes right after the block bridge rectifier.
> 
> Interesting, I replaced that one cap and every rail came right back up. Re-connected the CPU board to the PSU, and one 5V supply immediately dropped to about 3.5V. Then, over the course of letting the machine sit for about a half hour, it kept rising until it finally settled at about 4.95V and remained there ever since. Might that be a result of bypass caps on that CPU board re-forming, or...? That was a new thing for me.
> 
> Thanks for the help, y'all.
> 
> Eric
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From cary.roberts at retrosynth.net  Thu Nov  4 11:00:24 2010
From: cary.roberts at retrosynth.net (Cary Roberts)
Date: Thu, 4 Nov 2010 03:00:24 -0700
Subject: [sdiy] RFZ gear - negative voltage power supply?
Message-ID: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>

>Now how exactly does that work? Can I just take a normal AC-DC 24V
>supply, hook the +24V to the module's ground and the supply's ground
>to module's -24V input?
>Does anybody know these specific modules? I read somewhere they don't
>even need regulated voltage... any ideas?

If you don't have pinouts you're confident are correct, first ask on Prodigy
Pro or Gearslutz to make sure the modules are indeed -24V.  If the modules
are -24V and you're using a standard linear supply like a HA-24 or HB-24
from Power One, Condor, etc then connect -Out to the -24V input of the
module, +Out to ground, and connect the AC ground to the +Out at the power
supply.  I'd suggest fusing the DC side at .1 or .2A until you know it all
works.

-Cary



From andy at networkjabber.com  Thu Nov  4 11:18:03 2010
From: andy at networkjabber.com (Andrew Jury)
Date: Thu, 04 Nov 2010 10:18:03 +0000
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
Message-ID: <C8F838DB.7D10%andy@networkjabber.com>

Hi Eric,

Glad you got it fixed. You might want to try replacing the 78 series
regulator that feeds that particular +5v rail. That is not normal operation!
You might also want to make sure D4/6/13 aren't leaky.

Bye for now,
Andy


On 04/11/2010 08:25, "Eric Frampton" <eric at ericframpton.com> wrote:

> Resolved!
> 
> On Nov 3, 2010, at 1:43 PM, Harry Bissell wrote:
> 
>> ohmmeter across the power supply outputs... look for short circuits.
>> 
>> Suspect failed electrolytic caps...
> 
> then Andy Jury wrote:
> 
>> This PSU has two bridge rectifiers. One block device and another composing
>> D8/9/11/12, so check these. Other suspects are IC1 and C11. Looks for dead
> 
> Bingo. It was C11, the electrolytic that comes right after the block bridge
> rectifier.
> 
> Interesting, I replaced that one cap and every rail came right back up.
> Re-connected the CPU board to the PSU, and one 5V supply immediately dropped
> to about 3.5V. Then, over the course of letting the machine sit for about a
> half hour, it kept rising until it finally settled at about 4.95V and remained
> there ever since. Might that be a result of bypass caps on that CPU board
> re-forming, or...? That was a new thing for me.
> 
> Thanks for the help, y'all.
> 
> Eric
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy




From kokoon at gmail.com  Thu Nov  4 11:37:55 2010
From: kokoon at gmail.com (jure zitnik)
Date: Thu, 4 Nov 2010 11:37:55 +0100
Subject: [sdiy] RFZ gear - negative voltage power supply?
In-Reply-To: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>
References: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>
Message-ID: <AANLkTikH_nGKV9x8-L+a+bVKrJ_8DqPjTYtvRX8=dp7=@mail.gmail.com>

thanks for the reply.

i am quite certain that the modules are -24V, i have read about that
in a few different places.

since i don't have the specific PSU unit you're describing, am i
getting this right:
in linear AC-DC supplies the AC ground is usually connected to "DC
ground" which make the DC output positive, relative to the common
ground...
if i connected such power supply backwards, i would have problems with
common ground with the rest of the setup?
that is why i need to tie the (system) ground to what you call "+Out"?

kinda makes sense :)

also, about the current consumption - the EQ module is specced at max
45mA... i'm guessing 200mA would be enough for all 3 modules... or
should i need more?


cheers,
jure

On Thu, Nov 4, 2010 at 11:00 AM, Cary Roberts
<cary.roberts at retrosynth.net> wrote:
>>Now how exactly does that work? Can I just take a normal AC-DC 24V
>>supply, hook the +24V to the module's ground and the supply's ground
>>to module's -24V input?
>>Does anybody know these specific modules? I read somewhere they don't
>>even need regulated voltage... any ideas?
>
> If you don't have pinouts you're confident are correct, first ask on Prodigy
> Pro or Gearslutz to make sure the modules are indeed -24V. ?If the modules
> are -24V and you're using a standard linear supply like a HA-24 or HB-24
> from Power One, Condor, etc then connect -Out to the -24V input of the
> module, +Out to ground, and connect the AC ground to the +Out at the power
> supply. ?I'd suggest fusing the DC side at .1 or .2A until you know it all
> works.
>
> -Cary
>
>


From tony at makenoisemusic.com  Thu Nov  4 16:03:24 2010
From: tony at makenoisemusic.com (Tony Rolando)
Date: Thu, 04 Nov 2010 11:03:24 -0400
Subject: [sdiy]  Free Ensoniq Mirage and Marantz Tuner for parts
In-Reply-To: <AANLkTikH_nGKV9x8-L+a+bVKrJ_8DqPjTYtvRX8=dp7=@mail.gmail.com>
References: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>
	<AANLkTikH_nGKV9x8-L+a+bVKrJ_8DqPjTYtvRX8=dp7=@mail.gmail.com>
Message-ID: <4CD2CB3C.2020804@makenoisemusic.com>

I've got and Ensoniq Mirage Rackmount unit. Bad drive. All the CEM3328 
have been robbed for other repairs. Otherwise, plenty of other parts to 
repair your Mirage.

Marantz Stereo Tuner/ Amplifier. It is a nice one, but has one ailing 
channel.

Both of these items were in the back of my truck for the last year. They 
are pretty beat. If somebody could use them, I'd be glad to pack them up 
and ship, assuming you will pay shipping. OR, if you are in the 
Asheville, NC area, I'll meet you in town and hand them over.

Tony


From harrybissell at wowway.com  Thu Nov  4 17:13:38 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Thu, 4 Nov 2010 12:13:38 -0400 (EDT)
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <alpine.DEB.1.10.1011041047020.6568@athlon>
Message-ID: <936010569.134763.1288887218005.JavaMail.root@md01.wow.synacor.com>

hmmm... you could discharge your caps with a screwdriver   :^P

<do NOT try this at home>

H^) harry



----- Original Message -----
From: Rainer Buchty <rainer at buchty.net>
To: Tim Parkhurst <tim.parkhurst at gmail.com>
Cc: Harry Bissell <harrybissell at wowway.com>, SDIY <Synth-diy at dropmix.xs4all.nl>
Sent: Thu, 04 Nov 2010 05:47:19 -0400 (EDT)
Subject: Re: [sdiy] Korg DW-8000 power supply help?

On Wed, 3 Nov 2010, Tim Parkhurst wrote:

> Ohmmeter across the power supply outputs WITH THE POWER SUPPLY OFF.

Sheesh, why does nobody trust in Darwin anymore these days :)

Rainer


-- 
Harry Bissell & Nora Abdullah 4eva


From tony at makenoisemusic.com  Thu Nov  4 17:34:03 2010
From: tony at makenoisemusic.com (Tony Rolando)
Date: Thu, 04 Nov 2010 12:34:03 -0400
Subject: [sdiy] Free Ensoniq Mirage and Marantz Tuner for parts
In-Reply-To: <4CD2CB3C.2020804@makenoisemusic.com>
References: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>	<AANLkTikH_nGKV9x8-L+a+bVKrJ_8DqPjTYtvRX8=dp7=@mail.gmail.com>
	<4CD2CB3C.2020804@makenoisemusic.com>
Message-ID: <4CD2E07B.7090402@makenoisemusic.com>

Looks like shipping will be about $35 for both hunks o' junks.
I'm not going to ship separately, just one box. If any body wants, then 
get in touch and they are yours, as of tomorrow they will be donated to 
a local repair shop.

I'd like to keep them out of the dump, and I have not time to repair.

Tony

On 11/4/10 11:03 AM, Tony Rolando wrote:
> I've got and Ensoniq Mirage Rackmount unit. Bad drive. All the CEM3328 
> have been robbed for other repairs. Otherwise, plenty of other parts 
> to repair your Mirage.
>
> Marantz Stereo Tuner/ Amplifier. It is a nice one, but has one ailing 
> channel.
>
> Both of these items were in the back of my truck for the last year. 
> They are pretty beat. If somebody could use them, I'd be glad to pack 
> them up and ship, assuming you will pay shipping. OR, if you are in 
> the Asheville, NC area, I'll meet you in town and hand them over.
>
> Tony
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From tprivitera at nc.rr.com  Thu Nov  4 17:34:46 2010
From: tprivitera at nc.rr.com (Tim Privitera)
Date: Thu, 4 Nov 2010 12:34:46 -0400
Subject: [sdiy] Issue with Prophet 600 LEDs
Message-ID: <PGEMLJGCPNLAIINNIKAOOEFFFBAA.tprivitera@nc.rr.com>

Hi all,

I was having a problem with intermittent issues lighting the LEDs and
7-segment display on my Prophet 600 control panel.  I replaced the 4042 chip
and now exactly 1/2 of the LEDs and 1/2 of the segments in the 7-segment
display light up, same ones every time.

The membrane pad is ok, as I can change patches and get all the functions to
work, the LEDs just don't light.

While I was in there, I think I saw a second 4042.  Do multiple 4042 chips
control the membrane panel or does anyone know where the problem may lay?

Thanks in advance,

Tim



From dragon.servicing at googlemail.com  Thu Nov  4 17:46:09 2010
From: dragon.servicing at googlemail.com (dragons)
Date: Thu, 04 Nov 2010 16:46:09 +0000
Subject: [sdiy] Korg DW-8000 power supply
In-Reply-To: <C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
Message-ID: <4CD2E351.7070604@googlemail.com>

Hi,
I wasn't sure if you just replaced one cap or all of them ?
I feel if one has failed then it would be worth replacing the others as 
they may have lost value and cause problems later on.
after all the cost of the parts is probably quite small !
regards Peter


On 04/11/10 08:25, Eric Frampton wrote:
> Resolved!
>

>
>
> Bingo. It was C11, the electrolytic that comes right after the block bridge rectifier.
>
> Interesting, I replaced that one cap and every rail came right back up. Re-connected the CPU board to the PSU, and

  one 5V supply immediately dropped to about 3.5V. Then, over the course 
of letting the machine sit for about a half hour,

  it kept rising until it finally settled at about 4.95V and remained 
there ever since. Might that be a result of bypass

  caps on that CPU board re-forming, or...? That was a new thing for me.
>
> Thanks for the help, y'all.
>
> Ericiy
>


From klosmon at sbcglobal.net  Thu Nov  4 17:51:49 2010
From: klosmon at sbcglobal.net (klosmon)
Date: Thu, 04 Nov 2010 09:51:49 -0700
Subject: [sdiy] Issue with Prophet 600 LEDs
In-Reply-To: <PGEMLJGCPNLAIINNIKAOOEFFFBAA.tprivitera@nc.rr.com>
References: <PGEMLJGCPNLAIINNIKAOOEFFFBAA.tprivitera@nc.rr.com>
Message-ID: <4CD2E4A5.9030102@sbcglobal.net>

On the front panel, ICs 101, 102 and 103 all are involved in the LED matrix.
Wouldn't hurt to replace all (as they're CMOS, and due for replacement) 
-- just be careful of the adjoining circuit traces.
~GMM


Tim Privitera wrote:
> Hi all,
>
> I was having a problem with intermittent issues lighting the LEDs and
> 7-segment display on my Prophet 600 control panel.  I replaced the 4042 chip
> and now exactly 1/2 of the LEDs and 1/2 of the segments in the 7-segment
> display light up, same ones every time.
>
> The membrane pad is ok, as I can change patches and get all the functions to
> work, the LEDs just don't light.
>
> While I was in there, I think I saw a second 4042.  Do multiple 4042 chips
> control the membrane panel or does anyone know where the problem may lay?
>
> Thanks in advance,
>
> Tim
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>   



From harrybissell at wowway.com  Thu Nov  4 18:24:54 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Thu, 4 Nov 2010 13:24:54 -0400 (EDT)
Subject: [sdiy] Korg DW-8000 power supply
In-Reply-To: <4CD2E351.7070604@googlemail.com>
Message-ID: <1403325948.136568.1288891494930.JavaMail.root@md01.wow.synacor.com>

I'd agree. I find it really hard to believe that other caps were "re-forming" to make the voltage
slowly rise from 3.5V to 5V.  Re-forming usually does not take place politely unless you force it to do so.

Re-forming a dielectric in an electrolytic cap makes the layer thicker and able to withstand higher voltages.
Its likely that if you applied a higher voltage (5V) and the dielectric could not stand that voltage, it would
fail shorted. You would be relying on the regulator chip to limit the current in this case. I would not rule
out what you have reported, just that I'd look elsewhere (almost anywhere...) before settling on this as the
root cause.

I'd more suspect another capacitor that may have been shorted (like a tantalum) and that you heated it until
it opened up. Or some other explanation ???

Check your power supply current carefully on each rail if possible, and check to see if the regulator chips
are running hotter than you expect.

That sure is a curious observation. I'd look really hard, or put a lot of hours on the unit before I'd trust that
your repair is solid...

<twilight zone theme plays...>

H^) harry



----- Original Message -----
From: dragons <dragon.servicing at googlemail.com>
To: synth-diy at dropmix.xs4all.nl
Sent: Thu, 04 Nov 2010 12:46:09 -0400 (EDT)
Subject: Re: [sdiy] Korg DW-8000 power supply

Hi,
I wasn't sure if you just replaced one cap or all of them ?
I feel if one has failed then it would be worth replacing the others as 
they may have lost value and cause problems later on.
after all the cost of the parts is probably quite small !
regards Peter


On 04/11/10 08:25, Eric Frampton wrote:
> Resolved!
>

>
>
> Bingo. It was C11, the electrolytic that comes right after the block bridge rectifier.
>
> Interesting, I replaced that one cap and every rail came right back up. Re-connected the CPU board to the PSU, and

  one 5V supply immediately dropped to about 3.5V. Then, over the course 
of letting the machine sit for about a half hour,

  it kept rising until it finally settled at about 4.95V and remained 
there ever since. Might that be a result of bypass

  caps on that CPU board re-forming, or...? That was a new thing for me.
>
> Thanks for the help, y'all.
>
> Ericiy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From legion at helpwantedproductions.com  Thu Nov  4 19:58:27 2010
From: legion at helpwantedproductions.com (legion at helpwantedproductions.com)
Date: Thu, 4 Nov 2010 11:58:27 -0700
Subject: [sdiy] FS: Yamaha CS01, Akai S900. Frac modules, Vintage Fuzzi, more
Message-ID: <fd4a3bc02d61155414d00f4da1a86634.squirrel@webmail.helpwantedproductions.com>

For sale in Phila PA:

Pics/more info up at http://daedsound.com/Salez/FS.htm

1.   Vintage Roland Fuzz/Wah - AD50 Roland Doublebeat -$200
Fuzz from the 70s with an awesome wah combination.  Three fuzz settings as
well as level and sustain. Wah can be used with or without the fuzz and
vice-versa. Kind of an Uber 70s Big Muff that's perfect for
stoner/spacerok or pretty much anything with fuzzed out vision. Great on
drum machines too. Extrodinarily flexible unit and in great shape.

2. Heathkit 60s Fuzz - $175
Great vintage fuzz capable of rolling off to a unique distortion as well.
Controls are "distortion", "Boost" as well as two  way toggle to add more
bass to the signal. Sweet 60s germanium hand wired goodness.

3. 1970s Univox Uniwah - $75 - Classic!
I can't find a model # on this so I'm not sure if it's the UW1 or UW2. It
has the footswitch button on the right hands side under the pedal rocker
if that helps. it looks like this one:

http://www.bostonguitar.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=BGWI&Product_Code=VE-MISC-UNIVOX-UNIWAH&Category_Code=VE-MISC

4. Yamaha CS01 - V1 excellent shape with upgraded strap locks :) Makeshift
Battery cover. $225 obo

5. FRAC Rack format modular synth modules - 100% pro built and tested frac
modules. All run off standard +\- 15vt MOTM/Blacet style Power supply.

A. PAIA 9720 Dual VCO -  $150  - You cannot buy this module assembled and
this includes the faceplate. Working 100%.

B. Blacet 2510 Noise/Improbability Drive - $175 -  factory (blacet4)
assembled.  great noise source *and* S/H unit.

C. PAIA 9748 Balance Modulator - $40  - Assembled in top shape. cool ring
mod type unit nd very flexible.

D. Frac/Banana patch panel with 2 wired 1/4" jacks on cables. $50

E. Blacet 2210 Multiple/attenuator -  $25 - FREE if you buy the other
three modules or a fuzz or Wah pedal in this email).

6. Akai S900 sampler with disks.  - $75

(I originally posted the S900 for pickup only. If you pickup in Philly pa
I'll do a deal but I will sell for $75 plus you pay shipping.)

Classic unit with a few disks of 808/effects, and other sounds. Works 100%
and is later OS so you can boot to OS 4.0 if you wish. LCD pixels are
perfect and easy to see but there is no backlight anymore. Very cool beast
(look it up :))


I think all prices are fair and below Eb*y shite but I will listen to
serious offers. Multiple sales, QUICK sales, and local pickups will help
$$.

Plenty of references. Email any questions, thanks.




From jdec at mindspring.com  Thu Nov  4 21:11:44 2010
From: jdec at mindspring.com (BrightBoy)
Date: Thu, 4 Nov 2010 16:11:44 -0400 (GMT-04:00)
Subject: [sdiy] Fall Book Sale (Hal Chamberlin)
Message-ID: <14990818.1288901504678.JavaMail.root@mswamui-thinleaf.atl.sa.earthlink.net>

MUSICAL APPLICATIONS OF MICROPROCESSORS
By Hal Chamberlin
2nd Edition - Hardcover w/ DJ - 802 Pages

This long out-of-print book is a bible of analog, 
digital and analog/digital hybrid synthesizer design, 
complete with circuit theory and schematics.

The general contents can be viewed here:

http://www.mindspring.com/~jdec/book/MAM.jpg

CONDITION: new-old-stock, mint, unread, un-opened,
time machine quality, straight from the original 
Hayden Books shipping cartons.

Price: $50 USD + Shipping

I accept payment in the form of US Postal Money Order or
via PayPal (Personal/Gift option).  Ships from Michigan/USA.

Contact me if you are interested or have any questions.

Cheers,

Jeff





From dingebre at 3dphysics.net  Fri Nov  5 04:58:18 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Thu, 4 Nov 2010 21:58:18 -0600
Subject: [sdiy] Guard Rings
In-Reply-To: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
Message-ID: <000001cb7c9d$ae91c6d0$0bb55470$@net>

Hi all,

I'm still progressing and working on the Steiner Synthasystem.

I have a question. I am laying out the Dual Sample & Hold/Random Voltage
module schematic here:

http://www.xmission.com/~dingebre/SP_Samp_Hold_1.0.pdf

A current PCB layout closeup showing the guard ring such as it is, is here:

http://www.xmission.com/~dingebre/PCB_part.jpg

In conversations with Nyle, he recommends putting a guard ring around the
high impedance sections and tying it to the output of the voltage follower,
but I'm struggling trying to figure out what these are.

I've decided it should include the nodes/pads which connect to the two FETs
including a couple of resistor pads and the one capacitor pad.

The ring shows as a red line tracing close to the pads of the FETs, cap,
resistor, etc. The guard ring is a trace on both sides of the PCB. It starts
and ends on the emitter of the voltage follower which (I think) is Q9. I
excluded any pads going to ground or power.

First question, is this correct? I put a dashed line around the pads I'm
including in the ring on the schematic.

Second, I've read somewhat about guard rings but would love a link to other
information so I can understand this so I make an intelligent PCB.

Thanks everyone.

David



From obl64 at ix.netcom.com  Fri Nov  5 05:24:45 2010
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Thu, 04 Nov 2010 23:24:45 -0500
Subject: [sdiy] Guard Rings
In-Reply-To: <000001cb7c9d$ae91c6d0$0bb55470$@net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
Message-ID: <4CD3870D.4060503@ix.netcom.com>



On 11/4/2010 10:58 PM, David Ingebretsen wrote:
> Hi all,
>
> I'm still progressing and working on the Steiner Synthasystem.
>
> I have a question. I am laying out the Dual Sample&  Hold/Random Voltage
> module schematic here:
>
> http://www.xmission.com/~dingebre/SP_Samp_Hold_1.0.pdf
>
> A current PCB layout closeup showing the guard ring such as it is, is here:
>
> http://www.xmission.com/~dingebre/PCB_part.jpg
>
> In conversations with Nyle, he recommends putting a guard ring around the
> high impedance sections and tying it to the output of the voltage follower,
> but I'm struggling trying to figure out what these are.
>
> I've decided it should include the nodes/pads which connect to the two FETs
> including a couple of resistor pads and the one capacitor pad.
>
> The ring shows as a red line tracing close to the pads of the FETs, cap,
> resistor, etc. The guard ring is a trace on both sides of the PCB. It starts
> and ends on the emitter of the voltage follower which (I think) is Q9. I
> excluded any pads going to ground or power.
>
> First question, is this correct? I put a dashed line around the pads I'm
> including in the ring on the schematic.
>
> Second, I've read somewhat about guard rings but would love a link to other
> information so I can understand this so I make an intelligent PCB.
>
> Thanks everyone.
>
> David
>

David,

Looking at the pdf, you'll want to place the guard ring around the 
traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island" 
of high impedance while in "hold" mode. The ring is connected the output 
(emitter) of the emitter-follower Q9 which will be at the same potential 
but buffered.
Ditto for Q12, C14, R6, Q8.

- Oren


From dingebre at 3dphysics.net  Fri Nov  5 06:18:01 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Thu, 4 Nov 2010 23:18:01 -0600
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD3870D.4060503@ix.netcom.com>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<4CD3870D.4060503@ix.netcom.com>
Message-ID: <000701cb7ca8$d1ad8130$75088390$@net>

OK, thank you very much Oren. I think I see how that would be the island in
hold mode. 

David

~~ -----Original Message-----
~~ From: Oren Leavitt [mailto:obl64 at ix.netcom.com]
~~ Sent: Thursday, November 04, 2010 10:25 PM
~~ To: David Ingebretsen
~~ Cc: 'synth diy'
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ 
~~ 
~~ On 11/4/2010 10:58 PM, David Ingebretsen wrote:
~~ > Hi all,
~~ >
~~ > I'm still progressing and working on the Steiner Synthasystem.
~~ >
~~ > I have a question. I am laying out the Dual Sample&  Hold/Random
Voltage
~~ > module schematic here:
~~ >
~~ > http://www.xmission.com/~dingebre/SP_Samp_Hold_1.0.pdf
~~ >
~~ > A current PCB layout closeup showing the guard ring such as it is, is
~~ here:
~~ >
~~ > http://www.xmission.com/~dingebre/PCB_part.jpg
~~ >
~~ > In conversations with Nyle, he recommends putting a guard ring around
~~ the
~~ > high impedance sections and tying it to the output of the voltage
~~ follower,
~~ > but I'm struggling trying to figure out what these are.
~~ >
~~ > I've decided it should include the nodes/pads which connect to the two
~~ FETs
~~ > including a couple of resistor pads and the one capacitor pad.
~~ >
~~ > The ring shows as a red line tracing close to the pads of the FETs,
cap,
~~ > resistor, etc. The guard ring is a trace on both sides of the PCB. It
~~ starts
~~ > and ends on the emitter of the voltage follower which (I think) is Q9.
I
~~ > excluded any pads going to ground or power.
~~ >
~~ > First question, is this correct? I put a dashed line around the pads
I'm
~~ > including in the ring on the schematic.
~~ >
~~ > Second, I've read somewhat about guard rings but would love a link to
~~ other
~~ > information so I can understand this so I make an intelligent PCB.
~~ >
~~ > Thanks everyone.
~~ >
~~ > David
~~ >
~~ 
~~ David,
~~ 
~~ Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is connected the output
~~ (emitter) of the emitter-follower Q9 which will be at the same potential
~~ but buffered.
~~ Ditto for Q12, C14, R6, Q8.
~~ 
~~ - Oren



From dlmanley at sonic.net  Fri Nov  5 06:28:33 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Thu, 04 Nov 2010 22:28:33 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD3870D.4060503@ix.netcom.com>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<4CD3870D.4060503@ix.netcom.com>
Message-ID: <4CD39601.9020209@sonic.net>

On 11/4/2010 9:24 PM, Oren Leavitt wrote:

>
> Looking at the pdf, you'll want to place the guard ring around the traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island" of high impedance while in "hold" mode. The ring is
> connected the output (emitter) of the emitter-follower Q9 which will be at the same potential but buffered.
> Ditto for Q12, C14, R6, Q8.

I agree where the ring should go, and I'd be tempted to optimize the component
placement.

A couple of questions:

Is Q9 emitter really at the same potential as the voltage on the cap?

What's the point of R13?

David - the idea of the guard ring is to surround a high impedance node holding
a charge with a buffered potential of the same voltage.  This will isolate the
node from different nearby voltages so that it doesn't discharge due to leakage
currents on the board.  If the PCB is clean these leakage currents should be minimal.
Make sure the board is free of contamination on both sides.

-Dave



From dixon at interchange.ubc.ca  Fri Nov  5 06:30:40 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Thu, 04 Nov 2010 22:30:40 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <000001cb7c9d$ae91c6d0$0bb55470$@net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
Message-ID: <2E8CFB96181C4AB58E90DF5F24073D21@galvanox01>

Here is my "expert" opinion (if I'm smokin' crack, I'm sure I'll be
corrected in short order by a real "guru"):

The high impedance sections are the traces connecting the sources of Q11 and
Q12 to the gates of Q7 and Q8, across capacitors C5 and C6.  The guard rings
should be put around these traces, and ONLY these traces.

The junctions between the emitters of Q5 and Q6, resistors R16 and R18, and
the drains of Q11 and Q12, respectively, are emphatically NOT high
impedance.  In fact, their impedances are about 2.2k.  (Compare this to the
~1,000,000,000k impedances of the JFET gates.)  The guard rings should not
surround these junctions, as these constitute an unprotected low-impedance
leakage path.  The whole point of guard rings is to prevent surface leakage
from the high-impedance traces by surrounding them with a low-impedance
voltage source at the same voltage.  Including these variable-voltage
junctions inside the guard ring is akin to including the fox inside the
chicken coop!

Hence, referring the layout, I would re-route the guard ring so that it
loops around just the source pad of Q11, and does not extend around the
gate/R23 junction, nor around the drain/R16/Q5-emitter junction.  In order
to do this, you should straighten out the trace to the gate of Q11 so that
it runs perpendicular to the pins of Q11.

The source of Q7 and the base of Q9 are not part of the high-impedance
network either.  Bipolar transistors have measurable base current flow
(which the source of Q7 drives in this case).  There won't be much current
flowing into the base of Q9, but the extremely close proximity of these two
traces looks like another potential source of leakage to me.

Hence, referring again to the layout, I would separate those two blue traces
between R13/Q7-gate and Q9-base/Q7-source, and reroute the guard ring
between these traces.

Hope this helps!


> I have a question. I am laying out the Dual Sample & Hold/Random Voltage
> module schematic here:
> 
> http://www.xmission.com/~dingebre/SP_Samp_Hold_1.0.pdf
> 
> A current PCB layout closeup showing the guard ring such as it is, is
> here:
> 
> http://www.xmission.com/~dingebre/PCB_part.jpg
> 
> In conversations with Nyle, he recommends putting a guard ring around the
> high impedance sections and tying it to the output of the voltage
> follower,
> but I'm struggling trying to figure out what these are.
>
> I've decided it should include the nodes/pads which connect to the two
> FETs
> including a couple of resistor pads and the one capacitor pad.
> 
> The ring shows as a red line tracing close to the pads of the FETs, cap,
> resistor, etc. The guard ring is a trace on both sides of the PCB. It
> starts
> and ends on the emitter of the voltage follower which (I think) is Q9. I
> excluded any pads going to ground or power.
> 
> First question, is this correct? I put a dashed line around the pads I'm
> including in the ring on the schematic.
> 
> Second, I've read somewhat about guard rings but would love a link to
> other
> information so I can understand this so I make an intelligent PCB.
> 
> Thanks everyone.
> 
> David
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From dingebre at 3dphysics.net  Fri Nov  5 07:07:24 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Fri, 5 Nov 2010 00:07:24 -0600
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD39601.9020209@sonic.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>	<000001cb7c9d$ae91c6d0$0bb55470$@net>	<4CD3870D.4060503@ix.netcom.com>
	<4CD39601.9020209@sonic.net>
Message-ID: <000801cb7caf$ba2c7d70$2e857850$@net>

OK, that makes sense. The potential at the emitter of Q9 won't leak away,
and since it is the same potential as the nodes within the ring, the charge
being held has nowhere to go.

Honestly, I don't understand the circuit well enough to answer your
questions. I'll ask Nyle next time we talk.

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of Dave Manley
~~ Sent: Thursday, November 04, 2010 11:29 PM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ On 11/4/2010 9:24 PM, Oren Leavitt wrote:
~~ 
~~ >
~~ > Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is
~~ > connected the output (emitter) of the emitter-follower Q9 which will be
~~ at the same potential but buffered.
~~ > Ditto for Q12, C14, R6, Q8.
~~ 
~~ I agree where the ring should go, and I'd be tempted to optimize the
~~ component
~~ placement.
~~ 
~~ A couple of questions:
~~ 
~~ Is Q9 emitter really at the same potential as the voltage on the cap?
~~ 
~~ What's the point of R13?
~~ 
~~ David - the idea of the guard ring is to surround a high impedance node
~~ holding
~~ a charge with a buffered potential of the same voltage.  This will
isolate
~~ the
~~ node from different nearby voltages so that it doesn't discharge due to
~~ leakage
~~ currents on the board.  If the PCB is clean these leakage currents should
~~ be minimal.
~~ Make sure the board is free of contamination on both sides.
~~ 
~~ -Dave
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From veronica.merryfield at shaw.ca  Fri Nov  5 07:39:20 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Thu, 4 Nov 2010 23:39:20 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD39601.9020209@sonic.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<4CD3870D.4060503@ix.netcom.com> <4CD39601.9020209@sonic.net>
Message-ID: <8C00FC6D-0A1E-4C8E-BF3A-5087627B8128@shaw.ca>

> Is Q9 emitter really at the same potential as the voltage on the cap?

The voltage gain is GmRe/(GmRe+1), so in this case Gm.2200/Gm.2200+1 - close enough to 1 in this case

> What's the point of R13?

I can't figure that either.




From dlmanley at sonic.net  Fri Nov  5 08:26:05 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Fri, 05 Nov 2010 00:26:05 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <8C00FC6D-0A1E-4C8E-BF3A-5087627B8128@shaw.ca>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>	<000001cb7c9d$ae91c6d0$0bb55470$@net>	<4CD3870D.4060503@ix.netcom.com>
	<4CD39601.9020209@sonic.net>
	<8C00FC6D-0A1E-4C8E-BF3A-5087627B8128@shaw.ca>
Message-ID: <4CD3B18D.8050500@sonic.net>

On 11/4/2010 11:39 PM, Veronica Merryfield wrote:
>> Is Q9 emitter really at the same potential as the voltage on the cap?
>
> The voltage gain is GmRe/(GmRe+1), so in this case Gm.2200/Gm.2200+1 - close enough to 1 in this case
>

Thanks, it's an emitter follower isn't it?  Guess it's time to go back to my
basic transistor circuits books for a review.  :-0


>> What's the point of R13?
>
> I can't figure that either.
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>



From veronica.merryfield at shaw.ca  Fri Nov  5 08:32:06 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Fri, 5 Nov 2010 00:32:06 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD3B18D.8050500@sonic.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<4CD3870D.4060503@ix.netcom.com> <4CD39601.9020209@sonic.net>
	<8C00FC6D-0A1E-4C8E-BF3A-5087627B8128@shaw.ca>
	<4CD3B18D.8050500@sonic.net>
Message-ID: <E6D31158-4D54-48B3-8412-D38C9CC7C79D@shaw.ca>

> Thanks, it's an emitter follower isn't it?  Guess it's time to go back to my
> basic transistor circuits books for a review.  :-0

Yes, or a common collector.




From sounddoctorin at imt.net  Fri Nov  5 10:22:31 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Fri, 05 Nov 2010 03:22:31 -0600
Subject: [sdiy] Kawai SX240 service manual online
Message-ID: <4CD3CCD7.6010708@imt.net>

Hi all,  I finally got everything working right again and scanned in 
this thing at last that's been setting here for a couple years I think.  
4.5M roughly and just go to the site as always and follow the logical 
links to the global synth page, then production synths then kawai then 
sx240  (I figure if I train people how to work that aspect of it they'll 
find the resources more easily. lol. )   I ask anyone who feels like 
helping defray the cost (ie. not people who can't make their rent etc.) 
to chip in a coupe dollars since this one was a lot of work with 45 
pages many of which had to be stitched together.  What is UP with that 
corel photo paint?  I finally went to it from ixla I used for years when 
I upgraded to xp since ixla wouldn't work.  For some bizarre 
reason..when you try to drag an object it intermittently works.  Most of 
the time lets you drag but it goes nowhere.  Other times it drags but 
just shows you the edge instead of the object being dragged which makes 
it difficult to visualize where you are putting things.  RARELY it 
actually drags the object.  I couldn't see any rhyme or reason to it.  
It just seemed to be doing whatever it felt like.  It didn't matter 
where I drug it near as i could tell. lol.  what a pain.  I finally 
figure out that I could fine adjust using the position values in the 
movement box at the right.  I've never really used a decent paint 
program much.  I've gotten by on minimalist stuff for all these years.  
Finally learning a few things. lol.

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From Peter.Ullrich at kapsch.net  Fri Nov  5 10:49:41 2010
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Fri, 5 Nov 2010 10:49:41 +0100
Subject: [sdiy] Kawai SX240 service manual online
In-Reply-To: <4CD3CCD7.6010708@imt.net>
References: <4CD3CCD7.6010708@imt.net>
Message-ID: <B156A86831A33949A0977840648802475DF372D1A2@S060VS20.kapsch.co.at>

Hi Bob!

Thank you very much for your scanning effort!
The quality is OK, sometimes reading the pin numbers is a little bit difficult - but there
Has to be a compromise between size and quality...

I normally use an old Paint Shop Pro 6 for the scanning and stitching task- it works fine!
You can also stitch using soft edges so that the result looks smoother.

For reduction of the filesize I normally work with GIF files and make a reduction to 
16 greyscale levels before generating the PDF - this gave me a minimal size with nice quality.

If you have your original files and if you would send it to me  I could test if I get slightly 
better results. 

Thank you very much again - my 2 dollars are already sent by Paypal!

Ciao
Peter

http://www.ullrich.at.tf


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Bob Weigel
Sent: Friday, November 05, 2010 10:23 AM
To: synthdiy
Subject: [sdiy] Kawai SX240 service manual online

Hi all,  I finally got everything working right again and scanned in 
this thing at last that's been setting here for a couple years I think.  
4.5M roughly and just go to the site as always and follow the logical 
links to the global synth page, then production synths then kawai then 
sx240  (I figure if I train people how to work that aspect of it they'll 
find the resources more easily. lol. )   I ask anyone who feels like 
helping defray the cost (ie. not people who can't make their rent etc.) 
to chip in a coupe dollars since this one was a lot of work with 45 
pages many of which had to be stitched together.  What is UP with that 
corel photo paint?  I finally went to it from ixla I used for years when 
I upgraded to xp since ixla wouldn't work.  For some bizarre 
reason..when you try to drag an object it intermittently works.  Most of 
the time lets you drag but it goes nowhere.  Other times it drags but 
just shows you the edge instead of the object being dragged which makes 
it difficult to visualize where you are putting things.  RARELY it 
actually drags the object.  I couldn't see any rhyme or reason to it.  
It just seemed to be doing whatever it felt like.  It didn't matter 
where I drug it near as i could tell. lol.  what a pain.  I finally 
figure out that I could fine adjust using the position values in the 
movement box at the right.  I've never really used a decent paint 
program much.  I've gotten by on minimalist stuff for all these years.  
Finally learning a few things. lol.

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.




From cheater00 at gmail.com  Fri Nov  5 13:36:11 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Fri, 5 Nov 2010 13:36:11 +0100
Subject: [sdiy] Multimeter and oscilloscope probes
Message-ID: <AANLkTi=Juz+qdVRPcHq2SPUAC9OsD1v11DkPEGqgdqbe@mail.gmail.com>

Hi guys,
I have got a problem with selecting the right tools and I thought I
would ask the huge collective experience here what the best course of
action is :-)

I want to get more probes for my multimeters (both analog/VU and
digital ones). I would also like to get an oscilloscope at some point,
however for the purpose of synths (no gigahertz frequencies here) I am
assuming I could use the same probes with an adapter. I would also
like to be able to probe around and use the probes to listen to the
signals inside synths, on my headphones. There are several questions I
have ran into:

1. what's the best place to buy those things? After moving down to
Munich I have got most of my multimeters and repair equipment in
Conrad (except for another soldering iron and simple '813 DMM which I
got during my year in Berlin). I have a digital and an analogue
multimeter from Voltcraft that I got there.

2. What sort of leads will I find useful to have? Here's what I
thought might be useful:
a. 2x normal probes (that I have already, so no need to buy)
b. 2x super-thin probes (that I find I need already in some places I
can't reach otherwise)
c. 2x crocodile probes aka dolphin probes (no idea why??), for example
for clamping down on stuff
d. some crocodile leads (I think I have some of those already somewhere..)
e. 2x those syringe-style hook shaped probes
f. screw-down leads (screw down terminals, for example for ground)

are there any leads missing that I might need?

In addition I would like to get a BNC->4mm Banana converter, the kind
that you use with oscilloscopes. I don't have an oscilloscope here in
Germany, however here's the reasoning: i need a way to use all above
probes and convert them to 1/4" plug to plug into my mixer/preamp. I
need to be able to switch those probes around (so they can't be
soldered shut). I can't DIY because I'm unable to find plugs that I
can diy that will work with test leads where the banana plug is
surrounded by a protective sheath. However, I have found a bnc to 4mm
converter that does all that: works with the protected test leads and
is made already and only costs 4 euro. I can then make a BNC->1/4"
converter and use it that way. I can also use that later if I want to
use a scope.

3. if I get an oscilloscope, will I have good results using the
multimeter probes? It's not for debugging ddr memory busses, or for
counting jitter on an xtal, it's mostly for synth repair and/or
design. Mostly analogue, some digital design too, can't hurt to be
able to do low-frequency digital (up to say xx MHz speed uC's). So I
take those probes I have listed above, plug them into the converter,
and off I go. The bonus here is: I can mix and match, so for example I
can clamp down the GND, whereas I use a hand held probe for the +
signal. What are the negative sides of using such a converter? What
should I watch out for? What should I watch out for when buying the
test leads? I am thinking that maybe there's some sort of test leads
that I can buy for my dmm that will also be very good for the
oscilloscope, whereas if I just pay 5% less I will get something
that's still good for the DMM but very bad for the oscilloscope - I
want to prevent this mistake, and would like to get something that's
good for oscilloscopes too. What is the actual difference between
multimeter and oscilloscope probes?

4. can I get a solderable BNC plug (female) somewhere? Or is it better
to use a ready lead and just rip off one end, replacing it with a
1/4"? Or even cut it in half and have two 1/4" converters..

5. Is there anything else missing in your opinion? I am mostly unsure
about what test probes I should be getting in order to test things
like DIP packages. For example some hook style probes seemed to big
for that and it seemed like they were only made for use with
through-hole elements. I'm also thinking about some some sort of test
lead that can go under a tightly soldered capacitor and access the
leads there (it would have to be a very thin plate of some sort?)


From subjectivity at hotmail.com  Fri Nov  5 13:55:23 2010
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Fri, 5 Nov 2010 08:55:23 -0400
Subject: [sdiy] Free Ensoniq Mirage and Marantz Tuner for parts
In-Reply-To: <4CD2E07B.7090402@makenoisemusic.com>
References: <5A75563162F940ACA375EEFCA01E9BBB@onlive.corp>
	<AANLkTikH_nGKV9x8-L+a+bVKrJ_8DqPjTYtvRX8=dp7=@mail.gmail.com>
	<4CD2CB3C.2020804@makenoisemusic.com>
	<4CD2E07B.7090402@makenoisemusic.com>
Message-ID: <BLU0-SMTP66D6BC782E8D92CE8FF3DEC84C0@phx.gbl>

What else do drive around with in your truck tony??

Sent from my iPhone

On Nov 4, 2010, at 12:34 PM, Tony Rolando <tony at makenoisemusic.com> wrote:

> Looks like shipping will be about $35 for both hunks o' junks.
> I'm not going to ship separately, just one box. If any body wants, then get in touch and they are yours, as of tomorrow they will be donated to a local repair shop.
> 
> I'd like to keep them out of the dump, and I have not time to repair.
> 
> Tony
> 
> On 11/4/10 11:03 AM, Tony Rolando wrote:
>> I've got and Ensoniq Mirage Rackmount unit. Bad drive. All the CEM3328 have been robbed for other repairs. Otherwise, plenty of other parts to repair your Mirage.
>> 
>> Marantz Stereo Tuner/ Amplifier. It is a nice one, but has one ailing channel.
>> 
>> Both of these items were in the back of my truck for the last year. They are pretty beat. If somebody could use them, I'd be glad to pack them up and ship, assuming you will pay shipping. OR, if you are in the Asheville, NC area, I'll meet you in town and hand them over.
>> 
>> Tony
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From harrybissell at wowway.com  Fri Nov  5 14:13:15 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 09:13:15 -0400 (EDT)
Subject: [sdiy] Multimeter and oscilloscope probes
In-Reply-To: <AANLkTi=Juz+qdVRPcHq2SPUAC9OsD1v11DkPEGqgdqbe@mail.gmail.com>
Message-ID: <385234051.156889.1288962795808.JavaMail.root@md01.wow.synacor.com>

oooh I know <raises hand>

DO NOT consider multimeter probes suitable for an oscilloscope. They are
not useful in the least.

You need (imho, hell... in my very NON-humble o) a minimum of a 10X probe for an oscilloscope.
It may seem counter-intuitive, but a 10X (divides the signal by 10) probe is essential for
quality work. A 1X probe usually has an impedance of 1 meghom, far too low to observe circuit operation without seriously loading (changing) the circuit.  

There are switchable 1X/10X probes. They are OK. I bought a set from ProbeMasters (iirc) that had
(1) 1X, (1) 10X, and (1) 1X/10X so you could have a pair of matched probes of either 1X or 10X. This is important for making differential, pseudo-differential measurements, or just to compare two circuit points with identical response.

BE SURE to choose scope probes that match your scope's frequency response and input capacitance !
(they could be 'faster" ie 100MHz probes would usually work on a 50MHz scope, but if the capacitance is quite different, performance will suffer greatly - you won't be able to trust what you see...)

Someone on the list poined out some Chinese made probes that were like $7. I forget the link but I bought a couple of sets and they seem OK to me.

Treat the probes like gold, don't bend, twist etc. And WATCH them carefully. Do you know how they got the name "10 to 1" probes ??? Turn your back on them for a moment and the "ten to one" away...

Meter probes are usually "DC" and don't affect measurements much. The 'mini-hook' and crocodile
leads you suggest sound just fine. For DIP packages they make adapter clips that look like spring clothespins. I'd try to get some old ones as they are just about obsolete and not used much anymore, they should be easy to find in any engineering departments junk drawer or garbage can at this point...

H^) harry




----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: synth-diy <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 08:36:11 -0400 (EDT)
Subject: [sdiy] Multimeter and oscilloscope probes

Hi guys,
I have got a problem with selecting the right tools and I thought I
would ask the huge collective experience here what the best course of
action is :-)

I want to get more probes for my multimeters (both analog/VU and
digital ones). I would also like to get an oscilloscope at some point,
however for the purpose of synths (no gigahertz frequencies here) I am
assuming I could use the same probes with an adapter. I would also
like to be able to probe around and use the probes to listen to the
signals inside synths, on my headphones. There are several questions I
have ran into:

1. what's the best place to buy those things? After moving down to
Munich I have got most of my multimeters and repair equipment in
Conrad (except for another soldering iron and simple '813 DMM which I
got during my year in Berlin). I have a digital and an analogue
multimeter from Voltcraft that I got there.

2. What sort of leads will I find useful to have? Here's what I
thought might be useful:
a. 2x normal probes (that I have already, so no need to buy)
b. 2x super-thin probes (that I find I need already in some places I
can't reach otherwise)
c. 2x crocodile probes aka dolphin probes (no idea why??), for example
for clamping down on stuff
d. some crocodile leads (I think I have some of those already somewhere..)
e. 2x those syringe-style hook shaped probes
f. screw-down leads (screw down terminals, for example for ground)

are there any leads missing that I might need?

In addition I would like to get a BNC->4mm Banana converter, the kind
that you use with oscilloscopes. I don't have an oscilloscope here in
Germany, however here's the reasoning: i need a way to use all above
probes and convert them to 1/4" plug to plug into my mixer/preamp. I
need to be able to switch those probes around (so they can't be
soldered shut). I can't DIY because I'm unable to find plugs that I
can diy that will work with test leads where the banana plug is
surrounded by a protective sheath. However, I have found a bnc to 4mm
converter that does all that: works with the protected test leads and
is made already and only costs 4 euro. I can then make a BNC->1/4"
converter and use it that way. I can also use that later if I want to
use a scope.

3. if I get an oscilloscope, will I have good results using the
multimeter probes? It's not for debugging ddr memory busses, or for
counting jitter on an xtal, it's mostly for synth repair and/or
design. Mostly analogue, some digital design too, can't hurt to be
able to do low-frequency digital (up to say xx MHz speed uC's). So I
take those probes I have listed above, plug them into the converter,
and off I go. The bonus here is: I can mix and match, so for example I
can clamp down the GND, whereas I use a hand held probe for the +
signal. What are the negative sides of using such a converter? What
should I watch out for? What should I watch out for when buying the
test leads? I am thinking that maybe there's some sort of test leads
that I can buy for my dmm that will also be very good for the
oscilloscope, whereas if I just pay 5% less I will get something
that's still good for the DMM but very bad for the oscilloscope - I
want to prevent this mistake, and would like to get something that's
good for oscilloscopes too. What is the actual difference between
multimeter and oscilloscope probes?

4. can I get a solderable BNC plug (female) somewhere? Or is it better
to use a ready lead and just rip off one end, replacing it with a
1/4"? Or even cut it in half and have two 1/4" converters..

5. Is there anything else missing in your opinion? I am mostly unsure
about what test probes I should be getting in order to test things
like DIP packages. For example some hook style probes seemed to big
for that and it seemed like they were only made for use with
through-hole elements. I'm also thinking about some some sort of test
lead that can go under a tightly soldered capacitor and access the
leads there (it would have to be a very thin plate of some sort?)
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Fri Nov  5 14:46:37 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 09:46:37 -0400 (EDT)
Subject: [sdiy] Guard Rings
In-Reply-To: <000701cb7ca8$d1ad8130$75088390$@net>
Message-ID: <2130930441.158282.1288964797875.JavaMail.root@md01.wow.synacor.com>

Guard rings should go on both sides of the PCB, imho.

I agree, what is R13 ?  I'd use a jumper or low value
resistor on the OTHER side of the hold cap as a way to get the signal into
the island...

H^) harry


----- Original Message -----
From: David Ingebretsen <dingebre at 3dphysics.net>
To: 'Oren Leavitt' <obl64 at ix.netcom.com>
Cc: 'synth diy' <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 01:18:01 -0400 (EDT)
Subject: Re: [sdiy] Guard Rings

OK, thank you very much Oren. I think I see how that would be the island in
hold mode. 

David

~~ -----Original Message-----
~~ From: Oren Leavitt [mailto:obl64 at ix.netcom.com]
~~ Sent: Thursday, November 04, 2010 10:25 PM
~~ To: David Ingebretsen
~~ Cc: 'synth diy'
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ 
~~ 
~~ On 11/4/2010 10:58 PM, David Ingebretsen wrote:
~~ > Hi all,
~~ >
~~ > I'm still progressing and working on the Steiner Synthasystem.
~~ >
~~ > I have a question. I am laying out the Dual Sample&  Hold/Random
Voltage
~~ > module schematic here:
~~ >
~~ > http://www.xmission.com/~dingebre/SP_Samp_Hold_1.0.pdf
~~ >
~~ > A current PCB layout closeup showing the guard ring such as it is, is
~~ here:
~~ >
~~ > http://www.xmission.com/~dingebre/PCB_part.jpg
~~ >
~~ > In conversations with Nyle, he recommends putting a guard ring around
~~ the
~~ > high impedance sections and tying it to the output of the voltage
~~ follower,
~~ > but I'm struggling trying to figure out what these are.
~~ >
~~ > I've decided it should include the nodes/pads which connect to the two
~~ FETs
~~ > including a couple of resistor pads and the one capacitor pad.
~~ >
~~ > The ring shows as a red line tracing close to the pads of the FETs,
cap,
~~ > resistor, etc. The guard ring is a trace on both sides of the PCB. It
~~ starts
~~ > and ends on the emitter of the voltage follower which (I think) is Q9.
I
~~ > excluded any pads going to ground or power.
~~ >
~~ > First question, is this correct? I put a dashed line around the pads
I'm
~~ > including in the ring on the schematic.
~~ >
~~ > Second, I've read somewhat about guard rings but would love a link to
~~ other
~~ > information so I can understand this so I make an intelligent PCB.
~~ >
~~ > Thanks everyone.
~~ >
~~ > David
~~ >
~~ 
~~ David,
~~ 
~~ Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is connected the output
~~ (emitter) of the emitter-follower Q9 which will be at the same potential
~~ but buffered.
~~ Ditto for Q12, C14, R6, Q8.
~~ 
~~ - Oren

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From cheater00 at gmail.com  Fri Nov  5 15:00:38 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Fri, 5 Nov 2010 15:00:38 +0100
Subject: [sdiy] Multimeter and oscilloscope probes
In-Reply-To: <385234051.156889.1288962795808.JavaMail.root@md01.wow.synacor.com>
References: <AANLkTi=Juz+qdVRPcHq2SPUAC9OsD1v11DkPEGqgdqbe@mail.gmail.com>
	<385234051.156889.1288962795808.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTik_YBRqK8Z6xMGiH8tNLeoKePggmxammdaGv2Bk@mail.gmail.com>

Thanks! What about putting the MOhm stuff inside the adapter? I guess
that wouldn't be that great would it?...

I am guessing by the use of a capacitance meter I could also implant a
capacitor in there somewhere..

Cheers,
D.

On Fri, Nov 5, 2010 at 14:13, Harry Bissell <harrybissell at wowway.com> wrote:
> oooh I know <raises hand>
>
> DO NOT consider multimeter probes suitable for an oscilloscope. They are
> not useful in the least.
>
> You need (imho, hell... in my very NON-humble o) a minimum of a 10X probe for an oscilloscope.
> It may seem counter-intuitive, but a 10X (divides the signal by 10) probe is essential for
> quality work. A 1X probe usually has an impedance of 1 meghom, far too low to observe circuit operation without seriously loading (changing) the circuit.
>
> There are switchable 1X/10X probes. They are OK. I bought a set from ProbeMasters (iirc) that had
> (1) 1X, (1) 10X, and (1) 1X/10X so you could have a pair of matched probes of either 1X or 10X. This is important for making differential, pseudo-differential measurements, or just to compare two circuit points with identical response.
>
> BE SURE to choose scope probes that match your scope's frequency response and input capacitance !
> (they could be 'faster" ie 100MHz probes would usually work on a 50MHz scope, but if the capacitance is quite different, performance will suffer greatly - you won't be able to trust what you see...)
>
> Someone on the list poined out some Chinese made probes that were like $7. I forget the link but I bought a couple of sets and they seem OK to me.
>
> Treat the probes like gold, don't bend, twist etc. And WATCH them carefully. Do you know how they got the name "10 to 1" probes ??? Turn your back on them for a moment and the "ten to one" away...
>
> Meter probes are usually "DC" and don't affect measurements much. The 'mini-hook' and crocodile
> leads you suggest sound just fine. For DIP packages they make adapter clips that look like spring clothespins. I'd try to get some old ones as they are just about obsolete and not used much anymore, they should be easy to find in any engineering departments junk drawer or garbage can at this point...
>
> H^) harry
>
>
>
>
> ----- Original Message -----
> From: cheater cheater <cheater00 at gmail.com>
> To: synth-diy <synth-diy at dropmix.xs4all.nl>
> Sent: Fri, 05 Nov 2010 08:36:11 -0400 (EDT)
> Subject: [sdiy] Multimeter and oscilloscope probes
>
> Hi guys,
> I have got a problem with selecting the right tools and I thought I
> would ask the huge collective experience here what the best course of
> action is :-)
>
> I want to get more probes for my multimeters (both analog/VU and
> digital ones). I would also like to get an oscilloscope at some point,
> however for the purpose of synths (no gigahertz frequencies here) I am
> assuming I could use the same probes with an adapter. I would also
> like to be able to probe around and use the probes to listen to the
> signals inside synths, on my headphones. There are several questions I
> have ran into:
>
> 1. what's the best place to buy those things? After moving down to
> Munich I have got most of my multimeters and repair equipment in
> Conrad (except for another soldering iron and simple '813 DMM which I
> got during my year in Berlin). I have a digital and an analogue
> multimeter from Voltcraft that I got there.
>
> 2. What sort of leads will I find useful to have? Here's what I
> thought might be useful:
> a. 2x normal probes (that I have already, so no need to buy)
> b. 2x super-thin probes (that I find I need already in some places I
> can't reach otherwise)
> c. 2x crocodile probes aka dolphin probes (no idea why??), for example
> for clamping down on stuff
> d. some crocodile leads (I think I have some of those already somewhere..)
> e. 2x those syringe-style hook shaped probes
> f. screw-down leads (screw down terminals, for example for ground)
>
> are there any leads missing that I might need?
>
> In addition I would like to get a BNC->4mm Banana converter, the kind
> that you use with oscilloscopes. I don't have an oscilloscope here in
> Germany, however here's the reasoning: i need a way to use all above
> probes and convert them to 1/4" plug to plug into my mixer/preamp. I
> need to be able to switch those probes around (so they can't be
> soldered shut). I can't DIY because I'm unable to find plugs that I
> can diy that will work with test leads where the banana plug is
> surrounded by a protective sheath. However, I have found a bnc to 4mm
> converter that does all that: works with the protected test leads and
> is made already and only costs 4 euro. I can then make a BNC->1/4"
> converter and use it that way. I can also use that later if I want to
> use a scope.
>
> 3. if I get an oscilloscope, will I have good results using the
> multimeter probes? It's not for debugging ddr memory busses, or for
> counting jitter on an xtal, it's mostly for synth repair and/or
> design. Mostly analogue, some digital design too, can't hurt to be
> able to do low-frequency digital (up to say xx MHz speed uC's). So I
> take those probes I have listed above, plug them into the converter,
> and off I go. The bonus here is: I can mix and match, so for example I
> can clamp down the GND, whereas I use a hand held probe for the +
> signal. What are the negative sides of using such a converter? What
> should I watch out for? What should I watch out for when buying the
> test leads? I am thinking that maybe there's some sort of test leads
> that I can buy for my dmm that will also be very good for the
> oscilloscope, whereas if I just pay 5% less I will get something
> that's still good for the DMM but very bad for the oscilloscope - I
> want to prevent this mistake, and would like to get something that's
> good for oscilloscopes too. What is the actual difference between
> multimeter and oscilloscope probes?
>
> 4. can I get a solderable BNC plug (female) somewhere? Or is it better
> to use a ready lead and just rip off one end, replacing it with a
> 1/4"? Or even cut it in half and have two 1/4" converters..
>
> 5. Is there anything else missing in your opinion? I am mostly unsure
> about what test probes I should be getting in order to test things
> like DIP packages. For example some hook style probes seemed to big
> for that and it seemed like they were only made for use with
> through-hole elements. I'm also thinking about some some sort of test
> lead that can go under a tightly soldered capacitor and access the
> leads there (it would have to be a very thin plate of some sort?)
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
>


From jdec at mindspring.com  Fri Nov  5 15:34:59 2010
From: jdec at mindspring.com (BrightBoy)
Date: Fri, 5 Nov 2010 10:34:59 -0400 (GMT-04:00)
Subject: [sdiy] Multimeter and oscilloscope probes
Message-ID: <27844275.1288967699083.JavaMail.root@mswamui-cedar.atl.sa.earthlink.net>

Also make sure that you compensate your probes with the
test square wave signal that is available on the front 
panel of the scope.

(Unless you want your square wave to appear NOT square)

Jeff

-----Original Message-----

>From: Harry Bissell <harrybissell at wowway.com>
>Sent: Nov 5, 2010 9:13 AM
>To: cheater cheater <cheater00 at gmail.com>
>Cc: synth-diy <synth-diy at dropmix.xs4all.nl>
>Subject: Re: [sdiy] Multimeter and oscilloscope probes
>
>oooh I know <raises hand>
>
>DO NOT consider multimeter probes suitable for an oscilloscope. They are
>not useful in the least.
>
>You need (imho, hell... in my very NON-humble o) a minimum of a 10X probe for an oscilloscope.
>It may seem counter-intuitive, but a 10X (divides the signal by 10) probe is essential for
>quality work. A 1X probe usually has an impedance of 1 meghom, far too low to observe circuit operation without seriously loading (changing) the circuit.  
>
>There are switchable 1X/10X probes. They are OK. I bought a set from ProbeMasters (iirc) that had
>(1) 1X, (1) 10X, and (1) 1X/10X so you could have a pair of matched probes of either 1X or 10X. This is important for making differential, pseudo-differential measurements, or just to compare two circuit points with identical response.
>
>BE SURE to choose scope probes that match your scope's frequency response and input capacitance !
>(they could be 'faster" ie 100MHz probes would usually work on a 50MHz scope, but if the capacitance is quite different, performance will suffer greatly - you won't be able to trust what you see...)
>
>Someone on the list poined out some Chinese made probes that were like $7. I forget the link but I bought a couple of sets and they seem OK to me.
>
>Treat the probes like gold, don't bend, twist etc. And WATCH them carefully. Do you know how they got the name "10 to 1" probes ??? Turn your back on them for a moment and the "ten to one" away...
>
>Meter probes are usually "DC" and don't affect measurements much. The 'mini-hook' and crocodile
>leads you suggest sound just fine. For DIP packages they make adapter clips that look like spring clothespins. I'd try to get some old ones as they are just about obsolete and not used much anymore, they should be easy to find in any engineering departments junk drawer or garbage can at this point...
>
>H^) harry
>
>
>
>
>----- Original Message -----
>From: cheater cheater <cheater00 at gmail.com>
>To: synth-diy <synth-diy at dropmix.xs4all.nl>
>Sent: Fri, 05 Nov 2010 08:36:11 -0400 (EDT)
>Subject: [sdiy] Multimeter and oscilloscope probes
>
>Hi guys,
>I have got a problem with selecting the right tools and I thought I
>would ask the huge collective experience here what the best course of
>action is :-)
>
>I want to get more probes for my multimeters (both analog/VU and
>digital ones). I would also like to get an oscilloscope at some point,
>however for the purpose of synths (no gigahertz frequencies here) I am
>assuming I could use the same probes with an adapter. I would also
>like to be able to probe around and use the probes to listen to the
>signals inside synths, on my headphones. There are several questions I
>have ran into:
>
>1. what's the best place to buy those things? After moving down to
>Munich I have got most of my multimeters and repair equipment in
>Conrad (except for another soldering iron and simple '813 DMM which I
>got during my year in Berlin). I have a digital and an analogue
>multimeter from Voltcraft that I got there.
>
>2. What sort of leads will I find useful to have? Here's what I
>thought might be useful:
>a. 2x normal probes (that I have already, so no need to buy)
>b. 2x super-thin probes (that I find I need already in some places I
>can't reach otherwise)
>c. 2x crocodile probes aka dolphin probes (no idea why??), for example
>for clamping down on stuff
>d. some crocodile leads (I think I have some of those already somewhere..)
>e. 2x those syringe-style hook shaped probes
>f. screw-down leads (screw down terminals, for example for ground)
>
>are there any leads missing that I might need?
>
>In addition I would like to get a BNC->4mm Banana converter, the kind
>that you use with oscilloscopes. I don't have an oscilloscope here in
>Germany, however here's the reasoning: i need a way to use all above
>probes and convert them to 1/4" plug to plug into my mixer/preamp. I
>need to be able to switch those probes around (so they can't be
>soldered shut). I can't DIY because I'm unable to find plugs that I
>can diy that will work with test leads where the banana plug is
>surrounded by a protective sheath. However, I have found a bnc to 4mm
>converter that does all that: works with the protected test leads and
>is made already and only costs 4 euro. I can then make a BNC->1/4"
>converter and use it that way. I can also use that later if I want to
>use a scope.
>
>3. if I get an oscilloscope, will I have good results using the
>multimeter probes? It's not for debugging ddr memory busses, or for
>counting jitter on an xtal, it's mostly for synth repair and/or
>design. Mostly analogue, some digital design too, can't hurt to be
>able to do low-frequency digital (up to say xx MHz speed uC's). So I
>take those probes I have listed above, plug them into the converter,
>and off I go. The bonus here is: I can mix and match, so for example I
>can clamp down the GND, whereas I use a hand held probe for the +
>signal. What are the negative sides of using such a converter? What
>should I watch out for? What should I watch out for when buying the
>test leads? I am thinking that maybe there's some sort of test leads
>that I can buy for my dmm that will also be very good for the
>oscilloscope, whereas if I just pay 5% less I will get something
>that's still good for the DMM but very bad for the oscilloscope - I
>want to prevent this mistake, and would like to get something that's
>good for oscilloscopes too. What is the actual difference between
>multimeter and oscilloscope probes?
>
>4. can I get a solderable BNC plug (female) somewhere? Or is it better
>to use a ready lead and just rip off one end, replacing it with a
>1/4"? Or even cut it in half and have two 1/4" converters..
>
>5. Is there anything else missing in your opinion? I am mostly unsure
>about what test probes I should be getting in order to test things
>like DIP packages. For example some hook style probes seemed to big
>for that and it seemed like they were only made for use with
>through-hole elements. I'm also thinking about some some sort of test
>lead that can go under a tightly soldered capacitor and access the
>leads there (it would have to be a very thin plate of some sort?)
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>-- 
>Harry Bissell & Nora Abdullah 4eva
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy





From harrybissell at wowway.com  Fri Nov  5 15:56:53 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 10:56:53 -0400 (EDT)
Subject: [sdiy] Multimeter and oscilloscope probes
In-Reply-To: <AANLkTik_YBRqK8Z6xMGiH8tNLeoKePggmxammdaGv2Bk@mail.gmail.com>
Message-ID: <521399151.160621.1288969013222.JavaMail.root@md01.wow.synacor.com>

It would be really hard to make an adapter that would give good signal fidelity
and not affect the waveform on the scope. Would you want to make your own glasses
with home-ground lenses ?  MUCH cheaper to buy the probes.

iirc the chinese probes were like $7 each, price of a "Big Mac" and a shake,
and a lot healthier ;^)

H^) harry




----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: synth-diy <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 10:00:38 -0400 (EDT)
Subject: Re: [sdiy] Multimeter and oscilloscope probes

Thanks! What about putting the MOhm stuff inside the adapter? I guess
that wouldn't be that great would it?...

I am guessing by the use of a capacitance meter I could also implant a
capacitor in there somewhere..

Cheers,
D.

On Fri, Nov 5, 2010 at 14:13, Harry Bissell <harrybissell at wowway.com> wrote:
> oooh I know <raises hand>
>
> DO NOT consider multimeter probes suitable for an oscilloscope. They are
> not useful in the least.
>
> You need (imho, hell... in my very NON-humble o) a minimum of a 10X probe for an oscilloscope.
> It may seem counter-intuitive, but a 10X (divides the signal by 10) probe is essential for
> quality work. A 1X probe usually has an impedance of 1 meghom, far too low to observe circuit operation without seriously loading (changing) the circuit.
>
> There are switchable 1X/10X probes. They are OK. I bought a set from ProbeMasters (iirc) that had
> (1) 1X, (1) 10X, and (1) 1X/10X so you could have a pair of matched probes of either 1X or 10X. This is important for making differential, pseudo-differential measurements, or just to compare two circuit points with identical response.
>
> BE SURE to choose scope probes that match your scope's frequency response and input capacitance !
> (they could be 'faster" ie 100MHz probes would usually work on a 50MHz scope, but if the capacitance is quite different, performance will suffer greatly - you won't be able to trust what you see...)
>
> Someone on the list poined out some Chinese made probes that were like $7. I forget the link but I bought a couple of sets and they seem OK to me.
>
> Treat the probes like gold, don't bend, twist etc. And WATCH them carefully. Do you know how they got the name "10 to 1" probes ??? Turn your back on them for a moment and the "ten to one" away...
>
> Meter probes are usually "DC" and don't affect measurements much. The 'mini-hook' and crocodile
> leads you suggest sound just fine. For DIP packages they make adapter clips that look like spring clothespins. I'd try to get some old ones as they are just about obsolete and not used much anymore, they should be easy to find in any engineering departments junk drawer or garbage can at this point...
>
> H^) harry
>
>
>
>
> ----- Original Message -----
> From: cheater cheater <cheater00 at gmail.com>
> To: synth-diy <synth-diy at dropmix.xs4all.nl>
> Sent: Fri, 05 Nov 2010 08:36:11 -0400 (EDT)
> Subject: [sdiy] Multimeter and oscilloscope probes
>
> Hi guys,
> I have got a problem with selecting the right tools and I thought I
> would ask the huge collective experience here what the best course of
> action is :-)
>
> I want to get more probes for my multimeters (both analog/VU and
> digital ones). I would also like to get an oscilloscope at some point,
> however for the purpose of synths (no gigahertz frequencies here) I am
> assuming I could use the same probes with an adapter. I would also
> like to be able to probe around and use the probes to listen to the
> signals inside synths, on my headphones. There are several questions I
> have ran into:
>
> 1. what's the best place to buy those things? After moving down to
> Munich I have got most of my multimeters and repair equipment in
> Conrad (except for another soldering iron and simple '813 DMM which I
> got during my year in Berlin). I have a digital and an analogue
> multimeter from Voltcraft that I got there.
>
> 2. What sort of leads will I find useful to have? Here's what I
> thought might be useful:
> a. 2x normal probes (that I have already, so no need to buy)
> b. 2x super-thin probes (that I find I need already in some places I
> can't reach otherwise)
> c. 2x crocodile probes aka dolphin probes (no idea why??), for example
> for clamping down on stuff
> d. some crocodile leads (I think I have some of those already somewhere..)
> e. 2x those syringe-style hook shaped probes
> f. screw-down leads (screw down terminals, for example for ground)
>
> are there any leads missing that I might need?
>
> In addition I would like to get a BNC->4mm Banana converter, the kind
> that you use with oscilloscopes. I don't have an oscilloscope here in
> Germany, however here's the reasoning: i need a way to use all above
> probes and convert them to 1/4" plug to plug into my mixer/preamp. I
> need to be able to switch those probes around (so they can't be
> soldered shut). I can't DIY because I'm unable to find plugs that I
> can diy that will work with test leads where the banana plug is
> surrounded by a protective sheath. However, I have found a bnc to 4mm
> converter that does all that: works with the protected test leads and
> is made already and only costs 4 euro. I can then make a BNC->1/4"
> converter and use it that way. I can also use that later if I want to
> use a scope.
>
> 3. if I get an oscilloscope, will I have good results using the
> multimeter probes? It's not for debugging ddr memory busses, or for
> counting jitter on an xtal, it's mostly for synth repair and/or
> design. Mostly analogue, some digital design too, can't hurt to be
> able to do low-frequency digital (up to say xx MHz speed uC's). So I
> take those probes I have listed above, plug them into the converter,
> and off I go. The bonus here is: I can mix and match, so for example I
> can clamp down the GND, whereas I use a hand held probe for the +
> signal. What are the negative sides of using such a converter? What
> should I watch out for? What should I watch out for when buying the
> test leads? I am thinking that maybe there's some sort of test leads
> that I can buy for my dmm that will also be very good for the
> oscilloscope, whereas if I just pay 5% less I will get something
> that's still good for the DMM but very bad for the oscilloscope - I
> want to prevent this mistake, and would like to get something that's
> good for oscilloscopes too. What is the actual difference between
> multimeter and oscilloscope probes?
>
> 4. can I get a solderable BNC plug (female) somewhere? Or is it better
> to use a ready lead and just rip off one end, replacing it with a
> 1/4"? Or even cut it in half and have two 1/4" converters..
>
> 5. Is there anything else missing in your opinion? I am mostly unsure
> about what test probes I should be getting in order to test things
> like DIP packages. For example some hook style probes seemed to big
> for that and it seemed like they were only made for use with
> through-hole elements. I'm also thinking about some some sort of test
> lead that can go under a tightly soldered capacitor and access the
> leads there (it would have to be a very thin plate of some sort?)
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
>

-- 
Harry Bissell & Nora Abdullah 4eva


From neil.johnson97 at ntlworld.com  Fri Nov  5 16:02:14 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Fri, 5 Nov 2010 15:02:14 +0000
Subject: [sdiy] Guard Rings
In-Reply-To: <2130930441.158282.1288964797875.JavaMail.root@md01.wow.synacor.com>
References: <000701cb7ca8$d1ad8130$75088390$@net>
	<2130930441.158282.1288964797875.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTim4Jh+Mtm6cwLLFewqmoEwO5E-5BFq1rEb3H03t@mail.gmail.com>

Hi,

> I agree, what is R13 ?

My guess: it limits the peak current through the G-S junction
(remember, its a PN junction, so will conduct if forward biased).

But that's just a guess.

Neil
-- 
http://www.njohnson.co.uk


From harrybissell at wowway.com  Fri Nov  5 16:02:44 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 11:02:44 -0400 (EDT)
Subject: [sdiy] Multimeter and oscilloscope probes
In-Reply-To: <AANLkTik_YBRqK8Z6xMGiH8tNLeoKePggmxammdaGv2Bk@mail.gmail.com>
Message-ID: <1416798640.160856.1288969364721.JavaMail.root@md01.wow.synacor.com>

here's the link. 100 MHz scope probe. $6 and free shipping. So buy two...

http://www.dealextreme.com/search.dx/search.32422




----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: synth-diy <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 10:00:38 -0400 (EDT)
Subject: Re: [sdiy] Multimeter and oscilloscope probes

Thanks! What about putting the MOhm stuff inside the adapter? I guess
that wouldn't be that great would it?...

I am guessing by the use of a capacitance meter I could also implant a
capacitor in there somewhere..

Cheers,
D.

On Fri, Nov 5, 2010 at 14:13, Harry Bissell <harrybissell at wowway.com> wrote:
> oooh I know <raises hand>
>
> DO NOT consider multimeter probes suitable for an oscilloscope. They are
> not useful in the least.
>
> You need (imho, hell... in my very NON-humble o) a minimum of a 10X probe for an oscilloscope.
> It may seem counter-intuitive, but a 10X (divides the signal by 10) probe is essential for
> quality work. A 1X probe usually has an impedance of 1 meghom, far too low to observe circuit operation without seriously loading (changing) the circuit.
>
> There are switchable 1X/10X probes. They are OK. I bought a set from ProbeMasters (iirc) that had
> (1) 1X, (1) 10X, and (1) 1X/10X so you could have a pair of matched probes of either 1X or 10X. This is important for making differential, pseudo-differential measurements, or just to compare two circuit points with identical response.
>
> BE SURE to choose scope probes that match your scope's frequency response and input capacitance !
> (they could be 'faster" ie 100MHz probes would usually work on a 50MHz scope, but if the capacitance is quite different, performance will suffer greatly - you won't be able to trust what you see...)
>
> Someone on the list poined out some Chinese made probes that were like $7. I forget the link but I bought a couple of sets and they seem OK to me.
>
> Treat the probes like gold, don't bend, twist etc. And WATCH them carefully. Do you know how they got the name "10 to 1" probes ??? Turn your back on them for a moment and the "ten to one" away...
>
> Meter probes are usually "DC" and don't affect measurements much. The 'mini-hook' and crocodile
> leads you suggest sound just fine. For DIP packages they make adapter clips that look like spring clothespins. I'd try to get some old ones as they are just about obsolete and not used much anymore, they should be easy to find in any engineering departments junk drawer or garbage can at this point...
>
> H^) harry
>
>
>
>
> ----- Original Message -----
> From: cheater cheater <cheater00 at gmail.com>
> To: synth-diy <synth-diy at dropmix.xs4all.nl>
> Sent: Fri, 05 Nov 2010 08:36:11 -0400 (EDT)
> Subject: [sdiy] Multimeter and oscilloscope probes
>
> Hi guys,
> I have got a problem with selecting the right tools and I thought I
> would ask the huge collective experience here what the best course of
> action is :-)
>
> I want to get more probes for my multimeters (both analog/VU and
> digital ones). I would also like to get an oscilloscope at some point,
> however for the purpose of synths (no gigahertz frequencies here) I am
> assuming I could use the same probes with an adapter. I would also
> like to be able to probe around and use the probes to listen to the
> signals inside synths, on my headphones. There are several questions I
> have ran into:
>
> 1. what's the best place to buy those things? After moving down to
> Munich I have got most of my multimeters and repair equipment in
> Conrad (except for another soldering iron and simple '813 DMM which I
> got during my year in Berlin). I have a digital and an analogue
> multimeter from Voltcraft that I got there.
>
> 2. What sort of leads will I find useful to have? Here's what I
> thought might be useful:
> a. 2x normal probes (that I have already, so no need to buy)
> b. 2x super-thin probes (that I find I need already in some places I
> can't reach otherwise)
> c. 2x crocodile probes aka dolphin probes (no idea why??), for example
> for clamping down on stuff
> d. some crocodile leads (I think I have some of those already somewhere..)
> e. 2x those syringe-style hook shaped probes
> f. screw-down leads (screw down terminals, for example for ground)
>
> are there any leads missing that I might need?
>
> In addition I would like to get a BNC->4mm Banana converter, the kind
> that you use with oscilloscopes. I don't have an oscilloscope here in
> Germany, however here's the reasoning: i need a way to use all above
> probes and convert them to 1/4" plug to plug into my mixer/preamp. I
> need to be able to switch those probes around (so they can't be
> soldered shut). I can't DIY because I'm unable to find plugs that I
> can diy that will work with test leads where the banana plug is
> surrounded by a protective sheath. However, I have found a bnc to 4mm
> converter that does all that: works with the protected test leads and
> is made already and only costs 4 euro. I can then make a BNC->1/4"
> converter and use it that way. I can also use that later if I want to
> use a scope.
>
> 3. if I get an oscilloscope, will I have good results using the
> multimeter probes? It's not for debugging ddr memory busses, or for
> counting jitter on an xtal, it's mostly for synth repair and/or
> design. Mostly analogue, some digital design too, can't hurt to be
> able to do low-frequency digital (up to say xx MHz speed uC's). So I
> take those probes I have listed above, plug them into the converter,
> and off I go. The bonus here is: I can mix and match, so for example I
> can clamp down the GND, whereas I use a hand held probe for the +
> signal. What are the negative sides of using such a converter? What
> should I watch out for? What should I watch out for when buying the
> test leads? I am thinking that maybe there's some sort of test leads
> that I can buy for my dmm that will also be very good for the
> oscilloscope, whereas if I just pay 5% less I will get something
> that's still good for the DMM but very bad for the oscilloscope - I
> want to prevent this mistake, and would like to get something that's
> good for oscilloscopes too. What is the actual difference between
> multimeter and oscilloscope probes?
>
> 4. can I get a solderable BNC plug (female) somewhere? Or is it better
> to use a ready lead and just rip off one end, replacing it with a
> 1/4"? Or even cut it in half and have two 1/4" converters..
>
> 5. Is there anything else missing in your opinion? I am mostly unsure
> about what test probes I should be getting in order to test things
> like DIP packages. For example some hook style probes seemed to big
> for that and it seemed like they were only made for use with
> through-hole elements. I'm also thinking about some some sort of test
> lead that can go under a tightly soldered capacitor and access the
> leads there (it would have to be a very thin plate of some sort?)
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
>

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Fri Nov  5 16:07:10 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 11:07:10 -0400 (EDT)
Subject: [sdiy] Guard Rings
In-Reply-To: <AANLkTim4Jh+Mtm6cwLLFewqmoEwO5E-5BFq1rEb3H03t@mail.gmail.com>
Message-ID: <1489526707.160953.1288969630103.JavaMail.root@md01.wow.synacor.com>

I thought that too, but couldn't you put that resistor between the source of the FET and the base of the emitter-follower transistor and make life easier... ?

(unless you are worried about what might happen if the cap was holding a charge and you crowbar'd
the power supply suddenly....)

H^) harry

----- Original Message -----
From: Neil Johnson <neil.johnson97 at ntlworld.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: David Ingebretsen <dingebre at 3dphysics.net>, synth diy <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 11:02:14 -0400 (EDT)
Subject: Re: [sdiy] Guard Rings

Hi,

> I agree, what is R13 ?

My guess: it limits the peak current through the G-S junction
(remember, its a PN junction, so will conduct if forward biased).

But that's just a guess.

Neil
-- 
http://www.njohnson.co.uk

-- 
Harry Bissell & Nora Abdullah 4eva


From houshu at muj.biglobe.ne.jp  Fri Nov  5 16:08:42 2010
From: houshu at muj.biglobe.ne.jp (HOSHUYAMA)
Date: Sat, 6 Nov 2010 00:08:42 +0900 (JST)
Subject: [sdiy] Monotron Schematic
Message-ID: <20101106.000841.64915427.houshu@muj.biglobe.ne.jp>

Hello List,

Now Korg monotoron schematic is online officially!

http://www.korg.co.jp/Support/Manual/download.php?id=512

Click the bottom [Download] button.

Sam HOSHUYAMA
Saitama, JAPAN


From houshu at muj.biglobe.ne.jp  Fri Nov  5 16:29:51 2010
From: houshu at muj.biglobe.ne.jp (HOSHUYAMA)
Date: Sat, 6 Nov 2010 00:29:51 +0900 (JST)
Subject: [sdiy] Monotron Schematic
In-Reply-To: <20101106.000841.64915427.houshu@muj.biglobe.ne.jp>
References: <20101106.000841.64915427.houshu@muj.biglobe.ne.jp>
Message-ID: <20101106.002950.57136996.houshu@muj.biglobe.ne.jp>

Hello List,

English information is easier for you, isn't it.

http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-monotron-synth/

Sam HOSHUYAMA


HOSHUYAMA wrote:
> Hello List,
> 
> Now Korg monotoron schematic is online officially!
> 
> 
> http://www.korg.co.jp/Support/Manual/download.php?id=512
> 
> Click the bottom [Download] button.
> 
> Sam HOSHUYAMA
> Saitama, JAPAN
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> 
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
>  


From ijfritz at comcast.net  Fri Nov  5 16:32:06 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Fri, 05 Nov 2010 09:32:06 -0600
Subject: [sdiy] Guard Rings
In-Reply-To: <E6D31158-4D54-48B3-8412-D38C9CC7C79D@shaw.ca>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<4CD3870D.4060503@ix.netcom.com> <4CD39601.9020209@sonic.net>
	<8C00FC6D-0A1E-4C8E-BF3A-5087627B8128@shaw.ca>
	<4CD3B18D.8050500@sonic.net>
	<E6D31158-4D54-48B3-8412-D38C9CC7C79D@shaw.ca>
Message-ID: <6.2.1.2.2.20101105092957.023c7288@mail.comcast.net>

At 01:32 AM 11/5/2010, Veronica Merryfield wrote:
> > Thanks, it's an emitter follower isn't it?  Guess it's time to go back 
> to my
> > basic transistor circuits books for a review.  :-0
>
>Yes, or a common collector.

Hmmm...Looks like I'll have to review this too.  Aren't you calculating the 
AC gain? Doesn't the emitter have to be DC biased one diode drop below the 
base?

Ian 



From altitude at optrand.com  Fri Nov  5 16:32:52 2010
From: altitude at optrand.com (Altitude)
Date: Fri, 5 Nov 2010 11:32:52 -0400
Subject: [sdiy] WTB/WTT: CEM3379
In-Reply-To: <20101106.000841.64915427.houshu@muj.biglobe.ne.jp>
Message-ID: <389964.90173.qm@smtp104.sbc.mail.re3.yahoo.com>

Looking to buy or trade:

I have for trade (combinations of, + cash, etc)

MAX525ACPP (12bit DAC)
MAX529CPP (8bit DAC)
CEM3320
CEM3328

Cheers,
Raph



From igg.debus at t-online.de  Fri Nov  5 17:16:10 2010
From: igg.debus at t-online.de (Ingo Debus)
Date: Fri, 5 Nov 2010 17:16:10 +0100
Subject: [sdiy] Guard Rings
In-Reply-To: <2E8CFB96181C4AB58E90DF5F24073D21@galvanox01>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<2E8CFB96181C4AB58E90DF5F24073D21@galvanox01>
Message-ID: <7B2ABCDA-E52C-4310-BC38-EEE712D2A564@t-online.de>


Am 05.11.2010 um 06:30 schrieb David G. Dixon:

>
> The junctions between the emitters of Q5 and Q6, resistors R16 and  
> R18, and
> the drains of Q11 and Q12, respectively, are emphatically NOT high
> impedance.  In fact, their impedances are about 2.2k.

These are outputs of emitter followers, so their impedances are even  
lower.

Can someone explain to me how the "Random Voltage Generator" works?

Ingo


From senso at vintageplanet.nl  Fri Nov  5 17:17:44 2010
From: senso at vintageplanet.nl (Senso)
Date: Fri, 5 Nov 2010 17:17:44 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <20101106.002950.57136996.houshu@muj.biglobe.ne.jp>
References: <20101106.000841.64915427.houshu@muj.biglobe.ne.jp>
	<20101106.002950.57136996.houshu@muj.biglobe.ne.jp>
Message-ID: <a06240806c8f9ddeb967d@[192.168.254.1]>

Wow, thanks!

Such service is quite unusual for most synth manufacturers.
Do you happen to know if they published any other schematics or 
service manuals? Especially for the old analogue gear?

Senso


>Hello List,
>
>English information is easier for you, isn't it.
>
>http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-monotron-synth/
>
>Sam HOSHUYAMA
>
>
>HOSHUYAMA wrote:
>>  Hello List,
>>
>>  Now Korg monotoron schematic is online officially!
>>
>>
>>  http://www.korg.co.jp/Support/Manual/download.php?id=512
>>
>>  Click the bottom [Download] button.
>>
>>  Sam HOSHUYAMA
>>  Saitama, JAPAN
>>  _______________________________________________
>>  Synth-diy mailing list
>>  Synth-diy at dropmix.xs4all.nl
>>
>>  http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>> 
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From paul at fitvideo.co.uk  Fri Nov  5 17:44:47 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Fri, 5 Nov 2010 16:44:47 -0000
Subject: [sdiy] Monotron Schematic
Message-ID: <000001cb7d08$c4047d30$4c0d7790$@co.uk>

Many thanks Sam Hoshuyama for putting that up..



Re "Wow, thanks!

"Such service is quite unusual for most synth manufacturers.
Do you happen to know if they published any other schematics or service
manuals? Especially for the old analogue gear?

Senso"

Very unusual..

Schematics generally only appear in service manuals that I have helped
translate 20+ years ago... and made very unavailable to the public. this new
attitude speaks volumes and we may see others react. this is remember the
first purely analogue synth in 25 years by a big boy company imho. The
exception of including schematics that comes to mind is the Roland SH-101 in
that they put the schematics in the user manual. there are others as well
but few and far between ... 
 

>Hello List,
>
>English information is easier for you, isn't it.
>
>http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-mon
>otron-synth/
>
>Sam HOSHUYAMA
>
>
>HOSHUYAMA wrote:
>>  Hello List,
>>
>>  Now Korg monotoron schematic is online officially!
>>
>>
>>  http://www.korg.co.jp/Support/Manual/download.php?id=512
>>
>>  Click the bottom [Download] button.
>>
>>  Sam HOSHUYAMA
>>  Saitama, JAPAN




From harrybissell at wowway.com  Fri Nov  5 18:48:10 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 13:48:10 -0400 (EDT)
Subject: [sdiy] Guard Rings
In-Reply-To: <6.2.1.2.2.20101105092957.023c7288@mail.comcast.net>
Message-ID: <607347071.165455.1288979290676.JavaMail.root@md01.wow.synacor.com>

right. The flip side is that the guard ring might be best driven from the emitter anyway, even including the drop. If it were attached to the FET source, it would also be connected to the transistor base and might be an antenna...  As it is, it would guarantee that any board leakage would have only a .7V drop to discharge the hold cap with.

In classic form this would have been an opamp follower with only the offset voltage across
the guard ring and the hold cap...

H^) harry



----- Original Message -----
From: Ian Fritz <ijfritz at comcast.net>
To: Veronica Merryfield <veronica.merryfield at shaw.ca>, Dave Manley <dlmanley at sonic.net>
Cc: synth-diy at dropmix.xs4all.nl
Sent: Fri, 05 Nov 2010 11:32:06 -0400 (EDT)
Subject: Re: [sdiy] Guard Rings

At 01:32 AM 11/5/2010, Veronica Merryfield wrote:
> > Thanks, it's an emitter follower isn't it?  Guess it's time to go back 
> to my
> > basic transistor circuits books for a review.  :-0
>
>Yes, or a common collector.

Hmmm...Looks like I'll have to review this too.  Aren't you calculating the 
AC gain? Doesn't the emitter have to be DC biased one diode drop below the 
base?

Ian 

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Fri Nov  5 18:54:19 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 5 Nov 2010 13:54:19 -0400 (EDT)
Subject: [sdiy] Monotron Schematic
In-Reply-To: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
Message-ID: <834539456.165595.1288979659662.JavaMail.root@md01.wow.synacor.com>

They look like a sawtooth VCO whose frequency is set by whatever the last sample
voltage was... kind of a way of "shaking the dice" at different rates each time...

Clever, wonder if it works well... sure is simple (no noise generator needed)

H^) harry


----- Original Message -----
From: Paul Burns <paul at fitvideo.co.uk>
To: synth-diy at dropmix.xs4all.nl
Sent: Fri, 05 Nov 2010 12:44:47 -0400 (EDT)
Subject: Re: [sdiy] Monotron Schematic

Many thanks Sam Hoshuyama for putting that up..



Re "Wow, thanks!

"Such service is quite unusual for most synth manufacturers.
Do you happen to know if they published any other schematics or service
manuals? Especially for the old analogue gear?

Senso"

Very unusual..

Schematics generally only appear in service manuals that I have helped
translate 20+ years ago... and made very unavailable to the public. this new
attitude speaks volumes and we may see others react. this is remember the
first purely analogue synth in 25 years by a big boy company imho. The
exception of including schematics that comes to mind is the Roland SH-101 in
that they put the schematics in the user manual. there are others as well
but few and far between ... 
 

>Hello List,
>
>English information is easier for you, isn't it.
>
>http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-mon
>otron-synth/
>
>Sam HOSHUYAMA
>
>
>HOSHUYAMA wrote:
>>  Hello List,
>>
>>  Now Korg monotoron schematic is online officially!
>>
>>
>>  http://www.korg.co.jp/Support/Manual/download.php?id=512
>>
>>  Click the bottom [Download] button.
>>
>>  Sam HOSHUYAMA
>>  Saitama, JAPAN


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From synth at willacy.co.uk  Fri Nov  5 18:55:51 2010
From: synth at willacy.co.uk (Steve Carter)
Date: Fri, 5 Nov 2010 17:55:51 +0000
Subject: [sdiy] Monotron Schematic
In-Reply-To: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
Message-ID: <DF8A298C-E7D3-43C9-9FFB-5A01BC390D68@willacy.co.uk>

Yes thanks Sam.  Interesting circuit. I hadn't come across the IMX9 dual transistor before. It maybe a small box but SMD has allowed them not to scrimp on design. I now understand how they do the modulation sync by using an LFO reset line - couldn't figure that out by just staring at the board - it just wasn't talking to me.
Steve

On 5 Nov 2010, at 16:44, Paul Burns wrote:

> Many thanks Sam Hoshuyama for putting that up..
> 
> 
> 
> Re "Wow, thanks!
> 
> "Such service is quite unusual for most synth manufacturers.
> Do you happen to know if they published any other schematics or service
> manuals? Especially for the old analogue gear?
> 
> Senso"
> 
> Very unusual..
> 
> Schematics generally only appear in service manuals that I have helped
> translate 20+ years ago... and made very unavailable to the public. this new
> attitude speaks volumes and we may see others react. this is remember the
> first purely analogue synth in 25 years by a big boy company imho. The
> exception of including schematics that comes to mind is the Roland SH-101 in
> that they put the schematics in the user manual. there are others as well
> but few and far between ... 
> 
> 
>> Hello List,
>> 
>> English information is easier for you, isn't it.
>> 
>> http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-mon
>> otron-synth/
>> 
>> Sam HOSHUYAMA
>> 
>> 
>> HOSHUYAMA wrote:
>>> Hello List,
>>> 
>>> Now Korg monotoron schematic is online officially!
>>> 
>>> 
>>> http://www.korg.co.jp/Support/Manual/download.php?id=512
>>> 
>>> Click the bottom [Download] button.
>>> 
>>> Sam HOSHUYAMA
>>> Saitama, JAPAN
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From julian at port23.co.uk  Fri Nov  5 19:19:42 2010
From: julian at port23.co.uk (Julian)
Date: Fri, 5 Nov 2010 18:19:42 -0000
Subject: [sdiy] making traces curve in eagle
Message-ID: <E62DE7F79FC84AFE914E01C9E96EC05C@legba>

Im using Eagels auto route function, and trying to get it to make smooth curves and not angular changes in direction - the reason 
being is that my cnc machine will glide arround smooth curves, but has to decellerate for hard angles.

Ive been messing about with the costing, and have set evreything to zero, except for vias (i want it to keep on one side) but thats 
not working, so its evidently not in that section.

Any pointers?

Thank you,
Julian
 



From dixon at interchange.ubc.ca  Fri Nov  5 19:43:19 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Fri, 05 Nov 2010 11:43:19 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <7B2ABCDA-E52C-4310-BC38-EEE712D2A564@t-online.de>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net>
	<2E8CFB96181C4AB58E90DF5F24073D21@galvanox01>
	<7B2ABCDA-E52C-4310-BC38-EEE712D2A564@t-online.de>
Message-ID: <4028B9C6ABE64DE6B7ED6BD627532C6B@galvanox01>

> > The junctions between the emitters of Q5 and Q6, resistors R16 and
> > R18, and
> > the drains of Q11 and Q12, respectively, are emphatically NOT high
> > impedance.  In fact, their impedances are about 2.2k.
> 
> These are outputs of emitter followers, so their impedances are even
> lower.

Ah yes, of course, you are right.  The impedance of those traces will
actually be less than 50 ohms!  All the more reason not to include them
inside the "island".



From senso at vintageplanet.nl  Fri Nov  5 20:40:55 2010
From: senso at vintageplanet.nl (Senso)
Date: Fri, 5 Nov 2010 20:40:55 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
Message-ID: <a06240800c8fa0b9cae83@[192.168.254.1]>

Maybe someone at Korg got fed up from all the DIYers asking for it. :-)

Another one I can think of was the Polyvox. It had it included in the 
manual also. The only drawback was the fact that the whole thing was 
in Russian, but so what .
I seem to remember there were a few Crumar or Siel synths that came 
with schematics too.

>Very unusual..
>
>Schematics generally only appear in service manuals that I have helped
>translate 20+ years ago... and made very unavailable to the public. this new
>attitude speaks volumes and we may see others react. this is remember the
>first purely analogue synth in 25 years by a big boy company imho. The
>exception of including schematics that comes to mind is the Roland SH-101 in
>that they put the schematics in the user manual. there are others as well
>but few and far between ...


-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From ic1 at bell.net  Fri Nov  5 20:51:43 2010
From: ic1 at bell.net (Tony Kalomiris)
Date: Fri, 5 Nov 2010 15:51:43 -0400
Subject: [sdiy] Monotron Schematic
In-Reply-To: <a06240800c8fa0b9cae83@[192.168.254.1]>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
	<a06240800c8fa0b9cae83@[192.168.254.1]>
Message-ID: <BLU0-SMTP37361704A861545D49C8CA974C0@phx.gbl>

The Moog Prodigy had not only the schematic but complete theory of operation and tune-up procedure.
Guess they figured people are too dumb to bother with that stuff today - risk electrocution and law suits or to sell them separate service manuals.
The schematics that came with my dad's Telefunken 70's stereo is what got me into electronics - that and my his soldering prowess (DIN to RCA)- also remember my Realistic DX-302 communications receiver had one, which I  used to change the narrow filter to 12 khz for wide band AM.

I wholeheartedly vote for including schematics with user manuals - think of it as art for the uninitiated.

Tony Kalomiris


On 2010-11-05, at 3:40 PM, Senso wrote:

> Maybe someone at Korg got fed up from all the DIYers asking for it. :-)
> 
> Another one I can think of was the Polyvox. It had it included in the manual also. The only drawback was the fact that the whole thing was in Russian, but so what .
> I seem to remember there were a few Crumar or Siel synths that came with schematics too.
> 
>> Very unusual..
>> 
>> Schematics generally only appear in service manuals that I have helped
>> translate 20+ years ago... and made very unavailable to the public. this new
>> attitude speaks volumes and we may see others react. this is remember the
>> first purely analogue synth in 25 years by a big boy company imho. The
>> exception of including schematics that comes to mind is the Roland SH-101 in
>> that they put the schematics in the user manual. there are others as well
>> but few and far between ...
> 
> 
> -- 
> ----------------------------------------------
> ---------- VINTAGE PLANET ---------
> ----- Synthesizer Parts Service -----
> ---- http://www.vintageplanet.nl ----
> ----------------------------------------------
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From eric at ericframpton.com  Fri Nov  5 21:19:23 2010
From: eric at ericframpton.com (Eric Frampton)
Date: Fri, 5 Nov 2010 16:19:23 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
	<BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>
Message-ID: <F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>

Replies in the order I saw 'em...

On Nov 4, 2010, at 5:47 AM, Tony Kalomiris wrote:

> Nice job Eric,

Thank you sir!

> Are you saying C11 was shorted ? Or did you just find it by substitution ?

It was apparently shorted. I followed everybody's advice and metered all the outputs looking for shorts, and the unregulated 11.5V supply was faulty. I figured there weren't a whole lot of parts between the rectifier and the output except that cap (and Harry and Andy suggested I look at the electrolytics first), so I tried removing it, and the short cleared.

> I've seen tantalums short but don't recall this happening with electrolytics.

I've not seen it happen with an electrolytic, either.

> That's the longest time constant I've ever seen - half an hour !

Oh, it gets better. So after a half-hour, the voltage on that reg. hits 4.95, the CPU board comes up, and the instrument springs to life. I reloaded the factory patches, started playing, and could make out sound but it was incredibly distorted and full of DC-type hum. But funny, as I let the machine run over the course of another hour or so, the audio cleared up completely except for the effects board. Thinking I was on to something, I then let it run overnight, came back the next morning, and the effects board audio was completely clean. So the unit seems to be working 100% now by replacing that cap and just leaving it running.

Then, Andy Jury said:

> Glad you got it fixed. You might want to try replacing the 78 series
> regulator that feeds that particular +5v rail.

I plan to leave the unit baking for another couple of days, and if it goes weird then I'll replace it. Otherwise I'll leave it alone.

Then, Peter said:

> I wasn't sure if you just replaced one cap or all of them ?

I started with the one, then decided to replace the 4700uF and the 1000uF as well. I probably should've replaced every electrolytic in the whole box, but at a certain point that piece just isn't worth that kind of time investment.

Then, Harry Bissell said:

> I'd agree. I find it really hard to believe that other caps were "re-forming" to make the voltage
> slowly rise from 3.5V to 5V.  Re-forming usually does not take place politely unless you force it to do so.

I've only read about it - never experienced it first hand - so this is new territory for me.

> Re-forming a dielectric in an electrolytic cap makes the layer thicker and able to withstand higher voltages.
> Its likely that if you applied a higher voltage (5V) and the dielectric could not stand that voltage, it would
> fail shorted. You would be relying on the regulator chip to limit the current in this case. I would not rule
> out what you have reported, just that I'd look elsewhere (almost anywhere...) before settling on this as the
> root cause.
> 
> I'd more suspect another capacitor that may have been shorted (like a tantalum) and that you heated it until
> it opened up. Or some other explanation ???

If a tant opened up, I'd think the unit would've failed instead of working -better-...?

> Check your power supply current carefully on each rail if possible, and check to see if the regulator chips
> are running hotter than you expect.

The +5 rail dedicated to the CPU and Effects board was running warmer than the other +5 regs., but judging by the PSU layout it looked like Korg expected that to happen - they left extra space for heat dissipation.

> That sure is a curious observation. I'd look really hard, or put a lot of hours on the unit before I'd trust that
> your repair is solid...

It was weird to me, too. I figure I'll let it bake for 3 or 4 days solid, and if everything's still working I figure it's probably safe to let go.

Funny, I never intended to be repairing this piece in the first place. I'd never played with a DW-8000 before and wanted to hear what it sounded like, and my friend just got this on a trade with the suggestion that it only needed a fresh battery. So I thought I was just putting a battery in and re-loading the patches and farting around with it - I never meant to get into all of this! But it has been another good learning experience...

> <twilight zone theme plays...>

Indeed!!

e



From igg.debus at t-online.de  Fri Nov  5 21:58:49 2010
From: igg.debus at t-online.de (Ingo Debus)
Date: Fri, 5 Nov 2010 21:58:49 +0100
Subject: [sdiy] Monotron Schematic - Guard Rings
In-Reply-To: <834539456.165595.1288979659662.JavaMail.root@md01.wow.synacor.com>
References: <834539456.165595.1288979659662.JavaMail.root@md01.wow.synacor.com>
Message-ID: <694F7504-91CD-437E-A2CF-5FC9AD432B15@t-online.de>


Am 05.11.2010 um 18:54 schrieb Harry Bissell:

> They look like a sawtooth VCO whose frequency is set by whatever  
> the last sample
> voltage was... kind of a way of "shaking the dice" at different  
> rates each time...
>
> Clever, wonder if it works well... sure is simple (no noise  
> generator needed)
>

Is this an answer to my question re how the random voltage generator  
in the Steiner Synthasystem works?

So the UJT is the discharge switch of a relaxation oscillator?

Making an analog random generator this way is pretty brilliant. Hats  
off!
And then there's two of them in one module that can be run with the  
same trigger signal (if no plug is inserted in the trig 2 input). I  
wonder how similar the outputs are?

Ingo


From igg.debus at t-online.de  Fri Nov  5 22:27:14 2010
From: igg.debus at t-online.de (Ingo Debus)
Date: Fri, 5 Nov 2010 22:27:14 +0100
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
	<BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>
	<F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>
Message-ID: <A9B11833-1C36-48AD-80A0-80192A8B2133@t-online.de>


Am 05.11.2010 um 21:19 schrieb Eric Frampton:

>
>> That's the longest time constant I've ever seen - half an hour !
>
> Oh, it gets better. So after a half-hour, the voltage on that reg.  
> hits 4.95, the CPU board comes up, and the instrument springs to  
> life. I reloaded the factory patches, started playing, and could  
> make out sound but it was incredibly distorted and full of DC-type  
> hum. But funny, as I let the machine run over the course of another  
> hour or so, the audio cleared up completely except for the effects  
> board. Thinking I was on to something, I then let it run overnight,  
> came back the next morning, and the effects board audio was  
> completely clean. So the unit seems to be working 100% now by  
> replacing that cap and just leaving it running.

Recently someone suggested to me to find bad electrolytics by heating  
them up with a hair dryer. He said, sometimes they re-gain  
capacitance (or ESR goes down?) when getting hot.

Does the unit still work good after being off for some time?

Ingo


From gsn10 at hotmail.com  Fri Nov  5 22:34:12 2010
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Fri, 5 Nov 2010 17:34:12 -0400
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>,
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>,
	<BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>,
	<F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>
Message-ID: <SNT104-W55174ABEA7BF0F9799196DB44C0@phx.gbl>


> > That sure is a curious observation. I'd look really hard, or put a lot of hours on the unit before I'd trust that
> > your repair is solid...
>
>
It was weird to me, too. I figure I'll let it bake for 3 or 4 days
solid, and if everything's still working I figure it's probably safe to
let go.



Dunno how much you've tested it so far, but I'd expect it to go bad
again when it's cold.? I've noticed before that leaky electrolytic caps
can improve as they heat up.? I recently fixed a Kurzweil K2VX (these
are fairly notorious for inadequate capacitors in the PSU), I could
switch it on while watching the front panel and monitoring the +5v rail
on a scope: It started off crashed with nothing on the display and
large spikes on the power supply.? Slowly it would smooth out, the
front panel LEDs would start to flash as it would repeatedly reset and
crash again.? After a few minutes the spikes would disappear entirely
and it would boot up as normal.? This isn't the same as reforming the
oxide layer.? I think the cap had vented and lost a lot of electrolyte,
in the process greatly reducing its performance and increasing leakage
current.? The next time I'd switch it on after letting it cool down, it
would crash again.? It's possible that you have a part that's doing the
same.? And if it's drawing enough current to pull the power down that
much, it's likely getting very warm, so it shouldn't be hard to find.
 		 	   		  

From dingebre at 3dphysics.net  Fri Nov  5 23:20:34 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Fri, 5 Nov 2010 16:20:34 -0600
Subject: [sdiy] Guard Rings
In-Reply-To: <4CD39601.9020209@sonic.net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>	<000001cb7c9d$ae91c6d0$0bb55470$@net>	<4CD3870D.4060503@ix.netcom.com>
	<4CD39601.9020209@sonic.net>
Message-ID: <005e01cb7d37$accf2140$066d63c0$@net>

First, I really appreciate all the feedback.

I got hold of Nyle today and asked him about R13. He said when they started
building their circuits, they noticed some high frequency oscillations in
the voltage followers which was removed when they added a 1k or 1.2k
resistor in series with the transistor base. He didn't remember if they had
the same problem with FET followers, but thought he added R13 as a
preventative measure. 

He also thought the best idea for this PCB would be to just huddle the nodes
of Q11-S, C5, R13 and Q7-G close together and not put any other pads close
by and forego the guard ring. He said if he had used an FET input OpAmp, he
would recommend a guard ring.

But, what do I know. :) 

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of Dave Manley
~~ Sent: Thursday, November 04, 2010 11:29 PM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ On 11/4/2010 9:24 PM, Oren Leavitt wrote:
~~ 
~~ >
~~ > Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is
~~ > connected the output (emitter) of the emitter-follower Q9 which will be
~~ at the same potential but buffered.
~~ > Ditto for Q12, C14, R6, Q8.
~~ 
~~ I agree where the ring should go, and I'd be tempted to optimize the
~~ component
~~ placement.
~~ 
~~ A couple of questions:
~~ 
~~ Is Q9 emitter really at the same potential as the voltage on the cap?
~~ 
~~ What's the point of R13?
~~ 
~~ David - the idea of the guard ring is to surround a high impedance node
~~ holding
~~ a charge with a buffered potential of the same voltage.  This will
isolate
~~ the
~~ node from different nearby voltages so that it doesn't discharge due to
~~ leakage
~~ currents on the board.  If the PCB is clean these leakage currents should
~~ be minimal.
~~ Make sure the board is free of contamination on both sides.
~~ 
~~ -Dave
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From dixon at interchange.ubc.ca  Sat Nov  6 00:49:39 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Fri, 05 Nov 2010 16:49:39 -0700
Subject: [sdiy] Guard Rings
In-Reply-To: <005e01cb7d37$accf2140$066d63c0$@net>
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
	<000001cb7c9d$ae91c6d0$0bb55470$@net> <4CD3870D.4060503@ix.netcom.com>
	<4CD39601.9020209@sonic.net> <005e01cb7d37$accf2140$066d63c0$@net>
Message-ID: <F124E663B3C64867915E8E475C1867B8@galvanox01>

> He also thought the best idea for this PCB would be to just huddle the
> nodes
> of Q11-S, C5, R13 and Q7-G close together and not put any other pads close
> by and forego the guard ring. He said if he had used an FET input OpAmp,
> he
> would recommend a guard ring.

Why is a FET any different than a FET-input opamp vis-a-vis the guard ring?



From dlmanley at sonic.net  Sat Nov  6 05:05:43 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Fri, 05 Nov 2010 21:05:43 -0700
Subject: [sdiy] Random generator - Monotron Schematic - Guard Rings
In-Reply-To: <694F7504-91CD-437E-A2CF-5FC9AD432B15@t-online.de>
References: <834539456.165595.1288979659662.JavaMail.root@md01.wow.synacor.com>
	<694F7504-91CD-437E-A2CF-5FC9AD432B15@t-online.de>
Message-ID: <4CD4D417.6070300@sonic.net>

On 11/5/2010 1:58 PM, Ingo Debus wrote:
>
> Am 05.11.2010 um 18:54 schrieb Harry Bissell:
>
>> They look like a sawtooth VCO whose frequency is set by whatever the last sample
>> voltage was... kind of a way of "shaking the dice" at different rates each time...
>>
>> Clever, wonder if it works well... sure is simple (no noise generator needed)
>>
>
> Is this an answer to my question re how the random voltage generator in the Steiner Synthasystem works?
>
> So the UJT is the discharge switch of a relaxation oscillator?
>
> Making an analog random generator this way is pretty brilliant. Hats off!
> And then there's two of them in one module that can be run with the same trigger signal (if no plug is inserted in the trig 2 input). I wonder how similar the outputs are?

It's a clever way to start new discussions, you answer one thread under
another one, and see what happens. 8^)

The circuit isn't really random it just depends on the sample clock being
asynchronous and much slower than the relaxation oscillator. I spiced
it (but used a voltage controlled switch instead of the UJT) and got
a freq range from about 100Hz to 12KHz

Tying the previous sample CV back to control a VCO (VCLFO) is
interesting though - time to go patch that up, and vary the
sample clock, and scale the control voltage to the oscillator.
It might generate some interesting patterns.  I wonder if that's
in Strange's book.

-Dave


From sounddoctorin at imt.net  Sat Nov  6 09:02:43 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Sat, 06 Nov 2010 02:02:43 -0600
Subject: [sdiy] Fluke 97 scopemeter just beeps...
Message-ID: <4CD50BA3.3020306@imt.net>

Has anyone got any info on these?  Can't seem to find anything and last 
time I spoke with fluke they had abandoned it. Last issue btw was 
resolved by replacing the 10uF electrolytics.  This time I found the 
100uF had also gone high esr...replaced it..but it made no difference.

I then checked the other electros..no problems noted.  PS is putting 20V 
onto the lug.  Anybody got any ideas on it? Hate to scrap it if we can 
make it work reliably. OTHERWISE...anyone got recommendations for a 
replacement that's somewhere in the realm of a few hundred bucks? lol.  
I only paid 200 for the thing and initially it was working.  They don't 
usually go for too much I guess, there are so many options now that are 
better.

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From Peter.Ullrich at kapsch.net  Sat Nov  6 16:46:16 2010
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Sat, 6 Nov 2010 16:46:16 +0100
Subject: [sdiy] Fluke 97 scopemeter just beeps...
In-Reply-To: <4CD50BA3.3020306@imt.net>
References: <4CD50BA3.3020306@imt.net>
Message-ID: <B156A86831A33949A0977840648802475DF33F54BF@S060VS20.kapsch.co.at>

Hallo Bob!

Maybe the service manual of the Scopemeter 97 can help you a little bit.

You can load it from here:
http://service-manual.eu/model.php?id=1174

It seems to be a very useful manual with error finding help...

Ciao
Peter

http://www.ullrich.at.tf
________________________________________
Von: synth-diy-bounces at dropmix.xs4all.nl [synth-diy-bounces at dropmix.xs4all.nl] im Auftrag von Bob Weigel [sounddoctorin at imt.net]
Gesendet: Samstag, 06. November 2010 09:02
An: synthdiy
Betreff: [sdiy] Fluke 97 scopemeter just beeps...

Has anyone got any info on these?  Can't seem to find anything and last
time I spoke with fluke they had abandoned it. Last issue btw was
resolved by replacing the 10uF electrolytics.  This time I found the
100uF had also gone high esr...replaced it..but it made no difference.

I then checked the other electros..no problems noted.  PS is putting 20V
onto the lug.  Anybody got any ideas on it? Hate to scrap it if we can
make it work reliably. OTHERWISE...anyone got recommendations for a
replacement that's somewhere in the realm of a few hundred bucks? lol.
I only paid 200 for the thing and initially it was working.  They don't
usually go for too much I guess, there are so many options now that are
better.

--
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.




From aym-htnys at teaser.fr  Sat Nov  6 21:29:16 2010
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Sat, 6 Nov 2010 21:29:16 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <a06240800c8fa0b9cae83@[192.168.254.1]>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
	<a06240800c8fa0b9cae83@[192.168.254.1]>
Message-ID: <20101106202916.GA20093@aym.net2.nerim.net>

On 2010-11-05 20:40 +0100, Senso wrote:

> I seem to remember there were a few Crumar or Siel synths that
> came with schematics too.

The Mono and HB 725 did. Also, I'm told that some manufacturers
don't sand the chips. It's a crazy world we live in.

-- 
Andr? Majorel http://www.teaser.fr/~amajorel/


From cheater00 at gmail.com  Sat Nov  6 21:41:32 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sat, 6 Nov 2010 21:41:32 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
Message-ID: <AANLkTinAFLJF7_7tC7p6kQ-Xb2rGcsq1eK4k7p2sGHya@mail.gmail.com>

Yes, this service manual being made public definitely indicates
something great! I simply can't wait to see their next step!!!!

D.

On 05/11/2010, Paul Burns <paul at fitvideo.co.uk> wrote:
> Many thanks Sam Hoshuyama for putting that up..
>
>
>
> Re "Wow, thanks!
>
> "Such service is quite unusual for most synth manufacturers.
> Do you happen to know if they published any other schematics or service
> manuals? Especially for the old analogue gear?
>
> Senso"
>
> Very unusual..
>
> Schematics generally only appear in service manuals that I have helped
> translate 20+ years ago... and made very unavailable to the public. this new
> attitude speaks volumes and we may see others react. this is remember the
> first purely analogue synth in 25 years by a big boy company imho. The
> exception of including schematics that comes to mind is the Roland SH-101 in
> that they put the schematics in the user manual. there are others as well
> but few and far between ...
>
>
>>Hello List,
>>
>>English information is easier for you, isn't it.
>>
>>http://www.adafruit.com/blog/2010/11/05/korg-publishes-schematic-of-mon
>>otron-synth/
>>
>>Sam HOSHUYAMA
>>
>>
>>HOSHUYAMA wrote:
>>>  Hello List,
>>>
>>>  Now Korg monotoron schematic is online officially!
>>>
>>>
>>>  http://www.korg.co.jp/Support/Manual/download.php?id=512
>>>
>>>  Click the bottom [Download] button.
>>>
>>>  Sam HOSHUYAMA
>>>  Saitama, JAPAN
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From Peter.Ullrich at kapsch.net  Sat Nov  6 21:52:55 2010
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Sat, 6 Nov 2010 21:52:55 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <20101106202916.GA20093@aym.net2.nerim.net>
References: <000001cb7d08$c4047d30$4c0d7790$@co.uk>
	<a06240800c8fa0b9cae83@[192.168.254.1]>,
	<20101106202916.GA20093@aym.net2.nerim.net>
Message-ID: <B156A86831A33949A0977840648802475DF33F54C8@S060VS20.kapsch.co.at>


> I seem to remember there were a few Crumar or Siel synths that
> came with schematics too.

You are right: The Crumar bit one, Bit 01 and the crumar masterkeyboard came with schematics.

Ciao
Peter (I have a Crumar Bit01 and the masterkeyboard [which I am selling now])

http://www.ullrich.at.tf
The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.




From dougt55 at yahoo.com  Sat Nov  6 22:26:21 2010
From: dougt55 at yahoo.com (Doug Terrebonne)
Date: Sat, 6 Nov 2010 14:26:21 -0700 (PDT)
Subject: [sdiy] Monotron Schematic
Message-ID: <121248.15821.qm@web81203.mail.mud.yahoo.com>

Moog was also very good about including service manuals with their synths. My Micro, Multi, Rogue, Liberation, and Source all came with them. Ironically the Polymoog which needed it the most did not. 

Doug

On Nov 6, 2010, at 1:52 PM, Ullrich Peter <Peter.Ullrich at kapsch.net> wrote:


I seem to remember there were a few Crumar or Siel synths that
came with schematics too.

You are right: The Crumar bit one, Bit 01 and the crumar masterkeyboard came with schematics.

Ciao
Peter (I have a Crumar Bit01 and the masterkeyboard [which I am selling now])

http://www.ullrich.at.tf
The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From paul at fitvideo.co.uk  Sat Nov  6 22:45:55 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Sat, 6 Nov 2010 21:45:55 -0000
Subject: [sdiy] Monotron Schematic
Message-ID: <001b01cb7dfb$ffed82d0$ffc88870$@co.uk>

My comment was regarding the big (Japanese) manufacturers post 1984 ...
 
Imho , when I first got into translating technical Japanese to English
manuals in about 1987, ?at that time the digital revolution had truly
manifested itself and analogue was dead / pass? ( in the opinion of the
major manufacturers, Yamaha, Roland, Korg, et al). Later on by 1991 the
horror story that was the Yamaha SY99 had materialized and they could not
even put a manual together to define how to use RCM hybrid synthesis let
alone include a schematic
 they (the manufacturers) just did not seem to see
the need 
Joe Public would not get it ...

I took my 99 apart a few months ago
 what fun that was 
. I forget how many
screws , suffice to say , lots ... going to do it all again soon to replace
the floppy drive and also at the same time replace the backlit lcd 


Cheers

Paul Burns




??



From senso at vintageplanet.nl  Sun Nov  7 00:40:55 2010
From: senso at vintageplanet.nl (Senso)
Date: Sun, 7 Nov 2010 00:40:55 +0100
Subject: [sdiy] Monotron Schematic
In-Reply-To: <001b01cb7dfb$ffed82d0$ffc88870$@co.uk>
References: <001b01cb7dfb$ffed82d0$ffc88870$@co.uk>
Message-ID: <a06240805c8fb9615de52@[192.168.254.1]>

>My comment was regarding the big (Japanese) manufacturers post 1984 ...
>
>Imho , when I first got into translating technical Japanese to English
>manuals in about 1987,  at that time the digital revolution had truly
>manifested itself and analogue was dead / pass? ( in the opinion of the
>major manufacturers, Yamaha, Roland, Korg, et al). Later on by 1991 the
>horror story that was the Yamaha SY99 had materialized and they could not
>even put a manual together to define how to use RCM hybrid synthesis let
>alone include a schematic
 they (the manufacturers) just did not seem to see
>the need 
Joe Public would not get it ...

Yamaha manuals from that time are famous. I don't 
know what the situation is at this moment, but 
then it seemed they were translated by someone 
who normally does cook books only . I'll never 
forget how modulation of the operators in the 
DX-7 was described... it said you had to tickle 
them. :-)

Still most of the major manufacturers don't like 
their "industrial secrets" revealed, even for 
equipment that is considered obsolete.  Of course 
there is a very good reason for it. They call it 
"company policy".

Senso

-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From paul at fitvideo.co.uk  Sun Nov  7 08:00:03 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Sun, 7 Nov 2010 07:00:03 -0000
Subject: [sdiy] Monotron Schematic
In-Reply-To: <a06240805c8fb9615de52@[192.168.254.1]>
References: <001b01cb7dfb$ffed82d0$ffc88870$@co.uk>
	<a06240805c8fb9615de52@[192.168.254.1]>
Message-ID: <000901cb7e49$6a552b30$3eff8190$@co.uk>

Hi Senso , 

Re : Yamaha manuals from that time are famous. I don't 
know what the situation is at this moment, but 
then it seemed they were translated by someone 
who normally does cook books only .

Yeah, that is indeed why I got the gig ...some of those manuals were dire ,
case in point the SY99 manual it said it would do things it could not (part
of the MIDI master keyboard section) ... I was particularly frustrated with
that one as they would not change it ...

I once went to a R+D department at Sussex Uni in England, and there were
certain parts you could not get in to unless you held a Japanese passport...


cheers

Paul

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Senso
Sent: 06 November 2010 23:41
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Monotron Schematic

>My comment was regarding the big (Japanese) manufacturers post 1984 ...
>
>Imho , when I first got into translating technical Japanese to English
>manuals in about 1987,  at that time the digital revolution had truly
>manifested itself and analogue was dead / pass? ( in the opinion of the
>major manufacturers, Yamaha, Roland, Korg, et al). Later on by 1991 the
>horror story that was the Yamaha SY99 had materialized and they could not
>even put a manual together to define how to use RCM hybrid synthesis let
>alone include a schematic
 they (the manufacturers) just did not seem to
see
>the need 
Joe Public would not get it ...

Yamaha manuals from that time are famous. I don't 
know what the situation is at this moment, but 
then it seemed they were translated by someone 
who normally does cook books only . I'll never 
forget how modulation of the operators in the 
DX-7 was described... it said you had to tickle 
them. :-)

Still most of the major manufacturers don't like 
their "industrial secrets" revealed, even for 
equipment that is considered obsolete.  Of course 
there is a very good reason for it. They call it 
"company policy".

Senso

-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From dragon.servicing at googlemail.com  Sun Nov  7 09:24:00 2010
From: dragon.servicing at googlemail.com (dragons)
Date: Sun, 07 Nov 2010 08:24:00 +0000
Subject: [sdiy] service info,    was   Monotron Schematic
In-Reply-To: <000901cb7e49$6a552b30$3eff8190$@co.uk>
References: <001b01cb7dfb$ffed82d0$ffc88870$@co.uk>	<a06240805c8fb9615de52@[192.168.254.1]>
	<000901cb7e49$6a552b30$3eff8190$@co.uk>
Message-ID: <4CD66220.1000204@googlemail.com>

Hi,
I think that the situation with service info has always been that it 
depends on the manufacturer. when I used to work for one of the music 
shops in the early 1980's some of the service info was only available as 
the shop was agents for the company concerned.
this certainly applied to Sequential Circuits.
I seem to remember that they got some service info from Ensoniq in the 
usa and then when they tried to get some more info for another product 
were told that it would not  be released, as they had appointed someone 
else as uk agents !
presently both Roland and Yamaha may let you have service info if you 
are a repair person but not make it generally available.same applies to 
Marshall amplification.
I agree that some of the manuals from the late 1980's early 1990's 
aren't easy to follow.

regards Peter

P.S pleased that Korg have made the Monotron schematic available.





From madhun2001 at yahoo.com  Sun Nov  7 17:21:17 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Sun, 7 Nov 2010 08:21:17 -0800 (PST)
Subject: [sdiy] PWM Outputs
Message-ID: <367060.53156.qm@web55301.mail.re4.yahoo.com>

Hi everyone,

A technical question: if you have a PWM, say 0-5 volts from ttl or cmos, is it 
better to cap-couple it to the output jack, or not? My concern is the average DC 
level of PWMs varies over a wide range. This would cause a thump if cap-coupled, 
yes?

--Tim (doesn't know everything after all) Ressel



From eric at ericframpton.com  Sun Nov  7 17:40:30 2010
From: eric at ericframpton.com (Eric Frampton)
Date: Sun, 7 Nov 2010 11:40:30 -0500
Subject: [sdiy] Korg DW-8000 power supply help?
In-Reply-To: <AANLkTikfOspMbXd8gT_zAGnND6SZNkWbKrfEtAgHyYim@mail.gmail.com>
References: <227981773.106490.1288806212016.JavaMail.root@md01.wow.synacor.com>
	<C33F49F6-35A9-4447-AA04-0FA4CC04C236@ericframpton.com>
	<BLU0-SMTP118C91B0B51BA4A7DFB569974B0@phx.gbl>
	<F6D14B4E-BD55-41F3-A3F5-939EC544C6F4@ericframpton.com>
	<AANLkTikfOspMbXd8gT_zAGnND6SZNkWbKrfEtAgHyYim@mail.gmail.com>
Message-ID: <9D8F12DA-D1C1-43A5-BEEB-46DC92986DF4@ericframpton.com>

Final email on this (I hope)...

On Nov 5, 2010, at 4:50 PM, Chromatest J. Pantsmaker wrote:

> Seems like you also let it sit powered-off for a day or two and see if
> it comes back up nicely or not.

and Ingo Debus wrote:

> Does the unit still work good after being off for some time?

and Scott Nordlund wrote:

> Dunno how much you've tested it so far, but I'd expect it to go bad
> again when it's cold.  I've noticed before that leaky electrolytic caps
> can improve as they heat up.

...to which I'm happy to reply to all of you that, after running for four days without failure, we turned it off overnight to see what would happen. Fired it back up this morning and it's still working perfectly.

I don't pretend to have any idea what happened, but I'm not complaining.

Thanks again for everybody's help!

e



From dlmanley at sonic.net  Sun Nov  7 17:53:58 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Sun, 07 Nov 2010 08:53:58 -0800
Subject: [sdiy] PWM Outputs
In-Reply-To: <367060.53156.qm@web55301.mail.re4.yahoo.com>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
Message-ID: <4CD6D9A6.4000204@sonic.net>

On 11/7/2010 8:21 AM, Tim Ressel wrote:
> Hi everyone,
>
> A technical question: if you have a PWM, say 0-5 volts from ttl or cmos, is it
> better to cap-couple it to the output jack, or not? My concern is the average DC
> level of PWMs varies over a wide range. This would cause a thump if cap-coupled,
> yes?

For the sake of argument consider you buffered the output of the PWM with an
opamp.  Now it's just an opamp output like any other.  Does the nature of the
signal require capacitive coupling?

-Dave


From tom at electricdruid.net  Sun Nov  7 19:00:40 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 7 Nov 2010 18:00:40 +0000
Subject: [sdiy] PWM Outputs
In-Reply-To: <367060.53156.qm@web55301.mail.re4.yahoo.com>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
Message-ID: <8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>

The most elegant way around this problem that I've seen is what I think of as "the Chroma solution".
The Rhodes Chroma mixed the PWM CV into the PWM output to remove the DC offset.
If you did it this way you could DC-couple the outputs, and the average DC level would be constant.

What's the problem with capacitive coupling though? This is audio, right?

HTH,
Tom

On 7 Nov 2010, at 16:21, Tim Ressel wrote:

> Hi everyone,
> 
> A technical question: if you have a PWM, say 0-5 volts from ttl or cmos, is it 
> better to cap-couple it to the output jack, or not? My concern is the average DC 
> level of PWMs varies over a wide range. This would cause a thump if cap-coupled, 
> yes?
> 
> --Tim (doesn't know everything after all) Ressel
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From ijfritz at comcast.net  Sun Nov  7 19:45:30 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Sun, 07 Nov 2010 11:45:30 -0700
Subject: [sdiy] PWM Outputs
In-Reply-To: <367060.53156.qm@web55301.mail.re4.yahoo.com>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
Message-ID: <6.2.1.2.2.20101107111023.02463d00@mail.comcast.net>

At 09:21 AM 11/7/2010, Tim Ressel wrote:
>A technical question: if you have a PWM, say 0-5 volts from ttl or cmos, 
>is it
>better to cap-couple it to the output jack, or not? My concern is the 
>average DC
>level of PWMs varies over a wide range. This would cause a thump if 
>cap-coupled,
>yes?

I just tried it.  The best test, I think, is to modulate (square wave) 
equal amounts around 50% PW. The spectra are the same in the two cases so 
you pretty much hear a steady tone with clicks.  I don't hear any noticable 
difference in the two cases. Probably beause my mixer is AC coupled 
anyway.  (I don't think you'd want the DC levels ever hitting your speakers.)

So I guess it depends on what levels you want in your synth system.  With 
AC coupling the peaks move up and down on a time scale determined by the 
cap value, so there is some transient click. Also, do you want to use the 
output at very low frequencies?  Then the waveform is mangled.

Another method would be to dynamically offset the the output according to 
the PW CV to get a zero DC component. (Didn't someone do this?)

   Ian 



From madhun2001 at yahoo.com  Sun Nov  7 19:53:57 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Sun, 7 Nov 2010 10:53:57 -0800 (PST)
Subject: [sdiy] PWM Outputs
In-Reply-To: <6.2.1.2.2.20101107111023.02463d00@mail.comcast.net>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
	<6.2.1.2.2.20101107111023.02463d00@mail.comcast.net>
Message-ID: <954661.39610.qm@web55301.mail.re4.yahoo.com>

Man, it's the little things that get you. I like the notion of leaving the 
output TTL. That way it can be used as a gate or clock. Perhaps the thing to do 
is either have both outputs available, or else provide a jumper for user 
selection of ac/dc outputs. 


--tr




----- Original Message ----
From: Ian Fritz <ijfritz at comcast.net>
To: Tim Ressel <madhun2001 at yahoo.com>; Synth-Diy <synth-diy at dropmix.xs4all.nl>
Sent: Sun, November 7, 2010 10:45:30 AM
Subject: Re: [sdiy] PWM Outputs

At 09:21 AM 11/7/2010, Tim Ressel wrote:
> A technical question: if you have a PWM, say 0-5 volts from ttl or cmos, is it
> better to cap-couple it to the output jack, or not? My concern is the average 
>DC
> level of PWMs varies over a wide range. This would cause a thump if 
>cap-coupled,
> yes?

I just tried it.  The best test, I think, is to modulate (square wave) equal 
amounts around 50% PW. The spectra are the same in the two cases so you pretty 
much hear a steady tone with clicks.  I don't hear any noticable difference in 
the two cases. Probably beause my mixer is AC coupled anyway.  (I don't think 
you'd want the DC levels ever hitting your speakers.)

So I guess it depends on what levels you want in your synth system.  With AC 
coupling the peaks move up and down on a time scale determined by the cap value, 
so there is some transient click. Also, do you want to use the output at very 
low frequencies?  Then the waveform is mangled.

Another method would be to dynamically offset the the output according to the PW 
CV to get a zero DC component. (Didn't someone do this?)

  Ian 



From rob at emulatorarchive.com  Sun Nov  7 22:49:45 2010
From: rob at emulatorarchive.com (rob at emulatorarchive.com)
Date: Sun, 07 Nov 2010 21:49:45 +0000
Subject: [sdiy] FS: IR3109 VCF Chips
In-Reply-To: <954661.39610.qm@web55301.mail.re4.yahoo.com>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>	<6.2.1.2.2.20101107111023.02463d00@mail.comcast.net>
	<954661.39610.qm@web55301.mail.re4.yahoo.com>
Message-ID: <4CD71EF9.7000605@emulatorarchive.com>

Hi list,
I have located a large stock of NOS Roland IR3109 VCF chips, too many for me to use in my AMSynths modules.
This 4 stage OTA filter chip can be used to build 12 and 24db low, high pass, multi mode filters as well as phasers.
It has the same pin out as the SSM2040, and sounds just as nice.
I have PCB's for sale that use the IR3109, starting with the MultiMode Filter in 15V FracRac.
Low pass filter PCB's will be available later this month along with completed modules.

I have the chips up for sale on AH and Ebay, so Roland synth owners can get them too.
If you would like one for SDIY they are  available for 16 UK pounds at the AMSynths online shop at
http://www.amsynths.co.uk/Shop/shop.html

Regards
rob
www.amsynths.co.uk




From magnus at rubidium.dyndns.org  Sun Nov  7 22:50:48 2010
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sun, 07 Nov 2010 22:50:48 +0100
Subject: [sdiy] PWM Outputs
In-Reply-To: <8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
	<8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
Message-ID: <4CD71F38.2060706@rubidium.dyndns.org>

On 11/07/2010 07:00 PM, Tom Wiltshire wrote:
> The most elegant way around this problem that I've seen is what I think of as "the Chroma solution".
> The Rhodes Chroma mixed the PWM CV into the PWM output to remove the DC offset.
> If you did it this way you could DC-couple the outputs, and the average DC level would be constant.

I was just about to propose the same solution. I used the same trick in 
the sawtooth phase-shifter. The neat thing is that it almost completely 
cancels the DC offset as long as the CV is maintained within the active 
PWM range.

Cheers,
Magnus


From oakleylist at btinternet.com  Mon Nov  8 08:26:15 2010
From: oakleylist at btinternet.com (Oakley Sound)
Date: Mon, 08 Nov 2010 07:26:15 +0000
Subject: [sdiy] PWM Outputs
In-Reply-To: <4CD71F38.2060706@rubidium.dyndns.org>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>	<8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
	<4CD71F38.2060706@rubidium.dyndns.org>
Message-ID: <4CD7A617.7060900@btinternet.com>

 > The Rhodes Chroma mixed the PWM CV into the PWM output to remove the 
DC offset.

Didn't know that. But I've been doing it for years with my VCO.

The biggest benefit for me is to not have a thump when you modulate PW 
with a fast CV like an EG.

Tony

www.oakleysound.com


From dragon.servicing at googlemail.com  Mon Nov  8 09:08:08 2010
From: dragon.servicing at googlemail.com (dragons)
Date: Mon, 08 Nov 2010 08:08:08 +0000
Subject: [sdiy] Fwd: [HL] Notice: Fraudulent Ebay Listing of Moog Synthesizer
Message-ID: <4CD7AFE8.4020000@googlemail.com>

Hi,
I don't normally pass on messages about ebay items but I thought this 
message was appropriate.

regards Peter B

-------- Original Message --------
Subject: [HL] Fwd: Notice: Fraudulent Ebay Listing of Moog Synthesizer
Date: Sun, 7 Nov 2010 19:42:23 -0500
From: Linda Dachtyl
Reply-To: The Hammond Technical List <HAMTECH at MAIL.HAMTECH.ORG>
To: HAMTECH at MAIL.HAMTECH.ORG

FWIW.

Linda

Begin forwarded message:

> From: "Keith Emerson Info " <info at keith-emerson.com>
> Date: November 7, 2010 6:52:23 PM EST
> To: "Linda Dachtyl"
> Subject: Notice: Fraudulent Ebay Listing of Moog Synthesizer
>
> KEITH EMERSON NEWS & UPDATES
> Just a quick note:
>
> Please don't bet on this ebay item. It's a fraud! (We are working on
> removing the listing)
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220692890768#ht_69456wt_1172
> http://www.keithemerson.com





From cheater00 at gmail.com  Mon Nov  8 15:21:03 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 8 Nov 2010 15:21:03 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
	Needed
Message-ID: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>

Hi guys,

I am trying to resurrect this Tiracon 6V that I got off eBay some time
ago. It doesn't put out any sound.

It came to me in a non-functioning state. Since then I have repaired
the PSU (hopefully correctly) and have been trying to work out why it
doesn't work, and how it works in the first place.

I have tried contacting Vermona about the synthesizer, however have
had no luck with getting a reply about schematics etc.

Currently, the digital board with the LCD turns on, and I can load and
edit patches (haven't tried to save them yet, not sure if that's such
a good idea). I can also change the speed of LFOs which is depicted on
the LEDs pulsating quicker or slower. There is no sound coming out of
the synthesizer.

It does seem that the scanning matrix works to some extent, since the
voices do seem to get triggered.

About the synthesizer layout: if you look at the pictures here:

http://www.vermona.de/htm/tiracon2.htm

then you'll see the arrangement of the boards is as follows:
the top of the synthesizer opens and has the LCD board in it. When
that's open, we are presented with several boards. From left to right:

1. leftmost: digital board - http://www.vermona.de/Tiracon/digitalteil.jpg
2. main/analog board with six voice cards -
http://www.vermona.de/Tiracon/analogteil.jpg
3. regulator board
4. rightmost: transformer board

(both PSU boards can be seen here: http://www.vermona.de/Tiracon/netzteil.jpg )

The voice cards themselves have a 2mm pin interface of some sort that
they plug into. I have been trying to scope them out.

About the PSU repair: the top left regulator (B3170V, an LM317 clone
from the GDR) was not in circuit and one of the capacitors has broken
loose. After soldering it all back together, I have had +15V show up
on one of the pins, where it was 0V before.

About the voice cards:
Pictures can be seen here:
http://www.vermona.de/instrumente/tir3.jpg
http://www.vermona.de/Tiracon/6-voices.jpg

they have two connectors, call them the Left and Right connector. The
Left connector has 12 pins, the Right connector has 6 pins plus a "key
pin" which doesn't do anything.

Here are my notes for the connectors:
Left:
1. frequency CV, V/Hz
2. 15V
3. GND
4. -15V
5. ?
6. 3.69V with a lot of digital noise
7. digital gnd?
8. digital gnd again?
9. ?
10. 5.2V
11. unused
12. -12V with a lot of noise

Right:
1. ?
2. very very quiet white noise. Perhaps the output pin?
3. ?
4. white noise, probably an input from central distribution.
5. gate. off = -7.29V, on= -7.53V
6. -13.23V

About the Left connector signals:
The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
and C4 is -0.945V. Obviously has a scaling problem, which I hadn't
tried to address yet, since that's like waxing a train wreck. The
weird thing is that the voltages are all negative.

Pin 6 in reference to pin 7 still has the digital noise, but the
amplitude is reduced by 50%. Pin 5 seems to contain a very very quiet
mix of the output, I might be wrong though. Or maybe it's just some
current escaping through ground to somewhere, who knows.


About the cards:

I have been able to get the 6V to run to some extent: the voice boards
receive triggers and they change in pitch according to the note being
played. The oscillator is audibly changing pitch if you listen to it
by tapping the voltage on either of its terminals directly (which is
funny, because I had thought only one of the terminals would have
output, but both do - one of them is much quieter though). I have had
a look around the board as to what it has got and it basically has two
areas. On the left there is the VCO and on the right there is the
filter.

One weird thing is that there is a droop in the oscillator's pitch as
long as the key is being held down. That means, that I will press the
key (repeatedly until the voice I'm scoping gets triggered), and the
pitch will change to what it should be minus a few semitones. Then
when I let go of the key the pitch jumps up.

The Gate is VERY weird. you can see the voltages above - off is
-7.29V, on is -7.53V. Definitely something wrong going on there.

The VCO area contains resistors, some small capacitors, some other
stuff which I am unable to identify, and these chips:
V 4 082 (probably a TL082 clone)
B084D V7 (probably a TL084 clone)
V 4066 D (a CD4066 clone, a quad bilateral switch)
a second 4066
CD4013 BE (probably the only western chip in the whole voice board).

The presence of two quad bilateral switches and the fact that the VCO
wave is audible on both ends of the capacitor (which is 15nF) suggests
to me that it is a triangular core vco. I assume that the second
switch is used for creating a sawtooth wave. I'm assuming the CD4013
is used as the comparator in the reset circuit (it is a CMOS dual
D-type flip flop).

The filter board is about the right 45% width of the board, and it
contains four chips marked as IA317D UD, some resistors, and some
small foil capacitors as well as tantalums. The chips appear to be
also known as AK317DC. Here's a thread about it in Polish:

http://www.elektroda.pl/rtvforum/topic755331.html

(google translate might help)

For example it was used in some old laser printers to control motors.
In the thread it is mentioned that it is an OTA. The presence of four
OTAs implies to me that it is a COTA filter, which fits together with
what I remember about the demos.

One good thing about this situation is that I have multiple sets of
boards for this synth: I have got the one keyboard, and I have got two
pretty much complete sets of boards as bare parts. Of course, none of
them work.

Any clues, guys?

Please help!

Damian


From tom at electricdruid.net  Mon Nov  8 16:02:53 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 8 Nov 2010 15:02:53 +0000
Subject: [sdiy] PWM Outputs
In-Reply-To: <4CD7A617.7060900@btinternet.com>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>	<8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
	<4CD71F38.2060706@rubidium.dyndns.org>
	<4CD7A617.7060900@btinternet.com>
Message-ID: <65889A0C-EB1C-4518-AA75-44476A5A1641@electricdruid.net>

If anyone wants to look, all the schematics are at:

	http://www.rhodeschroma.com/?id=schematicsdrawings

The relevant page is:

	http://www.rhodeschroma.com/content/servicemanual/schematicsdrawings/dualchannelboardschematic1.pdf

It's pretty weird looking, but you can see the PWM CV ("Width") getting mixed in on both oscillators (on the left). It's a fascinating design, what with the highly unusual dual-channel structure and the various ways things can be routed. There's loads more info on this extremely good site.

Personally, I love reading old synth schematics!

Enjoy,
Tom


On 8 Nov 2010, at 07:26, Oakley Sound wrote:

> > The Rhodes Chroma mixed the PWM CV into the PWM output to remove the DC offset.
> 
> Didn't know that. But I've been doing it for years with my VCO.
> 
> The biggest benefit for me is to not have a thump when you modulate PW with a fast CV like an EG.
> 
> Tony
> 
> www.oakleysound.com
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From harrybissell at wowway.com  Mon Nov  8 16:48:58 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 8 Nov 2010 10:48:58 -0500 (EST)
Subject: [sdiy] Guard Rings
In-Reply-To: <005e01cb7d37$accf2140$066d63c0$@net>
Message-ID: <1486387544.219734.1289231338273.JavaMail.root@md01.wow.synacor.com>

If you has a DIP package, V- would be on the pin adjacent to the
non-inverting input. The guard ring would benefit you a lot
on separating that very different voltage potential.  The old
"can" style parts could have the leads bent out a lot, better.
SMT is even closer, worse :^)

H^) harry




----- Original Message -----
From: David Ingebretsen <dingebre at 3dphysics.net>
To: 'Dave Manley' <dlmanley at sonic.net>, synth-diy at dropmix.xs4all.nl
Sent: Fri, 05 Nov 2010 18:20:34 -0400 (EDT)
Subject: Re: [sdiy] Guard Rings

First, I really appreciate all the feedback.

I got hold of Nyle today and asked him about R13. He said when they started
building their circuits, they noticed some high frequency oscillations in
the voltage followers which was removed when they added a 1k or 1.2k
resistor in series with the transistor base. He didn't remember if they had
the same problem with FET followers, but thought he added R13 as a
preventative measure. 

He also thought the best idea for this PCB would be to just huddle the nodes
of Q11-S, C5, R13 and Q7-G close together and not put any other pads close
by and forego the guard ring. He said if he had used an FET input OpAmp, he
would recommend a guard ring.

But, what do I know. :) 

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of Dave Manley
~~ Sent: Thursday, November 04, 2010 11:29 PM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ On 11/4/2010 9:24 PM, Oren Leavitt wrote:
~~ 
~~ >
~~ > Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is
~~ > connected the output (emitter) of the emitter-follower Q9 which will be
~~ at the same potential but buffered.
~~ > Ditto for Q12, C14, R6, Q8.
~~ 
~~ I agree where the ring should go, and I'd be tempted to optimize the
~~ component
~~ placement.
~~ 
~~ A couple of questions:
~~ 
~~ Is Q9 emitter really at the same potential as the voltage on the cap?
~~ 
~~ What's the point of R13?
~~ 
~~ David - the idea of the guard ring is to surround a high impedance node
~~ holding
~~ a charge with a buffered potential of the same voltage.  This will
isolate
~~ the
~~ node from different nearby voltages so that it doesn't discharge due to
~~ leakage
~~ currents on the board.  If the PCB is clean these leakage currents should
~~ be minimal.
~~ Make sure the board is free of contamination on both sides.
~~ 
~~ -Dave
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov  8 16:51:36 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 8 Nov 2010 10:51:36 -0500 (EST)
Subject: [sdiy] Monotron Schematic - Guard Rings
In-Reply-To: <694F7504-91CD-437E-A2CF-5FC9AD432B15@t-online.de>
Message-ID: <826562153.219830.1289231496401.JavaMail.root@md01.wow.synacor.com>

The UJT is its own discharge switch for the relaxation oscillator. The othertransistors are a current source to charge the timing capacitor.

The UJT was popular for sawtooth oscillators at one time, but they were fickle and
expensive to get really good parts.

H^) harry




----- Original Message -----
From: Ingo Debus <igg.debus at t-online.de>
To: synth diy <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 05 Nov 2010 16:58:49 -0400 (EDT)
Subject: Re: [sdiy] Monotron Schematic - Guard Rings


Am 05.11.2010 um 18:54 schrieb Harry Bissell:

> They look like a sawtooth VCO whose frequency is set by whatever  
> the last sample
> voltage was... kind of a way of "shaking the dice" at different  
> rates each time...
>
> Clever, wonder if it works well... sure is simple (no noise  
> generator needed)
>

Is this an answer to my question re how the random voltage generator  
in the Steiner Synthasystem works?

So the UJT is the discharge switch of a relaxation oscillator?

Making an analog random generator this way is pretty brilliant. Hats  
off!
And then there's two of them in one module that can be run with the  
same trigger signal (if no plug is inserted in the trig 2 input). I  
wonder how similar the outputs are?

Ingo
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov  8 17:07:45 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 8 Nov 2010 11:07:45 -0500 (EST)
Subject: [sdiy] Guard Rings
In-Reply-To: <005e01cb7d37$accf2140$066d63c0$@net>
Message-ID: <692224142.220352.1289232465188.JavaMail.root@md01.wow.synacor.com>

I have seen that on IGBT gates, but not on a JFET. For IGBTs,
even a few ohms will cure the problem. Its a matter of gate inductance
and capacitance causing ringing, which the series resistor damps out.

The 1K value is what throws (threw) me...

H^) harry


----- Original Message -----
From: David Ingebretsen <dingebre at 3dphysics.net>
To: 'Dave Manley' <dlmanley at sonic.net>, synth-diy at dropmix.xs4all.nl
Sent: Fri, 05 Nov 2010 18:20:34 -0400 (EDT)
Subject: Re: [sdiy] Guard Rings

First, I really appreciate all the feedback.

I got hold of Nyle today and asked him about R13. He said when they started
building their circuits, they noticed some high frequency oscillations in
the voltage followers which was removed when they added a 1k or 1.2k
resistor in series with the transistor base. He didn't remember if they had
the same problem with FET followers, but thought he added R13 as a
preventative measure. 

He also thought the best idea for this PCB would be to just huddle the nodes
of Q11-S, C5, R13 and Q7-G close together and not put any other pads close
by and forego the guard ring. He said if he had used an FET input OpAmp, he
would recommend a guard ring.

But, what do I know. :) 

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of Dave Manley
~~ Sent: Thursday, November 04, 2010 11:29 PM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: Re: [sdiy] Guard Rings
~~ 
~~ On 11/4/2010 9:24 PM, Oren Leavitt wrote:
~~ 
~~ >
~~ > Looking at the pdf, you'll want to place the guard ring around the
~~ traces connecting (Q11-S, C5, R13) and (R13, Q7-G). That's your "island"
~~ of high impedance while in "hold" mode. The ring is
~~ > connected the output (emitter) of the emitter-follower Q9 which will be
~~ at the same potential but buffered.
~~ > Ditto for Q12, C14, R6, Q8.
~~ 
~~ I agree where the ring should go, and I'd be tempted to optimize the
~~ component
~~ placement.
~~ 
~~ A couple of questions:
~~ 
~~ Is Q9 emitter really at the same potential as the voltage on the cap?
~~ 
~~ What's the point of R13?
~~ 
~~ David - the idea of the guard ring is to surround a high impedance node
~~ holding
~~ a charge with a buffered potential of the same voltage.  This will
isolate
~~ the
~~ node from different nearby voltages so that it doesn't discharge due to
~~ leakage
~~ currents on the board.  If the PCB is clean these leakage currents should
~~ be minimal.
~~ Make sure the board is free of contamination on both sides.
~~ 
~~ -Dave
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From axisair at comcast.net  Mon Nov  8 17:15:02 2010
From: axisair at comcast.net (George Mattson)
Date: Mon, 8 Nov 2010 08:15:02 -0800
Subject: [sdiy] Mattson sale. 15% off entire catalog
In-Reply-To: <4CD71F38.2060706@rubidium.dyndns.org>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com><8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
	<4CD71F38.2060706@rubidium.dyndns.org>
Message-ID: <44F622198B1E4414BBDD1A1C20848737@BlackNBlue>

 
I usually just lurk here and rarely post anything.

But, I launched a 15% off sale on my entire catalog over on my MW sub-forum
and wanted to share it with everybody.

http://www.muffwiggler.com/forum/viewtopic.php?t=24368

Thanks all,

George





From cheater00 at gmail.com  Mon Nov  8 18:09:40 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 8 Nov 2010 18:09:40 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
	Needed
In-Reply-To: <COL117-W298E907D7E47696AB2FB54DA4F0@phx.gbl>
References: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
	<COL117-W298E907D7E47696AB2FB54DA4F0@phx.gbl>
Message-ID: <AANLkTik18yobgRDGnbxCTjNsT7jW1g2yRb7M2FnYn=DR@mail.gmail.com>

Hi,
thanks for your reply. I'll investigate the 12V, maybe some of the
filter caps are dried out or broken..

The 15V is available on the Left connector, on pin 2.

I wonder very much about that 3.69 thing on pin 6. I have traced
around a bit, and there's something which I don't understand: Left
connector pins 6, 7, 8, 9 go through parallel resistors to a single
node. That node is then coupled with a "yellow drop" to a resistor
which goes to the -13.23.. really weird! I think it might be possible
that one of the cards is broken, and breaks the voltages for all the
other cards. For example maybe the "yellow drop" is broken on one of
them. It's a weird part too: looks like a yellow drop capacitor,
kinda, however the marking on it is 104M and every one of them that I
measure with my DMM shows 11 or 9 kR. Time to investigate by swapping
some cards in and out... So anyways I think the -13.23 and Left pins
6-9 are somehow tied together in their failure mode. I think they
might be what's broken.

Cheers,
D.

On 08/11/2010, 3 vcos <moonmuseum at hotmail.com> wrote:
>
> If I had to take a guess...
>
> It seems very strange that the voice cards get -12v and -15v.  The poor
> -12v signal is another bad sign.  Considering you did a repair to a 15v
> supply without a schematic and you aren't seeing 15v on the voice card I
>  would start by investigating if that shitty -12v supply on the card
> should be +15v or at least why the cards aren't getting positive voltage
>  (ok, I'm guessing the +5v on the card is needed as a digital supply).
> Seems like the lack of a positive supply voltage on the card fits with
> some of your other findings as well.
>
>
>
>
>
> Good luck.  I've always been curious how the Tiracon sounded.
>
>
>
>> Date: Mon, 8 Nov 2010 15:21:03 +0100
>> From: cheater00 at gmail.com
>> To: synth-diy at dropmix.xs4all.nl
>> Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and
>> Schematics	Needed
>>
>> Hi guys,
>>
>> I am trying to resurrect this Tiracon 6V that I got off eBay some time
>> ago. It doesn't put out any sound.
>>
>> It came to me in a non-functioning state. Since then I have repaired
>> the PSU (hopefully correctly) and have been trying to work out why it
>> doesn't work, and how it works in the first place.
>>
>> I have tried contacting Vermona about the synthesizer, however have
>> had no luck with getting a reply about schematics etc.
>>
>> Currently, the digital board with the LCD turns on, and I can load and
>> edit patches (haven't tried to save them yet, not sure if that's such
>> a good idea). I can also change the speed of LFOs which is depicted on
>> the LEDs pulsating quicker or slower. There is no sound coming out of
>> the synthesizer.
>>
>> It does seem that the scanning matrix works to some extent, since the
>> voices do seem to get triggered.
>>
>> About the synthesizer layout: if you look at the pictures here:
>>
>> http://www.vermona.de/htm/tiracon2.htm
>>
>> then you'll see the arrangement of the boards is as follows:
>> the top of the synthesizer opens and has the LCD board in it. When
>> that's open, we are presented with several boards. From left to right:
>>
>> 1. leftmost: digital board - http://www.vermona.de/Tiracon/digitalteil.jpg
>> 2. main/analog board with six voice cards -
>> http://www.vermona.de/Tiracon/analogteil.jpg
>> 3. regulator board
>> 4. rightmost: transformer board
>>
>> (both PSU boards can be seen here:
>> http://www.vermona.de/Tiracon/netzteil.jpg )
>>
>> The voice cards themselves have a 2mm pin interface of some sort that
>> they plug into. I have been trying to scope them out.
>>
>> About the PSU repair: the top left regulator (B3170V, an LM317 clone
>> from the GDR) was not in circuit and one of the capacitors has broken
>> loose. After soldering it all back together, I have had +15V show up
>> on one of the pins, where it was 0V before.
>>
>> About the voice cards:
>> Pictures can be seen here:
>> http://www.vermona.de/instrumente/tir3.jpg
>> http://www.vermona.de/Tiracon/6-voices.jpg
>>
>> they have two connectors, call them the Left and Right connector. The
>> Left connector has 12 pins, the Right connector has 6 pins plus a "key
>> pin" which doesn't do anything.
>>
>> Here are my notes for the connectors:
>> Left:
>> 1. frequency CV, V/Hz
>> 2. 15V
>> 3. GND
>> 4. -15V
>> 5. ?
>> 6. 3.69V with a lot of digital noise
>> 7. digital gnd?
>> 8. digital gnd again?
>> 9. ?
>> 10. 5.2V
>> 11. unused
>> 12. -12V with a lot of noise
>>
>> Right:
>> 1. ?
>> 2. very very quiet white noise. Perhaps the output pin?
>> 3. ?
>> 4. white noise, probably an input from central distribution.
>> 5. gate. off = -7.29V, on= -7.53V
>> 6. -13.23V
>>
>> About the Left connector signals:
>> The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
>> and C4 is -0.945V. Obviously has a scaling problem, which I hadn't
>> tried to address yet, since that's like waxing a train wreck. The
>> weird thing is that the voltages are all negative.
>>
>> Pin 6 in reference to pin 7 still has the digital noise, but the
>> amplitude is reduced by 50%. Pin 5 seems to contain a very very quiet
>> mix of the output, I might be wrong though. Or maybe it's just some
>> current escaping through ground to somewhere, who knows.
>>
>>
>> About the cards:
>>
>> I have been able to get the 6V to run to some extent: the voice boards
>> receive triggers and they change in pitch according to the note being
>> played. The oscillator is audibly changing pitch if you listen to it
>> by tapping the voltage on either of its terminals directly (which is
>> funny, because I had thought only one of the terminals would have
>> output, but both do - one of them is much quieter though). I have had
>> a look around the board as to what it has got and it basically has two
>> areas. On the left there is the VCO and on the right there is the
>> filter.
>>
>> One weird thing is that there is a droop in the oscillator's pitch as
>> long as the key is being held down. That means, that I will press the
>> key (repeatedly until the voice I'm scoping gets triggered), and the
>> pitch will change to what it should be minus a few semitones. Then
>> when I let go of the key the pitch jumps up.
>>
>> The Gate is VERY weird. you can see the voltages above - off is
>> -7.29V, on is -7.53V. Definitely something wrong going on there.
>>
>> The VCO area contains resistors, some small capacitors, some other
>> stuff which I am unable to identify, and these chips:
>> V 4 082 (probably a TL082 clone)
>> B084D V7 (probably a TL084 clone)
>> V 4066 D (a CD4066 clone, a quad bilateral switch)
>> a second 4066
>> CD4013 BE (probably the only western chip in the whole voice board).
>>
>> The presence of two quad bilateral switches and the fact that the VCO
>> wave is audible on both ends of the capacitor (which is 15nF) suggests
>> to me that it is a triangular core vco. I assume that the second
>> switch is used for creating a sawtooth wave. I'm assuming the CD4013
>> is used as the comparator in the reset circuit (it is a CMOS dual
>> D-type flip flop).
>>
>> The filter board is about the right 45% width of the board, and it
>> contains four chips marked as IA317D UD, some resistors, and some
>> small foil capacitors as well as tantalums. The chips appear to be
>> also known as AK317DC. Here's a thread about it in Polish:
>>
>> http://www.elektroda.pl/rtvforum/topic755331.html
>>
>> (google translate might help)
>>
>> For example it was used in some old laser printers to control motors.
>> In the thread it is mentioned that it is an OTA. The presence of four
>> OTAs implies to me that it is a COTA filter, which fits together with
>> what I remember about the demos.
>>
>> One good thing about this situation is that I have multiple sets of
>> boards for this synth: I have got the one keyboard, and I have got two
>> pretty much complete sets of boards as bare parts. Of course, none of
>> them work.
>>
>> Any clues, guys?
>>
>> Please help!
>>
>> Damian
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From cheater00 at gmail.com  Mon Nov  8 18:23:44 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 8 Nov 2010 18:23:44 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
	Needed
In-Reply-To: <AANLkTik18yobgRDGnbxCTjNsT7jW1g2yRb7M2FnYn=DR@mail.gmail.com>
References: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
	<COL117-W298E907D7E47696AB2FB54DA4F0@phx.gbl>
	<AANLkTik18yobgRDGnbxCTjNsT7jW1g2yRb7M2FnYn=DR@mail.gmail.com>
Message-ID: <AANLkTin9r6aec75mV3DCJCT+LKYH70197jHkaM0VSb48@mail.gmail.com>

Some more news:

I have pulled out all the cards and the voltages stayed the same: on
Right pin 6 -13.23 and 3.69 on Left pin 6.

I have also identified that the Left pin 12 also carries the gate with
it, like the Right pin 5. The Left pin 12 has -12.6V for "off" and
-12.8V for "on".

On another note, I shorted two pins with my probe, there was a "crack"
heard somewhere and the whole synth shut down. Now the analog board
test LED doesn't light up.

Seems the analogue 5V and the bipolar 15V supply are gone. I think I
need some new fuses. And fuse holders. The holders have literally
disintegrated in the last 20 years!

Cheers,
D.

On 08/11/2010, cheater cheater <cheater00 at gmail.com> wrote:
> Hi,
> thanks for your reply. I'll investigate the 12V, maybe some of the
> filter caps are dried out or broken..
>
> The 15V is available on the Left connector, on pin 2.
>
> I wonder very much about that 3.69 thing on pin 6. I have traced
> around a bit, and there's something which I don't understand: Left
> connector pins 6, 7, 8, 9 go through parallel resistors to a single
> node. That node is then coupled with a "yellow drop" to a resistor
> which goes to the -13.23.. really weird! I think it might be possible
> that one of the cards is broken, and breaks the voltages for all the
> other cards. For example maybe the "yellow drop" is broken on one of
> them. It's a weird part too: looks like a yellow drop capacitor,
> kinda, however the marking on it is 104M and every one of them that I
> measure with my DMM shows 11 or 9 kR. Time to investigate by swapping
> some cards in and out... So anyways I think the -13.23 and Left pins
> 6-9 are somehow tied together in their failure mode. I think they
> might be what's broken.
>
> Cheers,
> D.
>
> On 08/11/2010, 3 vcos <moonmuseum at hotmail.com> wrote:
>>
>> If I had to take a guess...
>>
>> It seems very strange that the voice cards get -12v and -15v.  The poor
>> -12v signal is another bad sign.  Considering you did a repair to a 15v
>> supply without a schematic and you aren't seeing 15v on the voice card I
>>  would start by investigating if that shitty -12v supply on the card
>> should be +15v or at least why the cards aren't getting positive voltage
>>  (ok, I'm guessing the +5v on the card is needed as a digital supply).
>> Seems like the lack of a positive supply voltage on the card fits with
>> some of your other findings as well.
>>
>>
>>
>>
>>
>> Good luck.  I've always been curious how the Tiracon sounded.
>>
>>
>>
>>> Date: Mon, 8 Nov 2010 15:21:03 +0100
>>> From: cheater00 at gmail.com
>>> To: synth-diy at dropmix.xs4all.nl
>>> Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and
>>> Schematics	Needed
>>>
>>> Hi guys,
>>>
>>> I am trying to resurrect this Tiracon 6V that I got off eBay some time
>>> ago. It doesn't put out any sound.
>>>
>>> It came to me in a non-functioning state. Since then I have repaired
>>> the PSU (hopefully correctly) and have been trying to work out why it
>>> doesn't work, and how it works in the first place.
>>>
>>> I have tried contacting Vermona about the synthesizer, however have
>>> had no luck with getting a reply about schematics etc.
>>>
>>> Currently, the digital board with the LCD turns on, and I can load and
>>> edit patches (haven't tried to save them yet, not sure if that's such
>>> a good idea). I can also change the speed of LFOs which is depicted on
>>> the LEDs pulsating quicker or slower. There is no sound coming out of
>>> the synthesizer.
>>>
>>> It does seem that the scanning matrix works to some extent, since the
>>> voices do seem to get triggered.
>>>
>>> About the synthesizer layout: if you look at the pictures here:
>>>
>>> http://www.vermona.de/htm/tiracon2.htm
>>>
>>> then you'll see the arrangement of the boards is as follows:
>>> the top of the synthesizer opens and has the LCD board in it. When
>>> that's open, we are presented with several boards. From left to right:
>>>
>>> 1. leftmost: digital board -
>>> http://www.vermona.de/Tiracon/digitalteil.jpg
>>> 2. main/analog board with six voice cards -
>>> http://www.vermona.de/Tiracon/analogteil.jpg
>>> 3. regulator board
>>> 4. rightmost: transformer board
>>>
>>> (both PSU boards can be seen here:
>>> http://www.vermona.de/Tiracon/netzteil.jpg )
>>>
>>> The voice cards themselves have a 2mm pin interface of some sort that
>>> they plug into. I have been trying to scope them out.
>>>
>>> About the PSU repair: the top left regulator (B3170V, an LM317 clone
>>> from the GDR) was not in circuit and one of the capacitors has broken
>>> loose. After soldering it all back together, I have had +15V show up
>>> on one of the pins, where it was 0V before.
>>>
>>> About the voice cards:
>>> Pictures can be seen here:
>>> http://www.vermona.de/instrumente/tir3.jpg
>>> http://www.vermona.de/Tiracon/6-voices.jpg
>>>
>>> they have two connectors, call them the Left and Right connector. The
>>> Left connector has 12 pins, the Right connector has 6 pins plus a "key
>>> pin" which doesn't do anything.
>>>
>>> Here are my notes for the connectors:
>>> Left:
>>> 1. frequency CV, V/Hz
>>> 2. 15V
>>> 3. GND
>>> 4. -15V
>>> 5. ?
>>> 6. 3.69V with a lot of digital noise
>>> 7. digital gnd?
>>> 8. digital gnd again?
>>> 9. ?
>>> 10. 5.2V
>>> 11. unused
>>> 12. -12V with a lot of noise
>>>
>>> Right:
>>> 1. ?
>>> 2. very very quiet white noise. Perhaps the output pin?
>>> 3. ?
>>> 4. white noise, probably an input from central distribution.
>>> 5. gate. off = -7.29V, on= -7.53V
>>> 6. -13.23V
>>>
>>> About the Left connector signals:
>>> The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
>>> and C4 is -0.945V. Obviously has a scaling problem, which I hadn't
>>> tried to address yet, since that's like waxing a train wreck. The
>>> weird thing is that the voltages are all negative.
>>>
>>> Pin 6 in reference to pin 7 still has the digital noise, but the
>>> amplitude is reduced by 50%. Pin 5 seems to contain a very very quiet
>>> mix of the output, I might be wrong though. Or maybe it's just some
>>> current escaping through ground to somewhere, who knows.
>>>
>>>
>>> About the cards:
>>>
>>> I have been able to get the 6V to run to some extent: the voice boards
>>> receive triggers and they change in pitch according to the note being
>>> played. The oscillator is audibly changing pitch if you listen to it
>>> by tapping the voltage on either of its terminals directly (which is
>>> funny, because I had thought only one of the terminals would have
>>> output, but both do - one of them is much quieter though). I have had
>>> a look around the board as to what it has got and it basically has two
>>> areas. On the left there is the VCO and on the right there is the
>>> filter.
>>>
>>> One weird thing is that there is a droop in the oscillator's pitch as
>>> long as the key is being held down. That means, that I will press the
>>> key (repeatedly until the voice I'm scoping gets triggered), and the
>>> pitch will change to what it should be minus a few semitones. Then
>>> when I let go of the key the pitch jumps up.
>>>
>>> The Gate is VERY weird. you can see the voltages above - off is
>>> -7.29V, on is -7.53V. Definitely something wrong going on there.
>>>
>>> The VCO area contains resistors, some small capacitors, some other
>>> stuff which I am unable to identify, and these chips:
>>> V 4 082 (probably a TL082 clone)
>>> B084D V7 (probably a TL084 clone)
>>> V 4066 D (a CD4066 clone, a quad bilateral switch)
>>> a second 4066
>>> CD4013 BE (probably the only western chip in the whole voice board).
>>>
>>> The presence of two quad bilateral switches and the fact that the VCO
>>> wave is audible on both ends of the capacitor (which is 15nF) suggests
>>> to me that it is a triangular core vco. I assume that the second
>>> switch is used for creating a sawtooth wave. I'm assuming the CD4013
>>> is used as the comparator in the reset circuit (it is a CMOS dual
>>> D-type flip flop).
>>>
>>> The filter board is about the right 45% width of the board, and it
>>> contains four chips marked as IA317D UD, some resistors, and some
>>> small foil capacitors as well as tantalums. The chips appear to be
>>> also known as AK317DC. Here's a thread about it in Polish:
>>>
>>> http://www.elektroda.pl/rtvforum/topic755331.html
>>>
>>> (google translate might help)
>>>
>>> For example it was used in some old laser printers to control motors.
>>> In the thread it is mentioned that it is an OTA. The presence of four
>>> OTAs implies to me that it is a COTA filter, which fits together with
>>> what I remember about the demos.
>>>
>>> One good thing about this situation is that I have multiple sets of
>>> boards for this synth: I have got the one keyboard, and I have got two
>>> pretty much complete sets of boards as bare parts. Of course, none of
>>> them work.
>>>
>>> Any clues, guys?
>>>
>>> Please help!
>>>
>>> Damian
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>


From cheater00 at gmail.com  Mon Nov  8 18:25:12 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 8 Nov 2010 18:25:12 +0100
Subject: [sdiy] Mattson sale. 15% off entire catalog
In-Reply-To: <44F622198B1E4414BBDD1A1C20848737@BlackNBlue>
References: <367060.53156.qm@web55301.mail.re4.yahoo.com>
	<8705CDDD-6F87-40DE-8D3E-6176E9DB70BD@electricdruid.net>
	<4CD71F38.2060706@rubidium.dyndns.org>
	<44F622198B1E4414BBDD1A1C20848737@BlackNBlue>
Message-ID: <AANLkTik-=tHzN92-X5pvK7nwS7EW_ib_R-nMkkWOkHp9@mail.gmail.com>

Thanks, George!

The catalog looks very interesting. Hope this creates a lot of traffic
for you too!

Cheers,
D.

On 08/11/2010, George Mattson <axisair at comcast.net> wrote:
>
> I usually just lurk here and rarely post anything.
>
> But, I launched a 15% off sale on my entire catalog over on my MW sub-forum
> and wanted to share it with everybody.
>
> http://www.muffwiggler.com/forum/viewtopic.php?t=24368
>
> Thanks all,
>
> George
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From harrybissell at wowway.com  Mon Nov  8 18:27:13 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 8 Nov 2010 12:27:13 -0500 (EST)
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and
	Schematics	Needed
In-Reply-To: <AANLkTik18yobgRDGnbxCTjNsT7jW1g2yRb7M2FnYn=DR@mail.gmail.com>
Message-ID: <704843584.223284.1289237233399.JavaMail.root@md01.wow.synacor.com>

104M would be a .1uF +/-20% cap, probably multilayer
ceramic. It should NOT read 9 or 11K, probably there is something else
in parallel with it.

H^) harry


----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: 3 vcos <moonmuseum at hotmail.com>
Cc: synth-diy at dropmix.xs4all.nl
Sent: Mon, 08 Nov 2010 12:09:40 -0500 (EST)
Subject: Re: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics	Needed

Hi,
thanks for your reply. I'll investigate the 12V, maybe some of the
filter caps are dried out or broken..

The 15V is available on the Left connector, on pin 2.

I wonder very much about that 3.69 thing on pin 6. I have traced
around a bit, and there's something which I don't understand: Left
connector pins 6, 7, 8, 9 go through parallel resistors to a single
node. That node is then coupled with a "yellow drop" to a resistor
which goes to the -13.23.. really weird! I think it might be possible
that one of the cards is broken, and breaks the voltages for all the
other cards. For example maybe the "yellow drop" is broken on one of
them. It's a weird part too: looks like a yellow drop capacitor,
kinda, however the marking on it is 104M and every one of them that I
measure with my DMM shows 11 or 9 kR. Time to investigate by swapping
some cards in and out... So anyways I think the -13.23 and Left pins
6-9 are somehow tied together in their failure mode. I think they
might be what's broken.

Cheers,
D.

On 08/11/2010, 3 vcos <moonmuseum at hotmail.com> wrote:
>
> If I had to take a guess...
>
> It seems very strange that the voice cards get -12v and -15v.  The poor
> -12v signal is another bad sign.  Considering you did a repair to a 15v
> supply without a schematic and you aren't seeing 15v on the voice card I
>  would start by investigating if that shitty -12v supply on the card
> should be +15v or at least why the cards aren't getting positive voltage
>  (ok, I'm guessing the +5v on the card is needed as a digital supply).
> Seems like the lack of a positive supply voltage on the card fits with
> some of your other findings as well.
>
>
>
>
>
> Good luck.  I've always been curious how the Tiracon sounded.
>
>
>
>> Date: Mon, 8 Nov 2010 15:21:03 +0100
>> From: cheater00 at gmail.com
>> To: synth-diy at dropmix.xs4all.nl
>> Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and
>> Schematics	Needed
>>
>> Hi guys,
>>
>> I am trying to resurrect this Tiracon 6V that I got off eBay some time
>> ago. It doesn't put out any sound.
>>
>> It came to me in a non-functioning state. Since then I have repaired
>> the PSU (hopefully correctly) and have been trying to work out why it
>> doesn't work, and how it works in the first place.
>>
>> I have tried contacting Vermona about the synthesizer, however have
>> had no luck with getting a reply about schematics etc.
>>
>> Currently, the digital board with the LCD turns on, and I can load and
>> edit patches (haven't tried to save them yet, not sure if that's such
>> a good idea). I can also change the speed of LFOs which is depicted on
>> the LEDs pulsating quicker or slower. There is no sound coming out of
>> the synthesizer.
>>
>> It does seem that the scanning matrix works to some extent, since the
>> voices do seem to get triggered.
>>
>> About the synthesizer layout: if you look at the pictures here:
>>
>> http://www.vermona.de/htm/tiracon2.htm
>>
>> then you'll see the arrangement of the boards is as follows:
>> the top of the synthesizer opens and has the LCD board in it. When
>> that's open, we are presented with several boards. From left to right:
>>
>> 1. leftmost: digital board - http://www.vermona.de/Tiracon/digitalteil.jpg
>> 2. main/analog board with six voice cards -
>> http://www.vermona.de/Tiracon/analogteil.jpg
>> 3. regulator board
>> 4. rightmost: transformer board
>>
>> (both PSU boards can be seen here:
>> http://www.vermona.de/Tiracon/netzteil.jpg )
>>
>> The voice cards themselves have a 2mm pin interface of some sort that
>> they plug into. I have been trying to scope them out.
>>
>> About the PSU repair: the top left regulator (B3170V, an LM317 clone
>> from the GDR) was not in circuit and one of the capacitors has broken
>> loose. After soldering it all back together, I have had +15V show up
>> on one of the pins, where it was 0V before.
>>
>> About the voice cards:
>> Pictures can be seen here:
>> http://www.vermona.de/instrumente/tir3.jpg
>> http://www.vermona.de/Tiracon/6-voices.jpg
>>
>> they have two connectors, call them the Left and Right connector. The
>> Left connector has 12 pins, the Right connector has 6 pins plus a "key
>> pin" which doesn't do anything.
>>
>> Here are my notes for the connectors:
>> Left:
>> 1. frequency CV, V/Hz
>> 2. 15V
>> 3. GND
>> 4. -15V
>> 5. ?
>> 6. 3.69V with a lot of digital noise
>> 7. digital gnd?
>> 8. digital gnd again?
>> 9. ?
>> 10. 5.2V
>> 11. unused
>> 12. -12V with a lot of noise
>>
>> Right:
>> 1. ?
>> 2. very very quiet white noise. Perhaps the output pin?
>> 3. ?
>> 4. white noise, probably an input from central distribution.
>> 5. gate. off = -7.29V, on= -7.53V
>> 6. -13.23V
>>
>> About the Left connector signals:
>> The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
>> and C4 is -0.945V. Obviously has a scaling problem, which I hadn't
>> tried to address yet, since that's like waxing a train wreck. The
>> weird thing is that the voltages are all negative.
>>
>> Pin 6 in reference to pin 7 still has the digital noise, but the
>> amplitude is reduced by 50%. Pin 5 seems to contain a very very quiet
>> mix of the output, I might be wrong though. Or maybe it's just some
>> current escaping through ground to somewhere, who knows.
>>
>>
>> About the cards:
>>
>> I have been able to get the 6V to run to some extent: the voice boards
>> receive triggers and they change in pitch according to the note being
>> played. The oscillator is audibly changing pitch if you listen to it
>> by tapping the voltage on either of its terminals directly (which is
>> funny, because I had thought only one of the terminals would have
>> output, but both do - one of them is much quieter though). I have had
>> a look around the board as to what it has got and it basically has two
>> areas. On the left there is the VCO and on the right there is the
>> filter.
>>
>> One weird thing is that there is a droop in the oscillator's pitch as
>> long as the key is being held down. That means, that I will press the
>> key (repeatedly until the voice I'm scoping gets triggered), and the
>> pitch will change to what it should be minus a few semitones. Then
>> when I let go of the key the pitch jumps up.
>>
>> The Gate is VERY weird. you can see the voltages above - off is
>> -7.29V, on is -7.53V. Definitely something wrong going on there.
>>
>> The VCO area contains resistors, some small capacitors, some other
>> stuff which I am unable to identify, and these chips:
>> V 4 082 (probably a TL082 clone)
>> B084D V7 (probably a TL084 clone)
>> V 4066 D (a CD4066 clone, a quad bilateral switch)
>> a second 4066
>> CD4013 BE (probably the only western chip in the whole voice board).
>>
>> The presence of two quad bilateral switches and the fact that the VCO
>> wave is audible on both ends of the capacitor (which is 15nF) suggests
>> to me that it is a triangular core vco. I assume that the second
>> switch is used for creating a sawtooth wave. I'm assuming the CD4013
>> is used as the comparator in the reset circuit (it is a CMOS dual
>> D-type flip flop).
>>
>> The filter board is about the right 45% width of the board, and it
>> contains four chips marked as IA317D UD, some resistors, and some
>> small foil capacitors as well as tantalums. The chips appear to be
>> also known as AK317DC. Here's a thread about it in Polish:
>>
>> http://www.elektroda.pl/rtvforum/topic755331.html
>>
>> (google translate might help)
>>
>> For example it was used in some old laser printers to control motors.
>> In the thread it is mentioned that it is an OTA. The presence of four
>> OTAs implies to me that it is a COTA filter, which fits together with
>> what I remember about the demos.
>>
>> One good thing about this situation is that I have multiple sets of
>> boards for this synth: I have got the one keyboard, and I have got two
>> pretty much complete sets of boards as bare parts. Of course, none of
>> them work.
>>
>> Any clues, guys?
>>
>> Please help!
>>
>> Damian
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From mrmccrash at gmail.com  Mon Nov  8 18:33:20 2010
From: mrmccrash at gmail.com (Markus Schreiter)
Date: Mon, 08 Nov 2010 18:33:20 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
 Needed
In-Reply-To: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
References: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
Message-ID: <4CD83460.9090608@gmail.com>

Heyho!

Look around for a Book called "Moderne Musikelekronik" from Hans-Jochen
Schulze an Georg Engel. (Militaerbuchverlag der DDR, Berlin 1989, ISBN
3-327-00772-1).

There are the Schematics for the VCO/VCF/VCA Part and some other useful
information. I have the book here and could propably scan some pages, if
you need them quick.

The IA317/AK317 is a GDR-Clone of the LM13500.

The VCO is a Saw-Core type, where the first 4066 is used as Reset-switch
using all 4 channels in parallel (for lower R?). The -12V Rail goes to
the tuning trimpot (100k between +12V and -12V).

cu, Markus

Am 08.11.2010 15:21, schrieb cheater cheater:
> Hi guys,
> 
> I am trying to resurrect this Tiracon 6V that I got off eBay some time
> ago. It doesn't put out any sound.
> 
> It came to me in a non-functioning state. Since then I have repaired
> the PSU (hopefully correctly) and have been trying to work out why it
> doesn't work, and how it works in the first place.
> 
> I have tried contacting Vermona about the synthesizer, however have
> had no luck with getting a reply about schematics etc.
> 
> Currently, the digital board with the LCD turns on, and I can load and
> edit patches (haven't tried to save them yet, not sure if that's such
> a good idea). I can also change the speed of LFOs which is depicted on
> the LEDs pulsating quicker or slower. There is no sound coming out of
> the synthesizer.
> 
> It does seem that the scanning matrix works to some extent, since the
> voices do seem to get triggered.
> 
> About the synthesizer layout: if you look at the pictures here:
> 
> http://www.vermona.de/htm/tiracon2.htm
> 
> then you'll see the arrangement of the boards is as follows:
> the top of the synthesizer opens and has the LCD board in it. When
> that's open, we are presented with several boards. From left to right:
> 
> 1. leftmost: digital board - http://www.vermona.de/Tiracon/digitalteil.jpg
> 2. main/analog board with six voice cards -
> http://www.vermona.de/Tiracon/analogteil.jpg
> 3. regulator board
> 4. rightmost: transformer board
> 
> (both PSU boards can be seen here: http://www.vermona.de/Tiracon/netzteil.jpg )
> 
> The voice cards themselves have a 2mm pin interface of some sort that
> they plug into. I have been trying to scope them out.
> 
> About the PSU repair: the top left regulator (B3170V, an LM317 clone
> from the GDR) was not in circuit and one of the capacitors has broken
> loose. After soldering it all back together, I have had +15V show up
> on one of the pins, where it was 0V before.
> 
> About the voice cards:
> Pictures can be seen here:
> http://www.vermona.de/instrumente/tir3.jpg
> http://www.vermona.de/Tiracon/6-voices.jpg
> 
> they have two connectors, call them the Left and Right connector. The
> Left connector has 12 pins, the Right connector has 6 pins plus a "key
> pin" which doesn't do anything.
> 
> Here are my notes for the connectors:
> Left:
> 1. frequency CV, V/Hz
> 2. 15V
> 3. GND
> 4. -15V
> 5. ?
> 6. 3.69V with a lot of digital noise
> 7. digital gnd?
> 8. digital gnd again?
> 9. ?
> 10. 5.2V
> 11. unused
> 12. -12V with a lot of noise
> 
> Right:
> 1. ?
> 2. very very quiet white noise. Perhaps the output pin?
> 3. ?
> 4. white noise, probably an input from central distribution.
> 5. gate. off = -7.29V, on= -7.53V
> 6. -13.23V
> 
> About the Left connector signals:
> The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
> and C4 is -0.945V. Obviously has a scaling problem, which I hadn't
> tried to address yet, since that's like waxing a train wreck. The
> weird thing is that the voltages are all negative.
> 
> Pin 6 in reference to pin 7 still has the digital noise, but the
> amplitude is reduced by 50%. Pin 5 seems to contain a very very quiet
> mix of the output, I might be wrong though. Or maybe it's just some
> current escaping through ground to somewhere, who knows.
> 
> 
> About the cards:
> 
> I have been able to get the 6V to run to some extent: the voice boards
> receive triggers and they change in pitch according to the note being
> played. The oscillator is audibly changing pitch if you listen to it
> by tapping the voltage on either of its terminals directly (which is
> funny, because I had thought only one of the terminals would have
> output, but both do - one of them is much quieter though). I have had
> a look around the board as to what it has got and it basically has two
> areas. On the left there is the VCO and on the right there is the
> filter.
> 
> One weird thing is that there is a droop in the oscillator's pitch as
> long as the key is being held down. That means, that I will press the
> key (repeatedly until the voice I'm scoping gets triggered), and the
> pitch will change to what it should be minus a few semitones. Then
> when I let go of the key the pitch jumps up.
> 
> The Gate is VERY weird. you can see the voltages above - off is
> -7.29V, on is -7.53V. Definitely something wrong going on there.
> 
> The VCO area contains resistors, some small capacitors, some other
> stuff which I am unable to identify, and these chips:
> V 4 082 (probably a TL082 clone)
> B084D V7 (probably a TL084 clone)
> V 4066 D (a CD4066 clone, a quad bilateral switch)
> a second 4066
> CD4013 BE (probably the only western chip in the whole voice board).
> 
> The presence of two quad bilateral switches and the fact that the VCO
> wave is audible on both ends of the capacitor (which is 15nF) suggests
> to me that it is a triangular core vco. I assume that the second
> switch is used for creating a sawtooth wave. I'm assuming the CD4013
> is used as the comparator in the reset circuit (it is a CMOS dual
> D-type flip flop).
> 
> The filter board is about the right 45% width of the board, and it
> contains four chips marked as IA317D UD, some resistors, and some
> small foil capacitors as well as tantalums. The chips appear to be
> also known as AK317DC. Here's a thread about it in Polish:
> 
> http://www.elektroda.pl/rtvforum/topic755331.html
> 
> (google translate might help)
> 
> For example it was used in some old laser printers to control motors.
> In the thread it is mentioned that it is an OTA. The presence of four
> OTAs implies to me that it is a COTA filter, which fits together with
> what I remember about the demos.
> 
> One good thing about this situation is that I have multiple sets of
> boards for this synth: I have got the one keyboard, and I have got two
> pretty much complete sets of boards as bare parts. Of course, none of
> them work.
> 
> Any clues, guys?
> 
> Please help!
> 
> Damian
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From gil_we at yahoo.com  Mon Nov  8 18:52:02 2010
From: gil_we at yahoo.com (Gil W.)
Date: Mon, 8 Nov 2010 09:52:02 -0800 (PST)
Subject: [sdiy] Looking for a PG-800
Message-ID: <20473.87410.qm@web58004.mail.re3.yahoo.com>

If someone sells please email me with the price asked,
to: gil_we at yahoo.com

Please remove the "SDIY" sign from the subject line.

Thanks !


      


From tom at electricdruid.net  Mon Nov  8 19:00:13 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 8 Nov 2010 18:00:13 +0000
Subject: [sdiy] Mixing several noise generators
Message-ID: <09326FC7-3FCF-4223-A0C4-4B6F2870BF1E@electricdruid.net>

Hi all,

Most analogue polysynths that feature a noise generator use one common noise generator which is then fed to all the voices. Presumably when the voices are mixed in the mixer, the noise will add up linearly, since it is simply more copies of the same thing. By which I mean if voice A provides 1V of noise, then voices A+B will provide 2V of noise.

But let's assume we've got a synth that has a separate, independent noise generator per voice. The two noise signals will now cancel about as often as they'll reinforce. At least, that's my gut feeling, and what I'm dead sure of is that they won't reinforce *all* the time like the copies of the same noise source. So I'd expect the noise volume to not increase so much. So perhaps there are other reasons beyond the obvious cost-cutting to use one noise source only.

Does anyone know;
	how much the noise does increase if it is an unrelated source?
	any examples of instruments that use independent noise sources?

Thanks,
Tom




From ol.gillet at gmail.com  Mon Nov  8 19:16:41 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Mon, 8 Nov 2010 19:16:41 +0100
Subject: [sdiy] Mixing several noise generators
In-Reply-To: <09326FC7-3FCF-4223-A0C4-4B6F2870BF1E@electricdruid.net>
References: <09326FC7-3FCF-4223-A0C4-4B6F2870BF1E@electricdruid.net>
Message-ID: <AANLkTinm4KOsidDcq4Eb2rfOWZ+7iQjk9swWLYHOGDwr@mail.gmail.com>

If you add k independent, centered, gaussian sources of variance
sigma^2, the variance of the sum is k sigma^2.
If you multiply a gaussian source of variance sigma^2 by a constant k,
the variance of the product is k^2 sigma^2.

So in one case, the RMS raises linearly while it raises in n^0.5 with
independent sources.


From Stromeko at nexgo.de  Mon Nov  8 19:21:23 2010
From: Stromeko at nexgo.de (ASSI)
Date: Mon, 8 Nov 2010 19:21:23 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
	Needed
In-Reply-To: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
References: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>
Message-ID: <201011081921.23440.Stromeko@nexgo.de>

On Monday 08 November 2010, cheater cheater wrote:
> I have tried contacting Vermona about the synthesizer, however have
> had no luck with getting a reply about schematics etc.

Vermona had absolutely nothing to do with the Tiracon6V, apart from starting 
to sell EPROM copies a few years ago.  Tiracon6V schematics (without 
connector diagrams) together with extensive explanation were published in:

Hans-Jochen Schulze/ Georg Engel, Moderne Musikelektronik, Milit?rverlag der 
DDR 1989, ISBN 3-327-00772-1

http://www.ddrbuch.de/Belletristik/Moderne-Musikelektronik::2208.html

> About the Left connector signals:
> The Frequency CV is very weird. C3 is -0,470V, whereas C2 is -0.233V
> and C4 is -0.945V. Obviously has a scaling problem,

Obviously you don't understand what linear CV (V/Hz) is.

> V 4 082 (probably a TL082 clone)
> B084D V7 (probably a TL084 clone)

Correct.

> four chips marked as IA317D UD

A 13600 clone from HFO.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptation for Waldorf microQ V2.22R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada


From Stromeko at nexgo.de  Mon Nov  8 19:26:29 2010
From: Stromeko at nexgo.de (ASSI)
Date: Mon, 8 Nov 2010 19:26:29 +0100
Subject: [sdiy] Mixing several noise generators
In-Reply-To: <09326FC7-3FCF-4223-A0C4-4B6F2870BF1E@electricdruid.net>
References: <09326FC7-3FCF-4223-A0C4-4B6F2870BF1E@electricdruid.net>
Message-ID: <201011081926.29161.Stromeko@nexgo.de>

On Monday 08 November 2010, Tom Wiltshire wrote:
> 	how much the noise does increase if it is an unrelated source?

Depends on the pdf of the noise, but in most cases you'll end up with a 
geometric sum of amplitudes.  Add enough of those sources and you'll get a 
Gaussian distribution which makes the relation exact.

> 	any examples of instruments that use independent noise sources?

Most white noise sources can be thought of as a summation of individual 
noise sources, see above.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Factory and User Sound Singles for Waldorf rackAttack:
http://Synth.Stromeko.net/Downloads.html#WaldorfSounds


From sounddoctorin at imt.net  Mon Nov  8 19:59:43 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Mon, 08 Nov 2010 11:59:43 -0700
Subject: [sdiy] B566AC anyone? report on DK70 bender neck
Message-ID: <4CD8489F.4030402@imt.net>

Dang...it's in the package of an NE566 of course (8 pin dip)..what kind 
of knucklehead would name it that!  Someone thought that's what they 
were who ran the electronic store I got a bunch of stuff from years 
ago.  I thought I had 8 more of them than I have henceforth. Does anyone 
know what these really are?  I Am at this time designing a custom grip 
for the siel DK70 that will feature a much more ergonomic setup with a 
tilter instead of a pitch ribbon.  That way you can stay on the buttons 
with other fingers.  The thumb..however..will control an lfo with 
pressing in giving depth and tilting changing rate.  A switch for 
waveform type will also be provided and I may break it into ranges 
too...we'll see how it works out.  I'm going to try to get the prototype 
done soon here and then make enough of them to go on the units I've 
saved up here for that project. -Bob

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From sounddoctorin at imt.net  Mon Nov  8 20:02:42 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Mon, 08 Nov 2010 12:02:42 -0700
Subject: [sdiy] B566AC anyone? report on DK70 bender neck
In-Reply-To: <4CD8489F.4030402@imt.net>
References: <4CD8489F.4030402@imt.net>
Message-ID: <4CD84952.5060006@imt.net>

On 11/8/2010 11:59 AM, Bob Weigel wrote:
> Dang...it's in the package of an NE566 of course (8 pin dip)..what 
> kind of knucklehead would name it that!  Someone thought that's what 
> they were who ran the electronic store I got a bunch of stuff from 
> years ago.  I thought I had 8 more of them than I have henceforth. 
> Does anyone know what these really are?  I Am at this time designing a 
> custom grip for the siel DK70 that will feature a much more ergonomic 
> setup with a tilter instead of a pitch ribbon.  That way you can stay 
> on the buttons with other fingers.  The thumb..however..will control 
> an lfo with pressing in giving depth and tilting changing rate.  A 
> switch for waveform type will also be provided and I may break it into 
> ranges too...we'll see how it works out.  I'm going to try to get the 
> prototype done soon here and then make enough of them to go on the 
> units I've saved up here for that project. -Bob
>
PS I should have noted it's an NEC device.  That's about all I can find 
online about it.

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From dingebre at 3dphysics.net  Mon Nov  8 20:06:58 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Mon, 8 Nov 2010 12:06:58 -0700
Subject: [sdiy] Monotron Schematic - Guard Rings
In-Reply-To: <826562153.219830.1289231496401.JavaMail.root@md01.wow.synacor.com>
References: <694F7504-91CD-437E-A2CF-5FC9AD432B15@t-online.de>
	<826562153.219830.1289231496401.JavaMail.root@md01.wow.synacor.com>
Message-ID: <000d01cb7f78$1e3c6a30$5ab53e90$@net>

Hi Ingo,

In knowing and working with Nyle, he is one of the most clever individuals
with an amazing intuition and skill with analog electronics I've ever known.

I've been having the time of my life going through his old schematics and
capturing them into Eagle. Even better, I've renewed my friendship with Nyle
and he's been teaching me a lot of very interesting things about his
circuits.

As soon as I get the prototype built, I'll let you know how the outputs
compare.

David



Deleted...


~~ 
~~ Is this an answer to my question re how the random voltage generator
~~ in the Steiner Synthasystem works?
~~ 
~~ So the UJT is the discharge switch of a relaxation oscillator?
~~ 
~~ Making an analog random generator this way is pretty brilliant. Hats
~~ off!
~~ And then there's two of them in one module that can be run with the
~~ same trigger signal (if no plug is inserted in the trig 2 input). I
~~ wonder how similar the outputs are?
~~ 
~~ Ingo
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
~~ 



From veronica.merryfield at shaw.ca  Mon Nov  8 20:10:45 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Mon, 8 Nov 2010 11:10:45 -0800
Subject: [sdiy] B566AC anyone? report on DK70 bender neck
In-Reply-To: <4CD8489F.4030402@imt.net>
References: <4CD8489F.4030402@imt.net>
Message-ID: <52384083-6272-47BF-A4ED-4579703D01EB@shaw.ca>

I found this - no data sheet

The B566AC/C811 (W742C811 is mask type, B566AC811 is electrical erasable EPROM type) is a high- performance 4-bit microcontroller (?C) that built in 640-dot LCD driver. The device contains a 4-bit ALU, two 8-bit timers, two dividers in dual-clock operation, a 40 16 LCD driver, ten 4-bit I/O ports (including 2 output port for LED driving), multiple frequency output, and one channel DTMF generator. There are also eleven interrupt sources and 16-level stack buffer. The B566AC/C811 operates on very low current and has three power reduction modes, hold mode, stop mode and slow mode, which help to minimize power dissipation.


On 2010-11-08, at 10:59 AM, Bob Weigel wrote:

> Dang...it's in the package of an NE566 of course (8 pin dip)..what kind of knucklehead would name it that!  Someone thought that's what they were who ran the electronic store I got a bunch of stuff from years ago.  I thought I had 8 more of them than I have henceforth. Does anyone know what these really are?  I Am at this time designing a custom grip for the siel DK70 that will feature a much more ergonomic setup with a tilter instead of a pitch ribbon.  That way you can stay on the buttons with other fingers.  The thumb..however..will control an lfo with pressing in giving depth and tilting changing rate.  A switch for waveform type will also be provided and I may break it into ranges too...we'll see how it works out.  I'm going to try to get the prototype done soon here and then make enough of them to go on the units I've saved up here for that project. -Bob
> 
> -- 
> Check out sounddoctorin.com for songs, a studio tour, help
> repairing old synthesizers and parts or thought provoking
> articles that could help make your eternity!
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From sounddoctorin at imt.net  Mon Nov  8 20:16:48 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Mon, 08 Nov 2010 12:16:48 -0700
Subject: [sdiy] B566AC anyone? report on DK70 bender neck
In-Reply-To: <52384083-6272-47BF-A4ED-4579703D01EB@shaw.ca>
References: <4CD8489F.4030402@imt.net>
	<52384083-6272-47BF-A4ED-4579703D01EB@shaw.ca>
Message-ID: <4CD84CA0.4090302@imt.net>

On 11/8/2010 12:10 PM, Veronica Merryfield wrote:
>
> I found this - no data sheet
>
> The B566AC/C811 (W742C811 is mask type, B566AC811 is electrical erasable EPROM type) is a high- performance 4-bit microcontroller (?C) that built in 640-dot LCD driver. The device contains a 4-bit ALU, two 8-bit timers, two dividers in dual-clock operation, a 40 16 LCD driver, ten 4-bit I/O ports (including 2 output port for LED driving), multiple frequency output, and one channel DTMF generator. There are also eleven interrupt sources and 16-level stack buffer. The B566AC/C811 operates on very low current and has three power reduction modes, hold mode, stop mode and slow mode, which help to minimize power dissipation.
>
>
>    
I think it must be another random association Veronica.  Again this is 
an 8 pin package so..it can't have  10 i/o ports  etc.   Sounds like 
that thing is probably a quad pack


From jpdesroc at oricom.ca  Mon Nov  8 20:32:32 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 08 Nov 2010 14:32:32 -0500
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
Message-ID: <29366.1289244752@oricom.ca>



Which opamp pins wiring is best for CV out ?? A or B ??
Sorry for the bad drawing... no HTML so.
I'm in the CV out design of my sequencer and
I need so much your thoughts on that.

A:
          
              |\
              | \ 
              |  \ 
              |   \ 
              |    \ 
              |     \ 
 incoming CV  |  |   \ 
--------------| ---   \ 
              |  |     \_____/\/\/\____ CV OUT
              |        / | 
              |       /  | 
              |      /   | 
          ----| --- /    | 
          |   |    /     | 
          |   |   /      | 
          |   |  /       | 
          |   | /        | 
          |   |/         | 
          |   |          |
          |              | 
          |--------------| 
          
          B:
           
              |\
              | \ 
              |  \ 
              |   \ 
              |    \ 
              |     \ 
 incoming CV  |  |   \ 
--------------| ---   \ 
              |  |     \_____/\/\/\__ __ CV OUT
              |        /             |  
              |       /              |  
              |      /               |  
          ----| --- /                |  
          |   |    /                 |  
          |   |   /                  |  
          |   |  /                   |  
          |   | /                    |  
          |   |/                     |  
          |   |                      |  
          |                          |  
          |--------------------------|
          
Thanks
J-P


From jpdesroc at oricom.ca  Mon Nov  8 20:34:28 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 08 Nov 2010 14:34:28 -0500
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
Message-ID: <33751.1289244868@oricom.ca>

Sorry for the damaged drawing I'll try to email you something better..


 On Mon 08/11/10 14:32 , Jean-Pierre Desrochers jpdesroc at oricom.ca sent:
> 
> 
> Which opamp pins wiring is best for CV out ?? A or B ??
> Sorry for the bad drawing... no HTML so.
> I'm in the CV out design of my sequencer and
> I need so much your thoughts on that.
> 
> A:
> 
> |\
> | \ 
> |  \ 
> |   \ 
> |    \ 
> |     \ 
> incoming CV  |  |   \ 
> --------------| ---   \ 
> |  |     \_____/\/\/\____ CV OUT
> |        / | 
> |       /  | 
> |      /   | 
> ----| --- /    | 
> |   |    /     | 
> |   |   /      | 
> |   |  /       | 
> |   | /        | 
> |   |/         | 
> |   |          |
> |              | 
> |--------------| 
> 
> B:
> 
> |\
> | \ 
> |  \ 
> |   \ 
> |    \ 
> |     \ 
> incoming CV  |  |   \ 
> --------------| ---   \ 
> |  |     \_____/\/\/\__ __ CV OUT
> |        /             |  
> |       /              |  
> |      /               |  
> ----| --- /                |  
> |   |    /                 |  
> |   |   /                  |  
> |   |  /                   |  
> |   | /                    |  
> |   |/                     |  
> |   |                      |  
> |                          |  
> |--------------------------|
> 
> Thanks
> J-P
> _______________________________________________
> Synth-diy mailing list
> S
> ynth-diy at dropmix.xs4all.nlhttp://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 


From harrybissell at wowway.com  Mon Nov  8 20:39:49 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 8 Nov 2010 14:39:49 -0500 (EST)
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
In-Reply-To: <29366.1289244752@oricom.ca>
Message-ID: <403308453.226676.1289245189848.JavaMail.root@md01.wow.synacor.com>

I think this was discussed in a recent thread but I forget what the title might have been...

I like "a" because it puts the resistor between the opamp inverting input
and the real world, but it will have an error based on the value of the output
resistor and the input impedance of whatever you are driving...

Others did not agree...

H^) harry


----- Original Message -----
From: Jean-Pierre Desrochers <jpdesroc at oricom.ca>
To: synth-diy at dropmix.xs4all.nl
Sent: Mon, 08 Nov 2010 14:32:32 -0500 (EST)
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??



Which opamp pins wiring is best for CV out ?? A or B ??
Sorry for the bad drawing... no HTML so.
I'm in the CV out design of my sequencer and
I need so much your thoughts on that.

A:
          
              |\
              | \ 
              |  \ 
              |   \ 
              |    \ 
              |     \ 
 incoming CV  |  |   \ 
--------------| ---   \ 
              |  |     \_____/\/\/\____ CV OUT
              |        / | 
              |       /  | 
              |      /   | 
          ----| --- /    | 
          |   |    /     | 
          |   |   /      | 
          |   |  /       | 
          |   | /        | 
          |   |/         | 
          |   |          |
          |              | 
          |--------------| 
          
          B:
           
              |\
              | \ 
              |  \ 
              |   \ 
              |    \ 
              |     \ 
 incoming CV  |  |   \ 
--------------| ---   \ 
              |  |     \_____/\/\/\__ __ CV OUT
              |        /             |  
              |       /              |  
              |      /               |  
          ----| --- /                |  
          |   |    /                 |  
          |   |   /                  |  
          |   |  /                   |  
          |   | /                    |  
          |   |/                     |  
          |   |                      |  
          |                          |  
          |--------------------------|
          
Thanks
J-P
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From jpdesroc at oricom.ca  Mon Nov  8 20:44:42 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 08 Nov 2010 14:44:42 -0500
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
Message-ID: <56744.1289245482@oricom.ca>


What about using "B" but with a 10k resistor in series in the path
going back to inverting pin to protect from any incoming voltage spikes from 
the output connector..? 
Very low output impedance but protected inverting input..
Best of both world ?
JP

 On Mon 08/11/10 14:39 , Harry Bissell harrybissell at wowway.com sent:
> I think this was discussed in a recent thread but I forget what the title
> might have been...
> I like "a" because it puts the resistor between the opamp
> inverting inputand the real world, but it will have an error based on the value of the
> outputresistor and the input impedance of whatever you are driving...
> 
> Others did not agree...
> 
> H^) harry
> 
> 
> ----- Original Message -----
> From: Jean-Pierre Desrochers  ricom.ca>To: s
> ynth-diy at dropmix.xs4all.nlSent: Mon, 08 Nov 2010 14:32:32 -0500 (EST)
> Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
> 
> 
> 
> Which opamp pins wiring is best for CV out ?? A or B ??
> Sorry for the bad drawing... no HTML so.
> I'm in the CV out design of my sequencer and
> I need so much your thoughts on that.
> 
> A:
> 
> |\
> | \ 
> |  \ 
> |   \ 
> |    \ 
> |     \ 
> incoming CV  |  |   \ 
> --------------| ---   \ 
> |  |     \_____/\/\/\____ CV OUT
> |        / | 
> |       /  | 
> |      /   | 
> ----| --- /    | 
> |   |    /     | 
> |   |   /      | 
> |   |  /       | 
> |   | /        | 
> |   |/         | 
> |   |          |
> |              | 
> |--------------| 
> 
> B:
> 
> |\
> | \ 
> |  \ 
> |   \ 
> |    \ 
> |     \ 
> incoming CV  |  |   \ 
> --------------| ---   \ 
> |  |     \_____/\/\/\__ __ CV OUT
> |        /             |  
> |       /              |  
> |      /               |  
> ----| --- /                |  
> |   |    /                 |  
> |   |   /                  |  
> |   |  /                   |  
> |   | /                    |  
> |   |/                     |  
> |   |                      |  
> |                          |  
> |--------------------------|
> 
> Thanks
> J-P
> _______________________________________________
> Synth-diy mailing list
> S
> ynth-diy at dropmix.xs4all.nlhttp://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> -- 
> Harry Bissell & Nora Abdullah 4eva
> 
> 
> 


From jpdesroc at oricom.ca  Mon Nov  8 20:54:24 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 08 Nov 2010 14:54:24 -0500
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
Message-ID: <47009.1289246064@oricom.ca>

For better diagrams of both opamp configuration,
Go to 
http://www.bcae1.com/opamp.htm

Diagram of A:
(schematic under "OP AMP Operation: " explanation)

Diagram of B:
(schematic under "OP AMP Error Correction: " explanation)

What about using "B" but with a 10k resistor in series in the path
going back to inverting pin to protect from any incoming voltage spikes from 
the output connector..? 
Very low output impedance but protected inverting input..
Best of both world ?
Again,
I'm in the CV out design of my sequencer and
I need so much your thoughts on that.
Thanks
JP




From rburnett at richieburnett.co.uk  Mon Nov  8 22:07:03 2010
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Mon, 8 Nov 2010 21:07:03 -0000
Subject: [sdiy]  Mixing several noise generators
Message-ID: <CF50CC8AD23B47CC8B8258F81B6CBD5A@homepc002>

Hi Tom,

Independent noise generators that are not correlated add like orthogonal 
signals.  This applies to a bunch of analogue thermal noise generators, or a 
bunch of digital shift-register based noise generators using very long 
sequence lengths.

When you add two un-correlated sources together the amplitude goes up by 
only 3dB.  i.e. the resulting amplitude goes up by sqrt(2).  This can be 
contrasted to the doubling (+6dB) of amplitude that you'd get when you add 
two identical signals together.

It's easiest to think of the two independent noise sources as being 
orthogonal signals.  i.e. at 90 degrees to each other in space, like X and Y 
on a graph, or like a Sine and Cosine in the time domain.  When you add the 
two together the resultant is equal to the square-root of the sum of the 
squares of the other two amplitudes.  You can extend this analogy to three 
un-correlated noise sources, representing the X, Y and Z dimensions, and so 
on for more and more independent sources.

You are quite right that it has an effect in synthesis.  If you generate a 
flute sound with an equal balance of pitched tone and noise, then this 
balance will be upset in a polyphonic instrument that only uses one shared 
noise source.  As you add notes together, the different pitches of the tonal 
parts are orthogonal so add geometrically but the noise sources are all 
identical and add arithmetically.  The result is an overall change in 
tone-to-noise ratio for the complete sound.

As far as implementations go, I don't know of any synths that use 
independent noise sources for each voice.  If any synth does, it's probably 
going to be something like the Alesis Ion or its siblings as these use 
seperate mini-DSP chips for each voice.  In this case it is surely easier to 
have a seperate noise source running in each DSP than to pipe-in a common 
digital noise source to all eight voice DSPs.  Of course this still assumes 
that they don't just load all 8 voice DSPs with the same seed for their 
random number generators at startup resulting in eight independent but 
highly correlated noise sources!

I hope this helps,

Cheers,

-Richie Burnett, 



From rburnett at richieburnett.co.uk  Mon Nov  8 22:18:41 2010
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Mon, 8 Nov 2010 21:18:41 -0000
Subject: [sdiy]  Which opamp pins wiring is best for CV out ?? A or B ??
Message-ID: <931DA2A764694C5D81503355A3E0B60F@homepc002>

Circuit A does not compensate for the DC voltage drop across the 
current-limit resistor because it is outside the feedback loop.  However, 
it's high frequency stability is excellent because the op-amp output is 
decoupled from any load capacitance by the resistor.

Circuit B compensates for the DC voltage drop across the current-limiting 
resistor due to load current.  The only problem with it is that any load 
capacitance, e.g. capacitance from driving a long cable degrades the phase 
margin of the op-amp and is likely to make it oscillate.

The best solution is one that combines the advantages of both schematics.

-Richie Burnett,


From Peter.Ullrich at kapsch.net  Mon Nov  8 22:44:06 2010
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Mon, 8 Nov 2010 22:44:06 +0100
Subject: [sdiy] Tiracon 6V - Vermona / VEB Cottbus - Help and Schematics
 Needed
In-Reply-To: <4CD83460.9090608@gmail.com>
References: <AANLkTi=VkWjVNycZBYz9ayk6WkxD+pnmz_68w66OuS78@mail.gmail.com>,
	<4CD83460.9090608@gmail.com>
Message-ID: <B156A86831A33949A0977840648802475DF33F54CD@S060VS20.kapsch.co.at>


Hi Damian!

>Look around for a Book called "Moderne Musikelekronik" from Hans-Jochen
>Schulze an Georg Engel. (Militaerbuchverlag der DDR, Berlin 1989, ISBN
>3-327-00772-1).

I have this book and could sell it to you if you need it.
The book is in good shape. I could send you a photo if needed.
Asking 12.- Euro + postage from Austria/Europe to you.

Ciao
Peter

http://www.ullrich.at.tf
The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.




From dixon at interchange.ubc.ca  Mon Nov  8 23:02:41 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 08 Nov 2010 14:02:41 -0800
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A or B ??
In-Reply-To: <29366.1289244752@oricom.ca>
References: <29366.1289244752@oricom.ca>
Message-ID: <DED6FEE66F344F92AFEF31C16CFC1D1C@galvanox01>

For CV out, I always use B, because I don't want the voltage drop across the
external resistor, particularly if that CV is going to determine pitch,
because even small errors will be audible, and they get worse the farther
away from 0V you get.



From brockr0 at shaw.ca  Mon Nov  8 23:29:29 2010
From: brockr0 at shaw.ca (Brock Russell)
Date: Mon, 08 Nov 2010 14:29:29 -0800
Subject: [sdiy] B566AC anyone? report on DK70 bender neck
In-Reply-To: <4CD8489F.4030402@imt.net>
References: <4CD8489F.4030402@imt.net>
Message-ID: <1b23fb$47ro42@pd5mo1no-svcs.prod.shaw.ca>

Bob,

The full part number is uPB566AC and it's a 980 MHz prescaler with 
divide by 64/65 and 128/129 functions. Don't have the datasheet, just 
the listing in my 89-90 NEC product selector guide. Not going to cut 
it as an NE566 replacement.

Brock

At 10:59 AM 11/8/2010, you wrote:
>Dang...it's in the package of an NE566 of course (8 pin dip)..what 
>kind of knucklehead would name it that!  Someone thought that's what 
>they were who ran the electronic store I got a bunch of stuff from 
>years ago.  I thought I had 8 more of them than I have henceforth. 
>Does anyone know what these really are?  I Am at this time designing 
>a custom grip for the siel DK70 that will feature a much more 
>ergonomic setup with a tilter instead of a pitch ribbon.  That way 
>you can stay on the buttons with other fingers.  The 
>thumb..however..will control an lfo with pressing in giving depth 
>and tilting changing rate.  A switch for waveform type will also be 
>provided and I may break it into ranges too...we'll see how it works 
>out.  I'm going to try to get the prototype done soon here and then 
>make enough of them to go on the units I've saved up here for that 
>project. -Bob
>
>--
>Check out sounddoctorin.com for songs, a studio tour, help
>repairing old synthesizers and parts or thought provoking
>articles that could help make your eternity!
>
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From jpdesroc at oricom.ca  Tue Nov  9 01:47:21 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 8 Nov 2010 19:47:21 -0500
Subject: [sdiy] Which opamp pins wiring is best for CV out ??  A , B or C ???
Message-ID: <94FAFCB649E74B75A88E23A4D6F5C6E6@HPLYNE>

For better diagrams of  3 different opamps approaches,
Go to
http://www.arcenson.com/public/opamps.pdf

What about using "C" but with a 10k resistor in series in the path
going back to inverting pin to protect from any incoming voltage spikes from
the output connector..?
Very low output impedance but protected inverting input..
Best of both world ?
Again,
I'm in the CV out design of my sequencer and
I need so much your thoughts on that.
Thanks
JP




From dixon at interchange.ubc.ca  Tue Nov  9 02:30:28 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 08 Nov 2010 17:30:28 -0800
Subject: [sdiy] Which opamp pins wiring is best for CV out ??  A ,
 B or C ???
In-Reply-To: <94FAFCB649E74B75A88E23A4D6F5C6E6@HPLYNE>
References: <94FAFCB649E74B75A88E23A4D6F5C6E6@HPLYNE>
Message-ID: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>

> What about using "C" but with a 10k resistor in series in the path
> going back to inverting pin to protect from any incoming voltage spikes
> from
> the output connector..?
> Very low output impedance but protected inverting input..
> Best of both world ?
> Again,
> I'm in the CV out design of my sequencer and
> I need so much your thoughts on that.
> Thanks

This reminds me of that old joke where the guy goes to the doctor and says,
"Doc, it hurts when I do this," to which the doctor replies, "Don't do
that."

Yes, A cures oscillation with a capacitive load (by converting the output to
a first-order LPF), and B does not.  However, when does a CV input ever have
a significant input capacitance?  The input capacitance of a typical opamp
is on the level of 10pF, which does not qualify as a capacitive load.

Concerning option C, I can't see that the 10k feedback resistor or the 100pF
capacitor do anything at all separately.  However, together, they convert
the follower into a quadrature oscillator.  This oscillator will be damped
without a (significant) capacitive load, but will oscillate freely with a
capacitive load.  Hence, you definitely don't want to go anywhere near
option C!

Again, I suggest B, or A if you really are feeding a significant capacitive
load, in which case it is probably not a proper CV input anyway, and CV
accuracy doesn't actually matter.



From dave.leith at gmail.com  Tue Nov  9 05:50:05 2010
From: dave.leith at gmail.com (Dave Leith)
Date: Mon, 8 Nov 2010 20:50:05 -0800
Subject: [sdiy] old modular reverb units moog 905,
	buchla electric easel or other
Message-ID: <AANLkTimGrG5QpasdBoqd1VvXc9BRZrdA3tfCeWH4N0OL@mail.gmail.com>

Does anyone know the Accutronics (or other manufacturers) part code
number that indicates the the input/output coil impedances for these
reverbs?

It's relatively easy to find the schematics but not what tank maker or
impedances that work with the circuits.

Thanks Dave


From harrybissell at wowway.com  Tue Nov  9 14:38:50 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 9 Nov 2010 08:38:50 -0500 (EST)
Subject: [sdiy] Which opamp pins wiring is best for CV out ??  A ,
 B or C ???
In-Reply-To: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
Message-ID: <842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>

From: David G. Dixon <dixon at interchange.ubc.ca> wrote...


  However, when does a CV input ever have
a significant input capacitance?  The input capacitance of a typical opamp
is on the level of 10pF, which does not qualify as a capacitive load.

hmmm... when that input is on the end of a shielded cable. I've had LOTS of TL07x (08X)
opamps go NUTS when driving even a reasonably short cable, if there is no series resistance.
Even 10 ohms is enough to decouple the capacitive load...

even though I'm not from Canada, I'll say "A"   :^)

H^) harry


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From neil.johnson97 at ntlworld.com  Tue Nov  9 16:06:59 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 9 Nov 2010 15:06:59 +0000
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B or C ???
In-Reply-To: <842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>

Hi,

Harry wrote:
> hmmm... when that input is on the end of a shielded cable. I've had LOTS of TL07x (08X)
> opamps go NUTS when driving even a reasonably short cable, if there is no series resistance.
> Even 10 ohms is enough to decouple the capacitive load...

Yes indeed, those darn cables!  If we imagine a typical example:
output goes to a connector on the front panel.  This then goes into a
cable, lets assume shielded cable for those who like to use jacks.
Now I've seen cables a good couple meters long on modular systems
here.  Then that plugs into something else, which might be a passive
multi, that then breaks out to a couple more one-metre cables.  So,
load capacitance?  Looking at the VanDamme catalogue I see something
of the order of 100-160pF/m.  How many metres?  Lets say 4 (2+1+1).
So that's 400-640pF.

That's a lot of capacitance for a lowly op-amp to drive without going "NUTS".

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From rga24 at cantab.net  Tue Nov  9 16:16:51 2010
From: rga24 at cantab.net (Richard Atkinson)
Date: 09 Nov 2010 15:16:51 +0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
Message-ID: <Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>

This email may be of particular interest to anyone who has studied the 
first and second generations of Yamaha synthesizer, namely the SY-1 / SY-2 
/ GX-1 synthesizers with epoxy potted NE series modules in the first 
generation and the CS series of synthesizers with IG series chips in the 
second generation.

It turns out there is an intermediate generation of Yamaha synthesizer 
between these two generations. I found this when looking inside my newly 
acquired Yamaha CSY-2 organ yesterday. This is a later version of the CSY-1 
organ, which has been featured in a few web pages and Matrixsynth articles 
and which contains the same epoxy potted NE series modules as the GX-1.

I took the lid off my Yamaha CSY-2 yesterday with a friends's help. The 
insides of my CSY-2 were rather dirty, having played host to a number of 
spiders and other objects over the years. There was evidence of damp damage 
on the base of the machine; it has clearly been kept on a damp surface at 
some point for quite a while.

It turns out the CSY-2 is very, very different internally from the CSY-1.
Whereas the CSY-1 is a fully discrete design with many circuit boards, some
of them held vertically in a rack frame, the CSY-2 has the first signs of
integration.

In particular, the auto bass chord circuit board (ABC CSY-2) has two large
YM chips on it and there is another board with another large YM chip. The
function of the auto bass chord system on this organ is quite different
from the CSY-1, and this would seem to explain why. There is no rack of
vertically mounted boards; there are much fewer boards and these are all
mounted horizontally.

Of particular interest is the solo synthesizer section mounted on the
underside of the top panel of the organ. Like my CSY-1, the solo
synthesizer boards in my CSY-2 are very clean, much cleaner than the rest
of the instrument. This no doubt has to do with being mounted upside down,
gravity being in its favour.

The CSY-2 does not however contain either of the versions of the CSY-1 /
SY-1 solo synthesizer circuits. It's a completely different, much more
integrated version of the solo synthesizer. The boards are not named SM1,
SM2, SK, SP1 and SP2 as in the SY-2. Instead they are named VCO, VCF, VCA,
FEG, AEG, SK and SP.

VCO is the only board that contains any of the old NE series modules. It 
has the VCO-III module as seen in later versions of the CSY-1, SY-1 and all 
SY-2s.

The VCF board has four ICs on it, all by Rohm. Two BA626s and two BA627s. I
have been unable so far to identify what these are but what is most
peculiar about this is that the organ features neither the older NE module
based filters, nor the IG chip based filters of the CS synthesizers and the
later Electone organs, but a generation in between. This is the only
example of this generation of Yamaha synthesizer filter I have ever seen,
and as far as I'm aware it's completely undocumented on the internet.

VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can packaging
and so on. The VCA board is self explanatory, the FEG board is for the
filter envelope and the AEG board is for the amplifier envelope. No NE
modules here, in particular no VCF-EG or VCA-EG modules. This is the only
example of these Yamaha envelope generators I have seen, again completely
undocumented on the internet as far as I know.

The remaining boards, SK and SP, seem to be the same as in the older
machines. They are for the gate and trigger pulse recovery and for the
presets.

Sound-wise, it behaves much like a cross between the two generations. The 
oscillator definitely has the same timbral qualities as an SY-2, but the 
filters are much, much cleaner. I wouldn't go so far as to say they sound 
like CS series IG chip filters, but they are certainly more well behaved 
than the highly distorting diode bridge filters in the NE series epoxy 
filled modules.

Richard



From ijfritz at comcast.net  Tue Nov  9 16:47:07 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Tue, 09 Nov 2010 08:47:07 -0700
Subject: [sdiy] Which opamp pins wiring is best for CV out ??  A ,
 B or C ???
In-Reply-To: <842985516.244515.1289309930451.JavaMail.root@md01.wow.syna
	cor.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
Message-ID: <6.2.1.2.2.20101109084508.023128c8@mail.comcast.net>

At 06:38 AM 11/9/2010, Harry Bissell wrote:
>hmmm... when that input is on the end of a shielded cable. I've had LOTS 
>of TL07x (08X)
>opamps go NUTS when driving even a reasonably short cable, if there is no 
>series resistance.
>Even 10 ohms is enough to decouple the capacitive load...

Oh you've seen that too, eh? 



From dave.leith at gmail.com  Tue Nov  9 17:09:29 2010
From: dave.leith at gmail.com (Dave Leith)
Date: Tue, 9 Nov 2010 08:09:29 -0800
Subject: [sdiy] old modular reverb units moog 905,
 buchla electric easel or other
In-Reply-To: <AANLkTi=AhN2cQkwTJDM6D-eDDu3xWZHGcD9xn9VFUizv@mail.gmail.com>
References: <AANLkTimGrG5QpasdBoqd1VvXc9BRZrdA3tfCeWH4N0OL@mail.gmail.com>
	<AANLkTi=AhN2cQkwTJDM6D-eDDu3xWZHGcD9xn9VFUizv@mail.gmail.com>
Message-ID: <AANLkTinnWDfAYijq=HzYPdkJeWRCVYGzCUtgdHthpG=X@mail.gmail.com>

Thanks for the replies. I was already aware of the codes.
Unfortunately the schematics do not include these codes. Perhaps a
better question might be - how does one figure out what the required
coil impedance would be from looking at the schematics?



On Tue, Nov 9, 2010 at 5:53 AM, Mark Olson <lessismo at gmail.com> wrote:
> The accutronics Web site http://www.accutronicsreverb.com/ has the decoding
> info on the pages for each model/series.
>
>
> On Mon, Nov 8, 2010 at 10:50 PM, Dave Leith <dave.leith at gmail.com> wrote:
>>
>> Does anyone know the Accutronics (or other manufacturers) part code
>> number that indicates the the input/output coil impedances for these
>> reverbs?
>>
>> It's relatively easy to find the schematics but not what tank maker or
>> impedances that work with the circuits.
>>
>> Thanks Dave
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>


From davekendall at ntlworld.com  Tue Nov  9 17:33:53 2010
From: davekendall at ntlworld.com (Dave Kendall)
Date: Tue, 9 Nov 2010 16:33:53 +0000
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B or C ???
In-Reply-To: <AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
Message-ID: <240DBFFE-EC1F-11DF-B3D8-000393A85F9E@ntlworld.com>

Hi.

Interesting thread... If going with "A", what is the minimum resistance 
that is useful? 1K seems to be popular, although I've seen plenty of 
circuits with 330R, or even as low as 100R.
Can anyone throw some light on this?

cheers,
Dave
On Nov 9, 2010, at 15:06, Neil Johnson wrote:

> Hi,
>
> Harry wrote:
>> hmmm... when that input is on the end of a shielded cable. I've had 
>> LOTS of TL07x (08X)
>> opamps go NUTS when driving even a reasonably short cable, if there 
>> is no series resistance.
>> Even 10 ohms is enough to decouple the capacitive load...
>
> Yes indeed, those darn cables!  If we imagine a typical example:
> output goes to a connector on the front panel.  This then goes into a
> cable, lets assume shielded cable for those who like to use jacks.
> Now I've seen cables a good couple meters long on modular systems
> here.  Then that plugs into something else, which might be a passive
> multi, that then breaks out to a couple more one-metre cables.  So,
> load capacitance?  Looking at the VanDamme catalogue I see something
> of the order of 100-160pF/m.  How many metres?  Lets say 4 (2+1+1).
> So that's 400-640pF.
>
> That's a lot of capacitance for a lowly op-amp to drive without going 
> "NUTS".
>
> Cheers,
> Neil
> -- 
> http://www.njohnson.co.uk
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From ijfritz at comcast.net  Tue Nov  9 17:45:43 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Tue, 09 Nov 2010 09:45:43 -0700
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
 B  or C ???
In-Reply-To: <240DBFFE-EC1F-11DF-B3D8-000393A85F9E@ntlworld.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
	<240DBFFE-EC1F-11DF-B3D8-000393A85F9E@ntlworld.com>
Message-ID: <6.2.1.2.2.20101109094357.0233e9c8@mail.comcast.net>

At 09:33 AM 11/9/2010, Dave Kendall wrote:
>Hi.
>
>Interesting thread... If going with "A", what is the minimum resistance 
>that is useful? 1K seems to be popular, although I've seen plenty of 
>circuits with 330R, or even as low as 100R.
>Can anyone throw some light on this?

Part of the reason for 1k in synth circuits is so you can connect two 
outputs together to add the signals. (But does anyone actually do this?)

Ian 



From dixon at interchange.ubc.ca  Tue Nov  9 17:59:25 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 09 Nov 2010 08:59:25 -0800
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B or C ???
In-Reply-To: <AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
Message-ID: <80727F5596D64ABFA66C2F3113FE951D@galvanox01>

OK, so what y'all seem to be saying is that the small output resistor is
critical for neutralizing capacitive loads.  Fair enough.  I'm glad we
finally reached a consensus on this issue, which we have been arguing about,
off and on, for the last year!

On that basis, I did some more simulations, assuming a 560pF capacitive
(Neil's 4m cable at 140pF/m) load, and found that the ideal resistor value
is 220R.  Assuming a 100k input impedance downstream, this would cause a CV
error of 0.22%, or about the same as typical tuning errors in VCOs.

Also, it bears noting that this small resistor would do very little to
protect the opamp from current surges, a rail-to-ground short-circuit would
generate about 60mA through this resistor, which is 2 or 3 times higher than
most opamps allow.


> > hmmm... when that input is on the end of a shielded cable. I've had LOTS
> of TL07x (08X)
> > opamps go NUTS when driving even a reasonably short cable, if there is
> no series resistance.
> > Even 10 ohms is enough to decouple the capacitive load...
> 
> Yes indeed, those darn cables!  If we imagine a typical example:
> output goes to a connector on the front panel.  This then goes into a
> cable, lets assume shielded cable for those who like to use jacks.
> Now I've seen cables a good couple meters long on modular systems
> here.  Then that plugs into something else, which might be a passive
> multi, that then breaks out to a couple more one-metre cables.  So,
> load capacitance?  Looking at the VanDamme catalogue I see something
> of the order of 100-160pF/m.  How many metres?  Lets say 4 (2+1+1).
> So that's 400-640pF.
> 
> That's a lot of capacitance for a lowly op-amp to drive without going
> "NUTS".



From harrybissell at wowway.com  Tue Nov  9 18:01:54 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 9 Nov 2010 12:01:54 -0500 (EST)
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
 B or C ???
In-Reply-To: <80727F5596D64ABFA66C2F3113FE951D@galvanox01>
Message-ID: <581132889.250851.1289322114811.JavaMail.root@md01.wow.synacor.com>

then use a bulletproof 741...  :^)

H^) harry



----- Original Message -----
From: David G. Dixon <dixon at interchange.ubc.ca>
To: 'Neil Johnson' <neil.johnson97 at ntlworld.com>, 'Harry Bissell' <harrybissell at wowway.com>
Cc: 'synth diy' <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 09 Nov 2010 11:59:25 -0500 (EST)
Subject: RE: [sdiy] Which opamp pins wiring is best for CV out ?? A , B or C ???

OK, so what y'all seem to be saying is that the small output resistor is
critical for neutralizing capacitive loads.  Fair enough.  I'm glad we
finally reached a consensus on this issue, which we have been arguing about,
off and on, for the last year!

On that basis, I did some more simulations, assuming a 560pF capacitive
(Neil's 4m cable at 140pF/m) load, and found that the ideal resistor value
is 220R.  Assuming a 100k input impedance downstream, this would cause a CV
error of 0.22%, or about the same as typical tuning errors in VCOs.

Also, it bears noting that this small resistor would do very little to
protect the opamp from current surges, a rail-to-ground short-circuit would
generate about 60mA through this resistor, which is 2 or 3 times higher than
most opamps allow.


> > hmmm... when that input is on the end of a shielded cable. I've had LOTS
> of TL07x (08X)
> > opamps go NUTS when driving even a reasonably short cable, if there is
> no series resistance.
> > Even 10 ohms is enough to decouple the capacitive load...
> 
> Yes indeed, those darn cables!  If we imagine a typical example:
> output goes to a connector on the front panel.  This then goes into a
> cable, lets assume shielded cable for those who like to use jacks.
> Now I've seen cables a good couple meters long on modular systems
> here.  Then that plugs into something else, which might be a passive
> multi, that then breaks out to a couple more one-metre cables.  So,
> load capacitance?  Looking at the VanDamme catalogue I see something
> of the order of 100-160pF/m.  How many metres?  Lets say 4 (2+1+1).
> So that's 400-640pF.
> 
> That's a lot of capacitance for a lowly op-amp to drive without going
> "NUTS".


-- 
Harry Bissell & Nora Abdullah 4eva


From daugard at cox.net  Tue Nov  9 18:17:10 2010
From: daugard at cox.net (Tim Daugard)
Date: Tue, 9 Nov 2010 11:17:10 -0600
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B  or C ???
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01><842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com><AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com><240DBFFE-EC1F-11DF-B3D8-000393A85F9E@ntlworld.com>
	<6.2.1.2.2.20101109094357.0233e9c8@mail.comcast.net>
Message-ID: <005301cb8031$f19de200$0201a8c0@TIM>


From: "Ian Fritz" <ijfritz at comcast.net>

> Part of the reason for 1k in synth circuits is so you can connect two
outputs together to add the signals. (But does anyone actually do this?)

Yup.

Also use the 1k8 resitors I use on the output as parts of plugable filter 
networks. 1st stage uses output resistor and a cap - impediance approx. 2k 
Second stage uses resistors / caps with nothing active - impediance approx 
20k. This Feeds an input impediance of 100 to 200k. Each fliter stage is 
lightly loaded by the following, stage allowing plenty of passive shaping 
between modules. The filters are built into cables.

100R on the output would give me one more decade of impediance transforms. 
But lose the output protection so I stick with 1K. HOWEVER, I don't use 
accurate VCOs, Instead I use a fender bass as my primary signal source.

Tim Daugard
AG4GZ 30.4078N 86.6227W Alt: 12 feet above MSL
http://members.cox.net/synthfred/h_toctop.htm (Fred's online edition)






From gil_we at yahoo.com  Tue Nov  9 20:23:41 2010
From: gil_we at yahoo.com (Gil W.)
Date: Tue, 9 Nov 2010 11:23:41 -0800 (PST)
Subject: [sdiy] Special thanks to Amos and Russer from moogmusic !
Message-ID: <110157.75758.qm@web58007.mail.re3.yahoo.com>

I'd like to thank Amos and Russer from moog music who have been helping me settling my Little Phatty ground issue. Rosser has made modified cable to be installed instead of the stock one, and sent it to me at no cost. The mod is very simple, basically it connects between what seems to be two grounds on the power supply boards, directly, to each other. It looks like one of the ground point in the circuit had itself only touching the chassis for a direct connection with the other grounds. I will test my Phatty and post about the results ! If all works fine for a few weeks I will upload a small blog with the instructions. Reminder - the problem was that the Little Phatty used to freeze or have the rotation leds rotating themselves (affecting the actual sound). This was told to be caused by connecting the Phatty to a ground loop.

Thanks ;)



      


From tom at electricdruid.net  Tue Nov  9 20:26:35 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 9 Nov 2010 19:26:35 +0000
Subject: [sdiy] XOR as 'digital' ring modulator
Message-ID: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>

Hi again,

Continuing the series of "things Tom doesn't understand that he'd like to get cleared up for once and for all", I've got another question.

I've read in a couple of places (quoted below) that an XOR gate is not strictly equivalent to a ring modulator. 

Wikipedia says: "Though not equivalent to ring modulation, with square waves the resulting sound is quite similar." (Stinks of fudge to me!)

Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is really just an exclusive-or digital gate (using CMOS logic that provides exact 5V amplitude outputs) and generates true ring modulation only when the input waveforms are square. Nevertheless, the audible effect of ring modulation is adequately produced even when the signals are nonsquare."

The output from an XOR can be viewed like this:

	A	B	Q
	-1	-1	1
	-1	1	-1
	1	-1	-1
	1	1	1

This looks to me like it's a perfect ring mod (multiplication function) as long as you stick to digital signals, square or otherwise. So XOR could multiply two PWM'd pulse trains no problem according to me, but not according to Chamberlin.

So what am I missing?!

Thanks everyone,
Tom



From cheater00 at gmail.com  Tue Nov  9 20:48:40 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 9 Nov 2010 20:48:40 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <AANLkTi=Tos4MTixA7pu=7+mqM26a1AnLs5k8cfUQb=9z@mail.gmail.com>

Hi Tom,
You're missing non-linearities in the analog multiplier.

You're also missing the fact that no waveform is a true "square"
waveform: from what I understand, in a XOR gate, the output signal is
re-generated. It is not a derivative of either input signal. This
means that any deviations from ideal squares on the input will not
show up in the sound of the output.

D.

On 09/11/2010, Tom Wiltshire <tom at electricdruid.net> wrote:
> Hi again,
>
> Continuing the series of "things Tom doesn't understand that he'd like to
> get cleared up for once and for all", I've got another question.
>
> I've read in a couple of places (quoted below) that an XOR gate is not
> strictly equivalent to a ring modulator.
>
> Wikipedia says: "Though not equivalent to ring modulation, with square waves
> the resulting sound is quite similar." (Stinks of fudge to me!)
>
> Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is really
> just an exclusive-or digital gate (using CMOS logic that provides exact 5V
> amplitude outputs) and generates true ring modulation only when the input
> waveforms are square. Nevertheless, the audible effect of ring modulation is
> adequately produced even when the signals are nonsquare."
>
> The output from an XOR can be viewed like this:
>
> 	A	B	Q
> 	-1	-1	1
> 	-1	1	-1
> 	1	-1	-1
> 	1	1	1
>
> This looks to me like it's a perfect ring mod (multiplication function) as
> long as you stick to digital signals, square or otherwise. So XOR could
> multiply two PWM'd pulse trains no problem according to me, but not
> according to Chamberlin.
>
> So what am I missing?!
>
> Thanks everyone,
> Tom
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From neil.johnson97 at ntlworld.com  Tue Nov  9 20:48:45 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 9 Nov 2010 19:48:45 +0000
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B or C ???
In-Reply-To: <80727F5596D64ABFA66C2F3113FE951D@galvanox01>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
	<80727F5596D64ABFA66C2F3113FE951D@galvanox01>
Message-ID: <126AD57A-21F7-41BF-9175-AE1783922445@ntlworld.com>

Hi,

> OK, so what y'all seem to be saying is that the small output  
> resistor is
> critical for neutralizing capacitive loads.  Fair enough.  I'm glad we
> finally reached a consensus on this issue, which we have been  
> arguing about,
> off and on, for the last year!

I wouldn't call it arguing, more "educating" :)

> On that basis, I did some more simulations, assuming a 560pF  
> capacitive
> (Neil's 4m cable at 140pF/m) load, and found that the ideal  
> resistor value
> is 220R.  Assuming a 100k input impedance downstream, this would  
> cause a CV
> error of 0.22%, or about the same as typical tuning errors in VCOs.

But only if driving a single input.  Now with a 4-way passive multi,  
or stacked bananas, and your error is now nearer 0.88%.  Oh dear.

> Also, it bears noting that this small resistor would do very little to
> protect the opamp from current surges, a rail-to-ground short- 
> circuit would
> generate about 60mA through this resistor, which is 2 or 3 times  
> higher than
> most opamps allow.

Well, indeed.  But that's not the purpose for the damping resistor,  
so its not surprising that it in itself does not protect the op-amp  
to that degree.  You can either add more circuitry to protect the  
output from over current, or use an op-amp that is tolerant of  
shorted outputs (e.g. thermal protection) and keep the sensitive op- 
amps isolated from the outputs.

Cheers,
Neil
--
http://www.njohnson.co.uk





From Stromeko at nexgo.de  Tue Nov  9 20:55:37 2010
From: Stromeko at nexgo.de (ASSI)
Date: Tue, 9 Nov 2010 20:55:37 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <201011092055.37836.Stromeko@nexgo.de>

On Tuesday 09 November 2010, Tom Wiltshire wrote:
[...]
> This looks to me like it's a perfect ring mod (multiplication function)
> as long as you stick to digital signals, square or otherwise. 

...for a special encoding (0-->-1 and 1-->1) and single bit signals.

> So XOR
> could multiply two PWM'd pulse trains no problem according to me, but
> not according to Chamberlin.
> 
> So what am I missing?!

Maybe that the term "square wave" doesn't necessarily imply 50% duty cycle?


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptation for Waldorf rackAttack V1.04R1:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada


From harrybissell at wowway.com  Tue Nov  9 20:56:31 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 9 Nov 2010 14:56:31 -0500 (EST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <AANLkTi=Tos4MTixA7pu=7+mqM26a1AnLs5k8cfUQb=9z@mail.gmail.com>
Message-ID: <1486556740.256099.1289332591609.JavaMail.root@md01.wow.synacor.com>

I think that if you are willing to use only square or pulse
waves, the "x-or" gate is a true multiplier, therefore it ~is~ a
ring modulator.

An analog ring modulator is capable of handling both the signal
inversion (or not) and amplitude variations.

Now that "pwm" issue has me a bit perplexed.
Are you thinking you might input analog waveforms (encoded as PWM)
and then use the X-or, then decode (filter) the result back into
the analog domain ???   Wow I don't know. Have to try that in simulation...

H^) harry




----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: Tom Wiltshire <tom at electricdruid.net>
Cc: Synth DIY <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 09 Nov 2010 14:48:40 -0500 (EST)
Subject: Re: [sdiy] XOR as 'digital' ring modulator

Hi Tom,
You're missing non-linearities in the analog multiplier.

You're also missing the fact that no waveform is a true "square"
waveform: from what I understand, in a XOR gate, the output signal is
re-generated. It is not a derivative of either input signal. This
means that any deviations from ideal squares on the input will not
show up in the sound of the output.

D.

On 09/11/2010, Tom Wiltshire <tom at electricdruid.net> wrote:
> Hi again,
>
> Continuing the series of "things Tom doesn't understand that he'd like to
> get cleared up for once and for all", I've got another question.
>
> I've read in a couple of places (quoted below) that an XOR gate is not
> strictly equivalent to a ring modulator.
>
> Wikipedia says: "Though not equivalent to ring modulation, with square waves
> the resulting sound is quite similar." (Stinks of fudge to me!)
>
> Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is really
> just an exclusive-or digital gate (using CMOS logic that provides exact 5V
> amplitude outputs) and generates true ring modulation only when the input
> waveforms are square. Nevertheless, the audible effect of ring modulation is
> adequately produced even when the signals are nonsquare."
>
> The output from an XOR can be viewed like this:
>
> 	A	B	Q
> 	-1	-1	1
> 	-1	1	-1
> 	1	-1	-1
> 	1	1	1
>
> This looks to me like it's a perfect ring mod (multiplication function) as
> long as you stick to digital signals, square or otherwise. So XOR could
> multiply two PWM'd pulse trains no problem according to me, but not
> according to Chamberlin.
>
> So what am I missing?!
>
> Thanks everyone,
> Tom
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From blincoln at eventualdecline.com  Tue Nov  9 21:08:27 2010
From: blincoln at eventualdecline.com (Ben Lincoln)
Date: Tue, 9 Nov 2010 12:08:27 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <cfe13e7f015261f904da9e2d4c907558.squirrel@webmail.eventualdecline.com>

This may be my ignorance, but my reading of Chamberlin's statement is that
he means "square" in the "as opposed to sine, saw, triangle, or other
analogue waveforms" sense (since the Chroma is an analogue synth, right?).
IE he is referring to digital pulses when they're used as an audible
waveform, regardless of the pulse width.

On Tue, November 9, 2010 11:26 am, Tom Wiltshire wrote:
> Hi again,
>
> Continuing the series of "things Tom doesn't understand that he'd like to
> get cleared up for once and for all", I've got another question.
>
> I've read in a couple of places (quoted below) that an XOR gate is not
> strictly equivalent to a ring modulator.
>
> Wikipedia says: "Though not equivalent to ring modulation, with square
> waves the resulting sound is quite similar." (Stinks of fudge to me!)
>
> Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is
> really just an exclusive-or digital gate (using CMOS logic that provides
> exact 5V amplitude outputs) and generates true ring modulation only when
> the input waveforms are square. Nevertheless, the audible effect of ring
> modulation is adequately produced even when the signals are nonsquare."
>
> The output from an XOR can be viewed like this:
>
> 	A	B	Q
> 	-1	-1	1
> 	-1	1	-1
> 	1	-1	-1
> 	1	1	1
>
> This looks to me like it's a perfect ring mod (multiplication function) as
> long as you stick to digital signals, square or otherwise. So XOR could
> multiply two PWM'd pulse trains no problem according to me, but not
> according to Chamberlin.
>
> So what am I missing?!
>
> Thanks everyone,
> Tom
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From colin at colinfraser.com  Tue Nov  9 21:11:07 2010
From: colin at colinfraser.com (Colin f)
Date: Tue, 9 Nov 2010 20:11:07 -0000
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <1486556740.256099.1289332591609.JavaMail.root@md01.wow.synacor.com>
References: <AANLkTi=Tos4MTixA7pu=7+mqM26a1AnLs5k8cfUQb=9z@mail.gmail.com>
	<1486556740.256099.1289332591609.JavaMail.root@md01.wow.synacor.com>
Message-ID: <0F2B01AD00184FAAA2EA7718A9B5560F@zen>

 
> I think that if you are willing to use only square or pulse 
> waves, the "x-or" gate is a true multiplier, therefore it 
> ~is~ a ring modulator.
> 
> An analog ring modulator is capable of handling both the 
> signal inversion (or not) and amplitude variations.

The problem with the XOR ring-mod is that two ring-modulated square waves
produce an awful lot of over-tones.
For very little extra parts count, you can build a ring-mod with one input
that is square wave-only, but another than can take any waveform.
That would be a switchable inverting/non-inverting buffer.
Ring-modding a square wave with a triangle or sawtooth waves gives a rather
more useful choice of sounds than pure square waves only.

Cheers,
Colin f




From dixon at interchange.ubc.ca  Tue Nov  9 21:32:16 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 09 Nov 2010 12:32:16 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <688A6344BD394A4891903ADEE85D9D57@galvanox01>

> So what am I missing?!

A perfect 4-quadrant multiplier uses one wave to modulate both the amplitude
and polarity of the other wave, without fundamentally altering the content
of either wave.

If the modulating wave is a square wave, then only the polarity is being
modulated, not the amplitude.

If the signal wave is also a square wave, then there is no amplitude to
modulate.

I believe this latter situation describes a digital ring mod.

Whether the square waves have 50% duty cycles or not is immaterial, as it is
based purely on combinatorial logic (i.e., time is not a factor).

Hence, Tom, you are right and Chamberlin is wrong.



From colin at colinfraser.com  Tue Nov  9 21:45:46 2010
From: colin at colinfraser.com (Colin f)
Date: Tue, 9 Nov 2010 20:45:46 -0000
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <688A6344BD394A4891903ADEE85D9D57@galvanox01>
References: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
	<688A6344BD394A4891903ADEE85D9D57@galvanox01>
Message-ID: <08682DF78FC7444D90BC95A90E22A5B5@zen>

 
> If the modulating wave is a square wave, then only the 
> polarity is being modulated, not the amplitude.

You can't modulate the polarity without modulating the amplitude.
The polarity is the sign of the amplitude.
 
Cheers,
Colin f




From harrybissell at wowway.com  Tue Nov  9 22:07:01 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 9 Nov 2010 16:07:01 -0500 (EST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <08682DF78FC7444D90BC95A90E22A5B5@zen>
Message-ID: <1286898934.258099.1289336821642.JavaMail.root@md01.wow.synacor.com>

Of course the x-or must be thought of as being +/-2.5V, not 0-5V but
this can be easily achieved. For autio use a blocking cap is sufficient...

H^) harry



----- Original Message -----
From: Colin f <colin at colinfraser.com>
To: 'David G. Dixon' <dixon at interchange.ubc.ca>, 'Synth DIY' <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 09 Nov 2010 15:45:46 -0500 (EST)
Subject: Re: [sdiy] XOR as 'digital' ring modulator

 
> If the modulating wave is a square wave, then only the 
> polarity is being modulated, not the amplitude.

You can't modulate the polarity without modulating the amplitude.
The polarity is the sign of the amplitude.
 
Cheers,
Colin f


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Tue Nov  9 22:14:41 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 9 Nov 2010 16:14:41 -0500 (EST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <1918444373.258356.1289337281557.JavaMail.root@md01.wow.synacor.com>

It is indeed possible to convert two analog waves to PWM, exclusive-or them, and filter the output to achieve true ring modulation. In practice you'd need to band limit the input signals (LPF) and
reconstruct via a post filter. There will be phase shifts with this method, but it would make for
a semi-easy DIY project. You'd need a high frequency triangle wave generator, two compatators,
an x-or gate and an RC filter at the most simple...

It looks kind of cool, probably not worth the extra effort imho...

H^) harry



----- Original Message -----
From: Tom Wiltshire <tom at electricdruid.net>
To: Synth DIY <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 09 Nov 2010 14:26:35 -0500 (EST)
Subject: [sdiy] XOR as 'digital' ring modulator

Hi again,

Continuing the series of "things Tom doesn't understand that he'd like to get cleared up for once and for all", I've got another question.

I've read in a couple of places (quoted below) that an XOR gate is not strictly equivalent to a ring modulator. 

Wikipedia says: "Though not equivalent to ring modulation, with square waves the resulting sound is quite similar." (Stinks of fudge to me!)

Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is really just an exclusive-or digital gate (using CMOS logic that provides exact 5V amplitude outputs) and generates true ring modulation only when the input waveforms are square. Nevertheless, the audible effect of ring modulation is adequately produced even when the signals are nonsquare."

The output from an XOR can be viewed like this:

	A	B	Q
	-1	-1	1
	-1	1	-1
	1	-1	-1
	1	1	1

This looks to me like it's a perfect ring mod (multiplication function) as long as you stick to digital signals, square or otherwise. So XOR could multiply two PWM'd pulse trains no problem according to me, but not according to Chamberlin.

So what am I missing?!

Thanks everyone,
Tom

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From rburnett at richieburnett.co.uk  Tue Nov  9 22:17:15 2010
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Tue, 9 Nov 2010 21:17:15 -0000
Subject: [sdiy]  Which opamp pins wiring is best for CV out ?? A , B or C ???
Message-ID: <98698219CB114BAA96F75AC373B3C809@homepc002>

As you say it doesn't take many feet of cable capacitance to cause a 
wideband op-amp to oscillate at HF, particularly if it was operating near 
unity gain.  Add to this the fact that audio inputs frequently have discrete 
capacitance deliberately placed across them for ESD/EMC compliance and HF 
stability can become a real problem for op-amp line drivers!

Regarding this CV driver output discussion, there is a solution that 
provides the best of both worlds:

http://www.richieburnett.co.uk/temp/cv_out.GIF

Resistor R1 limits the maximum output current under short circuit conditions 
and decouples the output of the op-amp from the capacitance of the cable and 
the load at the end of the cable.  (It's value isn't critical, but it needs 
to be significantly greater than the open-loop output impedance of the 
op-amp at the cross-over frequency so that it effectively decouples the 
output node from the capacitive lag at the load.)

Resistor R2 takes negative feedback from the actual output at DC.  This 
means that any voltage drop across R1 due to load current is inside the 
feedback loop and is therefore compensated out.  (Under load the op-amp 
servos it's output to a higher voltage to make up for the volts dropped 
across R1, and ensure the output voltage is still what you wanted.)

Capacitor C2 takes negative feedback directly from the output of the op-amp 
at high frequencies.  This stops the op-amp ringing or breaking into 
oscillation due to load capacitance causing the feedback signal to diminish 
and start to lag at high frequencies.

Essentially the source of feedback gradually shifts from the output cable to 
the op-amp output as you go up in frequency.  At DC the feedback comes from 
the actual output to compensate for the DC voltage drop across R1.  At HF 
the feedback comes from the op-amp output directly to ensure "in-phase" 
negative feedback and guarantee stability as the op-amp's gain rolls off.

Another way you can look at it is by thinking of R2/C2 as a phase-lead 
network.  C2 imparts a phase-lead into the feedback signal around the break 
frequency where the output capacitance combined with R1 would otherwise 
cause a phase lag to kick in.

I hope this helps,

-Richie, 



From gsn10 at hotmail.com  Tue Nov  9 22:32:54 2010
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Tue, 9 Nov 2010 16:32:54 -0500
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>,
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>,
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
Message-ID: <SNT104-W23D94E4D24E65E1DBDBB7CB4300@phx.gbl>


> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can packaging
> and so on. The VCA board is self explanatory, the FEG board is for the
> filter envelope and the AEG board is for the amplifier envelope. No NE
> modules here, in particular no VCF-EG or VCA-EG modules. This is the only
> example of these Yamaha envelope generators I have seen, again completely
> undocumented on the internet as far as I know.
>
> The remaining boards, SK and SP, seem to be the same as in the older
> machines. They are for the gate and trigger pulse recovery and for the
> presets.
>
> Sound-wise, it behaves much like a cross between the two generations. The
> oscillator definitely has the same timbral qualities as an SY-2, but the
> filters are much, much cleaner. I wouldn't go so far as to say they sound
> like CS series IG chip filters, but they are certainly more well behaved
> than the highly distorting diode bridge filters in the NE series epoxy
> filled modules.
>
> Richard

I won't try to speculate too much, but those potted NE modules don't 
contain anything especially exotic.? Korg used similar modules in their 700,
700S and 800DV synths, but the 770 uses the same circuits without encasing
them in epoxy; they're described in the schematics also.? It may have been 
decided that the secrecy wasn't worth the trouble.? So it may be early 
versions of what was later integrated into the IG series chips (I think you 
can similarly follow the evolution of Roland VCFs from the BA662 ones to 
the IR3109), and/or the NE module contents laid out on a new circuit board.
Certainly of interest to anyone who wants to make replacement parts.

Organs can be strange beasts; higher end models sometimes used very exotic
synthesis techniques that never made it into synthesizers, and I think 
there are some interesting drum machine circuits that are still "unknown"
to the rest of the electronic music world. But there's very little interest
now, and given the opaque interface and lack of documentation, there's no
good way to know what's really going on in there.
 		 	   		  

From dixon at interchange.ubc.ca  Tue Nov  9 22:43:48 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 09 Nov 2010 13:43:48 -0800
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
	B or C ???
In-Reply-To: <126AD57A-21F7-41BF-9175-AE1783922445@ntlworld.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<AANLkTinaN1QJMoZXrG7NzXvFUzkfjy-Q6YtTXc8cMM8F@mail.gmail.com>
	<80727F5596D64ABFA66C2F3113FE951D@galvanox01>
	<126AD57A-21F7-41BF-9175-AE1783922445@ntlworld.com>
Message-ID: <9D91050802E44871933BB1A7546A2520@galvanox01>

Another solution to this problem is to use the resistor inside the feedback
loop (scenario "B"), but also to put a small capacitor between the -
terminal and the opamp output terminal (i.e. between the opamp output and
the resistor).  This compensates for the capacitive load by contributing a
counteracting positive phase shift, and it does so without loading the final
output.  However, the capacitor and resistor values must be carefully
selected and the selection depends on the magnitude of the capacitive loads.
Plus, it limits the bandwidth of the opamp, and it still isn't as effective
as just the outside resistor.



From dixon at interchange.ubc.ca  Tue Nov  9 23:04:07 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 09 Nov 2010 14:04:07 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <08682DF78FC7444D90BC95A90E22A5B5@zen>
References: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
	<688A6344BD394A4891903ADEE85D9D57@galvanox01>
	<08682DF78FC7444D90BC95A90E22A5B5@zen>
Message-ID: <5EFB24A113A64CF49EF906C84A9E43FA@galvanox01>

> You can't modulate the polarity without modulating the amplitude.
> The polarity is the sign of the amplitude.

Yes, and therefore you are modulating the "sign" and not the "amplitude".



From tom at electricdruid.net  Tue Nov  9 23:04:25 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 9 Nov 2010 22:04:25 +0000
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <1486556740.256099.1289332591609.JavaMail.root@md01.wow.synacor.com>
References: <1486556740.256099.1289332591609.JavaMail.root@md01.wow.synacor.com>
Message-ID: <551B3788-39E3-4D7A-8D0F-B65867CAD7C5@electricdruid.net>

Wow, loads of responses.

Let me answer a few things in the order they came up;

> You're missing non-linearities in the analog multiplier.


Cheater; No, not missing - ignoring. Fair enough an analog multiplier will be significantly imperfect. But I'm interested in the theoretical question about whether an XOR is the same as a Ring Mod for a limited set of signals.

> Now that "pwm" issue has me a bit perplexed.
> Are you thinking you might input analog waveforms (encoded as PWM)
> and then use the X-or, then decode (filter) the result back into
> the analog domain ???

Harry; No, I wasn't thinking that. I was just thinking that a couple of pulse waves with PWM are fairly 'unsquare', even if you're not playing Dave Brubeck.

> Maybe that the term "square wave" doesn't necessarily imply 50% duty cycle?

> my reading of Chamberlin's statement is that
> he means "square" in the "as opposed to sine, saw, triangle, or other
> analogue waveforms" sense


Assi, Ben; Yeah, you might be right. I think maybe Hal Chamberlin *was* meaning it that way - That 'square' includes all the 'pulse' and 'digital' signals we're talking about and 'non-square' is things like ramps and triangles. But that wasn't how I read it at first. My bad, I guess.

> For very little extra parts count, you can build a ring-mod with one input
> that is square wave-only, but another than can take any waveform.

Colin; Good point. Depends on the budget and available space I guess. The XOR route gets you 4 ring mods in one chip!

In summary, if you consider a digital signal as one that has two levels (call them -1 and +1) then an XOR gate is identical to a ring modulator.

Thanks all,
Tom




From ijfritz at comcast.net  Tue Nov  9 23:06:44 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Tue, 09 Nov 2010 15:06:44 -0700
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <6.2.1.2.2.20101109145656.02355b38@mail.comcast.net>

Well, if you really want to get confused, check out my "analog XOR" module.
http://www.electro-music.com/forum/topic-21851.html&postorder=asc
Hard to classify, but it gives some pretty cool sounds.

Ian



From colin at colinfraser.com  Tue Nov  9 23:18:10 2010
From: colin at colinfraser.com (Colin f)
Date: Tue, 9 Nov 2010 22:18:10 -0000
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <5EFB24A113A64CF49EF906C84A9E43FA@galvanox01>
References: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
	<688A6344BD394A4891903ADEE85D9D57@galvanox01>
	<08682DF78FC7444D90BC95A90E22A5B5@zen>
	<5EFB24A113A64CF49EF906C84A9E43FA@galvanox01>
Message-ID: <943A815EE0684C909733B96F744FE9B7@zen>

 
> > You can't modulate the polarity without modulating the amplitude.
> > The polarity is the sign of the amplitude.
> 
> Yes, and therefore you are modulating the "sign" and not the 
> "amplitude".

Well if we want to get pedantic about it, when you invert the sign of a
square wave with anything other than a perfect duty cycle of 50%, you shift
the DC level, so you would change the RMS amplitude.
Depends on which definition of amplitude you're using.
But I know what you mean.

Cheers,
Colin f




From dave.leith at gmail.com  Tue Nov  9 23:33:41 2010
From: dave.leith at gmail.com (Dave Leith)
Date: Tue, 9 Nov 2010 14:33:41 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <943A815EE0684C909733B96F744FE9B7@zen>
References: <14099_1289330802_1289330802_84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
	<688A6344BD394A4891903ADEE85D9D57@galvanox01>
	<08682DF78FC7444D90BC95A90E22A5B5@zen>
	<5EFB24A113A64CF49EF906C84A9E43FA@galvanox01>
	<943A815EE0684C909733B96F744FE9B7@zen>
Message-ID: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>

not sure but isn't this what the ARP Odyssey uses for a ring mod or
maybe it's 2 nand gates

On Tue, Nov 9, 2010 at 2:18 PM, Colin f <colin at colinfraser.com> wrote:
>
>> > You can't modulate the polarity without modulating the amplitude.
>> > The polarity is the sign of the amplitude.
>>
>> Yes, and therefore you are modulating the "sign" and not the
>> "amplitude".
>
> Well if we want to get pedantic about it, when you invert the sign of a
> square wave with anything other than a perfect duty cycle of 50%, you shift
> the DC level, so you would change the RMS amplitude.
> Depends on which definition of amplitude you're using.
> But I know what you mean.
>
> Cheers,
> Colin f
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From dougt55 at yahoo.com  Tue Nov  9 23:42:38 2010
From: dougt55 at yahoo.com (Doug Terrebonne)
Date: Tue, 9 Nov 2010 14:42:38 -0800 (PST)
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
Message-ID: <910752.23905.qm@web81207.mail.mud.yahoo.com>

Very interesting. I have a SY-1 and SY-2 and always assumed the versions they 
stuffed into their organs were identical...

Doug



----- Original Message ----
> From: Richard Atkinson <rga24 at cantab.net>
> To: synth diy <synth-diy at dropmix.xs4all.nl>
> Sent: Tue, November 9, 2010 7:16:51 AM
> Subject: [sdiy] Yamaha CSY-2 solo synthesizer
> 
> This email may be of particular interest to anyone who has studied the first 
>and second generations of Yamaha synthesizer, namely the SY-1 / SY-2 / GX-1 
>synthesizers with epoxy potted NE series modules in the first generation and the 
>CS series of synthesizers with IG series chips in the second generation.
> 
> It turns out there is an intermediate generation of Yamaha synthesizer between 
>these two generations. I found this when looking inside my newly acquired Yamaha 
>CSY-2 organ yesterday. This is a later version of the CSY-1 organ, which has 
>been featured in a few web pages and Matrixsynth articles and which contains the 
>same epoxy potted NE series modules as the GX-1.
> 
> I took the lid off my Yamaha CSY-2 yesterday with a friends's help. The insides 
>of my CSY-2 were rather dirty, having played host to a number of spiders and 
>other objects over the years. There was evidence of damp damage on the base of 
>the machine; it has clearly been kept on a damp surface at some point for quite 
>a while.
> 
> It turns out the CSY-2 is very, very different internally from the CSY-1.
> Whereas the CSY-1 is a fully discrete design with many circuit boards, some
> of them held vertically in a rack frame, the CSY-2 has the first signs of
> integration.
> 
> In particular, the auto bass chord circuit board (ABC CSY-2) has two large
> YM chips on it and there is another board with another large YM chip. The
> function of the auto bass chord system on this organ is quite different
> from the CSY-1, and this would seem to explain why. There is no rack of
> vertically mounted boards; there are much fewer boards and these are all
> mounted horizontally.
> 
> Of particular interest is the solo synthesizer section mounted on the
> underside of the top panel of the organ. Like my CSY-1, the solo
> synthesizer boards in my CSY-2 are very clean, much cleaner than the rest
> of the instrument. This no doubt has to do with being mounted upside down,
> gravity being in its favour.
> 
> The CSY-2 does not however contain either of the versions of the CSY-1 /
> SY-1 solo synthesizer circuits. It's a completely different, much more
> integrated version of the solo synthesizer. The boards are not named SM1,
> SM2, SK, SP1 and SP2 as in the SY-2. Instead they are named VCO, VCF, VCA,
> FEG, AEG, SK and SP.
> 
> VCO is the only board that contains any of the old NE series modules. It has 
>the VCO-III module as seen in later versions of the CSY-1, SY-1 and all SY-2s.
> 
> The VCF board has four ICs on it, all by Rohm. Two BA626s and two BA627s. I
> have been unable so far to identify what these are but what is most
> peculiar about this is that the organ features neither the older NE module
> based filters, nor the IG chip based filters of the CS synthesizers and the
> later Electone organs, but a generation in between. This is the only
> example of this generation of Yamaha synthesizer filter I have ever seen,
> and as far as I'm aware it's completely undocumented on the internet.
> 
> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can packaging
> and so on. The VCA board is self explanatory, the FEG board is for the
> filter envelope and the AEG board is for the amplifier envelope. No NE
> modules here, in particular no VCF-EG or VCA-EG modules. This is the only
> example of these Yamaha envelope generators I have seen, again completely
> undocumented on the internet as far as I know.
> 
> The remaining boards, SK and SP, seem to be the same as in the older
> machines. They are for the gate and trigger pulse recovery and for the
> presets.
> 
> Sound-wise, it behaves much like a cross between the two generations. The 
>oscillator definitely has the same timbral qualities as an SY-2, but the filters 
>are much, much cleaner. I wouldn't go so far as to say they sound like CS series 
>IG chip filters, but they are certainly more well behaved than the highly 
>distorting diode bridge filters in the NE series epoxy filled modules.
> 
> Richard
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From colin at colinfraser.com  Wed Nov 10 00:00:16 2010
From: colin at colinfraser.com (Colin f)
Date: Tue, 9 Nov 2010 23:00:16 -0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01><842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
Message-ID: <59653671F1EB4777A72A1EC51AE9C008@zen>


> The VCF board has four ICs on it, all by Rohm. Two BA626s and 
> two BA627s. I have been unable so far to identify what these 
> are but what is most peculiar about this is that the organ 
> features neither the older NE module based filters, nor the 
> IG chip based filters of the CS synthesizers

...unless those Rohm ICs are really transistor (or diode) arrays, and the
filters *are* essentially a re-hash of the contents of the NE modules.
Or even a discrete prototype of the topology used later in the IG chips.
There's a project for you ;-)

> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal 
> can packaging and so on.

The GX-1 uses CA3080 VCAs too.

Cheers,
Colin f




From dixon at interchange.ubc.ca  Wed Nov 10 00:37:32 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 09 Nov 2010 15:37:32 -0800
Subject: [sdiy] Which opamp pins wiring is best for CV out ?? A ,
 B or C ???
In-Reply-To: <98698219CB114BAA96F75AC373B3C809@homepc002>
References: <98698219CB114BAA96F75AC373B3C809@homepc002>
Message-ID: <8497FCBDEEC64F739FDDA8F1409FF177@galvanox01>

Sorry, Richie, I responded before seeing your post. 


> Regarding this CV driver output discussion, there is a solution that
> provides the best of both worlds:
> 
> http://www.richieburnett.co.uk/temp/cv_out.GIF
> 
> Resistor R1 limits the maximum output current under short circuit
> conditions
> and decouples the output of the op-amp from the capacitance of the cable
> and
> the load at the end of the cable.  (It's value isn't critical, but it
> needs
> to be significantly greater than the open-loop output impedance of the
> op-amp at the cross-over frequency so that it effectively decouples the
> output node from the capacitive lag at the load.)
> 
> Resistor R2 takes negative feedback from the actual output at DC.  This
> means that any voltage drop across R1 due to load current is inside the
> feedback loop and is therefore compensated out.  (Under load the op-amp
> servos it's output to a higher voltage to make up for the volts dropped
> across R1, and ensure the output voltage is still what you wanted.)
> 
> Capacitor C2 takes negative feedback directly from the output of the op-
> amp
> at high frequencies.  This stops the op-amp ringing or breaking into
> oscillation due to load capacitance causing the feedback signal to
> diminish
> and start to lag at high frequencies.
> 
> Essentially the source of feedback gradually shifts from the output cable
> to
> the op-amp output as you go up in frequency.  At DC the feedback comes
> from
> the actual output to compensate for the DC voltage drop across R1.  At HF
> the feedback comes from the op-amp output directly to ensure "in-phase"
> negative feedback and guarantee stability as the op-amp's gain rolls off.
> 
> Another way you can look at it is by thinking of R2/C2 as a phase-lead
> network.  C2 imparts a phase-lead into the feedback signal around the
> break
> frequency where the output capacitance combined with R1 would otherwise
> cause a phase lag to kick in.
> 
> I hope this helps,
> 
> -Richie,
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From jpdesroc at oricom.ca  Wed Nov 10 02:18:47 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Tue, 09 Nov 2010 20:18:47 -0500
Subject: [sdiy] DIY project Roland 61 keys keyboard on eBay...
Message-ID: <35670.1289351927@oricom.ca>

Hi list,
I just listed this keyboard on eBay
for anybody who could be interested.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250724561749

I hope this could help anybody..
Just email me offline for any info.
jpdesroc at oricom.ca
Sorry for interupting.
Thanks
J-Pierre


 


From jpdesroc at oricom.ca  Wed Nov 10 02:27:27 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Tue, 09 Nov 2010 20:27:27 -0500
Subject: [sdiy] DIY project Roland 61 keys keyboard on eBay...
Message-ID: <35722.1289352447@oricom.ca>

Hi list,
I just listed this keyboard on eBay
for anybody who could be interested.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250724561749

I hope this could help anybody..
Just email me offline for any info.
jpdesroc at oricom.ca
Sorry for interupting.
Thanks
J-Pierre


 




From rga24 at cantab.net  Wed Nov 10 12:21:24 2010
From: rga24 at cantab.net (Richard Atkinson)
Date: 10 Nov 2010 11:21:24 +0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <910752.23905.qm@web81207.mail.mud.yahoo.com>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<910752.23905.qm@web81207.mail.mud.yahoo.com>
Message-ID: <Prayer.1.3.3.1011101121240.32195@hermes-2.csi.cam.ac.uk>

You can summarise the differences as follows:

CSY-1 and SY-1 are the most similar. I believe they are contemporaneous. 
Both solo synthesizers exist in two forms, one with a single, large SM 
board containing all the NE modules, and a later version with SM1 and SM2 
boards, one containing VCO-III, VCF-LPF, VCF-HPF and EG-VCF, the other 
containing EG-VCA.

Incidentally the earlier version has a VCO-II module rather than a VCO-III 
module, this is documented in the SY-1 service manual. My CSY-1 service 
manual only mentions the earlier version; there is no mention of the later 
version, but these are known to exist because there are pictures of one at:

http://www.imoose.nl/electone/details/csy-1.htm

They both feature two effects called Attack Bend, one for Pitch and one for 
Tone. These are both decay envelopes which affect the VCO frequency and VCF 
frequencies respectively. On the CSY-1 organ both effects are preset, it's 
simply on or off. On the SY-1 synthesizer, Attack Bend Pitch is preset 
while Attack Bend Tone has controls for intensity and time.

It's interesting to note that the Attack Bend Tone envelope is in addition 
to the standard filter envelope, which is completely preset on the CSY-1 
and SY-1.

Additionally the SY-1 has a control for pulse width which the CSY-1 lacks.

SY-2 came later and exists only in a version with SM1 and SM2 boards. It 
may be that the change from a single SM board to SM1 and SM2 was prompted 
by the SY-2 design. SY-2 lacks Attack Bend Tone completely; instead the 
Tone Bend section allows you to vary three out of the five filter envelope 
parameters, namely Attack Time, Intensity (Attack Level) and Decay Time. 
The other two parameters are always preset, namely Initial Level and 
Release Time.

CSY-2 provides the same solo synthesizer controls as CSY-1 but with 
different internal construction, as outlined in my previous post. It 
evidently came last of all. Service manuals for the CSY-2 refer to the 
CSY-2 Series; it came in CSY-2 and CSY-2A versions where there are more 
Auto Bass Chord features in the CSY-2A. Some of the circuit boards in my 
CSY-2 have locations where missing components would go.

Richard


On Nov 9 2010, Doug Terrebonne wrote:

> Very interesting. I have a SY-1 and SY-2 and always assumed the versions 
> they stuffed into their organs were identical...
>
>Doug
>
>
>
>----- Original Message ----
>> From: Richard Atkinson <rga24 at cantab.net>
>> To: synth diy <synth-diy at dropmix.xs4all.nl>
>> Sent: Tue, November 9, 2010 7:16:51 AM
>> Subject: [sdiy] Yamaha CSY-2 solo synthesizer
>> 
>> This email may be of particular interest to anyone who has studied the 
>> first and second generations of Yamaha synthesizer, namely the SY-1 / 
>> SY-2 / GX-1 synthesizers with epoxy potted NE series modules in the 
>> first generation and the CS series of synthesizers with IG series chips 
>> in the second generation.
>> 
>> It turns out there is an intermediate generation of Yamaha synthesizer 
>> between these two generations. I found this when looking inside my newly 
>> acquired Yamaha CSY-2 organ yesterday. This is a later version of the 
>> CSY-1 organ, which has been featured in a few web pages and Matrixsynth 
>> articles and which contains the same epoxy potted NE series modules as 
>> the GX-1.
>> 
>> I took the lid off my Yamaha CSY-2 yesterday with a friends's help. The 
>> insides of my CSY-2 were rather dirty, having played host to a number of 
>> spiders and other objects over the years. There was evidence of damp 
>> damage on the base of the machine; it has clearly been kept on a damp 
>> surface at some point for quite a while.
>> 
>> It turns out the CSY-2 is very, very different internally from the 
>> CSY-1. Whereas the CSY-1 is a fully discrete design with many circuit 
>> boards, some of them held vertically in a rack frame, the CSY-2 has the 
>> first signs of integration.
>> 
>> In particular, the auto bass chord circuit board (ABC CSY-2) has two 
>> large YM chips on it and there is another board with another large YM 
>> chip. The function of the auto bass chord system on this organ is quite 
>> different from the CSY-1, and this would seem to explain why. There is 
>> no rack of vertically mounted boards; there are much fewer boards and 
>> these are all mounted horizontally.
>> 
>> Of particular interest is the solo synthesizer section mounted on the 
>> underside of the top panel of the organ. Like my CSY-1, the solo 
>> synthesizer boards in my CSY-2 are very clean, much cleaner than the 
>> rest of the instrument. This no doubt has to do with being mounted 
>> upside down, gravity being in its favour.
>> 
>> The CSY-2 does not however contain either of the versions of the CSY-1 
>> / SY-1 solo synthesizer circuits. It's a completely different, much more 
>> integrated version of the solo synthesizer. The boards are not named 
>> SM1, SM2, SK, SP1 and SP2 as in the SY-2. Instead they are named VCO, 
>> VCF, VCA, FEG, AEG, SK and SP.
>> 
>> VCO is the only board that contains any of the old NE series modules. 
>> It has the VCO-III module as seen in later versions of the CSY-1, SY-1 
>> and all SY-2s.
>> 
>> The VCF board has four ICs on it, all by Rohm. Two BA626s and two 
>> BA627s. I have been unable so far to identify what these are but what is 
>> most peculiar about this is that the organ features neither the older NE 
>> module based filters, nor the IG chip based filters of the CS 
>> synthesizers and the later Electone organs, but a generation in between. 
>> This is the only example of this generation of Yamaha synthesizer filter 
>> I have ever seen, and as far as I'm aware it's completely undocumented 
>> on the internet.
>> 
>> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can 
>> packaging and so on. The VCA board is self explanatory, the FEG board is 
>> for the filter envelope and the AEG board is for the amplifier envelope. 
>> No NE modules here, in particular no VCF-EG or VCA-EG modules. This is 
>> the only example of these Yamaha envelope generators I have seen, again 
>> completely undocumented on the internet as far as I know.
>> 
>> The remaining boards, SK and SP, seem to be the same as in the older
>> machines. They are for the gate and trigger pulse recovery and for the
>> presets.
>> 
>> Sound-wise, it behaves much like a cross between the two generations. 
>> The oscillator definitely has the same timbral qualities as an SY-2, but 
>> the filters are much, much cleaner. I wouldn't go so far as to say they 
>> sound like CS series IG chip filters, but they are certainly more well 
>> behaved than the highly distorting diode bridge filters in the NE series 
>> epoxy filled modules.
>> 
>> Richard
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> 
>


From jpdesroc at oricom.ca  Wed Nov 10 13:32:36 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Wed, 10 Nov 2010 07:32:36 -0500
Subject: [sdiy] DIY project Roland 61 keys keyboard on eBay...
References: <35670.1289351927@oricom.ca> <4CDA6A6C.4010300@imt.net>
Message-ID: <2601F5F0558A44F486BCD8FA2B1C422E@HPLYNE>

Bob Weigel wrote
> So I assume these were tested working?  The contacts are notoriously 
> unreliable on those things of course.  The contact disks I sell can 
> recondition them to like new unless the bubbles get busted of course...

This keyboard was removed from a non-working Roland D10
whose problem was an intermittent defective motherboard.
The keyboard was working fine.
JP

----- Original Message ----- 
From: "Bob Weigel" <sounddoctorin at imt.net>
To: <jpdesroc at oricom.ca>
Sent: Wednesday, November 10, 2010 4:48 AM
Subject: Re: [sdiy] DIY project Roland 61 keys keyboard on eBay...


> On 11/9/2010 6:18 PM, Jean-Pierre Desrochers wrote:
>> Hi list,
>> I just listed this keyboard on eBay
>> for anybody who could be interested.
>>
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250724561749
>>
>> I hope this could help anybody..
>> Just email me offline for any info.
>> jpdesroc at oricom.ca
>> Sorry for interupting.
>> Thanks
>> J-Pierre
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>
>>    
> So I assume these were tested working?  The contacts are notoriously 
> unreliable on those things of course.  The contact disks I sell can 
> recondition them to like new unless the bubbles get busted of course...
> 
> -- 
> Check out sounddoctorin.com for songs, a studio tour, help
> repairing old synthesizers and parts or thought provoking
> articles that could help make your eternity!
>


From harrybissell at wowway.com  Wed Nov 10 15:14:54 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 10 Nov 2010 09:14:54 -0500 (EST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
Message-ID: <313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>

I think the Odyssey used NAND gates configured as an exclusive-or (or nor, who cares ? :^)

H^) harry



----- Original Message -----
From: Dave Leith <dave.leith at gmail.com>
To: SDIY <synth-diy at dropmix.xs4all.nl>
Sent: Tue, 09 Nov 2010 17:33:41 -0500 (EST)
Subject: Re: [sdiy] XOR as 'digital' ring modulator

not sure but isn't this what the ARP Odyssey uses for a ring mod or
maybe it's 2 nand gates

On Tue, Nov 9, 2010 at 2:18 PM, Colin f <colin at colinfraser.com> wrote:
>
>> > You can't modulate the polarity without modulating the amplitude.
>> > The polarity is the sign of the amplitude.
>>
>> Yes, and therefore you are modulating the "sign" and not the
>> "amplitude".
>
> Well if we want to get pedantic about it, when you invert the sign of a
> square wave with anything other than a perfect duty cycle of 50%, you shift
> the DC level, so you would change the RMS amplitude.
> Depends on which definition of amplitude you're using.
> But I know what you mean.
>
> Cheers,
> Colin f
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From John.Speth at coherent.com  Wed Nov 10 17:29:53 2010
From: John.Speth at coherent.com (Speth, John)
Date: Wed, 10 Nov 2010 08:29:53 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>

Of course, it's the good sound we're after when all is said and done.  The MOTM-120 (http://www.synthtech.com/motm120.html) features a digital ring-mod.  I socketed the digital chip in my M120 so I could experiment with XOR vs NOR easily.

To my ears they both sounded the same when two waveforms were driven into it.  The XOR will sound the squared wave version of the sounding input if the other input is silent (IOW, out = in).

It was my opinion that a ring-mod should be silent when one of the inputs is silent so I left the NOR chip installed.  I still like it that way.  I wouldn't say a digital ring-mod is any kind of sub for the analog version.  It just sounds too different.

John Speth
mailto:john.speth at coherent.com

The information contained in this communication is confidential and may be legally privileged. It is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. If you are not the intended recipient you are hereby (a) notified that any disclosure, copying, distribution or taking any action with respect to the content of this information is strictly prohibited and may be unlawful, and (b) kindly requested to inform the sender immediately and delete any copies. Coherent is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.


From subjectivity at hotmail.com  Wed Nov 10 18:48:36 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Wed, 10 Nov 2010 12:48:36 -0500
Subject: [sdiy] diode filters
Message-ID: <BLU0-SMTP1335898B517C3F4BC23765EC8310@phx.gbl>

I tried building up the minisonic 2 diode filter today....no go


not sure why it didnt work but as i have never built a diode filter before, it is hard to say.

anyone have any recommendations for other diode filters that are pretty easy to breadboard?


thanks!






From daugard at cox.net  Wed Nov 10 19:18:27 2010
From: daugard at cox.net (Tim Daugard)
Date: Wed, 10 Nov 2010 12:18:27 -0600
Subject: [sdiy] diode filters
References: <BLU0-SMTP1335898B517C3F4BC23765EC8310@phx.gbl>
Message-ID: <005601cb8103$abc72070$0201a8c0@TIM>

From: "dan snazelle" <subjectivity at hotmail.com>
> anyone have any recommendations for other diode filters that are pretty 
> easy to breadboard?

Here's mine. You can build just the top half. I built mine first on a 
breadboard.
http://members.cox.net/synthfred/h_fal121.htm


Tim Daugard
AG4GZ 30.4078N 86.6227W Alt: 12 feet above MSL
http://members.cox.net/synthfred/h_toctop.htm (Fred's online edition)




From legion at helpwantedproductions.com  Wed Nov 10 19:42:55 2010
From: legion at helpwantedproductions.com (legion at helpwantedproductions.com)
Date: Wed, 10 Nov 2010 10:42:55 -0800
Subject: [sdiy] FS:  SCI Sixtrack, Frac modules, Vintage Fuzz, Wahs
In-Reply-To: <fd4a3bc02d61155414d00f4da1a86634.squirrel@webmail.helpwantedproductions.com>
References: <fd4a3bc02d61155414d00f4da1a86634.squirrel@webmail.helpwantedproductions.com>
Message-ID: <c13235457ec0a78624805bace1e2dc73.squirrel@webmail.helpwantedproductions.com>

Update form previous post. Will be flexible on prices as needed. Also
looking for a Tenori-On

For sale in Phila PA:
Pics/more info up at http://daedsound.com/Salez/FS.htm

1. SCI Sixtrack - $450
Latest ROM OS installed (essential for Midi) and pro done and working six
output mod.  Excellent shape with very nice padded custom case that fits
it perfectly.  Copy of manual.  I had a sale for this but he seems to have
disappeared. You will not find a nicer 6Track and the ROM upgrade costs $$
via Wine Country. The Output mod is serious plus as well - hence my asking
price.

Price is Firm on this unless you Pickup in phila or buy something else in
which case I'll be a bit flexible.


2. Heathkit 60s Fuzz - $175
Great vintage fuzz capable of rolling off to a unique distortion as well.
Controls are "distortion", "Boost" as well as two  way toggle to add more
bass to the signal. Sweet 60s germanium hand wired goodness.

3. 1970s Univox Uniwah - $75 - Classic!
I can't find a model # on this so I'm not sure if it's the UW1 or UW2. It
has the footswitch button on the right hands side under the pedal rocker
if that helps. it looks like this one:

http://www.bostonguitar.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=BGWI&Product_Code=VE-MISC-UNIVOX-UNIWAH&Category_Code=VE-MISC

4. FRAC Rack format modular synth modules - 100% pro built and tested frac
modules. All run off standard +\- 15vt MOTM/Blacet style Power supply.

A. PAIA 9720 Dual VCO -  $150  - You cannot buy this module assembled and
this includes the faceplate. Working 100%.

B. Blacet 2510 Noise/Improbability Drive - $175 -  factory (blacet4)
assembled.  great noise source *and* S/H unit.

C. PAIA 9748 Balance Modulator - $40  - Assembled in top shape. cool ring
mod type unit nd very flexible.

D. Frac/Banana patch panel with 2 wired 1/4" jacks on cables. $50

E. Blacet 2210 Multiple/attenuator -  $25 - FREE if you buy the other
three modules or a fuzz or Wah pedal in this email).


These are gone. Thanks!
Vintage Roland Fuzz/Wah - AD50 Roland Doublebeat _SOLD
Yamaha CS01 - SOLD
Akai S900 sampler with disks.  SOLD


I think all prices are fair and below Eb*y shite but I will listen to
serious offers. Multiple sales, QUICK sales, and local pickups will help
$$.

Plenty of references. Email any questions, thanks.

    ---------------------------------------
     NEW DAED SITE!!  -  Http://DaedSound.com
 DAED: Circuit Bent and Unusual Sound Devices
"Making Something Extrodinary from the Ordinary"

      Music and More at the Mothership:
    Http://www.HelpWantedProductions.com



From legion at helpwantedproductions.com  Wed Nov 10 19:43:10 2010
From: legion at helpwantedproductions.com (legion at helpwantedproductions.com)
Date: Wed, 10 Nov 2010 10:43:10 -0800
Subject: [sdiy] FS:  SCI Sixtrack, Frac modules, Vintage Fuzz, Wahs
In-Reply-To: <fd4a3bc02d61155414d00f4da1a86634.squirrel@webmail.helpwantedproductions.com>
References: <fd4a3bc02d61155414d00f4da1a86634.squirrel@webmail.helpwantedproductions.com>
Message-ID: <bfc9c54d814610a8ae9105504a5f0426.squirrel@webmail.helpwantedproductions.com>

Update form previous post. Will be flexible on prices as needed. Also
looking for a Tenori-On

For sale in Phila PA:
Pics/more info up at http://daedsound.com/Salez/FS.htm

1. SCI Sixtrack - $450
Latest ROM OS installed (essential for Midi) and pro done and working six
output mod.  Excellent shape with very nice padded custom case that fits
it perfectly.  Copy of manual.  I had a sale for this but he seems to have
disappeared. You will not find a nicer 6Track and the ROM upgrade costs $$
via Wine Country. The Output mod is serious plus as well - hence my asking
price.

Price is Firm on this unless you Pickup in phila or buy something else in
which case I'll be a bit flexible.


2. Heathkit 60s Fuzz - $175
Great vintage fuzz capable of rolling off to a unique distortion as well.
Controls are "distortion", "Boost" as well as two  way toggle to add more
bass to the signal. Sweet 60s germanium hand wired goodness.

3. 1970s Univox Uniwah - $75 - Classic!
I can't find a model # on this so I'm not sure if it's the UW1 or UW2. It
has the footswitch button on the right hands side under the pedal rocker
if that helps. it looks like this one:

http://www.bostonguitar.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=BGWI&Product_Code=VE-MISC-UNIVOX-UNIWAH&Category_Code=VE-MISC

4. FRAC Rack format modular synth modules - 100% pro built and tested frac
modules. All run off standard +\- 15vt MOTM/Blacet style Power supply.

A. PAIA 9720 Dual VCO -  $150  - You cannot buy this module assembled and
this includes the faceplate. Working 100%.

B. Blacet 2510 Noise/Improbability Drive - $175 -  factory (blacet4)
assembled.  great noise source *and* S/H unit.

C. PAIA 9748 Balance Modulator - $40  - Assembled in top shape. cool ring
mod type unit nd very flexible.

D. Frac/Banana patch panel with 2 wired 1/4" jacks on cables. $50

E. Blacet 2210 Multiple/attenuator -  $25 - FREE if you buy the other
three modules or a fuzz or Wah pedal in this email).


These are gone. Thanks!
Vintage Roland Fuzz/Wah - AD50 Roland Doublebeat _SOLD
Yamaha CS01 - SOLD
Akai S900 sampler with disks.  SOLD


I think all prices are fair and below Eb*y shite but I will listen to
serious offers. Multiple sales, QUICK sales, and local pickups will help
$$.

Plenty of references. Email any questions, thanks.

    ---------------------------------------
     NEW DAED SITE!!  -  Http://DaedSound.com
 DAED: Circuit Bent and Unusual Sound Devices
"Making Something Extrodinary from the Ordinary"

      Music and More at the Mothership:
    Http://www.HelpWantedProductions.com



From magnus at rubidium.dyndns.org  Wed Nov 10 19:43:53 2010
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 10 Nov 2010 19:43:53 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
References: <84385446-2C11-41A2-B53E-6C7DFDDDF945@electricdruid.net>
Message-ID: <4CDAE7E9.7070000@rubidium.dyndns.org>

On 11/09/2010 08:26 PM, Tom Wiltshire wrote:
> Hi again,
>
> Continuing the series of "things Tom doesn't understand that he'd like to get cleared up for once and for all", I've got another question.
>
> I've read in a couple of places (quoted below) that an XOR gate is not strictly equivalent to a ring modulator.
>
> Wikipedia says: "Though not equivalent to ring modulation, with square waves the resulting sound is quite similar." (Stinks of fudge to me!)
>
> Hal Chamberlin says (about the Rhodes Chroma): "The ring modulator is really just an exclusive-or digital gate (using CMOS logic that provides exact 5V amplitude outputs) and generates true ring modulation only when the input waveforms are square. Nevertheless, the audible effect of ring modulation is adequately produced even when the signals are nonsquare."
>
> The output from an XOR can be viewed like this:
>
> 	A	B	Q
> 	-1	-1	1
> 	-1	1	-1
> 	1	-1	-1
> 	1	1	1
>
> This looks to me like it's a perfect ring mod (multiplication function) as long as you stick to digital signals, square or otherwise. So XOR could multiply two PWM'd pulse trains no problem according to me, but not according to Chamberlin.
>
> So what am I missing?!

It sounds plain awful? :)

I agree, it's a 1 bit multiplication. Technically it would be XNOR but 
it is of little matter. But a ring-modulation has a "linear" response, 
so it would require more bits and the XOR doesn't match up.

For me the XOR "ring-mod" isn't the sound I usually want. It was a 
relief to finally get the pure ring-mod sound you get from a real ring 
mod and sine on one of the inputs.

Anyway, the XOR is not a ring-mod, but it is a 1 bit 4-quadrant 
multiplication... which for digital signals end up being the same.

Cheers,
Magnus


From cheater00 at gmail.com  Wed Nov 10 20:02:43 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Wed, 10 Nov 2010 20:02:43 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
Message-ID: <AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>

Hi John,
a typical multiplier works like this:

z = x * y

Now if you expand this to show the signs, it looks like this:

z = sgn(x) * |x| * sgn(y) * |y|
= sgn(x)*sgn(y) * |xy|

the xor table is as follows:

F \/ F == F
F \/ T == T
T \/ F == T
T \/ T == F

The table of sgn(x) * sgn(y) is as follows:

-1 * -1 = 1
-1 * 1 = -1
1 * -1 = -1
1 * 1 = 1
-1 * 0 = 0
1 * 0 = 0
0 * 1 = 0
0 * -1 = 0

So, if False is represented by 1 and True is represented by -1, then
we have a match for the first 4 rows of the table. However there is a
third item here. Of course to represent the whole function of a ring
modulator you'll at least need an operator that works in ternary
logic. Those are, from what I understand, possible to wire using
binary gates.

It appears this can be achieved in the ternary logic with null. See
the table here:

http://www.comsci.us/db/sqlnotes/sql03.html

Binary Ternary Logic Operators
Operands   AND OR XOR
null	null 	null	null	null
null	false 	false	null	null
null	true 	null	true	null
false	null 	false	null	null
false	false 	false	false	false
false	true 	false	true	true
true	null 	null	true	null
true	false 	false	true	true
true	true 	true	true	false

As you can see, the value combinations are the same as sgn(x) * sgn(y).

A ternary logic XOR can be created in this way: two signals are
ternary and encoded with -5V = False, 5V = True, 0V = Null.

Because the ternary logic XOR operator is an extension of the binary
logic XOR operator, we can use the usual XOR circuit in a very
specific monad; that means a circuit like this:

1. either signal gets checked for being 0 (Null). There is a wire that
shoots off to the side and bypasses the xor circuit completely, and
then goes to a multiplier, say an AND gate or transistor or op-amp. If
that bypass wire signals 0, then the AND outputs 0. If it doesn't
signal 0, the AND outputs what it gets from the XOR circuit. This wire
is our monad sub-channel.

2. After the signals got checked for being 0 with the special wire
coming off, there is a level shift to convert the signal to binary
logic. We ignore Null and replace it with e.g. False, or True, it
doesn't matter. Then we send that converted signal to the XOR block
which is able to process it. This is our converter, and we're "in the
monad" now.

3. After the signals have been processed in the monad by the XOR
block, we up-convert them to the ternary signal again. True gets
converted to 5V, False gets converted to -5V.

4. After this up-conversion we go to the multiplier which checks the
sub-channel. When the sub-channel says 0, the multiplier outputs 0V
(which is Null).

This should produce the behavior that you are looking for.

HTH,
D.

On 10/11/2010, Speth, John <John.Speth at coherent.com> wrote:
> Of course, it's the good sound we're after when all is said and done.  The
> MOTM-120 (http://www.synthtech.com/motm120.html) features a digital
> ring-mod.  I socketed the digital chip in my M120 so I could experiment with
> XOR vs NOR easily.
>
> To my ears they both sounded the same when two waveforms were driven into
> it.  The XOR will sound the squared wave version of the sounding input if
> the other input is silent (IOW, out = in).
>
> It was my opinion that a ring-mod should be silent when one of the inputs is
> silent so I left the NOR chip installed.  I still like it that way.  I
> wouldn't say a digital ring-mod is any kind of sub for the analog version.
> It just sounds too different.
>
> John Speth
> mailto:john.speth at coherent.com
>
> The information contained in this communication is confidential and may be
> legally privileged. It is intended solely for the use of the individual or
> entity to whom it is addressed and others authorized to receive it. If you
> are not the intended recipient you are hereby (a) notified that any
> disclosure, copying, distribution or taking any action with respect to the
> content of this information is strictly prohibited and may be unlawful, and
> (b) kindly requested to inform the sender immediately and delete any copies.
> Coherent is neither liable for the proper and complete transmission of the
> information contained in this communication nor for any delay in its
> receipt.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From rga24 at cantab.net  Wed Nov 10 20:51:25 2010
From: rga24 at cantab.net (Richard Atkinson)
Date: 10 Nov 2010 19:51:25 +0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <59653671F1EB4777A72A1EC51AE9C008@zen>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01><842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<59653671F1EB4777A72A1EC51AE9C008@zen>
Message-ID: <Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>

Hi Colin,

>...unless those Rohm ICs are really transistor (or diode) arrays, and the
>filters *are* essentially a re-hash of the contents of the NE modules.
>Or even a discrete prototype of the topology used later in the IG chips.
>There's a project for you ;-)

Indeed. Even if they are similar circuits, it's not unreasonable for them 
to sound different from either the NE diode bridges or the IG state 
variable filters. After all, SSM2040s are simply quad cascaded OTA filters, 
as are some IR3109 and CEM3320 configurations, but no-one accuses them of 
sounding the same :)

Richard



From madhun2001 at yahoo.com  Wed Nov 10 21:27:53 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Wed, 10 Nov 2010 12:27:53 -0800 (PST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
Message-ID: <934247.5730.qm@web55304.mail.re4.yahoo.com>

As a hopefully interesting side note, there are 2 ways to obtain the  "ring 
modulator" function. The popular one for the synth crowd is a  linear multiplier 
like the AD633. The other way is by polarity reversal.  This is how true "ring 
modulators" work: the carrier signal goes  through an amplifier that has a 
selectable gain of + or - 1.  The  modulation signal's sign determines the gain 
polarity: when the mod  signal is positive the gain is +1, when negative, -1. 


This is of course not nearly as clean as the linear multiplier, but hey, clean 
is over-rated. 


The XOR ring mod works as a true ring mod, as an XOR gate is a 
digitally-controlled inverter.

We return you now to your regularly scheduled programming.

--TimR


----- Original Message ----
From: cheater cheater <cheater00 at gmail.com>
To: "Speth, John" <John.Speth at coherent.com>
Cc: Dave Leith <dave.leith at gmail.com>; SDIY <synth-diy at dropmix.xs4all.nl>
Sent: Wed, November 10, 2010 11:02:43 AM
Subject: Re: [sdiy] XOR as 'digital' ring modulator

Hi John,
a typical multiplier works like this:

z = x * y

Now if you expand this to show the signs, it looks like this:

z = sgn(x) * |x| * sgn(y) * |y|
= sgn(x)*sgn(y) * |xy|

the xor table is as follows:

F \/ F == F
F \/ T == T
T \/ F == T
T \/ T == F

The table of sgn(x) * sgn(y) is as follows:

-1 * -1 = 1
-1 * 1 = -1
1 * -1 = -1
1 * 1 = 1
-1 * 0 = 0
1 * 0 = 0
0 * 1 = 0
0 * -1 = 0

So, if False is represented by 1 and True is represented by -1, then
we have a match for the first 4 rows of the table. However there is a
third item here. Of course to represent the whole function of a ring
modulator you'll at least need an operator that works in ternary
logic. Those are, from what I understand, possible to wire using
binary gates.

It appears this can be achieved in the ternary logic with null. See
the table here:

http://www.comsci.us/db/sqlnotes/sql03.html

Binary Ternary Logic Operators
Operands   AND OR XOR
null    null     null    null    null
null    false     false    null    null
null    true     null    true    null
false    null     false    null    null
false    false     false    false    false
false    true     false    true    true
true    null     null    true    null
true    false     false    true    true
true    true     true    true    false

As you can see, the value combinations are the same as sgn(x) * sgn(y).

A ternary logic XOR can be created in this way: two signals are
ternary and encoded with -5V = False, 5V = True, 0V = Null.

Because the ternary logic XOR operator is an extension of the binary
logic XOR operator, we can use the usual XOR circuit in a very
specific monad; that means a circuit like this:

1. either signal gets checked for being 0 (Null). There is a wire that
shoots off to the side and bypasses the xor circuit completely, and
then goes to a multiplier, say an AND gate or transistor or op-amp. If
that bypass wire signals 0, then the AND outputs 0. If it doesn't
signal 0, the AND outputs what it gets from the XOR circuit. This wire
is our monad sub-channel.

2. After the signals got checked for being 0 with the special wire
coming off, there is a level shift to convert the signal to binary
logic. We ignore Null and replace it with e.g. False, or True, it
doesn't matter. Then we send that converted signal to the XOR block
which is able to process it. This is our converter, and we're "in the
monad" now.

3. After the signals have been processed in the monad by the XOR
block, we up-convert them to the ternary signal again. True gets
converted to 5V, False gets converted to -5V.

4. After this up-conversion we go to the multiplier which checks the
sub-channel. When the sub-channel says 0, the multiplier outputs 0V
(which is Null).

This should produce the behavior that you are looking for.

HTH,
D.

On 10/11/2010, Speth, John <John.Speth at coherent.com> wrote:
> Of course, it's the good sound we're after when all is said and done.  The
> MOTM-120 (http://www.synthtech.com/motm120.html) features a digital
> ring-mod.  I socketed the digital chip in my M120 so I could experiment with
> XOR vs NOR easily.
>
> To my ears they both sounded the same when two waveforms were driven into
> it.  The XOR will sound the squared wave version of the sounding input if
> the other input is silent (IOW, out = in).
>
> It was my opinion that a ring-mod should be silent when one of the inputs is
> silent so I left the NOR chip installed.  I still like it that way.  I
> wouldn't say a digital ring-mod is any kind of sub for the analog version.
> It just sounds too different.
>
> John Speth
> mailto:john.speth at coherent.com
>
> The information contained in this communication is confidential and may be
> legally privileged. It is intended solely for the use of the individual or
> entity to whom it is addressed and others authorized to receive it. If you
> are not the intended recipient you are hereby (a) notified that any
> disclosure, copying, distribution or taking any action with respect to the
> content of this information is strictly prohibited and may be unlawful, and
> (b) kindly requested to inform the sender immediately and delete any copies.
> Coherent is neither liable for the proper and complete transmission of the
> information contained in this communication nor for any delay in its
> receipt.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From lanterma at ece.gatech.edu  Wed Nov 10 22:31:15 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Wed, 10 Nov 2010 21:31:15 +0000
Subject: [sdiy] Careful with the CEM3320s [was: Re: Yamaha CSY-2 solo
 synthesizer]
In-Reply-To: <Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01><842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<59653671F1EB4777A72A1EC51AE9C008@zen>
	<Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>
Message-ID: <3FF69571-BB71-40FF-AB36-56A3CD083B8C@ece.gatech.edu>

On Nov 10, 2010, at 2:51 PM, Richard Atkinson wrote:

> Indeed. Even if they are similar circuits, it's not unreasonable for them to sound different from either the NE diode bridges or the IG state variable filters. After all, SSM2040s are simply quad cascaded OTA filters, as are some IR3109 and CEM3320 configurations, but no-one accuses them of sounding the same :)

Be cautious with the CEM 3320 - the gain cells in it aren't usual voltage-in, current-out OTAs. They're current-in, current-out devices that have some strange biasing requirements. I don't recall seeing anything else like them.

- Aaron

From lanterma at ece.gatech.edu  Wed Nov 10 22:33:58 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Wed, 10 Nov 2010 21:33:58 +0000
Subject: [sdiy] Follow up on CEM3320 weirdness
In-Reply-To: <AANLkTin69wfrhV+wO0Bf3C172fTzzAGCt7Pq=WSsvp0Q@mail.gmail.com>
References: <AANLkTikmhnAgUVW2mrqDNnp32g9pLe9R7+C6s7_L2Xc3@mail.gmail.com>
	<2A7CBDD6-0821-4ECF-81BB-79955B1F0297@ece.gatech.edu>
	<AANLkTin69wfrhV+wO0Bf3C172fTzzAGCt7Pq=WSsvp0Q@mail.gmail.com>
Message-ID: <675A3892-666F-48F0-A73F-325725B4CB15@ece.gatech.edu>

The datasheet diagrams are tangled in confusing ways in order to show the pin layout on the chip; it's easier to see what's going on via the diagrams on Tom Wiltshire's page:

http://www.electricdruid.net/index.php?page=info.cem3320

Notice the strange biasing.

- Aaron

From tom at electricdruid.net  Wed Nov 10 22:43:31 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Wed, 10 Nov 2010 21:43:31 +0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01><842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<59653671F1EB4777A72A1EC51AE9C008@zen>
	<Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>
Message-ID: <409E0BFA-0784-41C3-AB6D-E618C078167A@electricdruid.net>


On 10 Nov 2010, at 19:51, Richard Atkinson wrote:

> After all, SSM2040s are simply quad cascaded OTA filters, as are some IR3109 and CEM3320 configurations, but no-one accuses them of sounding the same :)

But have you noticed how no-one actually does blind listening tests either?
;)

T.



From magnus at rubidium.dyndns.org  Wed Nov 10 22:59:46 2010
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 10 Nov 2010 22:59:46 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <934247.5730.qm@web55304.mail.re4.yahoo.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
	<934247.5730.qm@web55304.mail.re4.yahoo.com>
Message-ID: <4CDB15D2.4000505@rubidium.dyndns.org>

On 11/10/2010 09:27 PM, Tim Ressel wrote:
> As a hopefully interesting side note, there are 2 ways to obtain the  "ring
> modulator" function. The popular one for the synth crowd is a  linear multiplier
> like the AD633. The other way is by polarity reversal.  This is how true "ring
> modulators" work: the carrier signal goes  through an amplifier that has a
> selectable gain of + or - 1.  The  modulation signal's sign determines the gain
> polarity: when the mod  signal is positive the gain is +1, when negative, -1.
>
>
> This is of course not nearly as clean as the linear multiplier, but hey, clean
> is over-rated.
>
>
> The XOR ring mod works as a true ring mod, as an XOR gate is a
> digitally-controlled inverter.
>
> We return you now to your regularly scheduled programming.

No. The true ring mod does not have gain which shift between +1 and -1. 
It has a gain shifting between those two extremes. A true ring mod 
actually always have losses.

Modern ring-mod equivalents such as Gilbert cells can also be made to do 
4-quadrature multiplications like the old double-balanced diode rings.

Cheers,
Magnus


From rob at emulatorarchive.com  Wed Nov 10 23:06:33 2010
From: rob at emulatorarchive.com (rob at emulatorarchive.com)
Date: Wed, 10 Nov 2010 22:06:33 +0000
Subject: [sdiy] diode filters
In-Reply-To: <BLU0-SMTP1335898B517C3F4BC23765EC8310@phx.gbl>
References: <BLU0-SMTP1335898B517C3F4BC23765EC8310@phx.gbl>
Message-ID: <4CDB1769.9050908@emulatorarchive.com>

Hi,
Not sure what went wrong with your clone, but my Minisonic 2 diode 
filter clone worked first time.
Details are here, and the PCB can be purchased (15V version).
http://www.amsynths.co.uk/Filter_Bank2/AM8050/am8050.html
I also built the original in 1975 and that worked first time to.
Did you get the filter to cutoff?

Also other some other Roland like diode filters are here:
http://www.amsynths.co.uk/Filter_Bank/AM8003/am8003.html
http://www.amsynths.co.uk/Roland_100M/AM8005/am8005.html
And the Snowfall:
http://www.amsynths.co.uk/Filter_Bank2/AM8071/am8071.html

On a diode filter you do need to get the gain structure right to enable 
self oscillation, it takes more than on a transistor filter.
I will have some Eurorack diode filters for sale soon as completed modules.

Regards
Rob
www.amsynths.co.uk

On 10/11/2010 17:48, dan snazelle wrote:
> I tried building up the minisonic 2 diode filter today....no go
>
>
> not sure why it didnt work but as i have never built a diode filter before, it is hard to say.
>
> anyone have any recommendations for other diode filters that are pretty easy to breadboard?
>
>
> thanks!
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From cheater00 at gmail.com  Wed Nov 10 23:24:39 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Wed, 10 Nov 2010 23:24:39 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <4CDB15D2.4000505@rubidium.dyndns.org>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
	<934247.5730.qm@web55304.mail.re4.yahoo.com>
	<4CDB15D2.4000505@rubidium.dyndns.org>
Message-ID: <AANLkTikQmNfjUSK5W-pvHpqu1-q9Ht1YsL70He-R_6ga@mail.gmail.com>

Magnus,
I'm afraid I didn't understand what you said there. Could you elaborate please?

Thanks
D.

On 10/11/2010, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
> On 11/10/2010 09:27 PM, Tim Ressel wrote:
>> As a hopefully interesting side note, there are 2 ways to obtain the
>> "ring
>> modulator" function. The popular one for the synth crowd is a  linear
>> multiplier
>> like the AD633. The other way is by polarity reversal.  This is how true
>> "ring
>> modulators" work: the carrier signal goes  through an amplifier that has a
>> selectable gain of + or - 1.  The  modulation signal's sign determines the
>> gain
>> polarity: when the mod  signal is positive the gain is +1, when negative,
>> -1.
>>
>>
>> This is of course not nearly as clean as the linear multiplier, but hey,
>> clean
>> is over-rated.
>>
>>
>> The XOR ring mod works as a true ring mod, as an XOR gate is a
>> digitally-controlled inverter.
>>
>> We return you now to your regularly scheduled programming.
>
> No. The true ring mod does not have gain which shift between +1 and -1.
> It has a gain shifting between those two extremes. A true ring mod
> actually always have losses.
>
> Modern ring-mod equivalents such as Gilbert cells can also be made to do
> 4-quadrature multiplications like the old double-balanced diode rings.
>
> Cheers,
> Magnus
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From cheater00 at gmail.com  Wed Nov 10 23:27:16 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Wed, 10 Nov 2010 23:27:16 +0100
Subject: [sdiy] Careful with the CEM3320s [was: Re: Yamaha CSY-2 solo
	synthesizer]
In-Reply-To: <3FF69571-BB71-40FF-AB36-56A3CD083B8C@ece.gatech.edu>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<59653671F1EB4777A72A1EC51AE9C008@zen>
	<Prayer.1.3.3.1011101951250.19044@hermes-2.csi.cam.ac.uk>
	<3FF69571-BB71-40FF-AB36-56A3CD083B8C@ece.gatech.edu>
Message-ID: <AANLkTim7=4_cdbBPau9ZYAm+jzU97onSsEy5L2AZUn+L@mail.gmail.com>

so in fact they're op amps, not ota's?

Cheers,
D.

On 10/11/2010, lanterma at ece.gatech.edu <lanterma at ece.gatech.edu> wrote:
> On Nov 10, 2010, at 2:51 PM, Richard Atkinson wrote:
>
>> Indeed. Even if they are similar circuits, it's not unreasonable for them
>> to sound different from either the NE diode bridges or the IG state
>> variable filters. After all, SSM2040s are simply quad cascaded OTA
>> filters, as are some IR3109 and CEM3320 configurations, but no-one accuses
>> them of sounding the same :)
>
> Be cautious with the CEM 3320 - the gain cells in it aren't usual
> voltage-in, current-out OTAs. They're current-in, current-out devices that
> have some strange biasing requirements. I don't recall seeing anything else
> like them.
>
> - Aaron
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From magnus at rubidium.dyndns.org  Thu Nov 11 00:09:18 2010
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Thu, 11 Nov 2010 00:09:18 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <AANLkTikQmNfjUSK5W-pvHpqu1-q9Ht1YsL70He-R_6ga@mail.gmail.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>	<934247.5730.qm@web55304.mail.re4.yahoo.com>	<4CDB15D2.4000505@rubidium.dyndns.org>
	<AANLkTikQmNfjUSK5W-pvHpqu1-q9Ht1YsL70He-R_6ga@mail.gmail.com>
Message-ID: <4CDB261E.8010803@rubidium.dyndns.org>

On 11/10/2010 11:24 PM, cheater cheater wrote:
> Magnus,
> I'm afraid I didn't understand what you said there. Could you elaborate please?

A ring-modulator... the double-balanced diode ring, which is used for 
modulation and demodulation, a radio device... approximates a 4-quadrant 
multiplication. It does not have "a selectable gain of + or - 1".

The original ring-modulator isn't particular "linear", it has quite a 
bit of distortion in fact. It is also quite bulky for audio use due to 
the transformers. The Gilbert cell is another approach to achieve the 
same, using transistors rather than diodes. Linearisation is also attempted.

As for 4-quadrant multiplication is means multiplication covering the 4 
quadrants (of a circle) i.e. having both polarities on both input 
signals, but it assumes continuous scale to the respective inputs.

So, when I talk about ring-mod, I mean that... 4-quadrant multiplication.

Similar effects may be achieved using for instance switch-able gain, but 
it isn't a ring-mod, a ring-mod doesn't do that unless you use a 
balanced digital signal as input, but then you can't cover all the 
aspects of a ring-mod which a triangle and sine would cover for instance.

This is why I disagree with Tim.

Cheers,
Magnus

> Thanks
> D.
>
> On 10/11/2010, Magnus Danielson<magnus at rubidium.dyndns.org>  wrote:
>> On 11/10/2010 09:27 PM, Tim Ressel wrote:
>>> As a hopefully interesting side note, there are 2 ways to obtain the
>>> "ring
>>> modulator" function. The popular one for the synth crowd is a  linear
>>> multiplier
>>> like the AD633. The other way is by polarity reversal.  This is how true
>>> "ring
>>> modulators" work: the carrier signal goes  through an amplifier that has a
>>> selectable gain of + or - 1.  The  modulation signal's sign determines the
>>> gain
>>> polarity: when the mod  signal is positive the gain is +1, when negative,
>>> -1.
>>>
>>>
>>> This is of course not nearly as clean as the linear multiplier, but hey,
>>> clean
>>> is over-rated.
>>>
>>>
>>> The XOR ring mod works as a true ring mod, as an XOR gate is a
>>> digitally-controlled inverter.
>>>
>>> We return you now to your regularly scheduled programming.
>>
>> No. The true ring mod does not have gain which shift between +1 and -1.
>> It has a gain shifting between those two extremes. A true ring mod
>> actually always have losses.
>>
>> Modern ring-mod equivalents such as Gilbert cells can also be made to do
>> 4-quadrature multiplications like the old double-balanced diode rings.
>>
>> Cheers,
>> Magnus
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>



From madhun2001 at yahoo.com  Thu Nov 11 00:09:41 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Wed, 10 Nov 2010 15:09:41 -0800 (PST)
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <4CDB15D2.4000505@rubidium.dyndns.org>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
	<934247.5730.qm@web55304.mail.re4.yahoo.com>
	<4CDB15D2.4000505@rubidium.dyndns.org>
Message-ID: <865281.54010.qm@web55305.mail.re4.yahoo.com>

Sorry, I was speaking theoretical so as not to confuse the reader with details. 
A true diode ring mixer uses diode switching to reverse the polarity of the 
carrier signal. Since it is a passive system, it has loss and not gain.

--TimR



----- Original Message ----
From: Magnus Danielson <magnus at rubidium.dyndns.org>
To: synth-diy at dropmix.xs4all.nl
Sent: Wed, November 10, 2010 1:59:46 PM
Subject: Re: [sdiy] XOR as 'digital' ring modulator

On 11/10/2010 09:27 PM, Tim Ressel wrote:
> As a hopefully interesting side note, there are 2 ways to obtain the  "ring
> modulator" function. The popular one for the synth crowd is a  linear 
>multiplier
> like the AD633. The other way is by polarity reversal.  This is how true "ring
> modulators" work: the carrier signal goes  through an amplifier that has a
> selectable gain of + or - 1.  The  modulation signal's sign determines the 
gain
> polarity: when the mod  signal is positive the gain is +1, when negative, -1.
>
>
> This is of course not nearly as clean as the linear multiplier, but hey, clean
> is over-rated.
>
>
> The XOR ring mod works as a true ring mod, as an XOR gate is a
> digitally-controlled inverter.
>
> We return you now to your regularly scheduled programming.

No. The true ring mod does not have gain which shift between +1 and -1. 
It has a gain shifting between those two extremes. A true ring mod 
actually always have losses.

Modern ring-mod equivalents such as Gilbert cells can also be made to do 
4-quadrature multiplications like the old double-balanced diode rings.

Cheers,
Magnus
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From senso at vintageplanet.nl  Thu Nov 11 00:30:29 2010
From: senso at vintageplanet.nl (Senso)
Date: Thu, 11 Nov 2010 00:30:29 +0100
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
Message-ID: <a0624080fc900db4829f7@[192.168.254.1]>

>>After all, SSM2040s are simply quad cascaded OTA filters, as are 
>>some IR3109 and CEM3320 configurations, but no-one accuses them of 
>>sounding the same :)
>
>But have you noticed how no-one actually does blind listening tests either?
>;)
>
>T.

I'm (s)tone deaf but so what? I have a scope and a voltmeter. :o)

-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From rburnett at richieburnett.co.uk  Thu Nov 11 00:35:45 2010
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Wed, 10 Nov 2010 23:35:45 -0000
Subject: [sdiy] Ring modulators
Message-ID: <6E63A57EE3CA494F96EA99F71AEAD1FB@homepc002>

When talking about rough-and-ready ring modulators it's perhaps worth 
mentioning the original ring modulator...
The diode-ring modulator from which the name comes:

http://en.wikipedia.org/wiki/Ring_modulator

As the text on Wikipedia explains, the diodes are alternately driven into 
conduction in pairs by the alternating carrier signal.  This has the effect 
of "patching" the input through to the output with periodically alternating 
polarity.

The text suggests that this is an on/off DPDT switching type of action that 
periodically reverses the polarity of the input signal being passed to the 
output.  Whilst the diode-ring modulator can be made to operate in 
"switching mode" when one of its ports is over driven, it is actually a 
proportional device.  A correctly scaled AC signal applied to the carrier 
port actually modulates the conductivity of the diodes in the ring causing a 
proportional modulation of the input signal's amplitude.

The more carrier voltage you apply to the diodes the more they become 
forward biased and their incremental resistance falls.  This passes more of 
the input signal through to the load at the output port.  If you reverse the 
carrier voltage the vertical pair of diodes now become gradually forward 
biased instead of the horizontal pair.  This passes progressively more and 
more of the input signal through to the output except now with reversed 
polarity.  You essentially have a rough-and-ready analogue multiplier.

It's amazing what you can achieve with a passive arrangement of 4 diodes and 
two transformers.  Most low-frequency ring-modulation applications are now 
either done with highly linear gilbert-cell based VCAs, or implemented 
digitally.  But for RF use particularly at higher frequencies miniature 
diode-ring mixers are alive and well, and at the heart of any 
super-hetrodyne radio receiver...

http://www.mini-circuits.com/pdfs/ADE-1.pdf

-Richie, 



From dixon at interchange.ubc.ca  Thu Nov 11 06:18:15 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Wed, 10 Nov 2010 21:18:15 -0800
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <934247.5730.qm@web55304.mail.re4.yahoo.com>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
	<934247.5730.qm@web55304.mail.re4.yahoo.com>
Message-ID: <A0F060C01DC44BC8B05B4B429EFB2B96@galvanox01>

> As a hopefully interesting side note, there are 2 ways to obtain the
> "ring
> modulator" function. The popular one for the synth crowd is a  linear
> multiplier
> like the AD633. The other way is by polarity reversal.  This is how true
> "ring
> modulators" work: the carrier signal goes  through an amplifier that has a
> selectable gain of + or - 1.  The  modulation signal's sign determines the
> gain
> polarity: when the mod  signal is positive the gain is +1, when negative,
> -1.

But for true ring-modulation the amplifier's gain is not just selectable
between -1 and +1, but sweeps smoothly between those two limits.  My
"Multiplying Modulator" does this with two linearized VCAs by controlling
one with a modulating signal and the other with its inverse.  One VCA
processes the signal, and the other processes its inverse.

By panning the signal from one VCA to the other, you can sweep from positive
two-quadrant multiplication to balanced four-quadrant multiplication to
negative two-quadrant multiplication.  You can get a wide range of
"ring-mod" flavours at the various "unbalanced" settings.  I also have
switches to rectify both signal and modulator up or down, which also adds a
lot of character.

One really nice use of this device in four-quadrant mode is to feed a slow
LFO signal to the modulator, and an envelope to the signal, then send the
output to the FM of a filter.  In that sense, it is like a
voltage-controlled bipolar attenuator, which is another way to think about
ring-mod.



From thescum at surfree.com  Thu Nov 11 06:31:48 2010
From: thescum at surfree.com (Byron G. Jacquot)
Date: Wed, 10 Nov 2010 22:31:48 -0700 (GMT-07:00)
Subject: [sdiy] Buchla Dodecamodule docs?
Message-ID: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>

Howdy all,

A friend has a Buchla electronic music box.  He brought it to me for a little TLC.  I've been able to suss out and solve a few issues, but I've got one remaining that's not been so forthcoming:  The Random Voltage Source quits working as the machine warms up.  It runs fine when it's cool, but stalls after a few minutes.  

I've seen Magnus' schematic collection, but there's no 212.  Does anyone have any documentation for this guy, or any idea where I should be looking?

Thanks,

Byron Jacquot


From pfperry at melbpc.org.au  Thu Nov 11 07:40:28 2010
From: pfperry at melbpc.org.au (Paul Perry)
Date: Thu, 11 Nov 2010 17:40:28 +1100
Subject: [sdiy] Buchla Dodecamodule docs?
References: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
Message-ID: <33C15D86647A46988DAD76AF51A54030@ownerf0d9273f5>

I don't know what kind of random voltage generator is in there, but if
it is based on a zener diode, there is always a chance that the zener is
going open circuit when heated. I have seen zeners go open when hot before.

paul perry melbourne australia

----- Original Message ----- 
From: "Byron G. Jacquot" > Howdy all,
>
> A friend has a Buchla electronic music box.  He brought it to me for a 
> little TLC.  I've been able to suss out and solve a few issues, but I've 
> got one remaining that's not been so forthcoming:  The Random Voltage 
> Source quits working as the machine warms up.  It runs fine when it's 
> cool, but stalls after a few minutes.
>
> I've seen Magnus' schematic collection, but there's no 212.  Does anyone 
> have any documentation for this guy, or any idea where I should be 
> looking?
>
> Thanks,
>
> Byron Jacquot
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.869 / Virus Database: 271.1.1/3248 - Release Date: 11/10/10 
18:34:00



From dave.leith at gmail.com  Thu Nov 11 08:28:50 2010
From: dave.leith at gmail.com (Dave Leith)
Date: Wed, 10 Nov 2010 23:28:50 -0800
Subject: [sdiy] Buchla Dodecamodule docs?
In-Reply-To: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
References: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
Message-ID: <AANLkTin=Smbgvk6j=kKgihHxXu-MU_Ws81wfMqA0iyrP@mail.gmail.com>

I wonder if the design is anything like the Buchla 160 White Noise
Generator or B4100-3 Reverb and Noise Source. There is a schematic for
those on Magnus's site and both use a transistor junction for the
noise source.

Perhaps more likely from the description below on Buchla's site
http://www.buchla.com/historical/b200
The functions sound a bit like what the Buchla 265 and 266 (Source of
Uncertainty) do. The 265 uses a selected zener for the noise source.
The 266 uses the infamous MM5837 digital noise chip. These schematics
are both on Magnus's site as well.

Model 212
Stored random voltage
A source of unpredictable control voltage that changes when a pulse is
applied. Probability distribution (over control voltage range) is
flat; correlation is zero.
Random voltage source
A source of continuously changing random voltage with a modified
Gaussian probability distribution and voltage-controlled spectral
bandwidth (probable rate of change).


On Wed, Nov 10, 2010 at 9:31 PM, Byron G. Jacquot <thescum at surfree.com> wrote:
> Howdy all,
>
> A friend has a Buchla electronic music box. ?He brought it to me for a little TLC. ?I've been able to suss out and solve a few issues, but I've got one remaining that's not been so forthcoming: ?The Random Voltage Source quits working as the machine warms up. ?It runs fine when it's cool, but stalls after a few minutes.
>
> I've seen Magnus' schematic collection, but there's no 212. ?Does anyone have any documentation for this guy, or any idea where I should be looking?
>
> Thanks,
>
> Byron Jacquot
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From mverbos at earthlink.net  Thu Nov 11 10:13:55 2010
From: mverbos at earthlink.net (mark verbos)
Date: Thu, 11 Nov 2010 04:13:55 -0500
Subject: [sdiy] Buchla Dodecamodule docs?
In-Reply-To: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
References: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
Message-ID: <B5C35107-A137-4715-B918-4F4E23A4DF16@earthlink.net>

The random section of a 212 is the same as a 265. I have had that problem on a 227 and it turned out to be a vactrol that opened circuit when it heated up.

Mark






On Nov 11, 2010, at 12:31 AM, Byron G. Jacquot wrote:

> Howdy all,
> 
> A friend has a Buchla electronic music box.  He brought it to me for a little TLC.  I've been able to suss out and solve a few issues, but I've got one remaining that's not been so forthcoming:  The Random Voltage Source quits working as the machine warms up.  It runs fine when it's cool, but stalls after a few minutes.  
> 
> I've seen Magnus' schematic collection, but there's no 212.  Does anyone have any documentation for this guy, or any idea where I should be looking?
> 
> Thanks,
> 
> Byron Jacquot
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Thu Nov 11 10:43:17 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 11 Nov 2010 10:43:17 +0100
Subject: [sdiy] XOR as 'digital' ring modulator
In-Reply-To: <4CDB261E.8010803@rubidium.dyndns.org>
References: <AANLkTikTP7SOPQxM3xg-Ew-Ax46wK7ikS2Gced-Ui4Qr@mail.gmail.com>
	<313563882.275552.1289398494183.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF286BE6B@DC1EXC2.na.coherentinc.com>
	<AANLkTik=tVGGEwpiE2VenJSsUJzYZkJObnsQWuTEyGfd@mail.gmail.com>
	<934247.5730.qm@web55304.mail.re4.yahoo.com>
	<4CDB15D2.4000505@rubidium.dyndns.org>
	<AANLkTikQmNfjUSK5W-pvHpqu1-q9Ht1YsL70He-R_6ga@mail.gmail.com>
	<4CDB261E.8010803@rubidium.dyndns.org>
Message-ID: <AANLkTinbxaYT_Z=U6KLdpqTseQH7R1uF=0ANknVVB=1R@mail.gmail.com>

Hi Magnus,
thanks for your explanations. They were really helpful.

On 11/11/2010, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:
> On 11/10/2010 11:24 PM, cheater cheater wrote:
>> Magnus,
>> I'm afraid I didn't understand what you said there. Could you elaborate
>> please?
>
> A ring-modulator... the double-balanced diode ring, which is used for
> modulation and demodulation, a radio device... approximates a 4-quadrant
> multiplication. It does not have "a selectable gain of + or - 1".

Oh yes, that's definitely understood.

However, the "xor ring modulator", if realized with ternary logic
circuits, is just like a normal ring modulator put through a sgn(x)
function. The sgn(x) function has some very interesting properties.
It's on the one hand very much like a hard clipper. 0V goes to 0V,
anything above goes to say +5V, anything below goes to, for example,
-5V. So you can see it as a signal similar to one you could derive by
shaping a real ring modulator. One other important thing here is that
it keeps the zero crossings and therefore periods of at least some
fundamental most of the time, a property which makes our ears
associate the sound with a real ring modulator.

> The original ring-modulator isn't particular "linear", it has quite a
> bit of distortion in fact. It is also quite bulky for audio use due to
> the transformers. The Gilbert cell is another approach to achieve the
> same, using transistors rather than diodes. Linearisation is also attempted.
>
> As for 4-quadrant multiplication is means multiplication covering the 4
> quadrants (of a circle) i.e. having both polarities on both input
> signals, but it assumes continuous scale to the respective inputs.
>
> So, when I talk about ring-mod, I mean that... 4-quadrant multiplication.

Oh yes, ok. Fully agreed that's the right definition. The xor circuit
is only a derivation off the real ring mod. That is, you could take a
normal ring mod, and just have a comparator-based shaper (hard
clipper) after it, and have the same or nearly the same output. So,
this circuit is fun, but maybe not something original ring modulators
could do already.

> Similar effects may be achieved using for instance switch-able gain, but
> it isn't a ring-mod, a ring-mod doesn't do that unless you use a
> balanced digital signal as input, but then you can't cover all the
> aspects of a ring-mod which a triangle and sine would cover for instance.

Not sure what you mean here?

Cheers,
D.


> This is why I disagree with Tim.
>
> Cheers,
> Magnus
>
>> Thanks
>> D.
>>
>> On 10/11/2010, Magnus Danielson<magnus at rubidium.dyndns.org>  wrote:
>>> On 11/10/2010 09:27 PM, Tim Ressel wrote:
>>>> As a hopefully interesting side note, there are 2 ways to obtain the
>>>> "ring
>>>> modulator" function. The popular one for the synth crowd is a  linear
>>>> multiplier
>>>> like the AD633. The other way is by polarity reversal.  This is how true
>>>> "ring
>>>> modulators" work: the carrier signal goes  through an amplifier that has
>>>> a
>>>> selectable gain of + or - 1.  The  modulation signal's sign determines
>>>> the
>>>> gain
>>>> polarity: when the mod  signal is positive the gain is +1, when
>>>> negative,
>>>> -1.
>>>>
>>>>
>>>> This is of course not nearly as clean as the linear multiplier, but hey,
>>>> clean
>>>> is over-rated.
>>>>
>>>>
>>>> The XOR ring mod works as a true ring mod, as an XOR gate is a
>>>> digitally-controlled inverter.
>>>>
>>>> We return you now to your regularly scheduled programming.
>>>
>>> No. The true ring mod does not have gain which shift between +1 and -1.
>>> It has a gain shifting between those two extremes. A true ring mod
>>> actually always have losses.
>>>
>>> Modern ring-mod equivalents such as Gilbert cells can also be made to do
>>> 4-quadrature multiplications like the old double-balanced diode rings.
>>>
>>> Cheers,
>>> Magnus
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>
>


From jays at aracnet.com  Thu Nov 11 17:46:53 2010
From: jays at aracnet.com (Jay Schwichtenberg)
Date: Thu, 11 Nov 2010 08:46:53 -0800
Subject: [sdiy] Buchla Dodecamodule docs?
In-Reply-To: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
References: <9046560.1289453509080.JavaMail.root@mswamui-bichon.atl.sa.earthlink.net>
Message-ID: <001c01cb81c0$0b6b81d0$22428570$@com>

Byron,

I wouldn't think about it all that much. I'd just get a can of freeze spray
and use small squirts on various components until I got a suspicious one.
Then I would alternate between freezing it and put my finger on it to warm
it up and see if that issolates the part.

Good luck.
Jay S.

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Byron G. Jacquot
Sent: Wednesday, November 10, 2010 9:32 PM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] Buchla Dodecamodule docs?

Howdy all,

A friend has a Buchla electronic music box.  He brought it to me for a
little TLC.  I've been able to suss out and solve a few issues, but I've got
one remaining that's not been so forthcoming:  The Random Voltage Source
quits working as the machine warms up.  It runs fine when it's cool, but
stalls after a few minutes.  

I've seen Magnus' schematic collection, but there's no 212.  Does anyone
have any documentation for this guy, or any idea where I should be looking?

Thanks,

Byron Jacquot
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Thu Nov 11 18:31:39 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 11 Nov 2010 18:31:39 +0100
Subject: [sdiy]  Groove jitter in step sequencers
Message-ID: <AANLkTik5v4eBq54m0DzKOJUwccka6ZLYN_JvGZr9ny=W@mail.gmail.com>

It would be interesting to make something that simulates different
kinds of groove. You basically have a single master clock, and then a
"groove clock" which is around the same frequency as the master clock,
maybe more, maybe less. This groove clock has programmable jitter. The
final clock output works like this:

1. the master clock sends out a pulse which is latched somewhere
2. the pulse waits until the next groove clock happens and then is
sent out to the clock output


You could do the programmable-jitter clock this way: have a
current-out DAC working at clock rate. Have a capacitor. Every time a
new groove clock pulse happens, the capacitor is unloaded. Then, the
DAC pulses the capacitor with some sort of current. Of course the
higher the value, the higher the charge is going to be at the
capacitor after the pulse happens. Then, start discharging the
capacitor (or maybe just always have it grounded through a
current-limiting resistor?). When the capacitor falls below a certain
value, checked by a comparator, have the circuit send out a pulse.

You could have samples, maybe even looped samples, playing back
through the DAC. You could for example sample the jitter of the 808 by
checking when it does respond to interrupts (I'm sure someone creative
would find a way to do it). You could also make the sample index reset
every fourth bar, or something like that, to make the groove more
mechanical. Of you could have a looping sample of a length which is
not a divisor of the bar length, to have a nice jitter that does not
repeat and that "softens up" the rhythm.

Finally, both clocks could be run by analogue VCOs for more fun.

Cheers,
D.

On 11/11/2010, dancemachine <dancemachine at gmail.com> wrote:
> feel that midi groove.   since i started using midi for clock only I
> am having great results.  all thanks for flame clockwork, which gets
> all weird as soon as you send it notes instead of clock only
>
>
> On Thu, Nov 11, 2010 at 11:31 AM, Florian Anwander
> <fanwander at mnet-online.de> wrote:
>> Hi Nick
>>
>>> Hello, anybody have anything to say about the inherent 'groove' and or
>>> 'pocket of old hardware sequencers?
>>> MSQ700?
>>> MSQ100?
>>
>> No inherent groove here. Everything which could be "inherent groove" like
>> in
>> a TR808, is overridden by the inherent delay which is provided by the
>> length
>> of MIDI note events and the serial transmission of MIDI. Each MIDI Note
>> event takes 1 ms. If you play a three note chord, the third note will come
>> 2
>> ms after the first one. This will cause more unwanted "inherent groove"
>> than
>> any wiggling inside the devices clock reading could do.
>>
>> Florian
>>
>


From cheater00 at gmail.com  Thu Nov 11 19:06:05 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 11 Nov 2010 19:06:05 +0100
Subject: [sdiy] Groove jitter in step sequencers
In-Reply-To: <AANLkTikr4acgTsBshyvDOYxAOvorC5uayPie2SxNm2Kj@mail.gmail.com>
References: <AANLkTik5v4eBq54m0DzKOJUwccka6ZLYN_JvGZr9ny=W@mail.gmail.com>
	<AANLkTikr4acgTsBshyvDOYxAOvorC5uayPie2SxNm2Kj@mail.gmail.com>
Message-ID: <AANLkTikVs4i0PhLQ0rrRpjPWyj+V-_+e=v=sNCfEVAWW@mail.gmail.com>

Oh yeah, that can be really good. I tried this out in Sony ACID, where
each midi track can have separate groove settings. It can sound real
real interesting, especially if you change the groove amount.

D.

On Thu, Nov 11, 2010 at 18:42, dustin sedlacek
<dustin.sedlacek at gmail.com> wrote:
> I have ?3 drum machines, an Alesis HR16, a Boss DR5 and a Boss DR202, each
> of them have there own?characteristic?swing and can (to a limited extent)
> sequence external modules. I can get some really amazing grooves when I
> start using?multiple?machines with different swing settings on different
> sounds.
>
> On Thu, Nov 11, 2010 at 11:31 AM, cheater cheater <cheater00 at gmail.com>
> wrote:
>>
>> It would be interesting to make something that simulates different
>> kinds of groove. You basically have a single master clock, and then a
>> "groove clock" which is around the same frequency as the master clock,
>> maybe more, maybe less. This groove clock has programmable jitter. The
>> final clock output works like this:
>>
>> 1. the master clock sends out a pulse which is latched somewhere
>> 2. the pulse waits until the next groove clock happens and then is
>> sent out to the clock output
>>
>>
>> You could do the programmable-jitter clock this way: have a
>> current-out DAC working at clock rate. Have a capacitor. Every time a
>> new groove clock pulse happens, the capacitor is unloaded. Then, the
>> DAC pulses the capacitor with some sort of current. Of course the
>> higher the value, the higher the charge is going to be at the
>> capacitor after the pulse happens. Then, start discharging the
>> capacitor (or maybe just always have it grounded through a
>> current-limiting resistor?). When the capacitor falls below a certain
>> value, checked by a comparator, have the circuit send out a pulse.
>>
>> You could have samples, maybe even looped samples, playing back
>> through the DAC. You could for example sample the jitter of the 808 by
>> checking when it does respond to interrupts (I'm sure someone creative
>> would find a way to do it). You could also make the sample index reset
>> every fourth bar, or something like that, to make the groove more
>> mechanical. Of you could have a looping sample of a length which is
>> not a divisor of the bar length, to have a nice jitter that does not
>> repeat and that "softens up" the rhythm.
>>
>> Finally, both clocks could be run by analogue VCOs for more fun.
>>
>> Cheers,
>> D.
>>
>> On 11/11/2010, dancemachine <dancemachine at gmail.com> wrote:
>> > feel that midi groove. ? since i started using midi for clock only I
>> > am having great results. ?all thanks for flame clockwork, which gets
>> > all weird as soon as you send it notes instead of clock only
>> >
>> >
>> > On Thu, Nov 11, 2010 at 11:31 AM, Florian Anwander
>> > <fanwander at mnet-online.de> wrote:
>> >> Hi Nick
>> >>
>> >>> Hello, anybody have anything to say about the inherent 'groove' and or
>> >>> 'pocket of old hardware sequencers?
>> >>> MSQ700?
>> >>> MSQ100?
>> >>
>> >> No inherent groove here. Everything which could be "inherent groove"
>> >> like
>> >> in
>> >> a TR808, is overridden by the inherent delay which is provided by the
>> >> length
>> >> of MIDI note events and the serial transmission of MIDI. Each MIDI Note
>> >> event takes 1 ms. If you play a three note chord, the third note will
>> >> come
>> >> 2
>> >> ms after the first one. This will cause more unwanted "inherent groove"
>> >> than
>> >> any wiggling inside the devices clock reading could do.
>> >>
>> >> Florian
>> >>
>> >
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
>
> --
> Dustin Sedlacek
> 901-828-6801
>


From gsn10 at hotmail.com  Thu Nov 11 23:13:26 2010
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Thu, 11 Nov 2010 17:13:26 -0500
Subject: [sdiy] Groove jitter in step sequencers
In-Reply-To: <AANLkTikVs4i0PhLQ0rrRpjPWyj+V-_+e=v=sNCfEVAWW@mail.gmail.com>
References: <AANLkTik5v4eBq54m0DzKOJUwccka6ZLYN_JvGZr9ny=W@mail.gmail.com>,
	<AANLkTikr4acgTsBshyvDOYxAOvorC5uayPie2SxNm2Kj@mail.gmail.com>,
	<AANLkTikVs4i0PhLQ0rrRpjPWyj+V-_+e=v=sNCfEVAWW@mail.gmail.com>
Message-ID: <SNT104-W295E3E2468AD0285F3E4B1B4320@phx.gbl>


> Oh yeah, that can be really good. I tried this out in Sony ACID, where
> each midi track can have separate groove settings. It can sound real
> real interesting, especially if you change the groove amount.
>
> D.

Some of what's vaguely perceived as "groove" depends on the relative 
timing of individual sounds.? The Linn LM-1 has a good reputation for 
"feel"; if you look at the ROM dumps you'll find that the snare sample
starts 10 ms late.? This can even be varied somewhat since each sound
has its own tuning control. Of course, this was probably unintentional
on Roger Linn's part...

I haven't used one but I believe the Yamaha RY20 has a bunch of 
templates for messing with this sort of thing.? 

Anyone looking to seriously investigate it should do some real
measurements.? Qualitative value judgments are obviously the intended 
goal, but aren't particularly helpful or descriptive by themselves.
 		 	   		  

From oldcrow at oldcrows.net  Fri Nov 12 00:25:10 2010
From: oldcrow at oldcrows.net (The Old Crow)
Date: Thu, 11 Nov 2010 17:25:10 -0600
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
Message-ID: <4CDC7B56.3060106@oldcrows.net>

     Speaking as asomeone who tore apart some of the NE series modules 
six years ago (see: http://www.cs80.com/ne_proj.html ), I can say that 
the state of Yamaha's combo organ design paradigm was in a state of 
extreme flux in the mid-1970s.  The early (1973-74) synthesizer stuff 
was all potted "for temperature stability" (read: to hide it from Korg) 
as back then there was this mad rush to market for combo synthesizer 
portable gear.  Of course, Yamaha's 1970s stuff was designed at their 
Electone organ facility in Hamamatsu by organ engineers, not 
"synthesizer engineers" like Moog, Oberheim or Buchla.  To this end they 
used the parts they used in designs of Electone models of the day.  The 
GX-1 (according to lead engineer at that time, Mr. Nakamura) was an R&D 
experiment mainly to test all possible aspects of making a polyphonic 
combo instrument using the means they had available.

   Yamaha had what most electronics manufacturers envied at the time: 
their own chip fab.  While this is less of an issue today, back then it 
offered a big advantage in design cost savings as their circuits could 
be done in NMOS, PMOS or bipolar.  Many of their logic engines such as 
key assigners were made this way.  Later DSP engines, too, were made 
this way--from the wavetable engine of the 'PASS' Electones up to the DX 
FM engines of the 1980s Electones and synthesizers.

   Around 1975, they stopped making the cost-inefficient NE potted 
modules in favor of the easier-to- assembly-line discrete boards.  This 
was about when the first part feeders came into use, and fitting TO-5 
cans was not a part feeder friendly package.  Thus, they switched to 
SIL/DIL packages for everything when they could.  The "VCOIII" (NE11500) 
was the only module made in potted form for temperature stable reasons.  
The module contains a sample/hold amplifier made from a complementary 
FET, an op-amp, some polystyrene caps and a low-impedance FET switch to 
open the sample path.  The Oscillator portion is a really vanilla 
sawtooth relaxation type with a FET buffer hung on the timing cap.  I 
recall there was an interesting vibrato CV input that used a little bit 
of piecewise-linear curve fitting to bend the CV into something that 
sounded good along the range of the VCO.  The IG00153 (CS VCO) is 
totally different.  It's closest cousin is the Rhodes Chroma VCO.

   The filters on the later CSY-2 use BA626 and BA627 diode arrays (SIL 
parts) instead of the CA3019s, but the filters are essentially the same 
otherwise.  The GX1 bandpass (NE11000) module uses these as well.

   The EGs would have been a pain to figure out, but the circuits show 
up in the Yamaha patents.  Nothing particularly amazing there, other 
than they crammed all those parts into those boards.

Scott Rider
/**/


On 11/9/2010 9:16 AM, Richard Atkinson wrote:
> This email may be of particular interest to anyone who has studied the 
> first and second generations of Yamaha synthesizer, namely the SY-1 / 
> SY-2 / GX-1 synthesizers with epoxy potted NE series modules in the 
> first generation and the CS series of synthesizers with IG series 
> chips in the second generation.
>
> It turns out there is an intermediate generation of Yamaha synthesizer 
> between these two generations. I found this when looking inside my 
> newly acquired Yamaha CSY-2 organ yesterday. This is a later version 
> of the CSY-1 organ, which has been featured in a few web pages and 
> Matrixsynth articles and which contains the same epoxy potted NE 
> series modules as the GX-1.
>
> I took the lid off my Yamaha CSY-2 yesterday with a friends's help. 
> The insides of my CSY-2 were rather dirty, having played host to a 
> number of spiders and other objects over the years. There was evidence 
> of damp damage on the base of the machine; it has clearly been kept on 
> a damp surface at some point for quite a while.
>
> It turns out the CSY-2 is very, very different internally from the CSY-1.
> Whereas the CSY-1 is a fully discrete design with many circuit boards, 
> some
> of them held vertically in a rack frame, the CSY-2 has the first signs of
> integration.
>
> In particular, the auto bass chord circuit board (ABC CSY-2) has two 
> large
> YM chips on it and there is another board with another large YM chip. The
> function of the auto bass chord system on this organ is quite different
> from the CSY-1, and this would seem to explain why. There is no rack of
> vertically mounted boards; there are much fewer boards and these are all
> mounted horizontally.
>
> Of particular interest is the solo synthesizer section mounted on the
> underside of the top panel of the organ. Like my CSY-1, the solo
> synthesizer boards in my CSY-2 are very clean, much cleaner than the rest
> of the instrument. This no doubt has to do with being mounted upside 
> down,
> gravity being in its favour.
>
> The CSY-2 does not however contain either of the versions of the CSY-1 /
> SY-1 solo synthesizer circuits. It's a completely different, much more
> integrated version of the solo synthesizer. The boards are not named SM1,
> SM2, SK, SP1 and SP2 as in the SY-2. Instead they are named VCO, VCF, 
> VCA,
> FEG, AEG, SK and SP.
>
> VCO is the only board that contains any of the old NE series modules. 
> It has the VCO-III module as seen in later versions of the CSY-1, SY-1 
> and all SY-2s.
>
> The VCF board has four ICs on it, all by Rohm. Two BA626s and two 
> BA627s. I
> have been unable so far to identify what these are but what is most
> peculiar about this is that the organ features neither the older NE 
> module
> based filters, nor the IG chip based filters of the CS synthesizers 
> and the
> later Electone organs, but a generation in between. This is the only
> example of this generation of Yamaha synthesizer filter I have ever seen,
> and as far as I'm aware it's completely undocumented on the internet.
>
> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can 
> packaging
> and so on. The VCA board is self explanatory, the FEG board is for the
> filter envelope and the AEG board is for the amplifier envelope. No NE
> modules here, in particular no VCF-EG or VCA-EG modules. This is the only
> example of these Yamaha envelope generators I have seen, again completely
> undocumented on the internet as far as I know.
>
> The remaining boards, SK and SP, seem to be the same as in the older
> machines. They are for the gate and trigger pulse recovery and for the
> presets.
>
> Sound-wise, it behaves much like a cross between the two generations. 
> The oscillator definitely has the same timbral qualities as an SY-2, 
> but the filters are much, much cleaner. I wouldn't go so far as to say 
> they sound like CS series IG chip filters, but they are certainly more 
> well behaved than the highly distorting diode bridge filters in the NE 
> series epoxy filled modules.
>
> Richard
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From mverbos at earthlink.net  Fri Nov 12 00:27:04 2010
From: mverbos at earthlink.net (mark verbos)
Date: Thu, 11 Nov 2010 18:27:04 -0500
Subject: [sdiy] working with EPROMs
Message-ID: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>

Hi guys,


I've been looking at some 70s delay schematics that use EPROMs to create all of their timing signals for the converters and rams and everything and it makes me wonder how you create the data for those. I have a burner, but the only way I know of to create the binary files is with the Wiard/Darwin Grosse WAVE256 application. I mean, if I made some graph paper with 256 lines each way I could draw the timing that I want and then enter it line by line into WAVE256 in the "Numeric" section, but there has to be a better way. My googling has not gotten me anywhere. Does anyone have any suggestions? Chris Moore, the man behind  Ursa Major, mentions punch cards in his history section, but there must be some software...other than just HEX editors... right?


Thanks,

Mark

From John.Speth at coherent.com  Fri Nov 12 00:44:03 2010
From: John.Speth at coherent.com (Speth, John)
Date: Thu, 11 Nov 2010 15:44:03 -0800
Subject: [sdiy] working with EPROMs
In-Reply-To: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
References: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
Message-ID: <AB7F62BBA358E04FA919701B9703184AF286C51C@DC1EXC2.na.coherentinc.com>

> I've been looking at some 70s delay schematics that use EPROMs to
> create all of their timing signals for the converters and rams and
> everything and it makes me wonder how you create the data for
> those. I have a burner, but the only way I know of to create the
> binary files is with the Wiard/Darwin Grosse WAVE256 application.
> I mean, if I made some graph paper with 256 lines each way I could
> draw the timing that I want and then enter it line by line into
> WAVE256 in the "Numeric" section, but there has to be a better
> way. My googling has not gotten me anywhere. Does anyone have any
> suggestions? Chris Moore, the man behind  Ursa Major, mentions
> punch cards in his history section, but there must be some
> software...other than just HEX editors... right?

Editing by hand would be the last way you would want to do that.  You'd probably make a mistake that will be impossible to debug.

The way I'd do it is to write a desktop program of some sort that will generate the output file containing the data that you desire.  The output could either be generated with no input file (rules implemented in code) or, if you have the time and ability, take some kind of timing diagram file input (invent your own for simplicitys' sake).  The latter method requires a bit more up-front effort but you get a lot of flexibility when it's done.  It's not a small job, for sure.

The nice thing is that just about any programming language would do the trick (perl, C, basic, etc).

JJS


The information contained in this communication is confidential and may be legally privileged. It is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. If you are not the intended recipient you are hereby (a) notified that any disclosure, copying, distribution or taking any action with respect to the content of this information is strictly prohibited and may be unlawful, and (b) kindly requested to inform the sender immediately and delete any copies. Coherent is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.


From davekendall at ntlworld.com  Fri Nov 12 02:17:08 2010
From: davekendall at ntlworld.com (Dave Kendall)
Date: Fri, 12 Nov 2010 01:17:08 +0000
Subject: [sdiy] 0.100 pin header reliability.
Message-ID: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>

Hi All.

Do any of you have an opinion on the long-term reliability of 0.100  
connectors like these;
http://www.rapidonline.com/Cables-Connectors/Connectors-Multipole/PCB- 
Interconnect/Straight-pin-header/28953

They make assembly much easier and neater (at added cost), but how good  
are they in the long term? I'm not so bothered about the number of  
reliable make/break cycles, just whether they generally hold good once  
installed, and whether vibration from handling or road use causes any  
common problems. I once had an Ensoniq EPS that had known issues with a  
power multipin corroding and causing failures years ago (when ensoniq  
actually *had* a service centre in Putney, London, UK)

Anybody got any real-world advice?

Thanks in advance,

cheers,
Dave



From kevinvanwulpen at gmail.com  Fri Nov 12 02:17:27 2010
From: kevinvanwulpen at gmail.com (Kevin Vanwulpen)
Date: Thu, 11 Nov 2010 17:17:27 -0800
Subject: [sdiy] working with EPROMs
In-Reply-To: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
References: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
Message-ID: <4CDC95A7.4060201@gmail.com>

What are you trying to accomplish exactly?

Are you trying to repair a device where the EPROM is broken (and can't 
find another one which you can clone or so?). Any info on the specific 
device/schematic/EPROM you can share which would allow us to help you 
better?On 11/11/10 3:27 PM, mark verbos wrote:
> Hi guys,
>
>
> I've been looking at some 70s delay schematics that use EPROMs to create all of their timing signals for the converters and rams and everything and it makes me wonder how you create the data for those. I have a burner, but the only way I know of to create the binary files is with the Wiard/Darwin Grosse WAVE256 application. I mean, if I made some graph paper with 256 lines each way I could draw the timing that I want and then enter it line by line into WAVE256 in the "Numeric" section, but there has to be a better way. My googling has not gotten me anywhere. Does anyone have any suggestions? Chris Moore, the man behind  Ursa Major, mentions punch cards in his history section, but there must be some software...other than just HEX editors... right?
>
>
> Thanks,
>
> Mark
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From pfperry at melbpc.org.au  Fri Nov 12 02:39:07 2010
From: pfperry at melbpc.org.au (Paul Perry)
Date: Fri, 12 Nov 2010 12:39:07 +1100
Subject: [sdiy] 0.100 pin header reliability.
References: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
Message-ID: <AB439C5D4DDE4C5BB68324EF1E511A00@ownerf0d9273f5>

If the leads are made correctly, I can't see a problem.
But, I find it very difficult to make the leads myself.
Can one buy pre-made leads for this stuff?
Certainly, there is a lot of industrial & scientific stuff
from the 60s onwards that uses this stuff - and I have never
seen any failures.

paul perry Melbourne Australia


----- Original Message ----- 
From: "Dave Kendall" > Do any of you have an opinion on the long-term 
reliability of 0.100
> connectors like these;
> http://www.rapidonline.com/Cables-Connectors/Connectors-Multipole/PCB-
> Interconnect/Straight-pin-header/28953
>
> They make assembly much easier and neater (at added cost), but how good
> are they in the long term? I'm not so bothered about the number of
> reliable make/break cycles, just whether they generally hold good once
> installed, and whether vibration from handling or road use causes any
> common problems. I once had an Ensoniq EPS that had known issues with a
> power multipin corroding and causing failures years ago (when ensoniq
> actually *had* a service centre in Putney, London, UK)



From dixon at interchange.ubc.ca  Fri Nov 12 04:17:03 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Thu, 11 Nov 2010 19:17:03 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
References: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
Message-ID: <B7AFAF15E28240BB8CD248DDC87D29DC@galvanox01>

> Do any of you have an opinion on the long-term reliability of 0.100
> connectors like these;
> http://www.rapidonline.com/Cables-Connectors/Connectors-Multipole/PCB-
> Interconnect/Straight-pin-header/28953

I use 'em myself, and have never had any problems with them.  However, you
must ensure that you use high-quality crimp pins on the female connectors.
I was using ones from China that didn't have any "spring" in them, and they
started failing.  Now I'm using ones that are very springy and retain their
shape, and they're great.



From stewpye at optusnet.com.au  Fri Nov 12 05:31:34 2010
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Fri, 12 Nov 2010 14:31:34 +1000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
References: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
Message-ID: <4CDCC326.8030809@optusnet.com.au>

Hi Dave,

FWIW I'm an electronics technician. Here's my experiences...
I've generally only seen the contacts fail if the equipment is in hash 
corrosive environments.
However I have seen many failures where the wire was only crimped to the 
pin (I'm talking about the female housing now). After time it seems that 
the wire oxidises and the connection between the wire and pin becomes 
bad. I always solder the wire to the pin and have never had a problem 
with any connections I've done.

I find the easiest way to do this is to leave the pins on the strip, 
then just bend the sides of the pin in a bit so it will fit into the 
shell easily later, tin both the pin and the stripped wire, then solder 
them together. Once this is done you can squash the back end of the pin 
over the insulation of the wire. The guys I work with prefer to separate 
the pins and crimp them using the appropriate tool and then solder them. 
Maybe they can do it that way as fast as I do it my way but, but I'm 
damn sure I can't!

I would never use the insulation displacement type female connector that 
suits these headers as I've seen too many failures.


Cheers,
Stew.


Dave Kendall wrote:
> Hi All.
>
> Do any of you have an opinion on the long-term reliability of 0.100 
> connectors like these;
> http://www.rapidonline.com/Cables-Connectors/Connectors-Multipole/PCB-Interconnect/Straight-pin-header/28953 
>
>
> They make assembly much easier and neater (at added cost), but how 
> good are they in the long term? I'm not so bothered about the number 
> of reliable make/break cycles, just whether they generally hold good 
> once installed, and whether vibration from handling or road use causes 
> any common problems. I once had an Ensoniq EPS that had known issues 
> with a power multipin corroding and causing failures years ago (when 
> ensoniq actually *had* a service centre in Putney, London, UK)
>
> Anybody got any real-world advice?
>
> Thanks in advance,
>
> cheers,
> Dave
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From dingebre at 3dphysics.net  Fri Nov 12 06:06:21 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Thu, 11 Nov 2010 22:06:21 -0700
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <4CDCC326.8030809@optusnet.com.au>
References: <91725B2A-EDFA-11DF-94B2-000393A85F9E@ntlworld.com>
	<4CDCC326.8030809@optusnet.com.au>
Message-ID: <001001cb8227$58d21710$0a764530$@net>

I'll share some of my limited experiences. Stew makes some good points about
soldering v. crimping. However, in theory, if you use the proper tool for
inserting the wire into the female connector, the wire "cold welds" to the
female pin and forms an airtight, therefore corrosion resistant bond. I've
been using this tool:

http://www.mouser.com/Search/ProductDetail.aspx?R=58074-1virtualkey57100000v
irtualkey571-580741

with this head:

http://www.mouser.com/Search/ProductDetail.aspx?R=58246-1virtualkey57100000v
irtualkey571-58246-1

with these female connectors:

http://www.mouser.com/Search/ProductDetail.aspx?R=3-640440-6virtualkey571000
00virtualkey571-3-640440-6

They seem to make a very good mechanical connection and haven't had a
failure in several hundred individual connections.

As to the female to male reliability, I don't pack my stuff very often. I
recently took my two tall racks which contain several modules using this
type of connector in the back of my Tahoe and had no problem. But that is
only one trip.

I using these connectors exclusively with my Synthasystem resurrection which
will be racked into Gator portable cases. I'll know more as time goes on.

If you get the male/female with locking tabs, you will probably have better
luck with regard to vibration. Most commonly used metals in electronics will
oxidize especially if used in a corrosive environment so any connector,
short of an expensive specialized sealed connector, will probably oxidize
over time depending on where it is stored/used.

David 



~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of Stewart Pye
~~ Sent: Thursday, November 11, 2010 9:32 PM
~~ To: sdiy DIY
~~ Subject: Re: [sdiy] 0.100 pin header reliability.
~~ 
~~ Hi Dave,
~~ 
~~ FWIW I'm an electronics technician. Here's my experiences...
~~ I've generally only seen the contacts fail if the equipment is in hash
~~ corrosive environments.
~~ However I have seen many failures where the wire was only crimped to the
~~ pin (I'm talking about the female housing now). After time it seems that
~~ the wire oxidises and the connection between the wire and pin becomes
~~ bad. I always solder the wire to the pin and have never had a problem
~~ with any connections I've done.
~~ 
~~ I find the easiest way to do this is to leave the pins on the strip,
~~ then just bend the sides of the pin in a bit so it will fit into the
~~ shell easily later, tin both the pin and the stripped wire, then solder
~~ them together. Once this is done you can squash the back end of the pin
~~ over the insulation of the wire. The guys I work with prefer to separate
~~ the pins and crimp them using the appropriate tool and then solder them.
~~ Maybe they can do it that way as fast as I do it my way but, but I'm
~~ damn sure I can't!
~~ 
~~ I would never use the insulation displacement type female connector that
~~ suits these headers as I've seen too many failures.
~~ 
~~ 
~~ Cheers,
~~ Stew.
~~ 
~~ 
~~ Dave Kendall wrote:
~~ > Hi All.
~~ >
~~ > Do any of you have an opinion on the long-term reliability of 0.100
~~ > connectors like these;
~~ > http://www.rapidonline.com/Cables-Connectors/Connectors-Multipole/PCB-
~~ Interconnect/Straight-pin-header/28953
~~ >
~~ >
~~ > They make assembly much easier and neater (at added cost), but how
~~ > good are they in the long term? I'm not so bothered about the number
~~ > of reliable make/break cycles, just whether they generally hold good
~~ > once installed, and whether vibration from handling or road use causes
~~ > any common problems. I once had an Ensoniq EPS that had known issues
~~ > with a power multipin corroding and causing failures years ago (when
~~ > ensoniq actually *had* a service centre in Putney, London, UK)
~~ >
~~ > Anybody got any real-world advice?
~~ >
~~ > Thanks in advance,
~~ >
~~ > cheers,
~~ > Dave
~~ >
~~ > _______________________________________________
~~ > Synth-diy mailing list
~~ > Synth-diy at dropmix.xs4all.nl
~~ > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
~~ >
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From thescum at surfree.com  Fri Nov 12 06:39:23 2010
From: thescum at surfree.com (Byron G. Jacquot)
Date: Thu, 11 Nov 2010 22:39:23 -0700 (GMT-07:00)
Subject: [sdiy] Buchla Dodecamodule docs?
Message-ID: <7496652.1289540363688.JavaMail.root@elwamui-lapwing.atl.sa.earthlink.net>

>The random section of a 212 is the same as a 265. I have had that problem on a 227 and it turned out to be a vactrol that opened circuit when it heated up.

Mark & all,

Thanks for the pointers.  I'll see if I can get into diagnosing more over the weekend.  I'll figure out which signal is responsible for the stall, then look for temperature dependencies.

I have a feeling I'll be back in a couple days with a question about transistor and/or Vactrol substitution.

Thanks again!

Byron Jacquot


From subjectivity at hotmail.com  Fri Nov 12 07:54:48 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Fri, 12 Nov 2010 01:54:48 -0500
Subject: [sdiy] FORMANT 2? les extensions
Message-ID: <BLU0-SMTP15419C24AD64F023792AA96C8330@phx.gbl>

At yusynth's site, he has a bunch of Formant articles in French which are not in the original English Formant book number 1.(which I have)

http://yusynth.net/archives/formant.html

A voltage processor, a parametric equalizer, a sequencer, etc are all included in this edition 

I am trying to find out if these projects all came from Elektor issues or were they specially made for this elektor Formant book 2?

Also, has anyone tried them? anyone know were to find them in English or in what issues they were first published?


thanks so much!

From cary.roberts at retrosynth.net  Fri Nov 12 07:57:23 2010
From: cary.roberts at retrosynth.net (Cary Roberts)
Date: Thu, 11 Nov 2010 22:57:23 -0800
Subject: [sdiy] 0.100 pin header reliability.
Message-ID: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>

>Do any of you have an opinion on the long-term reliability of 0.100
>connectors like these;
>
>Anybody got any real-world advice?

Here's my advice gleaned from real world experience with my synthesizer
collection.  I will also note that I specify connectors for high volume
server and consumer hardware for my day job.

My first declaration is that any connector is failure prone if not used with
proper tooling.  Most of the crimpers I have cost in excess of $250.  This
includes tooling for Molex 2.54mm, 2mm, MiniFit Jr, and PicoBlade
connectors, Tyco MTA 100 and 156 connectors, and JST 2mm connectors.  The
Tyco 696202-1 Super Champ tool is barely passible for any of the
aforementioned connectors and it costs $90.  Some folks get by with the Tyco
59803-1 for MTA 100 connectors but I don't find that it makes for reliable
connections.  In fact, the only cheap crimper that comes to mind that does a
half way decent job is an IDC hand crimper for dual row .1" headers with
.050" flat cable.  They're available for $15 and if you have Eurorack stuff
they're handy for making power cables too.

One could (and should) look to how various connector types have held up on
30+ year old synthesizers and audio equipment.  

Winners:
-------
.1" dual row headers like those on the Prophet 5, OBXa, OB8, etc have held
up well.

.1" single row headers on Roland equipment have held up well and don't seem
prone to oxidization. 

.062" Molex connectors used on Oberheim SEMs are still holding up well.

.156" gold plated finger edge cards hold up extremely well. (API, Neve,
computers, etc)

Soldered stranded wire with non-corrosive flux.

EDAC 38/56/90/120 connectors are made of win. (patchbays, recording
consoles)

ITT Cannon DL connectors are made of win. (patchbays, recording consoles)


Failures:
--------
.1" tin plated Tyco/AMP MTA connectors used for critical CVs on the
memorymoog are prone to oxidization and are utter fail.

.156" round pin headers like those used on the motherboards of the OBX,
OBSX, and OBXa are very prone to oxidation and are utter fail.

.1" x .3" DIP style headers like those used on the memorymoog are frail,
sockets are prone to oxidization, and are utter fail.

.1" single row Dean's connectors like those on the Voyetra 8 can be
troublesome.

.1" FPC cables like those used on later Sequential and some Akais can
fracture and break.

Cheap .156" tin plated headers can fail in less than a year if poorly made.
(see Digidesign 002 and 002R)

Soldered stranded wire with corrosive flux.

Soldered solid core wire with corrosive or non-corrosive flux.

_ANY_ crimp connector that has been soldered.



From sounddoctorin at imt.net  Fri Nov 12 08:22:27 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Fri, 12 Nov 2010 00:22:27 -0700
Subject: [sdiy] boards for jupiter 4..anyone set up to do a few?
Message-ID: <4CDCEB33.2000804@imt.net>

I think we can get a good image to work from without too much trouble.  
The boards in this thing are absolutely smashed.  I think it would 
really be best to just get a totally new set of boards in the card cage 
at least.  The rest of it is easy to repair I think.  Someone hit this 
thing with a wrecking ball it appears!

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From carsten at analog-monster.de  Fri Nov 12 08:39:07 2010
From: carsten at analog-monster.de (Carsten Toensmann)
Date: Fri, 12 Nov 2010 08:39:07 +0100
Subject: [sdiy] FORMANT 2? les extensions
References: <BLU0-SMTP15419C24AD64F023792AA96C8330@phx.gbl>
Message-ID: <824E1031BE864F92AE53A80857363DCF@ww901.siemens.net>

Hi Dan,

as I know most of the additional modules of book 2 have been released by 
elektor as stand alone projects first, then adapted for the Formant as synth 
modules. Unfortunately I don't know the issues.

I built the voltage- (waveform-) processor, the parametric equalizer, the 
ring modulator (which is also part of the MSS2000 book), the voltage 
controlled LFO (well I added voltage control of pulswidth also) and 
integrated them into my MSS2000, see also:

http://www.analog-monster.de/waveform_en.html
http://www.analog-monster.de/rfm_en.html
http://www.analog-monster.de/ringmod_en.html
http://www.analog-monster.de/vc-lfo_en.html

As I know book 2 does not exist in english or french. I consider all modules 
as very useful, and my personal favorite is the parametric equalizer, 
although it adds some noise to the sound, but the spectrum enhancements are 
great, one of the most important sound forming modules in my opinion.

Regards

Carsten

----- Original Message ----- 
From: "dan snazelle" <subjectivity at hotmail.com>
To: "synth-diy DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Friday, November 12, 2010 7:54 AM
Subject: [sdiy] FORMANT 2? les extensions


> At yusynth's site, he has a bunch of Formant articles in French which are 
> not in the original English Formant book number 1.(which I have)
>
> http://yusynth.net/archives/formant.html
>
> A voltage processor, a parametric equalizer, a sequencer, etc are all 
> included in this edition
>
> I am trying to find out if these projects all came from Elektor issues or 
> were they specially made for this elektor Formant book 2?
>
> Also, has anyone tried them? anyone know were to find them in English or 
> in what issues they were first published?
>
>
> thanks so much!
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 



From marr at lumin.us  Fri Nov 12 09:12:20 2010
From: marr at lumin.us (Mark Rivera)
Date: Fri, 12 Nov 2010 02:12:20 -0600
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
Message-ID: <AANLkTinNjUNRge7DMb=C0RihGMths2jDVjFvzmrNCSyS@mail.gmail.com>

> Winners:
> -------
> .1" dual row headers like those on the Prophet 5, OBXa, OB8, etc have held
> up well.
>
> .1" single row headers on Roland equipment have held up well and don't seem
> prone to oxidization.

> Failures:
> --------
> .1" tin plated Tyco/AMP MTA connectors used for critical CVs on the
> memorymoog are prone to oxidization and are utter fail.

What's the difference between the two winners and the failure here?

If the tin is fail, then what is the recommended plating?


From cary.roberts at retrosynth.net  Fri Nov 12 09:40:29 2010
From: cary.roberts at retrosynth.net (Cary Roberts)
Date: Fri, 12 Nov 2010 00:40:29 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTinNjUNRge7DMb=C0RihGMths2jDVjFvzmrNCSyS@mail.gmail.com>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
	<AANLkTinNjUNRge7DMb=C0RihGMths2jDVjFvzmrNCSyS@mail.gmail.com>
Message-ID: <513379B7E89F4B80A60F18E70448ECB7@onlive.corp>

Gold flash or plate should always be used on anything carrying critical
(pitch) control voltages.  Dual row headers are available with gold flash
header pins and female crimp contacts off the shelf.  Gold flash Tyco MTA
parts are sometimes a little hard to get in small quantities in the exact
config you may want.  I've done a bit of research lately while preparing to
change out a couple hundred MTAs across three memorymoogs.  I'm not sure why
the non-gold flashed Roland stuff fared better than the Tyco/AMP MTAs.  The
MTA is a single leaf contact in most configurations, but I assume the Roland
contacts are as well.  A number of the connectors I mentioned that didn't
fail weren't gold flash, which indicates that crimp contact design and
forming can be just as critical as plating.

-Cary




-----Original Message-----
From: Mark Rivera [mailto:marr at lumin.us] 
Sent: Friday, November 12, 2010 12:12 AM
To: Cary Roberts
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] 0.100 pin header reliability.

> Winners:
> -------
> .1" dual row headers like those on the Prophet 5, OBXa, OB8, etc have held
> up well.
>
> .1" single row headers on Roland equipment have held up well and don't
seem
> prone to oxidization.

> Failures:
> --------
> .1" tin plated Tyco/AMP MTA connectors used for critical CVs on the
> memorymoog are prone to oxidization and are utter fail.

What's the difference between the two winners and the failure here?

If the tin is fail, then what is the recommended plating?



From cheater00 at gmail.com  Fri Nov 12 09:42:38 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Fri, 12 Nov 2010 09:42:38 +0100
Subject: [sdiy] boards for jupiter 4..anyone set up to do a few?
In-Reply-To: <4CDCEB33.2000804@imt.net>
References: <4CDCEB33.2000804@imt.net>
Message-ID: <AANLkTinC1Bu3ZRB80hzviXVPbF8Z7LQY8ZpuR71X2jjn@mail.gmail.com>

Hi Bob,
got any pics?

Cheers,
D.

On 12/11/2010, Bob Weigel <sounddoctorin at imt.net> wrote:
> I think we can get a good image to work from without too much trouble.
> The boards in this thing are absolutely smashed.  I think it would
> really be best to just get a totally new set of boards in the card cage
> at least.  The rest of it is easy to repair I think.  Someone hit this
> thing with a wrecking ball it appears!
>
> --
> Check out sounddoctorin.com for songs, a studio tour, help
> repairing old synthesizers and parts or thought provoking
> articles that could help make your eternity!
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From rainer at buchty.net  Fri Nov 12 10:55:05 2010
From: rainer at buchty.net (Rainer Buchty)
Date: Fri, 12 Nov 2010 10:55:05 +0100 (CET)
Subject: [sdiy] FORMANT 2? les extensions
In-Reply-To: <824E1031BE864F92AE53A80857363DCF@ww901.siemens.net>
References: <BLU0-SMTP15419C24AD64F023792AA96C8330@phx.gbl>
	<824E1031BE864F92AE53A80857363DCF@ww901.siemens.net>
Message-ID: <alpine.DEB.2.00.1011121049370.2992@archimobil.fritz.box>

On Fri, 12 Nov 2010, Carsten Toensmann wrote:

> as I know most of the additional modules of book 2 have been released 
> by elektor as stand alone projects first, then adapted for the Formant 
> as synth modules. Unfortunately I don't know the issues.

IIRC, the Book 1 modules were published 1976/77 and the Book 2 modules 
(or Formant adaptions of general Elektor modules) around 1978-1980.

To be entirely sure, I'd need to dedust my Elektor collection, though
(1971-1984).

Rainer


From davekendall at ntlworld.com  Fri Nov 12 13:57:07 2010
From: davekendall at ntlworld.com (Dave Kendall)
Date: Fri, 12 Nov 2010 12:57:07 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
Message-ID: <5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com>

Hi all.

Many thanks for all the detailed replies.

On Nov 12, 2010, at 06:57, Cary Roberts wrote:
> Failures:
> --------
> _ANY_ crimp connector that has been soldered.

Cary - any idea why that should be?, as it seems not to be the 
experience with some of the other respondents if I understand 
correctly....
perhaps deformation due to temperature?

A good crimping tool is out of my price range at the moment, and I'm 
not making vast amounts of them, so I was hoping to go with 
soldering....

cheers,
Dave




From harrybissell at wowway.com  Fri Nov 12 15:41:35 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 12 Nov 2010 09:41:35 -0500 (EST)
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTinNjUNRge7DMb=C0RihGMths2jDVjFvzmrNCSyS@mail.gmail.com>
Message-ID: <304000174.332886.1289572895421.JavaMail.root@md01.wow.synacor.com>










----- Original Message -----
From: Mark Rivera <marr at lumin.us>
To: Cary Roberts <cary.roberts at retrosynth.net>
Cc: synth-diy at dropmix.xs4all.nl
Sent: Fri, 12 Nov 2010 03:12:20 -0500 (EST)
Subject: Re: [sdiy] 0.100 pin header reliability.

> Winners:
> -------
> .1" dual row headers like those on the Prophet 5, OBXa, OB8, etc have held
> up well.
>
> .1" single row headers on Roland equipment have held up well and don't seem
> prone to oxidization.

> Failures:
> --------
> .1" tin plated Tyco/AMP MTA connectors used for critical CVs on the
> memorymoog are prone to oxidization and are utter fail.

What's the difference between the two winners and the failure here?

If the tin is fail, then what is the recommended plating?
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From stewpye at optusnet.com.au  Fri Nov 12 18:11:37 2010
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Sat, 13 Nov 2010 03:11:37 +1000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
	<5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com>
Message-ID: <4CDD7549.6060808@optusnet.com.au>

We've been soldering crimp connectors without a failure for over 20 
years so I'd be interested why you'd say that, especially considering 
the amount of  commercial "pro audio" products I've seen with failures 
of crimped pins.


Cheers,
Stew.


>
> On Nov 12, 2010, at 06:57, Cary Roberts wrote:
>> Failures:
>> --------
>> _ANY_ crimp connector that has been soldered.



From ka4hjh at gmail.com  Fri Nov 12 18:29:37 2010
From: ka4hjh at gmail.com (KA4HJH)
Date: Fri, 12 Nov 2010 12:29:37 -0500
Subject: [sdiy] Delia Derbyshire
Message-ID: <p06240804c90329e0a608@[192.168.1.66]>

Beeb to show unseen interview with Dr Who theme creator:

http://www.reghardware.com/2010/11/12/bbc_delia_derbyshire_doctor_who_interview/

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"


From grant at musictechnologiesgroup.com  Fri Nov 12 19:35:44 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Fri, 12 Nov 2010 11:35:44 -0700
Subject: [sdiy] Making flat cables
Message-ID: <20101112113544.c16e921f9c8655b42ea149fc1daa3492.40f90e28f8.wbe@email04.secureserver.net>

Hi,

Has anyone got any insights on how to make or find small flat cables. 
I've been doing a lot of 14- and 16- pin character LCD upgrades and I'm
getting to the bottom of my surplus flat cables box.  The requirement is
14 or 16 pins on 0.1" centers on each end ... a couple of inches long. 
I don't really want to strip 28 pins and then crimp them (see photo and
imagine single-row: http://112.120.67.124/W_DR_16P_PIN.jpg ) and I also
don't really like using double-wide (IDC computer style) cables either. 
But that's just cosmetic.  I can't find any pre-made ones on the
interweb either.  

GB



From Barry.L.Klein at wdc.com  Fri Nov 12 19:48:56 2010
From: Barry.L.Klein at wdc.com (Barry Klein)
Date: Fri, 12 Nov 2010 10:48:56 -0800
Subject: [sdiy] Making flat cables
References: <20101112113544.c16e921f9c8655b42ea149fc1daa3492.40f90e28f8.wbe@email04.secureserver.net>
Message-ID: <C651097094AAD54C846A5BAA28F7141D040060@wdscexbe08.sc.wdc.com>

Take a look at an old parallel IDE cable.  Those connectors are available
from Digikey/Mouser in various widths.  You need a vise or press to then
press the two halves against the cable.  Trim the end residual.  The cable
then can wrap around the backside with a snap over plastic C clamp holding
it all together.

Barry



-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of
grant at musictechnologiesgroup.com
Sent: Friday, November 12, 2010 10:36 AM
To: synth diy
Subject: [sdiy] Making flat cables

Hi,

Has anyone got any insights on how to make or find small flat cables. 
I've been doing a lot of 14- and 16- pin character LCD upgrades and I'm
getting to the bottom of my surplus flat cables box.  The requirement is
14 or 16 pins on 0.1" centers on each end ... a couple of inches long. 
I don't really want to strip 28 pins and then crimp them (see photo and
imagine single-row: http://112.120.67.124/W_DR_16P_PIN.jpg ) and I also
don't really like using double-wide (IDC computer style) cables either. 
But that's just cosmetic.  I can't find any pre-made ones on the
interweb either.  

GB

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From megaohm1 at gmail.com  Sat Nov 13 00:49:08 2010
From: megaohm1 at gmail.com (megaohm)
Date: Fri, 12 Nov 2010 17:49:08 -0600
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <4CDD7549.6060808@optusnet.com.au>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
	<5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com>
	<4CDD7549.6060808@optusnet.com.au>
Message-ID: <AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>

I won't argue against 20 years of positives. But maybe your experience
would have been just as positive without soldering?
The reason I don't crimp-then-solder is because the Molex info sheets
for the KK series state specifically not to do so. They claim the
soldering actually makes it less reliable.
Regardless, I plan on switching to IDC type connectors. While the
crimp method is supposed to be a superior connection (Molex KK series)
the contact pins of the AMP connectors seem to sit more snug in the
housing and show less play when fitted to the header pins than the
Molex type.
  Also, I started using connectors as a compromise to the best
connections (direct soldering, no connectors or headers). The Molex KK
take a lot longer to do than the IDC method and I wasn't saving any
time compared to hard soldering the leads to the pcb.

p.


On Fri, Nov 12, 2010 at 11:11 AM, Stewart Pye <stewpye at optusnet.com.au> wrote:
> We've been soldering crimp connectors without a failure for over 20 years so
> I'd be interested why you'd say that, especially considering the amount of
> ?commercial "pro audio" products I've seen with failures of crimped pins.
>
>
> Cheers,
> Stew.
>
>
>>
>> On Nov 12, 2010, at 06:57, Cary Roberts wrote:
>>>
>>> Failures:
>>> --------
>>> _ANY_ crimp connector that has been soldered.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From pfperry at melbpc.org.au  Sat Nov 13 01:50:07 2010
From: pfperry at melbpc.org.au (Paul Perry)
Date: Sat, 13 Nov 2010 11:50:07 +1100
Subject: [sdiy] 0.100 pin header reliability.
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp><5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com><4CDD7549.6060808@optusnet.com.au>
	<AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>
Message-ID: <F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>

I think that when soldering decreases reliability it is because
the solder wicks up the wire away from the joint & stiffens the wire,
which then tends to flex sharply at the end of the solder & break there.

Anything that can be done to make the "kinking" forces more evenly
distributed along and around the joint, helps reliability. Heatshrink is
the obvious.

Personally, I use IDC flat ribbon cable, and I have been astonished at how
reliable it is - even when using improvised methods like vices - but it is
quite essential to get the connector EXACTLY at right angles, and a jig is
a great help. If money were no object, I would definitely buy ready made 
from Digikey.
I've made several thousand, with no problems.

paul perry Melbourne Australia

----- Original Message ----- 
From: "megaohm" <megaohm1 at gmail.com>
To: "Stewart Pye" <stewpye at optusnet.com.au>
Cc: "sdiy DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Saturday, November 13, 2010 10:49 AM
Subject: Re: [sdiy] 0.100 pin header reliability.


>I won't argue against 20 years of positives. But maybe your experience
> would have been just as positive without soldering?
> The reason I don't crimp-then-solder is because the Molex info sheets
> for the KK series state specifically not to do so. They claim the
> soldering actually makes it less reliable.
> Regardless, I plan on switching to IDC type connectors. While the
> crimp method is supposed to be a superior connection (Molex KK series)
> the contact pins of the AMP connectors seem to sit more snug in the
> housing and show less play when fitted to the header pins than the
> Molex type.
>  Also, I started using connectors as a compromise to the best
> connections (direct soldering, no connectors or headers). The Molex KK
> take a lot longer to do than the IDC method and I wasn't saving any
> time compared to hard soldering the leads to the pcb.
>
> p.
>
>
> On Fri, Nov 12, 2010 at 11:11 AM, Stewart Pye <stewpye at optusnet.com.au> 
> wrote:
>> We've been soldering crimp connectors without a failure for over 20 years 
>> so
>> I'd be interested why you'd say that, especially considering the amount 
>> of
>> commercial "pro audio" products I've seen with failures of crimped pins.
>>
>>
>> Cheers,
>> Stew.
>>
>>
>>>
>>> On Nov 12, 2010, at 06:57, Cary Roberts wrote:
>>>>
>>>> Failures:
>>>> --------
>>>> _ANY_ crimp connector that has been soldered.
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 9.0.869 / Virus Database: 271.1.1/3253 - Release Date: 11/12/10 
21:40:00



From gatkins at blueyonder.co.uk  Sat Nov 13 02:07:33 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Sat, 13 Nov 2010 01:07:33 +0000
Subject: [sdiy]  Crimp Vs Soldering / was 0.100 pin header reliability.
In-Reply-To: <F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp><5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com><4CDD7549.6060808@optusnet.com.au>
	<AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>
	<F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>
Message-ID: <A39B4DE9-E218-4A7C-AAD9-CB4A5835DE38@blueyonder.co.uk>

On 13 Nov 2010, at 00:50, Paul Perry wrote:

> I think that when soldering decreases reliability it is because
> the solder wicks up the wire away from the joint & stiffens the wire,
> which then tends to flex sharply at the end of the solder & break  
> there.
>
> Anything that can be done to make the "kinking" forces more evenly
> distributed along and around the joint, helps reliability.  
> Heatshrink is
> the obvious.
>
> Personally, I use IDC flat ribbon cable, and I have been astonished  
> at how
> reliable it is - even when using improvised methods like vices - but  
> it is
> quite essential to get the connector EXACTLY at right angles, and a  
> jig is
> a great help. If money were no object, I would definitely buy ready  
> made from Digikey.
> I've made several thousand, with no problems.

Motor vehicle wiring harnesses always used to have crimp connections  
presumably
because of the stresses on the connectors from vibrations and shock.  
However a lot
of technicians fitting alarm systems etc (Aftermarket products) seem  
to use soldering
these days I notice.

Graham

(P.S. Webber for F1 champ this weekend !!)


From davekendall at ntlworld.com  Sat Nov 13 02:58:09 2010
From: davekendall at ntlworld.com (Dave Kendall)
Date: Sat, 13 Nov 2010 01:58:09 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp><5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com><4CDD7549.6060808@optusnet.com.au>
	<AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>
	<F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>
Message-ID: <76F7EC72-EEC9-11DF-ACF5-000393A85F9E@ntlworld.com>


On Nov 13, 2010, at 00:50, Paul Perry wrote:
> I think that when soldering decreases reliability it is because
> the solder wicks up the wire away from the joint & stiffens the wire,
> which then tends to flex sharply at the end of the solder & break 
> there.

That makes sense. But wouldn't that same potential weakness also apply 
to a wire either directly soldered to the PCB pad, or to a PCB pin?. 
I've had that happen on some perfboard prototype builds using stranded 
wire that got some rough handling. (the soldered joints to PCB pins 
weren't reinforced by heatshrink or hellerman sleeves or anything, so I 
wasn't too surprised...)

This is an interesting thread, thanks for everyone's input.

cheers,
Dave



From senso at vintageplanet.nl  Sat Nov 13 13:07:16 2010
From: senso at vintageplanet.nl (Senso)
Date: Sat, 13 Nov 2010 13:07:16 +0100
Subject: [sdiy] paging John Mahoney
Message-ID: <a06240802c9042f982154@[192.168.254.1]>

Hey John!

Are you there? To be more precise... are you alive and well?

Senso

-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From igg.debus at t-online.de  Sat Nov 13 14:48:27 2010
From: igg.debus at t-online.de (Ingo Debus)
Date: Sat, 13 Nov 2010 14:48:27 +0100
Subject: [sdiy] working with EPROMs
In-Reply-To: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
References: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
Message-ID: <9941B0DC-35B6-49C7-9E0E-02DA1DEA78A1@t-online.de>


Am 12.11.2010 um 00:27 schrieb mark verbos:

> I've been looking at some 70s delay schematics that use EPROMs to  
> create all of their timing signals for the converters and rams and  
> everything and it makes me wonder how you create the data for  
> those. I have a burner, but the only way I know of to create the  
> binary files is with the Wiard/Darwin Grosse WAVE256 application. I  
> mean, if I made some graph paper with 256 lines each way I could  
> draw the timing that I want and then enter it line by line into  
> WAVE256 in the "Numeric" section, but there has to be a better way.  
> My googling has not gotten me anywhere. Does anyone have any  
> suggestions?

How about using a spreadsheet program (like Excel)? First column is  
EPROM address, then eight (or how many you need) columns for the data  
bits. You fill these with 1s and 0s as needed. Then have another  
column where you concatenate the data bits to bytes and eventually  
convert them to hex format. With a little more Excel-Fu from there  
you can create an Intel hex file or whatever format you need fpr your  
EPROM programmer.

Ingo


From Stromeko at nexgo.de  Sat Nov 13 17:05:22 2010
From: Stromeko at nexgo.de (ASSI)
Date: Sat, 13 Nov 2010 17:05:22 +0100
Subject: [sdiy] working with EPROMs
In-Reply-To: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
References: <EB32AE24-6111-411B-BE2A-39EFA0FF570E@earthlink.net>
Message-ID: <201011131705.22531.Stromeko@nexgo.de>

On Friday 12 November 2010, mark verbos wrote:
> I've been looking at some 70s delay schematics that use EPROMs to create
> all of their timing signals for the converters and rams and everything
> and it makes me wonder how you create the data for those.

In the 70s you probably sat down with paper and pencil.

> I have a
> burner, but the only way I know of to create the binary files is with
> the Wiard/Darwin Grosse WAVE256 application. I mean, if I made some
> graph paper with 256 lines each way I could draw the timing that I want
> and then enter it line by line into WAVE256 in the "Numeric" section,
> but there has to be a better way. My googling has not gotten me
> anywhere. Does anyone have any suggestions? Chris Moore, the man behind 
> Ursa Major, mentions punch cards in his history section, but there must
> be some software...other than just HEX editors... right?

What you're after is an assembler for a microcode sequencer, but I think 
you'll have to write it yourself.

Condensing bitmaps into data is not all that difficult if you use one of the 
portable bitmap ASCII formats as an intermediate representation -- some 
editors can create them directly, otherwise use the netpbm tools.  You will 
have to do some light scripting (I prefer Perl for things like that).


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Waldorf MIDI Implementation & additional documentation:
http://Synth.Stromeko.net/Downloads.html#WaldorfDocs


From jmahoney at gate.net  Sat Nov 13 17:45:14 2010
From: jmahoney at gate.net (John Mahoney)
Date: Sat, 13 Nov 2010 11:45:14 -0500 (GMT-05:00)
Subject: [sdiy] paging John Mahoney
Message-ID: <29541398.1289666714291.JavaMail.root@mswamui-thinleaf.atl.sa.earthlink.net>

>Hey John!
>
>Are you there? To be more precise... are you alive and well?
>
>Senso


All's well, Senso, very nice of you to ask! Thanks so much.

I certainly don't post much, these days, do I? Main reason: In March, I stopped working from home and got a more normal office job (in IT doing back-office programming and such). That's when I stopped being on-line so much. Actually, though, just lately I have been easing back into the lists, groups, and Facebook.

I've also been doing more audio recording, tracking a number of my friends' bands. That's my favorite hobby, and a lot of free time has gone into that.

On top of all that, our 6-year old niece moved in with us (Temporarily? Not sure!) in August, so I lost my workshop area; I need to get things set up again before I can do any SDIY. C'est la vie, right? Or, as John Lennon said, "Life is what happens to you while you're busy making other plans." But, I'm not complaining. Life is pretty good. :-)

And that's my story, folks. I guess I didn't realize how much of a lurker I'd become. Ha!

Best regards,
John



From davekendall at ntlworld.com  Sat Nov 13 21:43:41 2010
From: davekendall at ntlworld.com (Dave Kendall)
Date: Sat, 13 Nov 2010 20:43:41 +0000
Subject: [sdiy] CGS30 BPF modded for guitar use
Message-ID: <B2EBC030-EF66-11DF-9B2A-000393A85F9E@ntlworld.com>

Hi all.

Mad idea I know, but it's a request from a guitarist mate. I want to 
find a way to mod this circuit  
http://www.cgs.synth.net/modules/cgs30_bpf.html
for use in a guitar stompbox. FWIW, I believe the circuit to be the 
same as, or a near clone of the roland SH5 BPF.

As noise levels are not critical for his intended use, for power, I 
guess I could use a resistor divider with a 9V battery to, generate 
?4.5V, with the centre tap to GND on the PCB, and something like a 47uF 
cap between the centre tap and 0V on the battery (which is now -4.5V on 
the PCB)

I 'll need to attenuate the level after the effect, which will have 
quite a lot of gain, in order to approach unity gain at the output.  
Question is, keeping a 1K output impedance, how could I alter values in 
the circuit to achieve this? I don't understand the circuit , and I 
guess I could always do the obvious, and use a voltage divider at the 
output using the 1K final output resistor as one half, and a pot or 
fixed resistor to GND as the other half of the voltage divider, but I 
suspect that might have a big effect on the output impedance - I don't 
know if that's a real problem or not. The output will directly drive a 
guitar combo input.

Would such a voltage divider make potential problems for a guitarist?

Any thoughts welcome.


cheers,
Dave



From dingebre at 3dphysics.net  Sun Nov 14 04:29:04 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Sat, 13 Nov 2010 20:29:04 -0700
Subject: [sdiy] FW: Synthasystem Frequency Divider trouble shooting
Message-ID: <000501cb83ac$181c6a00$48553e00$@net>

Hi group.

I?m trouble shooting the Synthasystem Frequency Divider prototype PCB. Since
these are all designs which were in actual production, I do make the
assumption the original schematic is correct and that my capture may have an
error. That said, I couldn?t find an error and Nyle said it looked ok. The
schematic is here:

http://www.xmission.com/~dingebre/SP_Freq_Divider_1.1.pdf

Nyle?s original is here:

http://www.xmission.com/~dingebre/SP_Frequency_Divider_0001.JPG

The project page is here:

http://www.xmission.com/~dingebre/Freq_Divider.html

I understand the basic ideas of the circuit and everything seems to be
working except the one-shot in the lower left side.? Basically, the four
Flip-Flops in the middle are a binary counter. The 8 position ?divide?
switch is hooked to discrete AND gates which select the denominator for the
divide. The way Nyle set it up, you get 3, 5, 7, 9, 11, and 15. The one shot
is supposed to fire when you hit the desired count and it should reset all
four FFs. The way I see it, the last FF should never even count if you
select a divide by 3 or 5, but it does count. I also never see a reset pulse
out of the one shot unless I force it by grounding the base of Q20.

The primary symptom is the divide by 11 divides by 7. When I?ve looked at
the scope, the first time I select the divide by 11, it divides the first
cycle only by 11. Thereafter, it divides by 7.

Secondarily, it appears the one-shot is not being triggered, therefore the
FFs are not being reset when the count reaches the selected count on the 8
position switch.

I understand the one shot and simulated it for good measure. What I don?t
understand is how Nyle is resetting it. I thought you need to pull the base
of Q20 low. When I do that, it resets.

I don?t get the little capacitor/diode/resistor connection to the pole of
the divide switch.

Any thoughts?

I?ve emailed Nyle, but sometimes he takes a few days to answer and I hate
pestering him.

David



From obl64 at ix.netcom.com  Sun Nov 14 06:21:23 2010
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Sat, 13 Nov 2010 23:21:23 -0600
Subject: [sdiy] FW: Synthasystem Frequency Divider trouble shooting
In-Reply-To: <000501cb83ac$181c6a00$48553e00$@net>
References: <000501cb83ac$181c6a00$48553e00$@net>
Message-ID: <4CDF71D3.40600@ix.netcom.com>



On 11/13/2010 9:29 PM, David Ingebretsen wrote:
> Hi group.
>
> I?m trouble shooting the Synthasystem Frequency Divider prototype PCB. Since
> these are all designs which were in actual production, I do make the
> assumption the original schematic is correct and that my capture may have an
> error. That said, I couldn?t find an error and Nyle said it looked ok. The
> schematic is here:
>
> http://www.xmission.com/~dingebre/SP_Freq_Divider_1.1.pdf
>
> Nyle?s original is here:
>
> http://www.xmission.com/~dingebre/SP_Frequency_Divider_0001.JPG
>
> The project page is here:
>
> http://www.xmission.com/~dingebre/Freq_Divider.html
>
> I understand the basic ideas of the circuit and everything seems to be
> working except the one-shot in the lower left side.  Basically, the four
> Flip-Flops in the middle are a binary counter. The 8 position ?divide?
> switch is hooked to discrete AND gates which select the denominator for the
> divide. The way Nyle set it up, you get 3, 5, 7, 9, 11, and 15. The one shot
> is supposed to fire when you hit the desired count and it should reset all
> four FFs. The way I see it, the last FF should never even count if you
> select a divide by 3 or 5, but it does count. I also never see a reset pulse
> out of the one shot unless I force it by grounding the base of Q20.
>
> The primary symptom is the divide by 11 divides by 7. When I?ve looked at
> the scope, the first time I select the divide by 11, it divides the first
> cycle only by 11. Thereafter, it divides by 7.
>
> Secondarily, it appears the one-shot is not being triggered, therefore the
> FFs are not being reset when the count reaches the selected count on the 8
> position switch.
>
> I understand the one shot and simulated it for good measure. What I don?t
> understand is how Nyle is resetting it. I thought you need to pull the base
> of Q20 low. When I do that, it resets.
>
> I don?t get the little capacitor/diode/resistor connection to the pole of
> the divide switch.
>
> Any thoughts?
>
> I?ve emailed Nyle, but sometimes he takes a few days to answer and I hate
> pestering him.
>
> David
>


Hi David,

Does your SP/6T divide switch "break before make" when you change position?
It looks like the one-shot circuit depends on R56 briefly pulling D21 
"high" while the switch wiper is transitioning between contacts. If your 
switch is a "make before break" type, that will not happen.


- Oren


From dingebre at 3dphysics.net  Sun Nov 14 06:40:45 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Sat, 13 Nov 2010 22:40:45 -0700
Subject: [sdiy] FW: Synthasystem Frequency Divider trouble shooting
In-Reply-To: <4CDF71D3.40600@ix.netcom.com>
References: <000501cb83ac$181c6a00$48553e00$@net>
	<4CDF71D3.40600@ix.netcom.com>
Message-ID: <000301cb83be$7f4d7a40$7de86ec0$@net>

Hi Oren,

It's a non-shorting contact.

I don't see how that would matter though once the switch is moved. 

I don't think turning the switch is what is supposed to reset the flip
flops. It's when the discrete AND gates are active. For example, on a divide
by 5, setting the switch to "G5", when Q4 and Q6 are "ones", the AND gate
formed with these two signals makes the AND gate high and in theory should
somehow reset the flip flops so they can count to 5 again. Similar for the
other "divide by" settings.

Thanks for having a look.

David 


~~ -----Original Message-----
~~ From: Oren Leavitt [mailto:obl64 at ix.netcom.com]
~~ Sent: Saturday, November 13, 2010 10:21 PM
~~ To: David Ingebretsen
~~ Cc: 'sdiy DIY'
~~ Subject: Re: [sdiy] FW: Synthasystem Frequency Divider trouble shooting
~~ 
~~ 
~~ 
~~ On 11/13/2010 9:29 PM, David Ingebretsen wrote:
~~ > Hi group.
~~ >
~~ > I'm trouble shooting the Synthasystem Frequency Divider prototype PCB.
~~ Since
~~ > these are all designs which were in actual production, I do make the
~~ > assumption the original schematic is correct and that my capture may
~~ have an
~~ > error. That said, I couldn't find an error and Nyle said it looked ok.
~~ The
~~ > schematic is here:
~~ >
~~ > http://www.xmission.com/~dingebre/SP_Freq_Divider_1.1.pdf
~~ >
~~ > Nyle's original is here:
~~ >
~~ > http://www.xmission.com/~dingebre/SP_Frequency_Divider_0001.JPG
~~ >
~~ > The project page is here:
~~ >
~~ > http://www.xmission.com/~dingebre/Freq_Divider.html
~~ >
~~ > I understand the basic ideas of the circuit and everything seems to be
~~ > working except the one-shot in the lower left side.  Basically, the
four
~~ > Flip-Flops in the middle are a binary counter. The 8 position "divide"
~~ > switch is hooked to discrete AND gates which select the denominator for
~~ the
~~ > divide. The way Nyle set it up, you get 3, 5, 7, 9, 11, and 15. The one
~~ shot
~~ > is supposed to fire when you hit the desired count and it should reset
~~ all
~~ > four FFs. The way I see it, the last FF should never even count if you
~~ > select a divide by 3 or 5, but it does count. I also never see a reset
~~ pulse
~~ > out of the one shot unless I force it by grounding the base of Q20.
~~ >
~~ > The primary symptom is the divide by 11 divides by 7. When I've looked
~~ at
~~ > the scope, the first time I select the divide by 11, it divides the
~~ first
~~ > cycle only by 11. Thereafter, it divides by 7.
~~ >
~~ > Secondarily, it appears the one-shot is not being triggered, therefore
~~ the
~~ > FFs are not being reset when the count reaches the selected count on
the
~~ 8
~~ > position switch.
~~ >
~~ > I understand the one shot and simulated it for good measure. What I
~~ don't
~~ > understand is how Nyle is resetting it. I thought you need to pull the
~~ base
~~ > of Q20 low. When I do that, it resets.
~~ >
~~ > I don't get the little capacitor/diode/resistor connection to the pole
~~ of
~~ > the divide switch.
~~ >
~~ > Any thoughts?
~~ >
~~ > I've emailed Nyle, but sometimes he takes a few days to answer and I
~~ hate
~~ > pestering him.
~~ >
~~ > David
~~ >
~~ 
~~ 
~~ Hi David,
~~ 
~~ Does your SP/6T divide switch "break before make" when you change
~~ position?
~~ It looks like the one-shot circuit depends on R56 briefly pulling D21
~~ "high" while the switch wiper is transitioning between contacts. If your
~~ switch is a "make before break" type, that will not happen.
~~ 
~~ 
~~ - Oren



From dingebre at 3dphysics.net  Sun Nov 14 07:18:35 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Sat, 13 Nov 2010 23:18:35 -0700
Subject: [sdiy] little followup,
	WAS RE:  FW: Synthasystem Frequency Divider trouble shooting
In-Reply-To: <000301cb83be$7f4d7a40$7de86ec0$@net>
References: <000501cb83ac$181c6a00$48553e00$@net>	<4CDF71D3.40600@ix.netcom.com>
	<000301cb83be$7f4d7a40$7de86ec0$@net>
Message-ID: <000701cb83c3$c50b3ae0$4f21b0a0$@net>

I just fired up the circuit and confirmed when the base of Q20is shorted to
ground I get a reset.

And, it I hit the base of Q19 with +12, I get the expected reset pulse
independent of how long I hold it positive and it resets all the flip flops.

Why aren't the AND gates sending a pulse to the base of Q19?

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of David Ingebretsen
~~ Sent: Saturday, November 13, 2010 10:41 PM
~~ To: 'Oren Leavitt'
~~ Cc: 'sdiy DIY'
~~ Subject: Re: [sdiy] FW: Synthasystem Frequency Divider trouble shooting
~~ 
~~ Hi Oren,
~~ 
~~ It's a non-shorting contact.
~~ 
~~ I don't see how that would matter though once the switch is moved.
~~ 
~~ I don't think turning the switch is what is supposed to reset the flip
~~ flops. It's when the discrete AND gates are active. For example, on a
~~ divide
~~ by 5, setting the switch to "G5", when Q4 and Q6 are "ones", the AND gate
~~ formed with these two signals makes the AND gate high and in theory
should
~~ somehow reset the flip flops so they can count to 5 again. Similar for
the
~~ other "divide by" settings.
~~ 
~~ Thanks for having a look.
~~ 
~~ David
~~ 
~~ 
~~ ~~ -----Original Message-----
~~ ~~ From: Oren Leavitt [mailto:obl64 at ix.netcom.com]
~~ ~~ Sent: Saturday, November 13, 2010 10:21 PM
~~ ~~ To: David Ingebretsen
~~ ~~ Cc: 'sdiy DIY'
~~ ~~ Subject: Re: [sdiy] FW: Synthasystem Frequency Divider trouble
shooting
~~ ~~
~~ ~~
~~ ~~
~~ ~~ On 11/13/2010 9:29 PM, David Ingebretsen wrote:
~~ ~~ > Hi group.
~~ ~~ >
~~ ~~ > I'm trouble shooting the Synthasystem Frequency Divider prototype
~~ PCB.
~~ ~~ Since
~~ ~~ > these are all designs which were in actual production, I do make the
~~ ~~ > assumption the original schematic is correct and that my capture may
~~ ~~ have an
~~ ~~ > error. That said, I couldn't find an error and Nyle said it looked
~~ ok.
~~ ~~ The
~~ ~~ > schematic is here:
~~ ~~ >
~~ ~~ > http://www.xmission.com/~dingebre/SP_Freq_Divider_1.1.pdf
~~ ~~ >
~~ ~~ > Nyle's original is here:
~~ ~~ >
~~ ~~ > http://www.xmission.com/~dingebre/SP_Frequency_Divider_0001.JPG
~~ ~~ >
~~ ~~ > The project page is here:
~~ ~~ >
~~ ~~ > http://www.xmission.com/~dingebre/Freq_Divider.html
~~ ~~ >
~~ ~~ > I understand the basic ideas of the circuit and everything seems to
~~ be
~~ ~~ > working except the one-shot in the lower left side.  Basically, the
~~ four
~~ ~~ > Flip-Flops in the middle are a binary counter. The 8 position
~~ "divide"
~~ ~~ > switch is hooked to discrete AND gates which select the denominator
~~ for
~~ ~~ the
~~ ~~ > divide. The way Nyle set it up, you get 3, 5, 7, 9, 11, and 15. The
~~ one
~~ ~~ shot
~~ ~~ > is supposed to fire when you hit the desired count and it should
~~ reset
~~ ~~ all
~~ ~~ > four FFs. The way I see it, the last FF should never even count if
~~ you
~~ ~~ > select a divide by 3 or 5, but it does count. I also never see a
~~ reset
~~ ~~ pulse
~~ ~~ > out of the one shot unless I force it by grounding the base of Q20.
~~ ~~ >
~~ ~~ > The primary symptom is the divide by 11 divides by 7. When I've
~~ looked
~~ ~~ at
~~ ~~ > the scope, the first time I select the divide by 11, it divides the
~~ ~~ first
~~ ~~ > cycle only by 11. Thereafter, it divides by 7.
~~ ~~ >
~~ ~~ > Secondarily, it appears the one-shot is not being triggered,
~~ therefore
~~ ~~ the
~~ ~~ > FFs are not being reset when the count reaches the selected count on
~~ the
~~ ~~ 8
~~ ~~ > position switch.
~~ ~~ >
~~ ~~ > I understand the one shot and simulated it for good measure. What I
~~ ~~ don't
~~ ~~ > understand is how Nyle is resetting it. I thought you need to pull
~~ the
~~ ~~ base
~~ ~~ > of Q20 low. When I do that, it resets.
~~ ~~ >
~~ ~~ > I don't get the little capacitor/diode/resistor connection to the
~~ pole
~~ ~~ of
~~ ~~ > the divide switch.
~~ ~~ >
~~ ~~ > Any thoughts?
~~ ~~ >
~~ ~~ > I've emailed Nyle, but sometimes he takes a few days to answer and I
~~ ~~ hate
~~ ~~ > pestering him.
~~ ~~ >
~~ ~~ > David
~~ ~~ >
~~ ~~
~~ ~~
~~ ~~ Hi David,
~~ ~~
~~ ~~ Does your SP/6T divide switch "break before make" when you change
~~ ~~ position?
~~ ~~ It looks like the one-shot circuit depends on R56 briefly pulling D21
~~ ~~ "high" while the switch wiper is transitioning between contacts. If
~~ your
~~ ~~ switch is a "make before break" type, that will not happen.
~~ ~~
~~ ~~
~~ ~~ - Oren
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From nicolas3141 at yahoo.com.au  Sun Nov 14 10:39:55 2010
From: nicolas3141 at yahoo.com.au (nicolas)
Date: Sun, 14 Nov 2010 01:39:55 -0800 (PST)
Subject: [sdiy] little followup,
	WAS RE:  FW: Synthasystem Frequency Divider trouble shooting
In-Reply-To: <000701cb83c3$c50b3ae0$4f21b0a0$@net>
Message-ID: <123784.40298.qm@web57004.mail.re3.yahoo.com>

Another thing to try would be to momentarily disconnect the switch from R56-D21 while it is running, that should also cause D21 to rise from about 0V to about 6V and that should cause the reset pulse.  If that doesn't happen then I would look very carefully at that network around R53-C24-R57-D21-R56.  Maybe R53 has been accidentally placed as 2.2k or D21 is the wrong way round?  

Are you using the same transistors as the original?  Perhaps try a larger value for C24.

Cheers,
Nicolas


--- On Sun, 14/11/10, David Ingebretsen <dingebre at 3dphysics.net> wrote:

> From: David Ingebretsen <dingebre at 3dphysics.net>
> Subject: [sdiy] little followup, WAS RE:  FW: Synthasystem Frequency Divider trouble shooting
> To: "'sdiy DIY'" <synth-diy at dropmix.xs4all.nl>
> Received: Sunday, 14 November, 2010, 7:18 PM
> I just fired up the circuit and
> confirmed when the base of Q20is shorted to
> ground I get a reset.
> 
> And, it I hit the base of Q19 with +12, I get the expected
> reset pulse
> independent of how long I hold it positive and it resets
> all the flip flops.
> 
> Why aren't the AND gates sending a pulse to the base of
> Q19?
> 
> David
> 
> ~~ -----Original Message-----
> ~~ From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-
> ~~ bounces at dropmix.xs4all.nl]
> On Behalf Of David Ingebretsen
> ~~ Sent: Saturday, November 13, 2010 10:41 PM
> ~~ To: 'Oren Leavitt'
> ~~ Cc: 'sdiy DIY'
> ~~ Subject: Re: [sdiy] FW: Synthasystem Frequency Divider
> trouble shooting
> ~~ 
> ~~ Hi Oren,
> ~~ 
> ~~ It's a non-shorting contact.
> ~~ 
> ~~ I don't see how that would matter though once the switch
> is moved.
> ~~ 
> ~~ I don't think turning the switch is what is supposed to
> reset the flip
> ~~ flops. It's when the discrete AND gates are active. For
> example, on a
> ~~ divide
> ~~ by 5, setting the switch to "G5", when Q4 and Q6 are
> "ones", the AND gate
> ~~ formed with these two signals makes the AND gate high
> and in theory
> should
> ~~ somehow reset the flip flops so they can count to 5
> again. Similar for
> the
> ~~ other "divide by" settings.
> ~~ 
> ~~ Thanks for having a look.
> ~~ 
> ~~ David
> ~~ 
> ~~ 
> ~~ ~~ -----Original Message-----
> ~~ ~~ From: Oren Leavitt [mailto:obl64 at ix.netcom.com]
> ~~ ~~ Sent: Saturday, November 13, 2010 10:21 PM
> ~~ ~~ To: David Ingebretsen
> ~~ ~~ Cc: 'sdiy DIY'
> ~~ ~~ Subject: Re: [sdiy] FW: Synthasystem Frequency
> Divider trouble
> shooting
> ~~ ~~
> ~~ ~~
> ~~ ~~
> ~~ ~~ On 11/13/2010 9:29 PM, David Ingebretsen wrote:
> ~~ ~~ > Hi group.
> ~~ ~~ >
> ~~ ~~ > I'm trouble shooting the Synthasystem Frequency
> Divider prototype
> ~~ PCB.
> ~~ ~~ Since
> ~~ ~~ > these are all designs which were in actual
> production, I do make the
> ~~ ~~ > assumption the original schematic is correct and
> that my capture may
> ~~ ~~ have an
> ~~ ~~ > error. That said, I couldn't find an error and
> Nyle said it looked
> ~~ ok.
> ~~ ~~ The
> ~~ ~~ > schematic is here:
> ~~ ~~ >
> ~~ ~~ > http://www.xmission.com/~dingebre/SP_Freq_Divider_1.1.pdf
> ~~ ~~ >
> ~~ ~~ > Nyle's original is here:
> ~~ ~~ >
> ~~ ~~ > http://www.xmission.com/~dingebre/SP_Frequency_Divider_0001.JPG
> ~~ ~~ >
> ~~ ~~ > The project page is here:
> ~~ ~~ >
> ~~ ~~ > http://www.xmission.com/~dingebre/Freq_Divider.html
> ~~ ~~ >
> ~~ ~~ > I understand the basic ideas of the circuit and
> everything seems to
> ~~ be
> ~~ ~~ > working except the one-shot in the lower left
> side.? Basically, the
> ~~ four
> ~~ ~~ > Flip-Flops in the middle are a binary counter.
> The 8 position
> ~~ "divide"
> ~~ ~~ > switch is hooked to discrete AND gates which
> select the denominator
> ~~ for
> ~~ ~~ the
> ~~ ~~ > divide. The way Nyle set it up, you get 3, 5, 7,
> 9, 11, and 15. The
> ~~ one
> ~~ ~~ shot
> ~~ ~~ > is supposed to fire when you hit the desired
> count and it should
> ~~ reset
> ~~ ~~ all
> ~~ ~~ > four FFs. The way I see it, the last FF should
> never even count if
> ~~ you
> ~~ ~~ > select a divide by 3 or 5, but it does count. I
> also never see a
> ~~ reset
> ~~ ~~ pulse
> ~~ ~~ > out of the one shot unless I force it by
> grounding the base of Q20.
> ~~ ~~ >
> ~~ ~~ > The primary symptom is the divide by 11 divides
> by 7. When I've
> ~~ looked
> ~~ ~~ at
> ~~ ~~ > the scope, the first time I select the divide by
> 11, it divides the
> ~~ ~~ first
> ~~ ~~ > cycle only by 11. Thereafter, it divides by 7.
> ~~ ~~ >
> ~~ ~~ > Secondarily, it appears the one-shot is not
> being triggered,
> ~~ therefore
> ~~ ~~ the
> ~~ ~~ > FFs are not being reset when the count reaches
> the selected count on
> ~~ the
> ~~ ~~ 8
> ~~ ~~ > position switch.
> ~~ ~~ >
> ~~ ~~ > I understand the one shot and simulated it for
> good measure. What I
> ~~ ~~ don't
> ~~ ~~ > understand is how Nyle is resetting it. I
> thought you need to pull
> ~~ the
> ~~ ~~ base
> ~~ ~~ > of Q20 low. When I do that, it resets.
> ~~ ~~ >
> ~~ ~~ > I don't get the little capacitor/diode/resistor
> connection to the
> ~~ pole
> ~~ ~~ of
> ~~ ~~ > the divide switch.
> ~~ ~~ >
> ~~ ~~ > Any thoughts?
> ~~ ~~ >
> ~~ ~~ > I've emailed Nyle, but sometimes he takes a few
> days to answer and I
> ~~ ~~ hate
> ~~ ~~ > pestering him.
> ~~ ~~ >
> ~~ ~~ > David
> ~~ ~~ >
> ~~ ~~
> ~~ ~~
> ~~ ~~ Hi David,
> ~~ ~~
> ~~ ~~ Does your SP/6T divide switch "break before make"
> when you change
> ~~ ~~ position?
> ~~ ~~ It looks like the one-shot circuit depends on R56
> briefly pulling D21
> ~~ ~~ "high" while the switch wiper is transitioning
> between contacts. If
> ~~ your
> ~~ ~~ switch is a "make before break" type, that will not
> happen.
> ~~ ~~
> ~~ ~~
> ~~ ~~ - Oren
> ~~ 
> ~~ _______________________________________________
> ~~ Synth-diy mailing list
> ~~ Synth-diy at dropmix.xs4all.nl
> ~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


      


From lanterma at ece.gatech.edu  Sun Nov 14 23:40:54 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Sun, 14 Nov 2010 22:40:54 +0000
Subject: [sdiy] CGS30 BPF modded for guitar use
In-Reply-To: <B2EBC030-EF66-11DF-9B2A-000393A85F9E@ntlworld.com>
References: <B2EBC030-EF66-11DF-9B2A-000393A85F9E@ntlworld.com>
Message-ID: <325B0AC2-7CB1-4513-92EF-80498A7656F4@ece.gatech.edu>

On Nov 13, 2010, at 3:43 PM, Dave Kendall wrote:

> Mad idea I know, but it's a request from a guitarist mate. I want to find a way to mod this circuit  http://www.cgs.synth.net/modules/cgs30_bpf.html
> for use in a guitar stompbox. FWIW, I believe the circuit to be the same as, or a near clone of the roland SH5 BPF.

....

> I don't understand the circuit , 

This is a fairly standard "state variable" filter design, although it's drawn in a way that makes it hard to see at first. Numbering the op amps 1 to 4 from left to right, OA1 is just an input mixer/buffer, OA2 mixes the input signal with two feedback paths. OA3 and OA4 are integrators. It's drawn so that the bandpass output is on the right, but that makes it hard to recognize at first, and requires the drawing to be kind of folded in and twisted strangely; most SVF schematics show OA4 to the left of OA3. You could tap a lowpass output at the output of OA3 if you wanted.

Anyway... the feedback path from OA3 to OA2 is a second-order feedback path that allows the filter to resonante. (I'm handwaving a bit here - the 100K pots control the gain of both integrators, which sets the resonant frequency.) The feedback path from OA4 to OA2 is a first-order feedback path that dampens the response; more feedback with this path means less Q, and less feedback equals more Q (take it out altogether and you'll get an oscillator.) That's how the 50K pot is controlling the resonance. The diodes in the feedback path prevent things from getting too crazy; you'll see similar diodes, IIRC, in things like the Oberheim SEM filter and the Roland Jupiter-6 filter (although I think only one of its SVF's has the diodes); in both those filters, OTAs are used instead of the 100K pots to get a  voltage-controllable critical frequency.

- Aaron

From mikebeauchamp at gmail.com  Mon Nov 15 02:29:46 2010
From: mikebeauchamp at gmail.com (Mike Beauchamp)
Date: Mon, 15 Nov 2010 14:29:46 +1300
Subject: [sdiy] Reliability: Share your lessons learned
Message-ID: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>

The recent .1" heading thread has me thinking about long-term
reliability. We all have experience building and repairing things that
employ different parts, techniques and finishes and we've all seen
what is still working and/or easily repaired.

So please share any lessons/experiences about what works and what
doesn't for the longer-term.


My experience is still rather limited and the stuff I've built hasn't
been around for too long, but I suppose I can say:

works:
-point to point wiring and eyelet boards. (more of a guitar amp thing).
-PCB's with a silkscreen legend designed for others to see and understand.
-PCB's with soldermask and cleaned after assembly. (I haven't tried a
conformal coating yet)
-socketed IC's
-Alpha pots (and I like that they can be disassembled for future
maintenance/cleaning).
-neutrix and switchcraft 1/4" jacks.
-electrolytic capacitors that are easily replaced.

doesn't work:
-lots of hardware from futurlec (especially their unusable 1/4" jacks)
-strain relief on most wallwarts.
-particle board, MDF, chipboard, etc. (if there's a possibility of
water contact.)
-perfboard. fails way too easily when being repaired/modified.
-the paint electro-harmonix used on my deluxe memory man reissue. epic fail.


-- 
[mike]


From 21pointy at tpg.com.au  Mon Nov 15 05:06:11 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Mon, 15 Nov 2010 14:06:11 +1000
Subject: [sdiy] test - please disregard
Message-ID: <D07A88D6-A32E-496D-9AA6-F720D306D5B7@tpg.com.au>

Test


regards
Adam Inglis
http://www.adambaby.com





From 21pointy at tpg.com.au  Mon Nov 15 05:30:44 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Mon, 15 Nov 2010 14:30:44 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
Message-ID: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>

Hi All

First post - long time lurker and learner here for many years. Self- 
taught in analogue audio electronics thanks to a studio full of old  
"junk" from the 70s and 80s, an oscilloscope from the 60s, and the  
first few chapters of Horowitz and Hill!

Question: Someone here mentioned not too long ago the idea of using  
the voice trigger signals in a Roland TR707 to trigger external  
instruments. It got me thinking, as I love the interface of this drum  
machine - quick and fun.
  I would like to be able to trigger the voices in my old preset  
Roland Rhythm TR77. This uses passive LC voice circuits, which  
respond fairly dynamically to voltage triggers of between -3 to -10  
volts. Looking at the 707, I found the voice group's envelope  
generators supplied a positive envelope CV of varying decay times and  
amplitudes (about 2-5 volts) depending on instrument. These CVs also  
respond to the 2 levels of programmable ACCENT, and so would appear  
to be a good source of triggering.

Any suggestions as to a simple, low-parts-count circuit I could  
install (several iterations of) into the 77 that would convert the  
positive CVs from the 707 into brief negative pulses for the 77s voices?
I should mention there is 0 - 12 - 24 volts available in the 77 with  
just basic filtering, no voltage regulators, so I was assuming it  
would need a transistor rather than a chip based solution.

Anyone interested in my crude investigations into the workings of the  
TR77 can have a look here...
http://www.adambaby.com/studiotech_TR-77.html




regards
Adam Inglis
http://www.adambaby.com





From madhun2001 at yahoo.com  Mon Nov 15 07:03:44 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Sun, 14 Nov 2010 22:03:44 -0800 (PST)
Subject: [sdiy] Reliability: Share your lessons learned
In-Reply-To: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>
References: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>
Message-ID: <590618.79023.qm@web55302.mail.re4.yahoo.com>

Here's a tip for those who don't want to give up on MDF: Shellac. It is 
alcohol-based so it doesn't raise the wood grain near as much as other coatings. 
And 2 coats of it seals MDF very nicely. My homebrew corner horns have been 
around for 16 years with no sign of degradation.

--TimR




----- Original Message ----
From: Mike Beauchamp <mikebeauchamp at gmail.com>
To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Sun, November 14, 2010 5:29:46 PM
Subject: [sdiy] Reliability: Share your lessons learned

The recent .1" heading thread has me thinking about long-term
reliability. We all have experience building and repairing things that
employ different parts, techniques and finishes and we've all seen
what is still working and/or easily repaired.

So please share any lessons/experiences about what works and what
doesn't for the longer-term.


My experience is still rather limited and the stuff I've built hasn't
been around for too long, but I suppose I can say:

works:
-point to point wiring and eyelet boards. (more of a guitar amp thing).
-PCB's with a silkscreen legend designed for others to see and understand.
-PCB's with soldermask and cleaned after assembly. (I haven't tried a
conformal coating yet)
-socketed IC's
-Alpha pots (and I like that they can be disassembled for future
maintenance/cleaning).
-neutrix and switchcraft 1/4" jacks.
-electrolytic capacitors that are easily replaced.

doesn't work:
-lots of hardware from futurlec (especially their unusable 1/4" jacks)
-strain relief on most wallwarts.
-particle board, MDF, chipboard, etc. (if there's a possibility of
water contact.)
-perfboard. fails way too easily when being repaired/modified.
-the paint electro-harmonix used on my deluxe memory man reissue. epic fail.


-- 
[mike]
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Mon Nov 15 10:05:11 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 15 Nov 2010 10:05:11 +0100
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <76F7EC72-EEC9-11DF-ACF5-000393A85F9E@ntlworld.com>
References: <E2AF5D68A67648B1A729C4541483ED57@onlive.corp>
	<5B14A6B8-EE5C-11DF-9AED-000393A85F9E@ntlworld.com>
	<4CDD7549.6060808@optusnet.com.au>
	<AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>
	<F33B81213EE14300B56F9A40B6E71494@ownerf0d9273f5>
	<76F7EC72-EEC9-11DF-ACF5-000393A85F9E@ntlworld.com>
Message-ID: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>

Hi Dave,
to prevent breaking of soldered cable, have it zip tied to the PCB
about 2 cm away from the spot it was soldered to. Zip tie first,
solder second, so that the solder solidifies in the right shape.

With regards to soldering of crimped connectors: there might be
several things at play here, but I'm not good enough with my chemistry
to know if they actually make an impact. Maybe someone can tell me if
my intuitions here are right or wrong.
1. three/four metals (aluminum for the connector, copper for the cable
and solder, tin for the solder) make for different electrical
properties, oxides migrate differently
2. the solder crystals change shape over time. I understand there's
some sort of evolution to solid solder that makes it eject oxides?
This could not only separate the cold weld but also make it dirty with
oxides. Maybe someone can confirm this.
3. Is solder perhaps more reluctant to make a cold weld with aluminum,
than bare copper touching bare aluminum? If you solder first and crimp
second, you're crimping against tin. This also has the effect that the
tin soldered to the cable and/or connector might separate off what it
was soldered to, making an even worse connection
4. If you crimp first and solder second, the heat is going to expand
the aluminum more than it expands the copper wire - aluminum has a
higher linear coefficient of thermal expansion - effectively
un-crimping the connector. I don't think it's going to re-seat itself
nicely back to being crimped afterwards, but I don't know. My guess
here is that you actually need a lot of force to create a cold weld,
and this force is not going to be supplied by the shrinking connector
alone. Besides, there might be solder in that space now, which messes
up the connection
5. My intuition is that at least the better connectors have the leafs
produced in such a way that the crystalline structure is good for
making cold welds. Heating up changes this structure, quite possibly
for worse.

It would be interesting to know if any of this actually holds up
according to theory.

Regarding saving time: I read this thread and I think to myself...
isn't it much better to just buy ready cables?... They'll be crimped
much better than you can do it anyways, they'll be much cheaper in the
end, and they don't cost you time..

Cheers,
D.

On Sat, Nov 13, 2010 at 02:58, Dave Kendall <davekendall at ntlworld.com> wrote:
>
> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>
>> I think that when soldering decreases reliability it is because
>> the solder wicks up the wire away from the joint & stiffens the wire,
>> which then tends to flex sharply at the end of the solder & break there.
>
> That makes sense. But wouldn't that same potential weakness also apply to a
> wire either directly soldered to the PCB pad, or to a PCB pin?. I've had
> that happen on some perfboard prototype builds using stranded wire that got
> some rough handling. (the soldered joints to PCB pins weren't reinforced by
> heatshrink or hellerman sleeves or anything, so I wasn't too surprised...)
>
> This is an interesting thread, thanks for everyone's input.
>
> cheers,
> Dave
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From subjectivity at hotmail.com  Mon Nov 15 14:42:11 2010
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Mon, 15 Nov 2010 08:42:11 -0500
Subject: [sdiy] Best kept secret of amazing electronics books
Message-ID: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>

i am in heaven right now reading through a previously unknown to me gem, not the art of electronics, but the art of electronics student manual!!

600 pages of in depth teaching...excellent sections on transistors, logic, opamps

Written in a way that is a joy to read. Gets in depth and without too much math, which is good for me. I stayed up all night excited about learning ( it has a very conversational style)



Seriously, check this book out. Not just a light companion but a great book in its own right.

Thanks!!

Sent from my iPhone

From thomas at pdp7.org  Mon Nov 15 15:14:38 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Mon, 15 Nov 2010 15:14:38 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
Message-ID: <4CE1404E.5060403@pdp7.org>

On 11/15/10 14:42 , Dan Snazelle wrote:
> i am in heaven right now reading through a previously unknown to me gem, not the art of electronics, but the art of electronics student manual!!
>
> 600 pages of in depth teaching...excellent sections on transistors, logic, opamps
>
> Written in a way that is a joy to read. Gets in depth and without too much math, which is good for me. I stayed up all night excited about learning ( it has a very conversational style)

I did not know this book either. It addresses one of the issues I had 
with Art of Electronics: Sometimes it's a very light on descriptions or 
explanations. The Student Manual seems to fix this. But I find it 
irritating that a book about electronics has so little maths. You can 
write in such a way that (a) the math content is not essential to the 
main text, but rather an addition for those who want an in-depth 
understanding, and (b) people who don't know about things like 
differential equations can learn the basics from an engineer's point of 
view along the way. Solving a linear ODE with fixed coefficients is just 
applying a recipe or algorithm if you will and until I learned about it 
I never had the feeling that I understand even the most basic circuits 
with capacitors or inductors.

On a slightly different note: Who wants to wager that the next edition 
of Art of Electronics comes out next year? ;-)

	Thomas


From harrybissell at wowway.com  Mon Nov 15 15:25:19 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 09:25:19 -0500 (EST)
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTimwp93mTXjgrd-gi9twDEZrokcqYphvvGgfraaj@mail.gmail.com>
Message-ID: <1404756200.396787.1289831119468.JavaMail.root@md01.wow.synacor.com>

A connector crimped with the proper tool probably does not benefit much from
solder.

A connector crimped with an improper tool benefits GREATLY from being soldered.

Solder need not wick up the wire much, if you don't use too much. for most
connector pins it should be only in the crimp area...

I solder when I really care about the connection... (my own preference)

H^) harry



----- Original Message -----
From: megaohm <megaohm1 at gmail.com>
To: Stewart Pye <stewpye at optusnet.com.au>
Cc: sdiy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 12 Nov 2010 18:49:08 -0500 (EST)
Subject: Re: [sdiy] 0.100 pin header reliability.

I won't argue against 20 years of positives. But maybe your experience
would have been just as positive without soldering?
The reason I don't crimp-then-solder is because the Molex info sheets
for the KK series state specifically not to do so. They claim the
soldering actually makes it less reliable.
Regardless, I plan on switching to IDC type connectors. While the
crimp method is supposed to be a superior connection (Molex KK series)
the contact pins of the AMP connectors seem to sit more snug in the
housing and show less play when fitted to the header pins than the
Molex type.
  Also, I started using connectors as a compromise to the best
connections (direct soldering, no connectors or headers). The Molex KK
take a lot longer to do than the IDC method and I wasn't saving any
time compared to hard soldering the leads to the pcb.

p.


On Fri, Nov 12, 2010 at 11:11 AM, Stewart Pye <stewpye at optusnet.com.au> wrote:
> We've been soldering crimp connectors without a failure for over 20 years so
> I'd be interested why you'd say that, especially considering the amount of
> ?commercial "pro audio" products I've seen with failures of crimped pins.
>
>
> Cheers,
> Stew.
>
>
>>
>> On Nov 12, 2010, at 06:57, Cary Roberts wrote:
>>>
>>> Failures:
>>> --------
>>> _ANY_ crimp connector that has been soldered.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov 15 15:31:23 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 09:31:23 -0500 (EST)
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
Message-ID: <993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>

I have rarely (in fact never) seen aluminum as a metal in connector pins.
Usually they are steel (cheap) or brass, or beryllium copper...

Aluminum does not solder well at all using any standard electronic
solders... (i hear there are fluxes for this, but have never needed them...)

H^) harry


----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: Dave Kendall <davekendall at ntlworld.com>
Cc: synth-diy at dropmix.xs4all.nl
Sent: Mon, 15 Nov 2010 04:05:11 -0500 (EST)
Subject: Re: [sdiy] 0.100 pin header reliability.

Hi Dave,
to prevent breaking of soldered cable, have it zip tied to the PCB
about 2 cm away from the spot it was soldered to. Zip tie first,
solder second, so that the solder solidifies in the right shape.

With regards to soldering of crimped connectors: there might be
several things at play here, but I'm not good enough with my chemistry
to know if they actually make an impact. Maybe someone can tell me if
my intuitions here are right or wrong.
1. three/four metals (aluminum for the connector, copper for the cable
and solder, tin for the solder) make for different electrical
properties, oxides migrate differently
2. the solder crystals change shape over time. I understand there's
some sort of evolution to solid solder that makes it eject oxides?
This could not only separate the cold weld but also make it dirty with
oxides. Maybe someone can confirm this.
3. Is solder perhaps more reluctant to make a cold weld with aluminum,
than bare copper touching bare aluminum? If you solder first and crimp
second, you're crimping against tin. This also has the effect that the
tin soldered to the cable and/or connector might separate off what it
was soldered to, making an even worse connection
4. If you crimp first and solder second, the heat is going to expand
the aluminum more than it expands the copper wire - aluminum has a
higher linear coefficient of thermal expansion - effectively
un-crimping the connector. I don't think it's going to re-seat itself
nicely back to being crimped afterwards, but I don't know. My guess
here is that you actually need a lot of force to create a cold weld,
and this force is not going to be supplied by the shrinking connector
alone. Besides, there might be solder in that space now, which messes
up the connection
5. My intuition is that at least the better connectors have the leafs
produced in such a way that the crystalline structure is good for
making cold welds. Heating up changes this structure, quite possibly
for worse.

It would be interesting to know if any of this actually holds up
according to theory.

Regarding saving time: I read this thread and I think to myself...
isn't it much better to just buy ready cables?... They'll be crimped
much better than you can do it anyways, they'll be much cheaper in the
end, and they don't cost you time..

Cheers,
D.

On Sat, Nov 13, 2010 at 02:58, Dave Kendall <davekendall at ntlworld.com> wrote:
>
> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>
>> I think that when soldering decreases reliability it is because
>> the solder wicks up the wire away from the joint & stiffens the wire,
>> which then tends to flex sharply at the end of the solder & break there.
>
> That makes sense. But wouldn't that same potential weakness also apply to a
> wire either directly soldered to the PCB pad, or to a PCB pin?. I've had
> that happen on some perfboard prototype builds using stranded wire that got
> some rough handling. (the soldered joints to PCB pins weren't reinforced by
> heatshrink or hellerman sleeves or anything, so I wasn't too surprised...)
>
> This is an interesting thread, thanks for everyone's input.
>
> cheers,
> Dave
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov 15 15:39:50 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 09:39:50 -0500 (EST)
Subject: [sdiy] Reliability: Share your lessons learned
In-Reply-To: <590618.79023.qm@web55302.mail.re4.yahoo.com>
Message-ID: <1078796881.397494.1289831990500.JavaMail.root@md01.wow.synacor.com>

Reliable

PERFBOARD (preferably epoxy-glass) .1 spacing .040" holes with
Vector T42-A push in terminals for all component leads, except ICs
which are installed in AMP Diplomate sockets (preferably the higher-quality
beryllium copper ones) but the cheap TIN plate is fine too...

My circuit boards using this technique have been in service for over
thirty years in many cases, with zero failures due to any PCB issue
(and very few other failures, usually due to design weaknesses...)

H^) harry





----- Original Message -----
From: Tim Ressel <madhun2001 at yahoo.com>
To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Mon, 15 Nov 2010 01:03:44 -0500 (EST)
Subject: Re: [sdiy] Reliability: Share your lessons learned

Here's a tip for those who don't want to give up on MDF: Shellac. It is 
alcohol-based so it doesn't raise the wood grain near as much as other coatings. 
And 2 coats of it seals MDF very nicely. My homebrew corner horns have been 
around for 16 years with no sign of degradation.

--TimR




----- Original Message ----
From: Mike Beauchamp <mikebeauchamp at gmail.com>
To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Sun, November 14, 2010 5:29:46 PM
Subject: [sdiy] Reliability: Share your lessons learned

The recent .1" heading thread has me thinking about long-term
reliability. We all have experience building and repairing things that
employ different parts, techniques and finishes and we've all seen
what is still working and/or easily repaired.

So please share any lessons/experiences about what works and what
doesn't for the longer-term.


My experience is still rather limited and the stuff I've built hasn't
been around for too long, but I suppose I can say:

works:
-point to point wiring and eyelet boards. (more of a guitar amp thing).
-PCB's with a silkscreen legend designed for others to see and understand.
-PCB's with soldermask and cleaned after assembly. (I haven't tried a
conformal coating yet)
-socketed IC's
-Alpha pots (and I like that they can be disassembled for future
maintenance/cleaning).
-neutrix and switchcraft 1/4" jacks.
-electrolytic capacitors that are easily replaced.

doesn't work:
-lots of hardware from futurlec (especially their unusable 1/4" jacks)
-strain relief on most wallwarts.
-particle board, MDF, chipboard, etc. (if there's a possibility of
water contact.)
-perfboard. fails way too easily when being repaired/modified.
-the paint electro-harmonix used on my deluxe memory man reissue. epic fail.


-- 
[mike]
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From dixon at interchange.ubc.ca  Mon Nov 15 16:38:49 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 07:38:49 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
Message-ID: <8CDB536082F94F87B0D144CED98A67F6@galvanox01>

> I have rarely (in fact never) seen aluminum as a metal in connector pins.
> Usually they are steel (cheap) or brass, or beryllium copper...
> 
> Aluminum does not solder well at all using any standard electronic
> solders... (i hear there are fluxes for this, but have never needed
> them...)

In my experience, aluminum repels solder, which forms droplets with acute
contact angles when splashed onto aluminum.

For what it's worth, my crimping tool looks like a big pair of pliers, and
those crimped joints ain't coming apart anytime soon!  The wire would break
before those bad boys came loose, and in any case, there is no pulling
stress on them, as I always leave some slack in the wire.




From neil.johnson97 at ntlworld.com  Mon Nov 15 17:28:38 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Mon, 15 Nov 2010 16:28:38 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <8CDB536082F94F87B0D144CED98A67F6@galvanox01>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<8CDB536082F94F87B0D144CED98A67F6@galvanox01>
Message-ID: <AANLkTiks733ePtw-7oavWEWNgXVY7OgVU9c4FYJ_T__F@mail.gmail.com>

Hi,

David G. Dixon wrote:
> In my experience, aluminum repels solder, which forms droplets with acute
> contact angles when splashed onto aluminum.

While soldering aluminium is possible, see for example

http://www.aws.org/wj/2004/02/046/

the fluxes involved are pretty nasty.  Even just bolting aluminium
conductors to copper you need to use special jointing compounds to
stop joint failure from accelerated corrosion.

> For what it's worth, my crimping tool looks like a big pair of pliers, and
> those crimped joints ain't coming apart anytime soon! ?The wire would break
> before those bad boys came loose, and in any case, there is no pulling
> stress on them, as I always leave some slack in the wire.

Ah, ok, the cheap $10 ones :)

Crimping is only guaranteed to work as stated by the manufacturer when
(a) you use the correct crimping tool, and (b) that tool is within
calibration (i.e., it needs regular checking and recalibration if
required).  If you spend $300 or more on a crimp tool then you're in
the right ballpark.

If you're patient enough you can find good ones on eBay.  A couple of
years ago I picked up a brand new large AMP crimp tool for not much,
although that starts at 6mm2 and goes up.

As far as reliability is concerned, something is only as reliable as
you are prepared to make it.  So its a cost/benefit issue.  If the
cost of failure is high, then you pay for good design, good assembly
people, good components and good tools (the defence/aerospace model).
If the cost of the product is the main factor, then you choose
low-cost design, cheap components, cheap tools, and either cheap
labour or design out manual assembly (the consumer product model).

If a connector is a crimp connector, and you are concerned about
reliability (including support from the connector manufacturer when
something goes wrong) you crimp it according to the manufacturer's
instructions.  Anything else and you have effectively voided the
manufacturer's warranty.

Same applies to soldered connections - don't try to crimp them.

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From profpep at hotmail.com  Mon Nov 15 17:58:07 2010
From: profpep at hotmail.com (Mike Pepper)
Date: Mon, 15 Nov 2010 16:58:07 -0000
Subject: [sdiy] Soldering aluminium,
	(was:  0.100 pin header reliability).
Message-ID: <005a01cb84e6$47714060$c800a8c0@desk>

Subject: Soldering aluminium, (was: 0.100 pin header reliability).


>
> >>David G. Dixon wrote:
> >> In my experience, aluminum repels solder, which forms droplets with
acute
> >>contact angles when splashed onto aluminum.
>
> >While soldering aluminium is possible, see for example
>
> > http://www.aws.org/wj/2004/02/046/
>
> >the fluxes involved are pretty nasty.  Even just bolting aluminium
> >conductors to copper you need to use special jointing compounds to
> >stop joint failure from accelerated corrosion.
>
> My adoptive Grandfather  told me of a WW1 technique, used for patching
alloy
> engine parts and fuel tanks. The surface is cleaned, then a film of light
> oil is put on the aluminium, and the surface further abraded with wire
wool
> through the oil. The alloy can then be tinned, because the air has not
been
> in contact with the alloy, due to the oil, for long enough for the surface
> oxide to form. The heat from the iron boils away the oil as tinning
> progresses. The patch is tinned up the same way, then the two 'sweated'
> together. I used the technique to form alloy screening compartments, when
> building stuff for radio amateurs I knew, though for UHF, we used  silver
> soldered brass, then had it silver plated to give the lowest reistance for
> the skin effect currents. Not much use for terminals I grant you, but
enough
> to form a solder patch if it's needed for a panel earth.
>
> ||\/||ike
>
>





From cheater00 at gmail.com  Mon Nov 15 18:32:34 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 15 Nov 2010 18:32:34 +0100
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>

Hi Harry,

On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com> wrote:
> I have rarely (in fact never) seen aluminum as a metal in connector pins.
> Usually they are steel (cheap) or brass, or beryllium copper...

People say the same about aluminum for 220V wiring in houses... well,
don't go to eastern Europe then :-) Some blocks have had each single
(brick) wall ripped up, 20-30 years after having been built :) The
"fake walls" out of wood and plaster are not popular at all these
parts.. it all goes into the wall between bricks etc.

What I've said applies to steel connectors in the same way, though.
The expansion coefficient is about 2% higher in steel than in copper,
so that's not much, but maybe it's enough to break a cold weld when
the crimped assembly is heated up to soldering temperatures..

Cheers,
D.

On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com> wrote:
> I have rarely (in fact never) seen aluminum as a metal in connector pins.
> Usually they are steel (cheap) or brass, or beryllium copper...
>
> Aluminum does not solder well at all using any standard electronic
> solders... (i hear there are fluxes for this, but have never needed them...)
>
> H^) harry
>
>
> ----- Original Message -----
> From: cheater cheater <cheater00 at gmail.com>
> To: Dave Kendall <davekendall at ntlworld.com>
> Cc: synth-diy at dropmix.xs4all.nl
> Sent: Mon, 15 Nov 2010 04:05:11 -0500 (EST)
> Subject: Re: [sdiy] 0.100 pin header reliability.
>
> Hi Dave,
> to prevent breaking of soldered cable, have it zip tied to the PCB
> about 2 cm away from the spot it was soldered to. Zip tie first,
> solder second, so that the solder solidifies in the right shape.
>
> With regards to soldering of crimped connectors: there might be
> several things at play here, but I'm not good enough with my chemistry
> to know if they actually make an impact. Maybe someone can tell me if
> my intuitions here are right or wrong.
> 1. three/four metals (aluminum for the connector, copper for the cable
> and solder, tin for the solder) make for different electrical
> properties, oxides migrate differently
> 2. the solder crystals change shape over time. I understand there's
> some sort of evolution to solid solder that makes it eject oxides?
> This could not only separate the cold weld but also make it dirty with
> oxides. Maybe someone can confirm this.
> 3. Is solder perhaps more reluctant to make a cold weld with aluminum,
> than bare copper touching bare aluminum? If you solder first and crimp
> second, you're crimping against tin. This also has the effect that the
> tin soldered to the cable and/or connector might separate off what it
> was soldered to, making an even worse connection
> 4. If you crimp first and solder second, the heat is going to expand
> the aluminum more than it expands the copper wire - aluminum has a
> higher linear coefficient of thermal expansion - effectively
> un-crimping the connector. I don't think it's going to re-seat itself
> nicely back to being crimped afterwards, but I don't know. My guess
> here is that you actually need a lot of force to create a cold weld,
> and this force is not going to be supplied by the shrinking connector
> alone. Besides, there might be solder in that space now, which messes
> up the connection
> 5. My intuition is that at least the better connectors have the leafs
> produced in such a way that the crystalline structure is good for
> making cold welds. Heating up changes this structure, quite possibly
> for worse.
>
> It would be interesting to know if any of this actually holds up
> according to theory.
>
> Regarding saving time: I read this thread and I think to myself...
> isn't it much better to just buy ready cables?... They'll be crimped
> much better than you can do it anyways, they'll be much cheaper in the
> end, and they don't cost you time..
>
> Cheers,
> D.
>
> On Sat, Nov 13, 2010 at 02:58, Dave Kendall <davekendall at ntlworld.com> wrote:
>>
>> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>>
>>> I think that when soldering decreases reliability it is because
>>> the solder wicks up the wire away from the joint & stiffens the wire,
>>> which then tends to flex sharply at the end of the solder & break there.
>>
>> That makes sense. But wouldn't that same potential weakness also apply to a
>> wire either directly soldered to the PCB pad, or to a PCB pin?. I've had
>> that happen on some perfboard prototype builds using stranded wire that got
>> some rough handling. (the soldered joints to PCB pins weren't reinforced by
>> heatshrink or hellerman sleeves or anything, so I wasn't too surprised...)
>>
>> This is an interesting thread, thanks for everyone's input.
>>
>> cheers,
>> Dave
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
>


From dixon at interchange.ubc.ca  Mon Nov 15 18:39:29 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 09:39:29 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTiks733ePtw-7oavWEWNgXVY7OgVU9c4FYJ_T__F@mail.gmail.com>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<8CDB536082F94F87B0D144CED98A67F6@galvanox01>
	<AANLkTiks733ePtw-7oavWEWNgXVY7OgVU9c4FYJ_T__F@mail.gmail.com>
Message-ID: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>

> Ah, ok, the cheap $10 ones :)
> 
> Crimping is only guaranteed to work as stated by the manufacturer when
> (a) you use the correct crimping tool, and (b) that tool is within
> calibration (i.e., it needs regular checking and recalibration if
> required).  If you spend $300 or more on a crimp tool then you're in
> the right ballpark.

My crimping pliers have two crimping locations: A and B.  One is a bit
smaller, and that's the one I use.  The two sides of the pliers come
together very tightly -- these pliers are probably at least 30 years old and
very well made.  I haven't seen any this nice in the stores, but I'm sure
they'd go for between $50 and $100.

The crimp pins I use have two sets of crimpable "wings" -- smaller ones in
the middle for crimping onto bare wire, and larger ones on the end for
crimping onto the insulation.

I strip about 1/8" of insulation off the end of the wire, put it in the pin
and crimp the small wings hard with the crimping pliers.  (I take pains to
ensure that all the little wire strands get crimped in, although very
occasionally a stray strand gets away.)  Then I crimp the large wings over
the insulation.  The pin is on that wire so damned hard that you could never
pull it off.

Once the PCB is attached to the panel and all the connectors are plugged in,
there is no pulling stress on the wires, and very little if any movement is
possible since I bundle them together with plastic ties.

So, what is going to fail here?  What does the $300 dollar machine do that
my crimping pliers don't?



From cheater00 at gmail.com  Mon Nov 15 18:40:38 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 15 Nov 2010 18:40:38 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <4CE1404E.5060403@pdp7.org>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
Message-ID: <AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>

On Mon, Nov 15, 2010 at 15:14, Thomas Strathmann <thomas at pdp7.org> wrote:
> On 11/15/10 14:42 , Dan Snazelle wrote:
>>
>> i am in heaven right now reading through a previously unknown to me gem,
>> not the art of electronics, but the art of electronics student manual!!
>>
>> 600 pages of in depth teaching...excellent sections on transistors, logic,
>> opamps
>>
>> Written in a way that is a joy to read. Gets in depth and without too much
>> math, which is good for me. I stayed up all night excited about learning (
>> it has a very conversational style)
>
> I did not know this book either. It addresses one of the issues I had with
> Art of Electronics: Sometimes it's a very light on descriptions or
> explanations. The Student Manual seems to fix this. But I find it irritating
> that a book about electronics has so little maths. You can write in such a
> way that (a) the math content is not essential to the main text, but rather
> an addition for those who want an in-depth understanding, and (b) people who
> don't know about things like differential equations can learn the basics
> from an engineer's point of view along the way. Solving a linear ODE with
> fixed coefficients is just applying a recipe or algorithm if you will and
> until I learned about it I never had the feeling that I understand even the
> most basic circuits with capacitors or inductors.

What book do you suggest that does that?
I'm very good with my maths...

Thanks,
D.

>
> On a slightly different note: Who wants to wager that the next edition of
> Art of Electronics comes out next year? ;-)
>
> ? ? ? ?Thomas
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From harrybissell at wowway.com  Mon Nov 15 18:44:29 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 12:44:29 -0500 (EST)
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
Message-ID: <1735561685.403621.1289843069299.JavaMail.root@md01.wow.synacor.com>

The aluminum house wiring issue is different. When Al wire was first
used with copper terminations, the difference in expansion rates would
eventually make the connection loosen, ~then~ fail.  Re-design of the
connectors (outlets, switches etc) can make Al work (some use spring
pressure to compensate). OTOH Al has a bad name now and no one would use it
these days.

They also made copper pigtails that could be joined to Al wire, then you attach
the copper to the outlet. Yes ... they are crimped :^)

H^) harry



----- Original Message -----
From: cheater cheater <cheater00 at gmail.com>
To: Harry Bissell <harrybissell at wowway.com>
Cc: Dave Kendall <davekendall at ntlworld.com>, synth-diy at dropmix.xs4all.nl
Sent: Mon, 15 Nov 2010 12:32:34 -0500 (EST)
Subject: Re: [sdiy] 0.100 pin header reliability.

Hi Harry,

On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com> wrote:
> I have rarely (in fact never) seen aluminum as a metal in connector pins.
> Usually they are steel (cheap) or brass, or beryllium copper...

People say the same about aluminum for 220V wiring in houses... well,
don't go to eastern Europe then :-) Some blocks have had each single
(brick) wall ripped up, 20-30 years after having been built :) The
"fake walls" out of wood and plaster are not popular at all these
parts.. it all goes into the wall between bricks etc.

What I've said applies to steel connectors in the same way, though.
The expansion coefficient is about 2% higher in steel than in copper,
so that's not much, but maybe it's enough to break a cold weld when
the crimped assembly is heated up to soldering temperatures..

Cheers,
D.

On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com> wrote:
> I have rarely (in fact never) seen aluminum as a metal in connector pins.
> Usually they are steel (cheap) or brass, or beryllium copper...
>
> Aluminum does not solder well at all using any standard electronic
> solders... (i hear there are fluxes for this, but have never needed them...)
>
> H^) harry
>
>
> ----- Original Message -----
> From: cheater cheater <cheater00 at gmail.com>
> To: Dave Kendall <davekendall at ntlworld.com>
> Cc: synth-diy at dropmix.xs4all.nl
> Sent: Mon, 15 Nov 2010 04:05:11 -0500 (EST)
> Subject: Re: [sdiy] 0.100 pin header reliability.
>
> Hi Dave,
> to prevent breaking of soldered cable, have it zip tied to the PCB
> about 2 cm away from the spot it was soldered to. Zip tie first,
> solder second, so that the solder solidifies in the right shape.
>
> With regards to soldering of crimped connectors: there might be
> several things at play here, but I'm not good enough with my chemistry
> to know if they actually make an impact. Maybe someone can tell me if
> my intuitions here are right or wrong.
> 1. three/four metals (aluminum for the connector, copper for the cable
> and solder, tin for the solder) make for different electrical
> properties, oxides migrate differently
> 2. the solder crystals change shape over time. I understand there's
> some sort of evolution to solid solder that makes it eject oxides?
> This could not only separate the cold weld but also make it dirty with
> oxides. Maybe someone can confirm this.
> 3. Is solder perhaps more reluctant to make a cold weld with aluminum,
> than bare copper touching bare aluminum? If you solder first and crimp
> second, you're crimping against tin. This also has the effect that the
> tin soldered to the cable and/or connector might separate off what it
> was soldered to, making an even worse connection
> 4. If you crimp first and solder second, the heat is going to expand
> the aluminum more than it expands the copper wire - aluminum has a
> higher linear coefficient of thermal expansion - effectively
> un-crimping the connector. I don't think it's going to re-seat itself
> nicely back to being crimped afterwards, but I don't know. My guess
> here is that you actually need a lot of force to create a cold weld,
> and this force is not going to be supplied by the shrinking connector
> alone. Besides, there might be solder in that space now, which messes
> up the connection
> 5. My intuition is that at least the better connectors have the leafs
> produced in such a way that the crystalline structure is good for
> making cold welds. Heating up changes this structure, quite possibly
> for worse.
>
> It would be interesting to know if any of this actually holds up
> according to theory.
>
> Regarding saving time: I read this thread and I think to myself...
> isn't it much better to just buy ready cables?... They'll be crimped
> much better than you can do it anyways, they'll be much cheaper in the
> end, and they don't cost you time..
>
> Cheers,
> D.
>
> On Sat, Nov 13, 2010 at 02:58, Dave Kendall <davekendall at ntlworld.com> wrote:
>>
>> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>>
>>> I think that when soldering decreases reliability it is because
>>> the solder wicks up the wire away from the joint & stiffens the wire,
>>> which then tends to flex sharply at the end of the solder & break there.
>>
>> That makes sense. But wouldn't that same potential weakness also apply to a
>> wire either directly soldered to the PCB pad, or to a PCB pin?. I've had
>> that happen on some perfboard prototype builds using stranded wire that got
>> some rough handling. (the soldered joints to PCB pins weren't reinforced by
>> heatshrink or hellerman sleeves or anything, so I wasn't too surprised...)
>>
>> This is an interesting thread, thanks for everyone's input.
>>
>> cheers,
>> Dave
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
>

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov 15 18:48:09 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 12:48:09 -0500 (EST)
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>
Message-ID: <1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>

The $300 crimpers allow Monkeys to make the cable assemblies   ;^)
(see Design News magazine "Monkeys made my ----- feature)

The $300 crimpers allow you to do a lot more connections a lot easier...
but for DIY work the low-cost ones can be effective. For my modular
(repackage) I chose Molex Centi-grid connectors because of the availability
of a low cost hand tool ($40), and an automated one for that series is only
about $150

H^) harry


----- Original Message -----
From: David G. Dixon <dixon at interchange.ubc.ca>
To: 'Neil Johnson' <neil.johnson97 at ntlworld.com>, synth-diy at dropmix.xs4all.nl
Sent: Mon, 15 Nov 2010 12:39:29 -0500 (EST)
Subject: Re: [sdiy] 0.100 pin header reliability.

> Ah, ok, the cheap $10 ones :)
> 
> Crimping is only guaranteed to work as stated by the manufacturer when
> (a) you use the correct crimping tool, and (b) that tool is within
> calibration (i.e., it needs regular checking and recalibration if
> required).  If you spend $300 or more on a crimp tool then you're in
> the right ballpark.

My crimping pliers have two crimping locations: A and B.  One is a bit
smaller, and that's the one I use.  The two sides of the pliers come
together very tightly -- these pliers are probably at least 30 years old and
very well made.  I haven't seen any this nice in the stores, but I'm sure
they'd go for between $50 and $100.

The crimp pins I use have two sets of crimpable "wings" -- smaller ones in
the middle for crimping onto bare wire, and larger ones on the end for
crimping onto the insulation.

I strip about 1/8" of insulation off the end of the wire, put it in the pin
and crimp the small wings hard with the crimping pliers.  (I take pains to
ensure that all the little wire strands get crimped in, although very
occasionally a stray strand gets away.)  Then I crimp the large wings over
the insulation.  The pin is on that wire so damned hard that you could never
pull it off.

Once the PCB is attached to the panel and all the connectors are plugged in,
there is no pulling stress on the wires, and very little if any movement is
possible since I bundle them together with plastic ties.

So, what is going to fail here?  What does the $300 dollar machine do that
my crimping pliers don't?

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From harrybissell at wowway.com  Mon Nov 15 18:50:09 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 12:50:09 -0500 (EST)
Subject: [sdiy] Soldering aluminium,
 (was:  0.100 pin header reliability).
In-Reply-To: <005a01cb84e6$47714060$c800a8c0@desk>
Message-ID: <1257218621.403835.1289843409823.JavaMail.root@md01.wow.synacor.com>

Thanks for the tip. that would be good to know in desperation, for sure !!!

H^) harry



----- Original Message -----
From: Mike Pepper <profpep at hotmail.com>
To: synth-diy at dropmix.xs4all.nl
Sent: Mon, 15 Nov 2010 11:58:07 -0500 (EST)
Subject: Re: [sdiy] Soldering aluminium,	(was:  0.100 pin header reliability).

Subject: Soldering aluminium, (was: 0.100 pin header reliability).


>
> >>David G. Dixon wrote:
> >> In my experience, aluminum repels solder, which forms droplets with
acute
> >>contact angles when splashed onto aluminum.
>
> >While soldering aluminium is possible, see for example
>
> > http://www.aws.org/wj/2004/02/046/
>
> >the fluxes involved are pretty nasty.  Even just bolting aluminium
> >conductors to copper you need to use special jointing compounds to
> >stop joint failure from accelerated corrosion.
>
> My adoptive Grandfather  told me of a WW1 technique, used for patching
alloy
> engine parts and fuel tanks. The surface is cleaned, then a film of light
> oil is put on the aluminium, and the surface further abraded with wire
wool
> through the oil. The alloy can then be tinned, because the air has not
been
> in contact with the alloy, due to the oil, for long enough for the surface
> oxide to form. The heat from the iron boils away the oil as tinning
> progresses. The patch is tinned up the same way, then the two 'sweated'
> together. I used the technique to form alloy screening compartments, when
> building stuff for radio amateurs I knew, though for UHF, we used  silver
> soldered brass, then had it silver plated to give the lowest reistance for
> the skin effect currents. Not much use for terminals I grant you, but
enough
> to form a solder patch if it's needed for a panel earth.
>
> ||\/||ike
>
>



_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From tom at electricdruid.net  Mon Nov 15 19:07:56 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 15 Nov 2010 18:07:56 +0000
Subject: [sdiy] Reliability: Share your lessons learned
In-Reply-To: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>
References: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>
Message-ID: <DDD82A17-5FA9-4643-8A4D-C43105AECA6B@electricdruid.net>

My own experience is from years of fixing stompboxes for mates and fixing dataloggers at work.

On the pedals, it's always the jacks, the pots, and the flying wires that give up. Actual electronic failures are much less common. But anything where a plug gets rammed in and out frequently is going to be a potential point of failure. Did I mention that I hate those stupid 2.1mm DC connectors too? Especially if they're soldered to the PCB - that's *asking* for trouble. Eventually the strains put on the socket will crack the solder joints and it'll stop working. I've seen this on the board-mounted jacks on my Pro-One too.

On the dataloggers, there were various things that used to give us problems, and mostly that was to do with temperature or temperature changes. One particular type of unit had a pair of boards stacked on top of each other with a 0.1pin header and socket row connecting the top board to the lower one. Although the whole lot was potted in clear resin and so protected from moisture, over time the expansion and contraction caused by temperature changes could cause this connection to fail. Bear in mind these boxes were stuck outside or down a manhole for most of their lives, so the temperature range was reasonably wide. The batteries were also a  common failure in cold weather, where the voltage would drop low enough to crash the uP and then it'd go into a high current draw state and flatten what was left of the battery. With decent quality batteries we expected a 10 year service life and many did better than this before they came back for a new one.
The inputs were protected by optoisolators and in general this was very successful, although I remember one unit that had been connected to something that had been struck by lightning. This was sufficient to blow the opto chip to pieces, even within the potting compound. Never seen that before or since!
The connectors on these units were all Milspec and consequently didn't give us many problems.

So, in summary:

Works:

	Electronics!
	Potting compound
	Milspec connectors (and probably other parts too)
	Optoisolation of inputs

Doesn't work:

	Mechanical parts!
	PCB mounting of commonly used jacks and connectors
	Cheap pots (although these are easily repaired)
	Batteries in cold weather
	Interconnection wires that aren't properly heatshrinked to prevent them snapping off

I'd have hoped I'd learned something more than that, but that is pretty much it. Sigh.

T.


On 15 Nov 2010, at 01:29, Mike Beauchamp wrote:

> The recent .1" heading thread has me thinking about long-term
> reliability. We all have experience building and repairing things that
> employ different parts, techniques and finishes and we've all seen
> what is still working and/or easily repaired.
> 
> So please share any lessons/experiences about what works and what
> doesn't for the longer-term.
> 
> 
> My experience is still rather limited and the stuff I've built hasn't
> been around for too long, but I suppose I can say:
> 
> works:
> -point to point wiring and eyelet boards. (more of a guitar amp thing).
> -PCB's with a silkscreen legend designed for others to see and understand.
> -PCB's with soldermask and cleaned after assembly. (I haven't tried a
> conformal coating yet)
> -socketed IC's
> -Alpha pots (and I like that they can be disassembled for future
> maintenance/cleaning).
> -neutrix and switchcraft 1/4" jacks.
> -electrolytic capacitors that are easily replaced.
> 
> doesn't work:
> -lots of hardware from futurlec (especially their unusable 1/4" jacks)
> -strain relief on most wallwarts.
> -particle board, MDF, chipboard, etc. (if there's a possibility of
> water contact.)
> -perfboard. fails way too easily when being repaired/modified.
> -the paint electro-harmonix used on my deluxe memory man reissue. epic fail.
> 
> 
> -- 
> [mike]
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From dixon at interchange.ubc.ca  Mon Nov 15 19:08:30 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 10:08:30 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
References: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>
	<1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
Message-ID: <24CE72D7C29D4371912934CFC17E8AA4@galvanox01>

> The $300 crimpers allow you to do a lot more connections a lot easier...

Fair enough.  However, for me, crimping is never the rate-limiting step in
panel wiring.  Plus, having a hand-held crimping tool is very important for
the way I do my panel wiring.  The multipin connectors on my board are
organized in a fairly logical fashion, and I tend to make all the
connections to a given connector at once.  For example, if I've got a 6-pin
connector with wires going to a couple of pots, say, then I solder all the
leads to the pots first.  Then I gather the wires into a bunch and cut them
all to the proper length (much like a barber cuts hair).  Then I strip and
crimp, plug the pins into the connector, plug the connector to the board,
bundle up the wires with a plastic tie, and move on to the next connector.
For this technique, a hand-held crimper is essential.



From dixon at interchange.ubc.ca  Mon Nov 15 19:16:04 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 10:16:04 -0800
Subject: [sdiy] Reliability: Share your lessons learned
In-Reply-To: <12475_1289844487_1289844487_DDD82A17-5FA9-4643-8A4D-C43105AECA6B@electricdruid.net>
References: <AANLkTi=LVssvuBV-kYycsv_8UERGYyook=XuQPeO6Cfz@mail.gmail.com>
	<12475_1289844487_1289844487_DDD82A17-5FA9-4643-8A4D-C43105AECA6B@electricdruid.net>
Message-ID: <B2084C68C6E448C8A34774283972CDAB@galvanox01>

> Did I mention that I hate those stupid 2.1mm DC
> connectors too? Especially if they're soldered to the PCB - that's
> *asking* for trouble. Eventually the strains put on the socket will crack
> the solder joints and it'll stop working.

Everyone hates those!  IME, that's always the first thing that fails on a
laptop computer as well.  All hail Steve for the Mac magnetic power plug!

> Doesn't work:
> 	PCB mounting of commonly used jacks and connectors
> 	Cheap pots (although these are easily repaired)

Ditto on the cheap pots!  Concerning board-mounted jacks, I'm wondering just
how long all this cheap-ass Euro crap flooding the modular market is going
to last...  :)



From harrybissell at wowway.com  Mon Nov 15 19:32:06 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 15 Nov 2010 13:32:06 -0500 (EST)
Subject: [sdiy] Reliability: Share your lessons learned
In-Reply-To: <B2084C68C6E448C8A34774283972CDAB@galvanox01>
Message-ID: <714317595.404989.1289845926234.JavaMail.root@md01.wow.synacor.com>

well.. I'm all FOR those euro board mounted jacks. Then I can find your
effects and amps sitting at the curb on trash day, take them home and
add a simple FLEXIBLE jumper wire past the broken spot on the PCB and
I'm good to go with your ex-gear :^)

(I have actually done this MANY times :^)

H^) harry



----- Original Message -----
From: David G. Dixon <dixon at interchange.ubc.ca>
To: 'Tom Wiltshire' <tom at electricdruid.net>, 'Mike Beauchamp' <mikebeauchamp at gmail.com>
Cc: 'sdiy DIY' <synth-diy at dropmix.xs4all.nl>
Sent: Mon, 15 Nov 2010 13:16:04 -0500 (EST)
Subject: Re: [sdiy] Reliability: Share your lessons learned

> Did I mention that I hate those stupid 2.1mm DC
> connectors too? Especially if they're soldered to the PCB - that's
> *asking* for trouble. Eventually the strains put on the socket will crack
> the solder joints and it'll stop working.

Everyone hates those!  IME, that's always the first thing that fails on a
laptop computer as well.  All hail Steve for the Mac magnetic power plug!

> Doesn't work:
> 	PCB mounting of commonly used jacks and connectors
> 	Cheap pots (although these are easily repaired)

Ditto on the cheap pots!  Concerning board-mounted jacks, I'm wondering just
how long all this cheap-ass Euro crap flooding the modular market is going
to last...  :)

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From jays at aracnet.com  Mon Nov 15 19:56:51 2010
From: jays at aracnet.com (jays at aracnet.com)
Date: Mon, 15 Nov 2010 10:56:51 -0800
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
References: "<BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>"
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
Message-ID: <eaf26fba1a3ddf4dc2260a0dcdb57218@localhost>

I would say that the Student Guide is essentual for using The Art of
Electronics. It fills in a lot of details and has a lot of things that
aren't in the book.

But in general I'm not a big fan of The Art of Electronics either. The
basics haven't changed all that much and it is a decent reference for
that. A number of things are dated now and there has been a lot of
changes and advancements in components which aren't in there. The
computer section is so dated that it should be removed from the book.
Usually I'll go to my ARRL Handbook (Radio Amateurs Handbook)first. To
me that would be the 'Best kept secret of amazing electronics books'.

Jay S.


From davebr at earthlink.net  Mon Nov 15 20:14:35 2010
From: davebr at earthlink.net (David Brown)
Date: Mon, 15 Nov 2010 11:14:35 -0800
Subject: [sdiy] Soldering aluminium,
 (was:  0.100 pin header  reliability).
In-Reply-To: <1257218621.403835.1289843409823.JavaMail.root@md01.wow.syn
	acor.com>
References: <005a01cb84e6$47714060$c800a8c0@desk>
	<1257218621.403835.1289843409823.JavaMail.root@md01.wow.synacor.com>
Message-ID: <20101115191431.A98DB10258@relay03.roch.ny.frontiernet.net>

I bought some aluminum brazing (soldering) rod years ago.  It was 
made in Olympia, Washington, but I don't see it now in a Google 
search.  I think it was a zinc alloy.  I probably have a lifetime supply.

It "solders" aluminum pretty well.  I've done a reasonable amount of 
brazing with it.  The main issue is aluminum goes from the solid to 
liquid state with no change in appearance (unlike steel).  One 
moment, what you are brazing is there, and the next moment it's 
gone.  You have to continuously monitor the heat.  Also, if you are 
brazing on opposite ends of a piece, aluminum conducts heat so well 
that you will "un"braze the opposite end you are working on.  You 
have to use heat sinks to keep the brazed work cool.

For Synth-DIY I brazed an aluminum bracket for my Blacet Miniwave.  I 
needed a top on the mounting bracket for the Tellun JLH2090CV 
board.  There is a picture of the brazed bracket on my Miniwave page.
http://modularsynthesis.com/blacet/miniwave/miniwave.htm

Dave

>----- Original Message -----
>From: Mike Pepper <profpep at hotmail.com>
>To: synth-diy at dropmix.xs4all.nl
>Sent: Mon, 15 Nov 2010 11:58:07 -0500 (EST)
>Subject: Re: [sdiy] Soldering aluminium,        (was:  0.100 pin 
>header reliability).
>
>Subject: Soldering aluminium, (was: 0.100 pin header reliability).



From thomas at pdp7.org  Mon Nov 15 20:17:03 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Mon, 15 Nov 2010 20:17:03 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
Message-ID: <4CE1872F.3060104@pdp7.org>

On 11/15/10 18:40 , cheater cheater wrote:
>> I did not know this book either. It addresses one of the issues I had with
>> Art of Electronics: Sometimes it's a very light on descriptions or
>> explanations. The Student Manual seems to fix this. But I find it irritating
>> that a book about electronics has so little maths. You can write in such a
>> way that (a) the math content is not essential to the main text, but rather
>> an addition for those who want an in-depth understanding, and (b) people who
>> don't know about things like differential equations can learn the basics
>> from an engineer's point of view along the way. Solving a linear ODE with
>> fixed coefficients is just applying a recipe or algorithm if you will and
>> until I learned about it I never had the feeling that I understand even the
>> most basic circuits with capacitors or inductors.
>
> What book do you suggest that does that?
> I'm very good with my maths...

Then you don't need a book that holds your hand with calculus and stuff. 
I like Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not 
ideal, but it covers a lot of ground including the maths involved, 
signal transmission, basic control theory, etc. Dunno about the English 
translation (in case you need that). One thing the authors got right was 
the omission of a chapter on microcomputers. Older editions had that, 
but such a chapter just gets old and is not really useful. Certainly 
much less material in the current edition that gets obsolete any time soon.

	Thomas


From gatkins at blueyonder.co.uk  Mon Nov 15 20:18:56 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Mon, 15 Nov 2010 19:18:56 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
Message-ID: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>

Aluminium for wiring ?

Are you sure about that, sounds highly unlikely, never heard of  
aluminium
conductors. Steel, copper alloys, silver, even gold but not aluminium.

Graham

On 15 Nov 2010, at 17:32, cheater cheater wrote:

> Hi Harry,
>
> On Mon, Nov 15, 2010 at 15:31, Harry Bissell  
> <harrybissell at wowway.com> wrote:
>> I have rarely (in fact never) seen aluminum as a metal in connector  
>> pins.
>> Usually they are steel (cheap) or brass, or beryllium copper...
>
> People say the same about aluminum for 220V wiring in houses... well,
> don't go to eastern Europe then :-) Some blocks have had each single
> (brick) wall ripped up, 20-30 years after having been built :) The
> "fake walls" out of wood and plaster are not popular at all these
> parts.. it all goes into the wall between bricks etc.
>
> What I've said applies to steel connectors in the same way, though.
> The expansion coefficient is about 2% higher in steel than in copper,
> so that's not much, but maybe it's enough to break a cold weld when
> the crimped assembly is heated up to soldering temperatures..
>
> Cheers,
> D.
>
> On Mon, Nov 15, 2010 at 15:31, Harry Bissell  
> <harrybissell at wowway.com> wrote:
>> I have rarely (in fact never) seen aluminum as a metal in connector  
>> pins.
>> Usually they are steel (cheap) or brass, or beryllium copper...
>>
>> Aluminum does not solder well at all using any standard electronic
>> solders... (i hear there are fluxes for this, but have never needed  
>> them...)
>>
>> H^) harry
>>
>>
>> ----- Original Message -----
>> From: cheater cheater <cheater00 at gmail.com>
>> To: Dave Kendall <davekendall at ntlworld.com>
>> Cc: synth-diy at dropmix.xs4all.nl
>> Sent: Mon, 15 Nov 2010 04:05:11 -0500 (EST)
>> Subject: Re: [sdiy] 0.100 pin header reliability.
>>
>> Hi Dave,
>> to prevent breaking of soldered cable, have it zip tied to the PCB
>> about 2 cm away from the spot it was soldered to. Zip tie first,
>> solder second, so that the solder solidifies in the right shape.
>>
>> With regards to soldering of crimped connectors: there might be
>> several things at play here, but I'm not good enough with my  
>> chemistry
>> to know if they actually make an impact. Maybe someone can tell me if
>> my intuitions here are right or wrong.
>> 1. three/four metals (aluminum for the connector, copper for the  
>> cable
>> and solder, tin for the solder) make for different electrical
>> properties, oxides migrate differently
>> 2. the solder crystals change shape over time. I understand there's
>> some sort of evolution to solid solder that makes it eject oxides?
>> This could not only separate the cold weld but also make it dirty  
>> with
>> oxides. Maybe someone can confirm this.
>> 3. Is solder perhaps more reluctant to make a cold weld with  
>> aluminum,
>> than bare copper touching bare aluminum? If you solder first and  
>> crimp
>> second, you're crimping against tin. This also has the effect that  
>> the
>> tin soldered to the cable and/or connector might separate off what it
>> was soldered to, making an even worse connection
>> 4. If you crimp first and solder second, the heat is going to expand
>> the aluminum more than it expands the copper wire - aluminum has a
>> higher linear coefficient of thermal expansion - effectively
>> un-crimping the connector. I don't think it's going to re-seat itself
>> nicely back to being crimped afterwards, but I don't know. My guess
>> here is that you actually need a lot of force to create a cold weld,
>> and this force is not going to be supplied by the shrinking connector
>> alone. Besides, there might be solder in that space now, which messes
>> up the connection
>> 5. My intuition is that at least the better connectors have the leafs
>> produced in such a way that the crystalline structure is good for
>> making cold welds. Heating up changes this structure, quite possibly
>> for worse.
>>
>> It would be interesting to know if any of this actually holds up
>> according to theory.
>>
>> Regarding saving time: I read this thread and I think to myself...
>> isn't it much better to just buy ready cables?... They'll be crimped
>> much better than you can do it anyways, they'll be much cheaper in  
>> the
>> end, and they don't cost you time..
>>
>> Cheers,
>> D.
>>
>> On Sat, Nov 13, 2010 at 02:58, Dave Kendall  
>> <davekendall at ntlworld.com> wrote:
>>>
>>> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>>>
>>>> I think that when soldering decreases reliability it is because
>>>> the solder wicks up the wire away from the joint & stiffens the  
>>>> wire,
>>>> which then tends to flex sharply at the end of the solder & break  
>>>> there.
>>>
>>> That makes sense. But wouldn't that same potential weakness also  
>>> apply to a
>>> wire either directly soldered to the PCB pad, or to a PCB pin?.  
>>> I've had
>>> that happen on some perfboard prototype builds using stranded wire  
>>> that got
>>> some rough handling. (the soldered joints to PCB pins weren't  
>>> reinforced by
>>> heatshrink or hellerman sleeves or anything, so I wasn't too  
>>> surprised...)
>>>
>>> This is an interesting thread, thanks for everyone's input.
>>>
>>> cheers,
>>> Dave
>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>> --
>> Harry Bissell & Nora Abdullah 4eva
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Mon Nov 15 20:32:34 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 15 Nov 2010 20:32:34 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <4CE1872F.3060104@pdp7.org>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
Message-ID: <AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>

I'll try to find it. Given that I'm in Germany right now, and can read
German, I could easily see myself getting a nice collection of used
books in the language. If you have any other tips, keep 'em coming!

Cheers,
D.

On Mon, Nov 15, 2010 at 20:17, Thomas Strathmann <thomas at pdp7.org> wrote:
> On 11/15/10 18:40 , cheater cheater wrote:
>>>
>>> I did not know this book either. It addresses one of the issues I had
>>> with
>>> Art of Electronics: Sometimes it's a very light on descriptions or
>>> explanations. The Student Manual seems to fix this. But I find it
>>> irritating
>>> that a book about electronics has so little maths. You can write in such
>>> a
>>> way that (a) the math content is not essential to the main text, but
>>> rather
>>> an addition for those who want an in-depth understanding, and (b) people
>>> who
>>> don't know about things like differential equations can learn the basics
>>> from an engineer's point of view along the way. Solving a linear ODE with
>>> fixed coefficients is just applying a recipe or algorithm if you will and
>>> until I learned about it I never had the feeling that I understand even
>>> the
>>> most basic circuits with capacitors or inductors.
>>
>> What book do you suggest that does that?
>> I'm very good with my maths...
>
> Then you don't need a book that holds your hand with calculus and stuff. I
> like Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
> but it covers a lot of ground including the maths involved, signal
> transmission, basic control theory, etc. Dunno about the English translation
> (in case you need that). One thing the authors got right was the omission of
> a chapter on microcomputers. Older editions had that, but such a chapter
> just gets old and is not really useful. Certainly much less material in the
> current edition that gets obsolete any time soon.
>
> ? ? ? ?Thomas
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From ijfritz at comcast.net  Mon Nov 15 20:34:00 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Mon, 15 Nov 2010 12:34:00 -0700
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
Message-ID: <6.2.1.2.2.20101115123212.0231e128@mail.comcast.net>

At 12:18 PM 11/15/2010, Graham Atkins wrote:
>Aluminium for wiring ?
>
>Are you sure about that, sounds highly unlikely, never heard of
>aluminium
>conductors. Steel, copper alloys, silver, even gold but not aluminium.

Oh absolutely!  This was used in the 1970s at a time when copper prices 
were extremely high.  I had a house for a while with that stuff in 
it.  Fortunately I sold it before I had any problems.

Ian



From xyzzy at sysabend.org  Mon Nov 15 20:34:16 2010
From: xyzzy at sysabend.org (Tom Arnold)
Date: Mon, 15 Nov 2010 11:34:16 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
Message-ID: <20101115193416.GB9110@moo.sysabend.org>

On Mon, Nov 15, 2010 at 07:18:56PM +0000, Graham Atkins wrote:
> Aluminium for wiring ?
> 
> Are you sure about that, sounds highly unlikely, never heard of  
> aluminium
> conductors. Steel, copper alloys, silver, even gold but not aluminium.

Aluminum was used for a while until it hit snags that involved huge lawsuits
and entire episodes of 60 Minutes.

Its still used for pole wiring in some places, ground braids for same, and
its making a comeback as house wiring with the price of copper so high.

Lots of info online about it.  I've been looking into it as I house hunt
because I need/want fairly vast wiring and copper has gotten a bit pricey.

-- 
 -----------------------------------------------------------------
 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -
 - BBD Fanatic      -  "...is it a virus, a drug, or a religion?" 
 - echo evho wjxo   -    Juanita Shrugs. "What's the difference?" 
 --------------------  



From dixon at interchange.ubc.ca  Mon Nov 15 21:01:04 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 12:01:04 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
Message-ID: <AC971CF9105340C98D70ED81865103E6@galvanox01>

> Aluminium for wiring ?
> 
> Are you sure about that, sounds highly unlikely, never heard of
> aluminium
> conductors. Steel, copper alloys, silver, even gold but not aluminium.

Here in Vancouver, virtually every house built before a certain date had
aluminum wiring.  Of course, it is all ripped out during renovations,
because it presents a fire hazard.



From chromatest at azburners.org  Mon Nov 15 21:30:52 2010
From: chromatest at azburners.org (Chromatest J. Pantsmaker)
Date: Mon, 15 Nov 2010 13:30:52 -0700
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
Message-ID: <AANLkTi=qdCr8Hu+Be_ezrwOzbC4c_y6OyTDrmTtk-y7Y@mail.gmail.com>

Yeah, mobile homes (the kind of pre-built house that gets delivered on
a trailer, but then doesn't really ever move again) always had
aluminum wiring.  It was cheaper and it was lighter.

On Mon, Nov 15, 2010 at 12:18 PM, Graham Atkins
<gatkins at blueyonder.co.uk> wrote:
> Aluminium for wiring ?
>
> Are you sure about that, sounds highly unlikely, never heard of aluminium
> conductors. Steel, copper alloys, silver, even gold but not aluminium.
>
> Graham
>
> On 15 Nov 2010, at 17:32, cheater cheater wrote:
>
>> Hi Harry,
>>
>> On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com>
>> wrote:
>>>
>>> I have rarely (in fact never) seen aluminum as a metal in connector pins.
>>> Usually they are steel (cheap) or brass, or beryllium copper...
>>
>> People say the same about aluminum for 220V wiring in houses... well,
>> don't go to eastern Europe then :-) Some blocks have had each single
>> (brick) wall ripped up, 20-30 years after having been built :) The
>> "fake walls" out of wood and plaster are not popular at all these
>> parts.. it all goes into the wall between bricks etc.
>>
>> What I've said applies to steel connectors in the same way, though.
>> The expansion coefficient is about 2% higher in steel than in copper,
>> so that's not much, but maybe it's enough to break a cold weld when
>> the crimped assembly is heated up to soldering temperatures..
>>
>> Cheers,
>> D.
>>
>> On Mon, Nov 15, 2010 at 15:31, Harry Bissell <harrybissell at wowway.com>
>> wrote:
>>>
>>> I have rarely (in fact never) seen aluminum as a metal in connector pins.
>>> Usually they are steel (cheap) or brass, or beryllium copper...
>>>
>>> Aluminum does not solder well at all using any standard electronic
>>> solders... (i hear there are fluxes for this, but have never needed
>>> them...)
>>>
>>> H^) harry
>>>
>>>
>>> ----- Original Message -----
>>> From: cheater cheater <cheater00 at gmail.com>
>>> To: Dave Kendall <davekendall at ntlworld.com>
>>> Cc: synth-diy at dropmix.xs4all.nl
>>> Sent: Mon, 15 Nov 2010 04:05:11 -0500 (EST)
>>> Subject: Re: [sdiy] 0.100 pin header reliability.
>>>
>>> Hi Dave,
>>> to prevent breaking of soldered cable, have it zip tied to the PCB
>>> about 2 cm away from the spot it was soldered to. Zip tie first,
>>> solder second, so that the solder solidifies in the right shape.
>>>
>>> With regards to soldering of crimped connectors: there might be
>>> several things at play here, but I'm not good enough with my chemistry
>>> to know if they actually make an impact. Maybe someone can tell me if
>>> my intuitions here are right or wrong.
>>> 1. three/four metals (aluminum for the connector, copper for the cable
>>> and solder, tin for the solder) make for different electrical
>>> properties, oxides migrate differently
>>> 2. the solder crystals change shape over time. I understand there's
>>> some sort of evolution to solid solder that makes it eject oxides?
>>> This could not only separate the cold weld but also make it dirty with
>>> oxides. Maybe someone can confirm this.
>>> 3. Is solder perhaps more reluctant to make a cold weld with aluminum,
>>> than bare copper touching bare aluminum? If you solder first and crimp
>>> second, you're crimping against tin. This also has the effect that the
>>> tin soldered to the cable and/or connector might separate off what it
>>> was soldered to, making an even worse connection
>>> 4. If you crimp first and solder second, the heat is going to expand
>>> the aluminum more than it expands the copper wire - aluminum has a
>>> higher linear coefficient of thermal expansion - effectively
>>> un-crimping the connector. I don't think it's going to re-seat itself
>>> nicely back to being crimped afterwards, but I don't know. My guess
>>> here is that you actually need a lot of force to create a cold weld,
>>> and this force is not going to be supplied by the shrinking connector
>>> alone. Besides, there might be solder in that space now, which messes
>>> up the connection
>>> 5. My intuition is that at least the better connectors have the leafs
>>> produced in such a way that the crystalline structure is good for
>>> making cold welds. Heating up changes this structure, quite possibly
>>> for worse.
>>>
>>> It would be interesting to know if any of this actually holds up
>>> according to theory.
>>>
>>> Regarding saving time: I read this thread and I think to myself...
>>> isn't it much better to just buy ready cables?... They'll be crimped
>>> much better than you can do it anyways, they'll be much cheaper in the
>>> end, and they don't cost you time..
>>>
>>> Cheers,
>>> D.
>>>
>>> On Sat, Nov 13, 2010 at 02:58, Dave Kendall <davekendall at ntlworld.com>
>>> wrote:
>>>>
>>>> On Nov 13, 2010, at 00:50, Paul Perry wrote:
>>>>>
>>>>> I think that when soldering decreases reliability it is because
>>>>> the solder wicks up the wire away from the joint & stiffens the wire,
>>>>> which then tends to flex sharply at the end of the solder & break
>>>>> there.
>>>>
>>>> That makes sense. But wouldn't that same potential weakness also apply
>>>> to a
>>>> wire either directly soldered to the PCB pad, or to a PCB pin?. I've had
>>>> that happen on some perfboard prototype builds using stranded wire that
>>>> got
>>>> some rough handling. (the soldered joints to PCB pins weren't reinforced
>>>> by
>>>> heatshrink or hellerman sleeves or anything, so I wasn't too
>>>> surprised...)
>>>>
>>>> This is an interesting thread, thanks for everyone's input.
>>>>
>>>> cheers,
>>>> Dave
>>>>
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at dropmix.xs4all.nl
>>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>> --
>>> Harry Bissell & Nora Abdullah 4eva
>>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



-- 
.sig
-Chromatest J. Pantsmaker
http://www.chromatest.net


From tom.corbitt at gmail.com  Mon Nov 15 21:38:38 2010
From: tom.corbitt at gmail.com (Tom Corbitt)
Date: Mon, 15 Nov 2010 15:38:38 -0500
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <20101115193416.GB9110@moo.sysabend.org>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
	<20101115193416.GB9110@moo.sysabend.org>
Message-ID: <AANLkTincH8NoBjoUvazPosRrir1-qheMBqO1mSRBP+bH@mail.gmail.com>

Maybe it differs across the US, here in the South I've never seen
anything but AL from the pole to the house.

The two big issues with AL is that you have to bump up in size for the
same current (12 AWG AL for the load carrying of 14 AWG CU) and that
if you splice to copper you must add a compound to control oxidation
(creep as well) The problem came from using copper
receptacles/switches with AL wire. Given the ever upward price of
copper, I think we'll see it used to wire houses again in the near
future.

Tom

On Mon, Nov 15, 2010 at 2:34 PM, Tom Arnold <xyzzy at sysabend.org> wrote:
> On Mon, Nov 15, 2010 at 07:18:56PM +0000, Graham Atkins wrote:
>> Aluminium for wiring ?
>>
>> Are you sure about that, sounds highly unlikely, never heard of
>> aluminium
>> conductors. Steel, copper alloys, silver, even gold but not aluminium.
>
> Aluminum was used for a while until it hit snags that involved huge lawsuits
> and entire episodes of 60 Minutes.
>
> Its still used for pole wiring in some places, ground braids for same, and
> its making a comeback as house wiring with the price of copper so high.
>
> Lots of info online about it. ?I've been looking into it as I house hunt
> because I need/want fairly vast wiring and copper has gotten a bit pricey.
>
> --
> ?-----------------------------------------------------------------
> ?- Tom Arnold ? ? ? - ?Free Synth DIY webspace http://www.sdiy.org
> ?- SynthGeek ? ? ? ?-
> ?- BBD Fanatic ? ? ?- ?"...is it a virus, a drug, or a religion?"
> ?- echo evho wjxo ? - ? ?Juanita Shrugs. "What's the difference?"
> ?--------------------
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From gatkins at blueyonder.co.uk  Mon Nov 15 22:35:21 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Mon, 15 Nov 2010 21:35:21 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <20101115193416.GB9110@moo.sysabend.org>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
	<20101115193416.GB9110@moo.sysabend.org>
Message-ID: <29209888-BED7-4EE9-9488-F025FDA24137@blueyonder.co.uk>

I don't think it was ever used in the past in the UK for domestic  
wiring.
Some Googling suggests it is used at the power distribution end and
for industrial applications such as railway signalling.

As to the future copper continues to go up in price and has done rapidly
in recent years so alternatives will become important.

Graham

On 15 Nov 2010, at 19:34, Tom Arnold wrote:

> On Mon, Nov 15, 2010 at 07:18:56PM +0000, Graham Atkins wrote:
>> Aluminium for wiring ?
>>
>> Are you sure about that, sounds highly unlikely, never heard of
>> aluminium
>> conductors. Steel, copper alloys, silver, even gold but not  
>> aluminium.
>
> Aluminum was used for a while until it hit snags that involved huge  
> lawsuits
> and entire episodes of 60 Minutes.
>
> Its still used for pole wiring in some places, ground braids for  
> same, and
> its making a comeback as house wiring with the price of copper so  
> high.
>
> Lots of info online about it.  I've been looking into it as I house  
> hunt
> because I need/want fairly vast wiring and copper has gotten a bit  
> pricey.
>
> -- 
> -----------------------------------------------------------------
> - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org
> - SynthGeek        -
> - BBD Fanatic      -  "...is it a virus, a drug, or a religion?"
> - echo evho wjxo   -    Juanita Shrugs. "What's the difference?"
> --------------------
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From profpep at hotmail.com  Mon Nov 15 23:23:03 2010
From: profpep at hotmail.com (Mike Pepper)
Date: Mon, 15 Nov 2010 22:23:03 -0000
Subject: [sdiy] 0.100 pin header reliability.
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com><993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com><AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com><E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk><20101115193416.GB9110@moo.sysabend.org>
	<29209888-BED7-4EE9-9488-F025FDA24137@blueyonder.co.uk>
Message-ID: <00bf01cb8513$ac15be10$c800a8c0@desk>


----- Original Message ----- 
From: "Graham Atkins" <gatkins at blueyonder.co.uk>
> I don't think it was ever used in the past in the UK for domestic
> wiring.
> Some Googling suggests it is used at the power distribution end and
> for industrial applications such as railway signalling.
>
> As to the future copper continues to go up in price and has done rapidly
> in recent years so alternatives will become important.
>
I think most of  the side mounted 3 phase cables on pylon lines are
aluminium over a steel core. The ACSR, (Aluminium Conductor Steel
Reinforced), cable is used because it's current capacity to weight ratio is
better than copper, allowing longer spans, and lower stress. The top earth
cable is copper, (which I think is also reinforced).. I once had a  rather
grisly job helping to sift through the evidence when one of a group of cable
thieves had slipped and reached out for one of the phases to stop himself
falling. He might have lived if he's just fallen. The 220KV didn't give him
a chance: he'd burned out like a fuse. They were after the top earth cable,
and had done a bit of liquid courage to psych themselves up. I heard that
the police who rounded the gang up made them all 'identify' the body. In
another case I heard of, but didn't see, the cut end of the stolen earth
cable had swung into one of the phases, burnng it through at the pointof
impact. The high voltage end hit the, (damp) ground, and several of the
would be robbers were hurt by shock from the earth. It's take no prosoners
stuff up on those lines.

||\/||ike





From neil.johnson97 at ntlworld.com  Mon Nov 15 23:36:57 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Mon, 15 Nov 2010 22:36:57 +0000
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <24CE72D7C29D4371912934CFC17E8AA4@galvanox01>
References: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>
	<1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
	<24CE72D7C29D4371912934CFC17E8AA4@galvanox01>
Message-ID: <B41F9950-9A9C-4DEB-99DA-8BDE6290168A@ntlworld.com>

Hi,

David G. Dixon wrote:
> Fair enough.  However, for me, crimping is never the rate-limiting  
> step in
> panel wiring.  Plus, having a hand-held crimping tool is very  
> important for
> the way I do my panel wiring.

That _is_ for a handheld tool!  For some googling, if you're  
interested, look up DMC or Daniels or any of the professional AMP  
crimp tools.

> The multipin connectors on my board are
> organized in a fairly logical fashion, and I tend to make all the
> connections to a given connector at once.  For example, if I've got  
> a 6-pin
> connector with wires going to a couple of pots, say, then I solder  
> all the
> leads to the pots first.  Then I gather the wires into a bunch and  
> cut them
> all to the proper length (much like a barber cuts hair).  Then I  
> strip and
> crimp, plug the pins into the connector, plug the connector to the  
> board,
> bundle up the wires with a plastic tie, and move on to the next  
> connector.
> For this technique, a hand-held crimper is essential.

Hmmmphh.... sounds like you need to read up about IDC connectors.  6  
wires you say?  Get a 6-pin IDC header and socket, strip out a length  
of 6-wide IDC cable, and you can crimp on the IDC socket in a vice  
in, oh, 5 seconds.  Job done.  No need to mess around with a  
soldering iron.

Cheers,
Neil
--
http://www.njohnson.co.uk





From cheater00 at gmail.com  Tue Nov 16 00:00:13 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 16 Nov 2010 00:00:13 +0100
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
References: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>
	<1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTimfLMk3vVRDDqR1ym+FBMmpqp_Yww3Rtk29Efyf@mail.gmail.com>

So you never got to the stage where the cable is so oxidized that any
attempt at doing anything with the cable just crumbles it to little
pieces?

D.

On Mon, Nov 15, 2010 at 18:48, Harry Bissell <harrybissell at wowway.com> wrote:
> The $300 crimpers allow Monkeys to make the cable assemblies ? ;^)
> (see Design News magazine "Monkeys made my ----- feature)
>
> The $300 crimpers allow you to do a lot more connections a lot easier...
> but for DIY work the low-cost ones can be effective. For my modular
> (repackage) I chose Molex Centi-grid connectors because of the availability
> of a low cost hand tool ($40), and an automated one for that series is only
> about $150
>
> H^) harry
>
>
> ----- Original Message -----
> From: David G. Dixon <dixon at interchange.ubc.ca>
> To: 'Neil Johnson' <neil.johnson97 at ntlworld.com>, synth-diy at dropmix.xs4all.nl
> Sent: Mon, 15 Nov 2010 12:39:29 -0500 (EST)
> Subject: Re: [sdiy] 0.100 pin header reliability.
>
>> Ah, ok, the cheap $10 ones :)
>>
>> Crimping is only guaranteed to work as stated by the manufacturer when
>> (a) you use the correct crimping tool, and (b) that tool is within
>> calibration (i.e., it needs regular checking and recalibration if
>> required). ?If you spend $300 or more on a crimp tool then you're in
>> the right ballpark.
>
> My crimping pliers have two crimping locations: A and B. ?One is a bit
> smaller, and that's the one I use. ?The two sides of the pliers come
> together very tightly -- these pliers are probably at least 30 years old and
> very well made. ?I haven't seen any this nice in the stores, but I'm sure
> they'd go for between $50 and $100.
>
> The crimp pins I use have two sets of crimpable "wings" -- smaller ones in
> the middle for crimping onto bare wire, and larger ones on the end for
> crimping onto the insulation.
>
> I strip about 1/8" of insulation off the end of the wire, put it in the pin
> and crimp the small wings hard with the crimping pliers. ?(I take pains to
> ensure that all the little wire strands get crimped in, although very
> occasionally a stray strand gets away.) ?Then I crimp the large wings over
> the insulation. ?The pin is on that wire so damned hard that you could never
> pull it off.
>
> Once the PCB is attached to the panel and all the connectors are plugged in,
> there is no pulling stress on the wires, and very little if any movement is
> possible since I bundle them together with plastic ties.
>
> So, what is going to fail here? ?What does the $300 dollar machine do that
> my crimping pliers don't?
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From dixon at interchange.ubc.ca  Tue Nov 16 00:11:40 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 15:11:40 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <29209888-BED7-4EE9-9488-F025FDA24137@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
	<20101115193416.GB9110@moo.sysabend.org>
	<29209888-BED7-4EE9-9488-F025FDA24137@blueyonder.co.uk>
Message-ID: <64BAE090EC9D410CBF354E27FFAB51F4@galvanox01>

> As to the future copper continues to go up in price and has done rapidly
> in recent years so alternatives will become important.

The long-term outlook for copper price is about $2.25/lb, which is just over
half of today's price.  It won't go much higher than it is right now.



From rob at emulatorarchive.com  Tue Nov 16 00:19:22 2010
From: rob at emulatorarchive.com (rob at emulatorarchive.com)
Date: Mon, 15 Nov 2010 23:19:22 +0000
Subject: [sdiy] 1M Log Sliders
In-Reply-To: <B41F9950-9A9C-4DEB-99DA-8BDE6290168A@ntlworld.com>
References: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>	<1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>	<24CE72D7C29D4371912934CFC17E8AA4@galvanox01>
	<B41F9950-9A9C-4DEB-99DA-8BDE6290168A@ntlworld.com>
Message-ID: <4CE1BFFA.2020505@emulatorarchive.com>

Hi list,
I have been trying to locate 30mm 1M log slide potentiometers to build 
traditional ADSR enevelope generators.
I can find 60mm versions but not 30mm. Any ideas on a supplier?

If I cannot find them I thought I would have a few made in Taiwan (x1000 
MOQ). Alps like, so the 10k/100k sustain slider can be matched up.
Anyone interested in contributing to a Group buy? Price per 
potentiometer will be aound 50 - 75 pence, less than 1 US dollar.
Doesn't have to be larger order, just 10 or 20 per person.

There is nothing better than an ADSR with real slide pots :-)

Regards
Rob
www.amsynths.co.uk




From neil.johnson97 at ntlworld.com  Tue Nov 16 00:37:23 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Mon, 15 Nov 2010 23:37:23 +0000
Subject: [sdiy] MIDI bytestream parser
Message-ID: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>

Hi all,

A long while back I mentioned a little side project I've been working  
on to write a general-purpose MIDI bytestream parser.  Well, the  
first initial version is now online for anyone to use.  Documentation  
is a little sketchy at the moment (!!!) but will improve.

See here:

http://code.google.com/p/miby/

Comments welcome!  It hasn't been used in anger yet, and I know there  
are opportunities for optimising it further (for example, if SysEx is  
not needed), but for now the target is correctness.

To come are parsers for the various SysEx Universals (sample dump,  
file dump, time code, machine control, etc).  Plus all the continuous  
controllers, including RPN and NRPN.

Cheers,
Neil
--
http://www.njohnson.co.uk





From dingebre at 3dphysics.net  Tue Nov 16 00:42:55 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Mon, 15 Nov 2010 16:42:55 -0700
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <eaf26fba1a3ddf4dc2260a0dcdb57218@localhost>
References: "<BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>"	<4CE1404E.5060403@pdp7.org>	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<eaf26fba1a3ddf4dc2260a0dcdb57218@localhost>
Message-ID: <004d01cb851e$d3b8d550$7b2a7ff0$@net>

I remember reading there is a new edition of Art of Electronics due out the
first part of 2011.

David

~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of jays at aracnet.com
~~ Sent: Monday, November 15, 2010 11:57 AM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: Re: [sdiy] Best kept secret of amazing electronics books
~~ 
~~ I would say that the Student Guide is essentual for using The Art of
~~ Electronics. It fills in a lot of details and has a lot of things that
~~ aren't in the book.
~~ 
~~ But in general I'm not a big fan of The Art of Electronics either. The
~~ basics haven't changed all that much and it is a decent reference for
~~ that. A number of things are dated now and there has been a lot of
~~ changes and advancements in components which aren't in there. The
~~ computer section is so dated that it should be removed from the book.
~~ Usually I'll go to my ARRL Handbook (Radio Amateurs Handbook)first. To
~~ me that would be the 'Best kept secret of amazing electronics books'.
~~ 
~~ Jay S.
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From gil_we at yahoo.com  Tue Nov 16 01:11:29 2010
From: gil_we at yahoo.com (Gil W.)
Date: Mon, 15 Nov 2010 16:11:29 -0800 (PST)
Subject: [sdiy] Looking for Juno/Jupiter bender and slider caps
Message-ID: <232967.30373.qm@web58004.mail.re3.yahoo.com>

Looking for a bender and a slider cap.

If you have any for sale please send an email...
please remove the [AH] text from the subject line so I can get it.

Thanks !


      


From 21pointy at tpg.com.au  Tue Nov 16 02:20:33 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Tue, 16 Nov 2010 11:20:33 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
Message-ID: <E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>

Cheers - I was hoping to avoid building a negative rail, the 77  
manages without one (The negative-edge detector circuits that make up  
the matrix generate a brief negative pulse on the falling edge of the  
square waves from the multivibrator counters).

Hanging a common-emitter amp off the 24 volt rail to invert the  
signal, and running this into a similar edge-detector seems to work,  
but thats a lot of parts if I have to make one for every voice.

regards
Adam Inglis
http://www.adambaby.com

On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:

> I'm thinking a voltage regulator to get you your -7 volts.. and then a
> transistor for each voice. use the 707 CV to trip the transistor
> letting the -7 through?  Probably a current limiting resistor on each
> one?
>
> Of course, this is how I design my own stuff... and sometimes it
> works.  I really have no idea of the "correct" way to do things.
>
> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au>  
> wrote:
>
>> Hi All
>>
>> First post - long time lurker and learner here for many years.  
>> Self-taught
>> in analogue audio electronics thanks to a studio full of old  
>> "junk" from the
>> 70s and 80s, an oscilloscope from the 60s, and the first few  
>> chapters of
>> Horowitz and Hill!
>>
>> Question: Someone here mentioned not too long ago the idea of  
>> using the
>> voice trigger signals in a Roland TR707 to trigger external  
>> instruments. It
>> got me thinking, as I love the interface of this drum machine -  
>> quick and
>> fun.
>>  I would like to be able to trigger the voices in my old preset  
>> Roland
>> Rhythm TR77. This uses passive LC voice circuits, which respond  
>> fairly
>> dynamically to voltage triggers of between -3 to -10 volts.  
>> Looking at the
>> 707, I found the voice group's envelope generators supplied a  
>> positive
>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>> depending on instrument. These CVs also respond to the 2 levels of
>> programmable ACCENT, and so would appear to be a good source of  
>> triggering.
>>
>> Any suggestions as to a simple, low-parts-count circuit I could  
>> install
>> (several iterations of) into the 77 that would convert the  
>> positive CVs from
>> the 707 into brief negative pulses for the 77s voices?
>> I should mention there is 0 - 12 - 24 volts available in the 77  
>> with just
>> basic filtering, no voltage regulators, so I was assuming it would  
>> need a
>> transistor rather than a chip based solution.
>>
>> Anyone interested in my crude investigations into the workings of  
>> the TR77
>> can have a look here...
>> http://www.adambaby.com/studiotech_TR-77.html
>>
>>
>>
>>
>> regards
>> Adam Inglis
>> http://www.adambaby.com
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>
>
>
>
> -- 
> .sig
> -Chromatest J. Pantsmaker
> http://www.chromatest.net
>
>
>








From gatkins at blueyonder.co.uk  Tue Nov 16 02:20:48 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Tue, 16 Nov 2010 01:20:48 +0000
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <004d01cb851e$d3b8d550$7b2a7ff0$@net>
References: "<BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>"	<4CE1404E.5060403@pdp7.org>	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<eaf26fba1a3ddf4dc2260a0dcdb57218@localhost>
	<004d01cb851e$d3b8d550$7b2a7ff0$@net>
Message-ID: <A1F042C0-E612-4050-9C91-C3EB8CD45BEA@blueyonder.co.uk>

Supposedly a rumour. I believe they are working on a new edition but the
publishing date is not yet defined.

Graham

On 15 Nov 2010, at 23:42, David Ingebretsen wrote:

> I remember reading there is a new edition of Art of Electronics due  
> out the
> first part of 2011.
>
> David
>
> ~~ -----Original Message-----
> ~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
> ~~ bounces at dropmix.xs4all.nl] On Behalf Of jays at aracnet.com
> ~~ Sent: Monday, November 15, 2010 11:57 AM
> ~~ To: synth-diy at dropmix.xs4all.nl
> ~~ Subject: Re: [sdiy] Best kept secret of amazing electronics books
> ~~
> ~~ I would say that the Student Guide is essentual for using The Art  
> of
> ~~ Electronics. It fills in a lot of details and has a lot of things  
> that
> ~~ aren't in the book.
> ~~
> ~~ But in general I'm not a big fan of The Art of Electronics  
> either. The
> ~~ basics haven't changed all that much and it is a decent reference  
> for
> ~~ that. A number of things are dated now and there has been a lot of
> ~~ changes and advancements in components which aren't in there. The
> ~~ computer section is so dated that it should be removed from the  
> book.
> ~~ Usually I'll go to my ARRL Handbook (Radio Amateurs  
> Handbook)first. To
> ~~ me that would be the 'Best kept secret of amazing electronics  
> books'.
> ~~
> ~~ Jay S.
> ~~ _______________________________________________
> ~~ Synth-diy mailing list
> ~~ Synth-diy at dropmix.xs4all.nl
> ~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From gjames at kddlab.com  Tue Nov 16 03:14:18 2010
From: gjames at kddlab.com (Greg James)
Date: Mon, 15 Nov 2010 21:14:18 -0500
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <A1F042C0-E612-4050-9C91-C3EB8CD45BEA@blueyonder.co.uk>
References: "<BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>"	<4CE1404E.5060403@pdp7.org>	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><eaf26fba1a3ddf4dc2260a0dcdb57218@localhost><004d01cb851e$d3b8d550$7b2a7ff0$@net>
	<A1F042C0-E612-4050-9C91-C3EB8CD45BEA@blueyonder.co.uk>
Message-ID: <86FD8D3499274FD28610F7DA960DFC04@KDDLab05>

It's held-up in translation to Hindi and Cantonese - the only two languages
with enough student and job demand to generate the required sales volume.

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Graham Atkins
Sent: Monday, November 15, 2010 8:21 PM
To: David Ingebretsen
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Best kept secret of amazing electronics books

Supposedly a rumour. I believe they are working on a new edition but the
publishing date is not yet defined.

Graham

On 15 Nov 2010, at 23:42, David Ingebretsen wrote:

> I remember reading there is a new edition of Art of Electronics due  
> out the
> first part of 2011.
>
> David
>
> ~~ -----Original Message-----
> ~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
> ~~ bounces at dropmix.xs4all.nl] On Behalf Of jays at aracnet.com
> ~~ Sent: Monday, November 15, 2010 11:57 AM
> ~~ To: synth-diy at dropmix.xs4all.nl
> ~~ Subject: Re: [sdiy] Best kept secret of amazing electronics books
> ~~
> ~~ I would say that the Student Guide is essentual for using The Art  
> of
> ~~ Electronics. It fills in a lot of details and has a lot of things  
> that
> ~~ aren't in the book.
> ~~
> ~~ But in general I'm not a big fan of The Art of Electronics  
> either. The
> ~~ basics haven't changed all that much and it is a decent reference  
> for
> ~~ that. A number of things are dated now and there has been a lot of
> ~~ changes and advancements in components which aren't in there. The
> ~~ computer section is so dated that it should be removed from the  
> book.
> ~~ Usually I'll go to my ARRL Handbook (Radio Amateurs  
> Handbook)first. To
> ~~ me that would be the 'Best kept secret of amazing electronics  
> books'.
> ~~
> ~~ Jay S.
> ~~ _______________________________________________
> ~~ Synth-diy mailing list
> ~~ Synth-diy at dropmix.xs4all.nl
> ~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From pfperry at melbpc.org.au  Tue Nov 16 03:45:18 2010
From: pfperry at melbpc.org.au (Paul Perry)
Date: Tue, 16 Nov 2010 13:45:18 +1100
Subject: [sdiy] Best kept secret of amazing electronics books
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
Message-ID: <059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>

>Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
> but it covers a lot of ground including the maths involved, signal
> transmission, basic control theory, etc. Dunno about the English 
> translation

I've read the English translation, and it is very good.
But, the book is pretty scarce and very expensive.
I don't think I will ever own a copy.

As for AoE - it has the advantage of being written by people who know their 
stuff,
and written for a very specific & well-defined audience.
I think it is a great success - in the same way that a synth that is 
designed by
someone who knows their stuff, with a well-defined aim in mind, would be.

All I can say is, the books that always seemed to end up on my bench (as 
opposed
to the bookshelves) were AoE, Pease on troubleshooting, and  the books by 
Jung and
by Lancaster. Plus the Linear & National applications notes.

paul perry Melbourne Australia 



From rga24 at cantab.net  Tue Nov 16 04:40:31 2010
From: rga24 at cantab.net (Richard Atkinson)
Date: 16 Nov 2010 03:40:31 +0000
Subject: [sdiy] Yamaha CSY-2 solo synthesizer
In-Reply-To: <4CDC7B56.3060106@oldcrows.net>
References: <E5F63E1EB41049DAB15479D6E5295040@galvanox01>
	<842985516.244515.1289309930451.JavaMail.root@md01.wow.synacor.com>
	<Prayer.1.3.3.1011091516510.4341@hermes-2.csi.cam.ac.uk>
	<4CDC7B56.3060106@oldcrows.net>
Message-ID: <Prayer.1.3.3.1011160340310.31753@hermes-2.csi.cam.ac.uk>

Interesting that Yamaha would go to all the trouble of potting those 
modules just to hide them from Korg. It doesn't appear to have worked! 
Korg's low pass and high pass filters in the 700S and 800DV use the same 
filter design anyway.

The modules allowed a higher circuit density compared with the CSY-2 solo 
synthesizer boards. I've taken some pictures of the inside of the CSY-2 for 
comparison with the CSY-1 internals. The CSY-2 solo synthesizer boards 
occupy a much greater PCB area. There are a few locations where unpopulated 
components would go.

http://www.flickr.com/photos/56036944 at N08/

The CSY-2 filters definitely sound 'cleaner' to me than the CSY-1 filters. 
Maybe the diode arrays in the CSY-2 are better matched than in the CSY-1, 
or maybe the circuit doesn't drive the diodes in the CSY-2 with as great a 
CV excursion for the audio signal.


On Nov 11 2010, The Old Crow wrote:

>     Speaking as asomeone who tore apart some of the NE series modules 
>six years ago (see: http://www.cs80.com/ne_proj.html ), I can say that 
>the state of Yamaha's combo organ design paradigm was in a state of 
>extreme flux in the mid-1970s.  The early (1973-74) synthesizer stuff 
>was all potted "for temperature stability" (read: to hide it from Korg) 
>as back then there was this mad rush to market for combo synthesizer 
>portable gear.  Of course, Yamaha's 1970s stuff was designed at their 
>Electone organ facility in Hamamatsu by organ engineers, not 
>"synthesizer engineers" like Moog, Oberheim or Buchla.  To this end they 
>used the parts they used in designs of Electone models of the day.  The 
>GX-1 (according to lead engineer at that time, Mr. Nakamura) was an R&D 
>experiment mainly to test all possible aspects of making a polyphonic 
>combo instrument using the means they had available.
>
>   Yamaha had what most electronics manufacturers envied at the time: 
>their own chip fab.  While this is less of an issue today, back then it 
>offered a big advantage in design cost savings as their circuits could 
>be done in NMOS, PMOS or bipolar.  Many of their logic engines such as 
>key assigners were made this way.  Later DSP engines, too, were made 
>this way--from the wavetable engine of the 'PASS' Electones up to the DX 
>FM engines of the 1980s Electones and synthesizers.
>
>   Around 1975, they stopped making the cost-inefficient NE potted 
>modules in favor of the easier-to- assembly-line discrete boards.  This 
>was about when the first part feeders came into use, and fitting TO-5 
>cans was not a part feeder friendly package.  Thus, they switched to 
>SIL/DIL packages for everything when they could.  The "VCOIII" (NE11500) 
>was the only module made in potted form for temperature stable reasons.  
>The module contains a sample/hold amplifier made from a complementary 
>FET, an op-amp, some polystyrene caps and a low-impedance FET switch to 
>open the sample path.  The Oscillator portion is a really vanilla 
>sawtooth relaxation type with a FET buffer hung on the timing cap.  I 
>recall there was an interesting vibrato CV input that used a little bit 
>of piecewise-linear curve fitting to bend the CV into something that 
>sounded good along the range of the VCO.  The IG00153 (CS VCO) is 
>totally different.  It's closest cousin is the Rhodes Chroma VCO.
>
>   The filters on the later CSY-2 use BA626 and BA627 diode arrays (SIL 
>parts) instead of the CA3019s, but the filters are essentially the same 
>otherwise.  The GX1 bandpass (NE11000) module uses these as well.
>
>   The EGs would have been a pain to figure out, but the circuits show 
>up in the Yamaha patents.  Nothing particularly amazing there, other 
>than they crammed all those parts into those boards.
>
>Scott Rider
>/**/
>
>
>On 11/9/2010 9:16 AM, Richard Atkinson wrote:
>> This email may be of particular interest to anyone who has studied the 
>> first and second generations of Yamaha synthesizer, namely the SY-1 / 
>> SY-2 / GX-1 synthesizers with epoxy potted NE series modules in the 
>> first generation and the CS series of synthesizers with IG series 
>> chips in the second generation.
>>
>> It turns out there is an intermediate generation of Yamaha synthesizer 
>> between these two generations. I found this when looking inside my 
>> newly acquired Yamaha CSY-2 organ yesterday. This is a later version 
>> of the CSY-1 organ, which has been featured in a few web pages and 
>> Matrixsynth articles and which contains the same epoxy potted NE 
>> series modules as the GX-1.
>>
>> I took the lid off my Yamaha CSY-2 yesterday with a friends's help. 
>> The insides of my CSY-2 were rather dirty, having played host to a 
>> number of spiders and other objects over the years. There was evidence 
>> of damp damage on the base of the machine; it has clearly been kept on 
>> a damp surface at some point for quite a while.
>>
>> It turns out the CSY-2 is very, very different internally from the CSY-1.
>> Whereas the CSY-1 is a fully discrete design with many circuit boards, 
>> some
>> of them held vertically in a rack frame, the CSY-2 has the first signs of
>> integration.
>>
>> In particular, the auto bass chord circuit board (ABC CSY-2) has two 
>> large
>> YM chips on it and there is another board with another large YM chip. The
>> function of the auto bass chord system on this organ is quite different
>> from the CSY-1, and this would seem to explain why. There is no rack of
>> vertically mounted boards; there are much fewer boards and these are all
>> mounted horizontally.
>>
>> Of particular interest is the solo synthesizer section mounted on the
>> underside of the top panel of the organ. Like my CSY-1, the solo
>> synthesizer boards in my CSY-2 are very clean, much cleaner than the rest
>> of the instrument. This no doubt has to do with being mounted upside 
>> down,
>> gravity being in its favour.
>>
>> The CSY-2 does not however contain either of the versions of the CSY-1 /
>> SY-1 solo synthesizer circuits. It's a completely different, much more
>> integrated version of the solo synthesizer. The boards are not named SM1,
>> SM2, SK, SP1 and SP2 as in the SY-2. Instead they are named VCO, VCF, 
>> VCA,
>> FEG, AEG, SK and SP.
>>
>> VCO is the only board that contains any of the old NE series modules. 
>> It has the VCO-III module as seen in later versions of the CSY-1, SY-1 
>> and all SY-2s.
>>
>> The VCF board has four ICs on it, all by Rohm. Two BA626s and two 
>> BA627s. I
>> have been unable so far to identify what these are but what is most
>> peculiar about this is that the organ features neither the older NE 
>> module
>> based filters, nor the IG chip based filters of the CS synthesizers 
>> and the
>> later Electone organs, but a generation in between. This is the only
>> example of this generation of Yamaha synthesizer filter I have ever seen,
>> and as far as I'm aware it's completely undocumented on the internet.
>>
>> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal can 
>> packaging
>> and so on. The VCA board is self explanatory, the FEG board is for the
>> filter envelope and the AEG board is for the amplifier envelope. No NE
>> modules here, in particular no VCF-EG or VCA-EG modules. This is the only
>> example of these Yamaha envelope generators I have seen, again completely
>> undocumented on the internet as far as I know.
>>
>> The remaining boards, SK and SP, seem to be the same as in the older
>> machines. They are for the gate and trigger pulse recovery and for the
>> presets.
>>
>> Sound-wise, it behaves much like a cross between the two generations. 
>> The oscillator definitely has the same timbral qualities as an SY-2, 
>> but the filters are much, much cleaner. I wouldn't go so far as to say 
>> they sound like CS series IG chip filters, but they are certainly more 
>> well behaved than the highly distorting diode bridge filters in the NE 
>> series epoxy filled modules.
>>
>> Richard
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From pfperry at melbpc.org.au  Tue Nov 16 05:35:39 2010
From: pfperry at melbpc.org.au (Paul Perry)
Date: Tue, 16 Nov 2010 15:35:39 +1100
Subject: [sdiy] Best kept secret of amazing electronics books
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<F1FE1BA8-32BE-4CB5-A199-6C10523EB7AA@adambaby.com>
Message-ID: <D304470462BA4B5DB0B43E97D45CD5F5@ownerf0d9273f5>

http://www.national.com/rap/Book/0,1565,0,00.html
"Troubleshooting Analog Circuits".

----- Original Message ----- 
From: "Adam Inglis" 
> Hi Paul - what's the Pease book?



From tony at makenoisemusic.com  Tue Nov 16 05:42:25 2010
From: tony at makenoisemusic.com (Tony Rolando)
Date: Mon, 15 Nov 2010 23:42:25 -0500
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <D304470462BA4B5DB0B43E97D45CD5F5@ownerf0d9273f5>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>	<F1FE1BA8-32BE-4CB5-A199-6C10523EB7AA@adambaby.com>
	<D304470462BA4B5DB0B43E97D45CD5F5@ownerf0d9273f5>
Message-ID: <4CE20BB1.60801@makenoisemusic.com>

For those in NYC, the Brooklyn Public library had a copy of this one, 
and I agree with Paul, it is very good.

Tony

On 11/15/10 11:35 PM, Paul Perry wrote:
> http://www.national.com/rap/Book/0,1565,0,00.html
> "Troubleshooting Analog Circuits".
>
> ----- Original Message ----- From: "Adam Inglis"
>> Hi Paul - what's the Pease book?
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From jimp at pobox.com  Tue Nov 16 06:27:25 2010
From: jimp at pobox.com (jimp at pobox.com)
Date: Mon, 15 Nov 2010 23:27:25 -0600
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <D304470462BA4B5DB0B43E97D45CD5F5@ownerf0d9273f5>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<F1FE1BA8-32BE-4CB5-A199-6C10523EB7AA@adambaby.com>
	<D304470462BA4B5DB0B43E97D45CD5F5@ownerf0d9273f5>
Message-ID: <4CE2163D.1020502@pobox.com>

+1,

hehe, i was initially attracted by the cover, which looks exactly like 
my lab.
mmmmm spaghetti...

On 11/15/2010 10:35 PM, Paul Perry wrote:
> http://www.national.com/rap/Book/0,1565,0,00.html
> "Troubleshooting Analog Circuits".
>
> ----- Original Message ----- From: "Adam Inglis"
>> Hi Paul - what's the Pease book?
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From dixon at interchange.ubc.ca  Tue Nov 16 08:22:05 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 15 Nov 2010 23:22:05 -0800
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <B41F9950-9A9C-4DEB-99DA-8BDE6290168A@ntlworld.com>
References: <6A2BE4EAB17444E0BFAFDC8B731A1F23@galvanox01>
	<1708242225.403795.1289843289933.JavaMail.root@md01.wow.synacor.com>
	<24CE72D7C29D4371912934CFC17E8AA4@galvanox01>
	<B41F9950-9A9C-4DEB-99DA-8BDE6290168A@ntlworld.com>
Message-ID: <F670E0887C3E45A298827F0685A95E27@galvanox01>

> That _is_ for a handheld tool!  For some googling, if you're
> interested, look up DMC or Daniels or any of the professional AMP
> crimp tools.

I had a look at the Daniels website.  That's a pretty fancy crimp tool!
However, it's not a terribly informative website: click on "Crimp Tools" and
it leads you to 668 different tools, all with the same price and picture,
and all called "Special Purpose Tool" with no further description.

I think the guy who put that webpage together was a Special Purpose Tool!



From cheater00 at gmail.com  Tue Nov 16 09:11:42 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 16 Nov 2010 09:11:42 +0100
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
Message-ID: <AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>

Hi Adam,
can't you use the trigger that goes into the 707's envelopes? I
believe there's a separate accent line (as far as I remember the
schematics). You can AND that with a separate copy of the trigger
lines, and add it to the original trigger lines. That's probably one
AND array, together with just some logic buffers or whatevers (I'm not
that great with digital logic hardware, just software!)

Maybe you can use those directly in the 77 without any conversion.

Cheers,
D.

On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au> wrote:
> Cheers - I was hoping to avoid building a negative rail, the 77 manages
> without one (The negative-edge detector circuits that make up the matrix
> generate a brief negative pulse on the falling edge of the square waves from
> the multivibrator counters).
>
> Hanging a common-emitter amp off the 24 volt rail to invert the signal, and
> running this into a similar edge-detector seems to work, but thats a lot of
> parts if I have to make one for every voice.
>
> regards
> Adam Inglis
> http://www.adambaby.com
>
> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>
>> I'm thinking a voltage regulator to get you your -7 volts.. and then a
>> transistor for each voice. use the 707 CV to trip the transistor
>> letting the -7 through? ?Probably a current limiting resistor on each
>> one?
>>
>> Of course, this is how I design my own stuff... and sometimes it
>> works. ?I really have no idea of the "correct" way to do things.
>>
>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au> wrote:
>>
>>> Hi All
>>>
>>> First post - long time lurker and learner here for many years.
>>> Self-taught
>>> in analogue audio electronics thanks to a studio full of old "junk" from
>>> the
>>> 70s and 80s, an oscilloscope from the 60s, and the first few chapters of
>>> Horowitz and Hill!
>>>
>>> Question: Someone here mentioned not too long ago the idea of using the
>>> voice trigger signals in a Roland TR707 to trigger external instruments.
>>> It
>>> got me thinking, as I love the interface of this drum machine - quick and
>>> fun.
>>> ?I would like to be able to trigger the voices in my old preset Roland
>>> Rhythm TR77. This uses passive LC voice circuits, which respond fairly
>>> dynamically to voltage triggers of between -3 to -10 volts. Looking at
>>> the
>>> 707, I found the voice group's envelope generators supplied a positive
>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>> depending on instrument. These CVs also respond to the 2 levels of
>>> programmable ACCENT, and so would appear to be a good source of
>>> triggering.
>>>
>>> Any suggestions as to a simple, low-parts-count circuit I could install
>>> (several iterations of) into the 77 that would convert the positive CVs
>>> from
>>> the 707 into brief negative pulses for the 77s voices?
>>> I should mention there is 0 - 12 - 24 volts available in the 77 with just
>>> basic filtering, no voltage regulators, so I was assuming it would need a
>>> transistor rather than a chip based solution.
>>>
>>> Anyone interested in my crude investigations into the workings of the
>>> TR77
>>> can have a look here...
>>> http://www.adambaby.com/studiotech_TR-77.html
>>>
>>>
>>>
>>>
>>> regards
>>> Adam Inglis
>>> http://www.adambaby.com
>>>
>>>
>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>>
>>
>>
>>
>> --
>> .sig
>> -Chromatest J. Pantsmaker
>> http://www.chromatest.net
>>
>>
>>
>
>
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From tom at electricdruid.net  Tue Nov 16 10:49:38 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 16 Nov 2010 09:49:38 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
Message-ID: <E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>

Very interesting, Neil. I've got one or two questions though;

What's all this 'real' and 'encoded' stuff? Is that what the hash is for? What are you up to?

When you do further documentation, I'd appreciate an overview of the general structure or form of the code. I often find people write a comment by each line telling you what that line does, and sometimes you get decent comments at the top of a function telling you what the function does (although how often have you seen stuff like "function bunny_boiler($rabbit) { /* This function boils $rabbit */ etcetc }"? - not a comment that adds anything useful.)
The point is that as well as the microscopic detail, documentation needs to give a macroscopic overview of the basic principles and structure.

T.



On 15 Nov 2010, at 23:37, Neil Johnson wrote:

> Hi all,
> 
> A long while back I mentioned a little side project I've been working on to write a general-purpose MIDI bytestream parser.  Well, the first initial version is now online for anyone to use.  Documentation is a little sketchy at the moment (!!!) but will improve.
> 
> See here:
> 
> http://code.google.com/p/miby/
> 
> Comments welcome!  It hasn't been used in anger yet, and I know there are opportunities for optimising it further (for example, if SysEx is not needed), but for now the target is correctness.
> 
> To come are parsers for the various SysEx Universals (sample dump, file dump, time code, machine control, etc).  Plus all the continuous controllers, including RPN and NRPN.
> 
> Cheers,
> Neil
> --
> http://www.njohnson.co.uk
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From hughes_david_j at btopenworld.com  Tue Nov 16 10:54:07 2010
From: hughes_david_j at btopenworld.com (David J. Hughes)
Date: Tue, 16 Nov 2010 09:54:07 +0000
Subject: [sdiy] Synthfest@Maker Faire 2011 / March 12-13 2011
Message-ID: <C908053F.13573%hughes_david_j@btopenworld.com>

Dear All,

The Centre for Life in Newcastle (http://www.life.org.uk
<http://www.life.org.uk/> ) is hosting the Maker Faire in 2011. Maker Faire,
which takes place over the weekend of March 12-13, is an event created by
Make Magazine to celebrate arts, crafts, engineering, science projects and
the Do-It-Yourself (DIY) mindset.

In the past, there have been one or two projects involving electronic music
and synth DIY though they've been few and far between. However, next year's
event will have a very strong synth DIY flavour and Saturday 12th March has
been designated "SynthFest Day". We're now recruiting artists and companies
who would like to get involved.

Contributors are invited to bring along DIY instruments for the public to
see and use. We're also looking at setting up a performance area so that
artists can either perform a small concert or participate in a collaborative
jam.

My understanding is that contributors don't pay to hire space and they are
able to sell merchandise i.e. instruments, CD, DVDs etc.

The event should be a terrific showcase and, with the backing of Life, the
promotional opportunities should be superb. If successful, there is the
possibility that this could become an annual event.

We'd love to have you involved so please register your interest at :
www.MakerFaireUK.com <http://www.MakerFaireUK.com>

The deadline for applications is 26th November 2010.

Best regards
Synth Builder
synthbuilder at gmail.com




From tom at electricdruid.net  Tue Nov 16 10:54:12 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 16 Nov 2010 09:54:12 +0000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
Message-ID: <CFBB32AE-291F-4A2A-BE88-F1FE6B72D668@electricdruid.net>

If you've got 0V/12V/24V, you could regard it as -12V/0V/+12V and use it to drive an op-amp wired as an inverting highpass filter (edge detector). Inverting so you get a negative-going pulse from the positive input. Since you'd get 4 such filters on a quad-amp chip, it wouldn't take up much space.

But I'm only saying that 'cause the sight of all those transistors gives me the willies. Discrete! Even flip-flops! Yikes!

T.

On 16 Nov 2010, at 01:20, Adam Inglis wrote:

> Cheers - I was hoping to avoid building a negative rail, the 77 manages without one (The negative-edge detector circuits that make up the matrix generate a brief negative pulse on the falling edge of the square waves from the multivibrator counters).
> 
> Hanging a common-emitter amp off the 24 volt rail to invert the signal, and running this into a similar edge-detector seems to work, but thats a lot of parts if I have to make one for every voice.
> 
> regards
> Adam Inglis
> http://www.adambaby.com
> 
> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
> 
>> I'm thinking a voltage regulator to get you your -7 volts.. and then a
>> transistor for each voice. use the 707 CV to trip the transistor
>> letting the -7 through?  Probably a current limiting resistor on each
>> one?
>> 
>> Of course, this is how I design my own stuff... and sometimes it
>> works.  I really have no idea of the "correct" way to do things.
>> 
>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au> wrote:
>> 
>>> Hi All
>>> 
>>> First post - long time lurker and learner here for many years. Self-taught
>>> in analogue audio electronics thanks to a studio full of old "junk" from the
>>> 70s and 80s, an oscilloscope from the 60s, and the first few chapters of
>>> Horowitz and Hill!
>>> 
>>> Question: Someone here mentioned not too long ago the idea of using the
>>> voice trigger signals in a Roland TR707 to trigger external instruments. It
>>> got me thinking, as I love the interface of this drum machine - quick and
>>> fun.
>>> I would like to be able to trigger the voices in my old preset Roland
>>> Rhythm TR77. This uses passive LC voice circuits, which respond fairly
>>> dynamically to voltage triggers of between -3 to -10 volts. Looking at the
>>> 707, I found the voice group's envelope generators supplied a positive
>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>> depending on instrument. These CVs also respond to the 2 levels of
>>> programmable ACCENT, and so would appear to be a good source of triggering.
>>> 
>>> Any suggestions as to a simple, low-parts-count circuit I could install
>>> (several iterations of) into the 77 that would convert the positive CVs from
>>> the 707 into brief negative pulses for the 77s voices?
>>> I should mention there is 0 - 12 - 24 volts available in the 77 with just
>>> basic filtering, no voltage regulators, so I was assuming it would need a
>>> transistor rather than a chip based solution.
>>> 
>>> Anyone interested in my crude investigations into the workings of the TR77
>>> can have a look here...
>>> http://www.adambaby.com/studiotech_TR-77.html
>>> 
>>> 
>>> 
>>> 
>>> regards
>>> Adam Inglis
>>> http://www.adambaby.com
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>> 
>>> 
>> 
>> 
>> 
>> -- 
>> .sig
>> -Chromatest J. Pantsmaker
>> http://www.chromatest.net
>> 
>> 
>> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From ol.gillet at gmail.com  Tue Nov 16 11:08:57 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Tue, 16 Nov 2010 11:08:57 +0100
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
Message-ID: <AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>

> What's all this 'real' and 'encoded' stuff? Is that what the hash is for? What are you up to?

I think it's just shifting the channel number from 1-16 (what's
exposed to the user) to 0-15 values (what's used internally by MIDI).

The HASH( ) is used to implement a lookup map from status byte to
handler function, by observing that there are no two status byte with
the same nibble checksum (they are either nx, with n between 8 and E
and x for channel messages, or Fn, with n below 8 for system messages.


From tom at electricdruid.net  Tue Nov 16 11:36:33 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 16 Nov 2010 10:36:33 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
Message-ID: <3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>


On 16 Nov 2010, at 10:08, Olivier Gillet wrote:

>> What's all this 'real' and 'encoded' stuff? Is that what the hash is for? What are you up to?
> 
> I think it's just shifting the channel number from 1-16 (what's
> exposed to the user) to 0-15 values (what's used internally by MIDI).

The MIDI bytestream never shows you the channel values as displayed to the user. Channel "One" is always '0x0'. In fact, aside from the actual user display, there isn't anywhere that MIDI channel 16 actually exists, is there?

> The HASH( ) is used to implement a lookup map from status byte to
> handler function, by observing that there are no two status byte with
> the same nibble checksum (they are either nx, with n between 8 and E
> and x for channel messages, or Fn, with n below 8 for system messages.

I'm not sure I get this. Ok, status bytes are unique, I get that. And there are only certain values possible, I get that. And we have a function to call for each type of message. So far so good.
But what's the point of the hash? A lookup map, you say? So it maps from status byte x to function y? Why not use an array, a switch statement, a long if/elseif, or any of the other possible constructions that would provide this mapping? If that is really what it's for, I still don't understand why you'd do it like this.

Thanks,
Tom



From ijfritz at comcast.net  Tue Nov 16 11:40:12 2010
From: ijfritz at comcast.net (Ian Fritz)
Date: Tue, 16 Nov 2010 03:40:12 -0700
Subject: [sdiy] copper prices
In-Reply-To: <AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.c
 om>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
Message-ID: <6.2.1.2.2.20101116033642.0230e238@mail.comcast.net>

I think these folks have it right:
http://www.sharenet.co.za/v3/news_disp.php?id=602695
"There will be additional consumption by China and India, while production 
bottlenecks will increase due to the lack of capital investment," ...

Ian



From ol.gillet at gmail.com  Tue Nov 16 11:51:36 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Tue, 16 Nov 2010 11:51:36 +0100
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
Message-ID: <AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>

> The MIDI bytestream never shows you the channel values as displayed to the user. Channel "One" is always '0x0'. In fact, aside from the actual user display, there isn't anywhere that MIDI channel 16 actually exists, is there?

When I mean user I really mean "user of the library". It looks like
Neil's library exposes to the user of the library the channel numbers
as 1-16. Just look here:
http://code.google.com/p/miby/source/browse/trunk/src/miby.c#148

> I'm not sure I get this. Ok, status bytes are unique, I get that. And there are only certain values possible, I get that. And we have a function to call for each type of message. So far so good.
> But what's the point of the hash? A lookup map, you say? So it maps from status byte x to function y? Why not use an array, a switch statement, a long if/elseif, or any of the other possible constructions that would provide this mapping?

Switch statements are likely to generate heavier code, because some
compilers are unable to optimize them properly as jump tables - and
they end up being compiled as a bunch of comparison / jump. Given that
this kind of code could very well be embedded on platforms with 2 or
4k of code memory with lousy compilers, this is a sane thing to do.

Olivier


From tom at electricdruid.net  Tue Nov 16 12:07:42 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 16 Nov 2010 11:07:42 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
Message-ID: <2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>


On 16 Nov 2010, at 10:51, Olivier Gillet wrote:
>> I'm not sure I get this. Ok, status bytes are unique, I get that. And there are only certain values possible, I get that. And we have a function to call for each type of message. So far so good.
>> But what's the point of the hash? A lookup map, you say? So it maps from status byte x to function y? Why not use an array, a switch statement, a long if/elseif, or any of the other possible constructions that would provide this mapping?
> 
> Switch statements are likely to generate heavier code, because some
> compilers are unable to optimize them properly as jump tables - and
> they end up being compiled as a bunch of comparison / jump. Given that
> this kind of code could very well be embedded on platforms with 2 or
> 4k of code memory with lousy compilers, this is a sane thing to do.

Ok, *now* I get it, thanks!
It's a workaround for crap compilers to ensure that they produce something that is a reasonable approximation to efficient code. Because although the point of higher level languages is the easy readability and useful structures like switch, if you actually use them you finish up with hideous bloatware that won't go in your chip, let alone run fast and do the job in hand? Am I close?!

Grrr...not convinced by C. If that's the kind of stuff you have to do to make things work, I'm going back to assembly language...

Thanks for explaning, Olivier
Tom



From usenet at teply.info  Tue Nov 16 12:35:54 2010
From: usenet at teply.info (Florian E. Teply)
Date: Tue, 16 Nov 2010 12:35:54 +0100
Subject: [sdiy] 0.100 pin header reliability.
In-Reply-To: <E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
References: <AANLkTikL4LudCcMdAKRj8oXDw3A34BJoNYO_UZ6pFvO4@mail.gmail.com>
	<993960882.397059.1289831483984.JavaMail.root@md01.wow.synacor.com>
	<AANLkTikcO2U22L8vG3-jG0SvqYqUwgg=AZQB5W9uJSfZ@mail.gmail.com>
	<E2A57C80-4560-40F9-A1DD-DECC95C3993D@blueyonder.co.uk>
Message-ID: <20101116123554.3eb35f8a@vz127.worldserver.net>

On Mon, 15 Nov 2010 19:18:56 +0000
Graham Atkins <gatkins at blueyonder.co.uk> wrote:

> Aluminium for wiring ?
> 
> Are you sure about that, sounds highly unlikely, never heard of  
> aluminium
> conductors. Steel, copper alloys, silver, even gold but not aluminium.
> 
Actually, there have been two main reasons especially for eastern europe
to go for aluminium in house wirings (and even long distance power
grids). For one, copper has become quite expensive in the 70ies. Even
though not as expensive as it is nowadays IMO. Second reason is, that
behind the iron curtain they had virtually no copper ores, so they'd
have to import the stuff from the western world. But aluminium ores
were comparably abundant, so aluminium was quite cheap and easy to get.

Nowadays with all the problems aluminium poses for connections, i start
to see more and more compound cables (especially in the Car-HiFi market
with all those thick speaker cables), where an inner aluminium wire has
an outer shell of copper. No idea though whether or not they solved the
corrosion problem between copper and aluminium...

HTH,
Florian


From ol.gillet at gmail.com  Tue Nov 16 12:36:20 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Tue, 16 Nov 2010 12:36:20 +0100
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
	<2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
Message-ID: <AANLkTinw7KGYSDU2zYYxdEpmwaAe6hK19y2g_N=TSLKc@mail.gmail.com>

> Ok, *now* I get it, thanks!
> It's a workaround for crap compilers to ensure that they produce something that is a reasonable approximation to efficient code. Because although the point of higher level languages is the easy readability and useful structures like switch, if you actually use them you finish up with hideous bloatware that won't go in your chip, let alone run fast and do the job in hand? Am I close?!

I actually find that the "handlers table" solution is more readable,
elegant and is a higher level "structure" than 120 lines of switch /
case /break (Here's how I wrote it with the switch:
https://github.com/pichenettes/shruthi-1/blob/master/hardware/midi/midi.h#L163).
It's not a hack, it's a common programming idiom seen in protocol
handling.

As a side-effect, it also adds a useful level of indirection, since
the handlers table can be hijacked at runtime to change how some
messages are handled.

> Grrr...not convinced by C. If that's the kind of stuff you have to do to make things work, I'm going back to assembly language...

Nothing prevents you from using a switch, but then you depend on your
compiler writing the best code for you. But even with a crappy
compiler, the generated code is likely to be of higher quality than
what an average assembly programmer does... I'm not sure every
assembly programmer would know how to code a jump table anyway!

Interestingly, I've rewritten my MIDI parser using this lookup table
approach (since I'm trying to put the Shruthi-1 code on a diet to add
new feature) and the code size was in the end very similar to the
switch approach (+50 bytes of data, -52 bytes of code). Maybe avr-gcc
is not that bad at all, and maybe the additional level of indirections
this adds can't be flatten as easily as with a switch (the way things
are currently done is such that the MIDI handlers are in the end
directly inlined at compile-time within the MIDI parser code) ; but
this is specific to the way I'm writing most of my code so this is not
something I would recommend to do in a library that aims to be as
cross-platform and universal as Neil's.

Olivier


From 21pointy at tpg.com.au  Tue Nov 16 12:42:46 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Tue, 16 Nov 2010 21:42:46 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
Message-ID: <643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>

er.. I'm not yet actually up to the chapters on logic in  
Horowitz&Hill, ha ha!!

You're right - there are negative triggers to be found in the 707 (+5  
to ground) going to the bases of each transistor in each envelope  
generator. The Accent line is a positive CV line going to all the  
collectors of these transistors, can't remember the levels, prob  
around 5 volts (there are two levels of accent).
Not sure - does that sound like something I could AND??

On 16/11/2010, at 6:11 PM, cheater cheater wrote:

> Hi Adam,
> can't you use the trigger that goes into the 707's envelopes? I
> believe there's a separate accent line (as far as I remember the
> schematics). You can AND that with a separate copy of the trigger
> lines, and add it to the original trigger lines. That's probably one
> AND array, together with just some logic buffers or whatevers (I'm not
> that great with digital logic hardware, just software!)
>
> Maybe you can use those directly in the 77 without any conversion.
>
> Cheers,
> D.
>
> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au>  
> wrote:
>
>> Cheers - I was hoping to avoid building a negative rail, the 77  
>> manages
>> without one (The negative-edge detector circuits that make up the  
>> matrix
>> generate a brief negative pulse on the falling edge of the square  
>> waves from
>> the multivibrator counters).
>>
>> Hanging a common-emitter amp off the 24 volt rail to invert the  
>> signal, and
>> running this into a similar edge-detector seems to work, but thats  
>> a lot of
>> parts if I have to make one for every voice.
>>
>> regards
>> Adam Inglis
>> http://www.adambaby.com
>>
>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>
>>
>>> I'm thinking a voltage regulator to get you your -7 volts.. and  
>>> then a
>>> transistor for each voice. use the 707 CV to trip the transistor
>>> letting the -7 through?  Probably a current limiting resistor on  
>>> each
>>> one?
>>>
>>> Of course, this is how I design my own stuff... and sometimes it
>>> works.  I really have no idea of the "correct" way to do things.
>>>
>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis  
>>> <21pointy at tpg.com.au> wrote:
>>>
>>>
>>>> Hi All
>>>>
>>>> First post - long time lurker and learner here for many years.
>>>> Self-taught
>>>> in analogue audio electronics thanks to a studio full of old  
>>>> "junk" from
>>>> the
>>>> 70s and 80s, an oscilloscope from the 60s, and the first few  
>>>> chapters of
>>>> Horowitz and Hill!
>>>>
>>>> Question: Someone here mentioned not too long ago the idea of  
>>>> using the
>>>> voice trigger signals in a Roland TR707 to trigger external  
>>>> instruments.
>>>> It
>>>> got me thinking, as I love the interface of this drum machine -  
>>>> quick and
>>>> fun.
>>>>  I would like to be able to trigger the voices in my old preset  
>>>> Roland
>>>> Rhythm TR77. This uses passive LC voice circuits, which respond  
>>>> fairly
>>>> dynamically to voltage triggers of between -3 to -10 volts.  
>>>> Looking at
>>>> the
>>>> 707, I found the voice group's envelope generators supplied a  
>>>> positive
>>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>> programmable ACCENT, and so would appear to be a good source of
>>>> triggering.
>>>>
>>>> Any suggestions as to a simple, low-parts-count circuit I could  
>>>> install
>>>> (several iterations of) into the 77 that would convert the  
>>>> positive CVs
>>>> from
>>>> the 707 into brief negative pulses for the 77s voices?
>>>> I should mention there is 0 - 12 - 24 volts available in the 77  
>>>> with just
>>>> basic filtering, no voltage regulators, so I was assuming it  
>>>> would need a
>>>> transistor rather than a chip based solution.
>>>>
>>>> Anyone interested in my crude investigations into the workings  
>>>> of the
>>>> TR77
>>>> can have a look here...
>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>> Adam Inglis
>>>> http://www.adambaby.com
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at dropmix.xs4all.nl
>>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> .sig
>>> -Chromatest J. Pantsmaker
>>> http://www.chromatest.net
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>
>
>
>



From 21pointy at tpg.com.au  Tue Nov 16 12:47:57 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Tue, 16 Nov 2010 21:47:57 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <CFBB32AE-291F-4A2A-BE88-F1FE6B72D668@electricdruid.net>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<CFBB32AE-291F-4A2A-BE88-F1FE6B72D668@electricdruid.net>
Message-ID: <FB3658F2-3534-4C3D-879E-F82F83C041BA@tpg.com.au>

That sounds good - and then you'd need a capacitor at the output of  
the op amp to remove the DC offset?

On 16/11/2010, at 7:54 PM, Tom Wiltshire wrote:

> If you've got 0V/12V/24V, you could regard it as -12V/0V/+12V and  
> use it to drive an op-amp wired as an inverting highpass filter  
> (edge detector). Inverting so you get a negative-going pulse from  
> the positive input. Since you'd get 4 such filters on a quad-amp  
> chip, it wouldn't take up much space.
>
> But I'm only saying that 'cause the sight of all those transistors  
> gives me the willies. Discrete! Even flip-flops! Yikes!
>
> T.
>
> On 16 Nov 2010, at 01:20, Adam Inglis wrote:
>
>
>> Cheers - I was hoping to avoid building a negative rail, the 77  
>> manages without one (The negative-edge detector circuits that make  
>> up the matrix generate a brief negative pulse on the falling edge  
>> of the square waves from the multivibrator counters).
>>
>> Hanging a common-emitter amp off the 24 volt rail to invert the  
>> signal, and running this into a similar edge-detector seems to  
>> work, but thats a lot of parts if I have to make one for every voice.
>>
>> regards
>> Adam Inglis
>> http://www.adambaby.com
>>
>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>
>>
>>> I'm thinking a voltage regulator to get you your -7 volts.. and  
>>> then a
>>> transistor for each voice. use the 707 CV to trip the transistor
>>> letting the -7 through?  Probably a current limiting resistor on  
>>> each
>>> one?
>>>
>>> Of course, this is how I design my own stuff... and sometimes it
>>> works.  I really have no idea of the "correct" way to do things.
>>>
>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis  
>>> <21pointy at tpg.com.au> wrote:
>>>
>>>
>>>> Hi All
>>>>
>>>> First post - long time lurker and learner here for many years.  
>>>> Self-taught
>>>> in analogue audio electronics thanks to a studio full of old  
>>>> "junk" from the
>>>> 70s and 80s, an oscilloscope from the 60s, and the first few  
>>>> chapters of
>>>> Horowitz and Hill!
>>>>
>>>> Question: Someone here mentioned not too long ago the idea of  
>>>> using the
>>>> voice trigger signals in a Roland TR707 to trigger external  
>>>> instruments. It
>>>> got me thinking, as I love the interface of this drum machine -  
>>>> quick and
>>>> fun.
>>>> I would like to be able to trigger the voices in my old preset  
>>>> Roland
>>>> Rhythm TR77. This uses passive LC voice circuits, which respond  
>>>> fairly
>>>> dynamically to voltage triggers of between -3 to -10 volts.  
>>>> Looking at the
>>>> 707, I found the voice group's envelope generators supplied a  
>>>> positive
>>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>> programmable ACCENT, and so would appear to be a good source of  
>>>> triggering.
>>>>
>>>> Any suggestions as to a simple, low-parts-count circuit I could  
>>>> install
>>>> (several iterations of) into the 77 that would convert the  
>>>> positive CVs from
>>>> the 707 into brief negative pulses for the 77s voices?
>>>> I should mention there is 0 - 12 - 24 volts available in the 77  
>>>> with just
>>>> basic filtering, no voltage regulators, so I was assuming it  
>>>> would need a
>>>> transistor rather than a chip based solution.
>>>>
>>>> Anyone interested in my crude investigations into the workings  
>>>> of the TR77
>>>> can have a look here...
>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>
>>>>
>>>>
>>>>
>>>> regards
>>>> Adam Inglis
>>>> http://www.adambaby.com
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at dropmix.xs4all.nl
>>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> -- 
>>> .sig
>>> -Chromatest J. Pantsmaker
>>> http://www.chromatest.net
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>
>
>



From usenet at teply.info  Tue Nov 16 13:46:04 2010
From: usenet at teply.info (Florian E. Teply)
Date: Tue, 16 Nov 2010 13:46:04 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
Message-ID: <20101116134604.4c3fb31f@vz127.worldserver.net>

On Tue, 16 Nov 2010 13:45:18 +1100
"Paul Perry" <pfperry at melbpc.org.au> wrote:

> >Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not
> >ideal,
> > but it covers a lot of ground including the maths involved, signal
> > transmission, basic control theory, etc. Dunno about the English 
> > translation
> 
> I've read the English translation, and it is very good.
> But, the book is pretty scarce and very expensive.
> I don't think I will ever own a copy.
> 
Especially the English edition is hard to come by and damn expensive
(usually north of 250 USD). I've seen only one for less than 100 EUR
right now, and thats apparently from a library.
It's not that bad with the german edition, where you can easily get
older editions for about 25 EUR. The new ones are still way expensive
and out of reach for the average student, but apart from the
computer-related stuff (which basically isn't in there nowadays) the
basics don't change by much. That's why you usually can find an older
edition for said 25 bucks, use it in your studies and sell it again for
the same price if you're in a university city ;-)

HTH,
Florian


From tom at electricdruid.net  Tue Nov 16 14:00:28 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 16 Nov 2010 13:00:28 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <AANLkTinw7KGYSDU2zYYxdEpmwaAe6hK19y2g_N=TSLKc@mail.gmail.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
	<2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
	<AANLkTinw7KGYSDU2zYYxdEpmwaAe6hK19y2g_N=TSLKc@mail.gmail.com>
Message-ID: <65654750-EB06-4F9B-B01E-5CEB5834DDF7@electricdruid.net>


On 16 Nov 2010, at 11:36, Olivier Gillet wrote:

> But even with a crappy
> compiler, the generated code is likely to be of higher quality than
> what an average assembly programmer does... I'm not sure every
> assembly programmer would know how to code a jump table anyway!

Those kind of assembly "programmers" had better stay out of my way, then.

I've been trying to get back into C for exactly this kind of job, but have spent so long doing assembly now that I actually find it easier, since it's what I'm used to. I need to be able to see some good reasons to make the effort to get over the hump with C, but to be honest I'm not finding them.

But your comments are all very interesting, and I see the development from one style to the other that you've gone through. I also understand your remark about Neil needing to write good, clean, cross-platform code.

Thanks,
Tom




From thomas at pdp7.org  Tue Nov 16 15:39:24 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Tue, 16 Nov 2010 15:39:24 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <20101116134604.4c3fb31f@vz127.worldserver.net>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>	<4CE1404E.5060403@pdp7.org>	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>	<4CE1872F.3060104@pdp7.org>	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<20101116134604.4c3fb31f@vz127.worldserver.net>
Message-ID: <4CE2979C.8020505@pdp7.org>

On 11/16/10 13:46 , Florian E. Teply wrote:
> Especially the English edition is hard to come by and damn expensive
> (usually north of 250 USD). I've seen only one for less than 100 EUR
> right now, and thats apparently from a library.
> It's not that bad with the german edition, where you can easily get
> older editions for about 25 EUR. The new ones are still way expensive
> and out of reach for the average student, but apart from the
> computer-related stuff (which basically isn't in there nowadays) the
> basics don't change by much. That's why you usually can find an older
> edition for said 25 bucks, use it in your studies and sell it again for
> the same price if you're in a university city ;-)

I paid 80 Euros for the newest edition not so long ago after being fed 
up with lending it from the university's library. It's not terribly 
cheap, but then again it's roughly 1600 pages worth of material. Most of 
it is probably not relevant to students, but it's always good to have a 
few books in which you can look up things, not having to resort to the 
Web all the time. Side note: I'm always suspicious of students who don't 
own/keep a few books, but that's because I like books and apart from 
papers/datasheets/application notes use them more than anything else as 
a source of information -- added benefit being: you can cite them if you 
have to.

	Thomas


From subjectivity at hotmail.com  Tue Nov 16 16:18:37 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Tue, 16 Nov 2010 10:18:37 -0500
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
Message-ID: <BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>

>> Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
>> but it covers a lot of ground including the maths involved, signal
>> transmission, basic control theory, etc. Dunno about the English translation
> 
> I've read the English translation, and it is very good.
> But, the book is pretty scarce and very expensive.
> I don't think I will ever own a copy.



what is the name of the book in english???


thanks




From Peter.Ullrich at kapsch.net  Tue Nov 16 16:24:52 2010
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Tue, 16 Nov 2010 16:24:52 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
Message-ID: <B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>

Should be this one:

http://www.amazon.co.uk/Electronic-Circuits-Handbook-Design-Application/dp/3540004297


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
Sent: Tuesday, November 16, 2010 4:19 PM
To: Paul Perry
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] Best kept secret of amazing electronics books

>> Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
>> but it covers a lot of ground including the maths involved, signal
>> transmission, basic control theory, etc. Dunno about the English translation
> 
> I've read the English translation, and it is very good.
> But, the book is pretty scarce and very expensive.
> I don't think I will ever own a copy.



what is the name of the book in english???


thanks


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

The information contained in this e-mail message is privileged and
confidential and is for the exclusive use of the addressee. The person
who receives this message and who is not the addressee, one of his
employees or an agent entitled to hand it over to the addressee, is
informed that he may not use, disclose or reproduce the contents
thereof, and is kindly asked to notify the sender and delete the e-mail
immediately.




From mcbinc at panix.com  Tue Nov 16 16:25:01 2010
From: mcbinc at panix.com (m brandenberg)
Date: Tue, 16 Nov 2010 10:25:01 -0500 (EST)
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
Message-ID: <Pine.NEB.4.64.1011161022390.27230@panix2.panix.com>

On Tue, 16 Nov 2010, dan snazelle wrote:

> what is the name of the book in english???

LMATFY:  http://www.amazon.com/gp/product/3540004297

Electronic Circuits: Handbook for Design and Application

--
Monty Brandenberg


From thomas at pdp7.org  Tue Nov 16 16:26:03 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Tue, 16 Nov 2010 16:26:03 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
Message-ID: <4CE2A28B.5000608@pdp7.org>

On 11/16/10 16:18 , dan snazelle wrote:
>>> Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
>>> but it covers a lot of ground including the maths involved, signal
>>> transmission, basic control theory, etc. Dunno about the English translation
>>
>> I've read the English translation, and it is very good.
>> But, the book is pretty scarce and very expensive.
>> I don't think I will ever own a copy.
>
>
>
> what is the name of the book in english???

Electronic Circuits --- Handbook for Design and Applications.

You can get a sample section at this URL:
http://www.springer.com/engineering/circuits+%26+systems/book/978-3-540-00429-5

	Thomas


From blacet at blacet.com  Tue Nov 16 16:56:10 2010
From: blacet at blacet.com (blacet at blacet.com)
Date: Tue, 16 Nov 2010 07:56:10 -0800
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <4CE2A28B.5000608@pdp7.org>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl><4CE1404E.5060403@pdp7.org><AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com><4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<4CE2A28B.5000608@pdp7.org>
Message-ID: <37324e913c3750e87afdb5f27a09a6f3.squirrel@webmail.blacet.com>

If you Google the title, you can find some used copies a bit more
reasonable, since these show up as used textbooks.

> On 11/16/10 16:18 , dan snazelle wrote:
>>>> Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not ideal,
>>>> but it covers a lot of ground including the maths involved, signal
>>>> transmission, basic control theory, etc. Dunno about the English
>>>> translation
>>>
>>> I've read the English translation, and it is very good.
>>> But, the book is pretty scarce and very expensive.
>>> I don't think I will ever own a copy.
>>
>>
>>
>> what is the name of the book in english???
>
> Electronic Circuits --- Handbook for Design and Applications.
>
> You can get a sample section at this URL:
> http://www.springer.com/engineering/circuits+%26+systems/book/978-3-540-00429-5
>
> 	Thomas
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From dixon at interchange.ubc.ca  Tue Nov 16 18:16:08 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Tue, 16 Nov 2010 09:16:08 -0800
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
Message-ID: <BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>

> http://www.amazon.co.uk/Electronic-Circuits-Handbook-Design-
> Application/dp/3540004297

Oh yeah, I keep seeing that book at Powell's Technical Bookstore in Portland
on my way to California.  It's a right brick and bloody expensive, but it
looks exhaustive.



From blacet at blacet.com  Tue Nov 16 20:41:41 2010
From: blacet at blacet.com (blacet at blacet.com)
Date: Tue, 16 Nov 2010 11:41:41 -0800
Subject: [sdiy] MN3005/Time Machines?
In-Reply-To: <BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
	<BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
Message-ID: <e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>

I see a bunch of MN3005s for sale on ebay. Anyone bought any of these
lately? Had any good ones or fraud?

I guess the second part of the question is anyone up for some Time Machine
bare boards?

John Blacet



From neil.johnson97 at ntlworld.com  Tue Nov 16 21:07:38 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 16 Nov 2010 20:07:38 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
Message-ID: <BAE3892A-8B0C-400B-A8D0-576AF883D83D@ntlworld.com>

Hi Tom,

> Very interesting, Neil. I've got one or two questions though;

Thanks!

> What's all this 'real' and 'encoded' stuff? Is that what the hash  
> is for? What are you up to?

The MIDI Specification defines the sixteen MIDI channels as '1' to  
'16', however the channel is encoded in status bytes using the values  
0 to 15.  But this is just an implementation detail.  So the 'real'  
and 'encoded' maps between the correct user-view and the internal  
representation.

The hash function compresses the size of the hander table.

> When you do further documentation, I'd appreciate an overview of  
> the general structure or form of the code.

I've uploaded a diagram showing the main flows through the parser.   
Its in "trunk/doc".

> The point is that as well as the microscopic detail, documentation  
> needs to give a macroscopic overview of the basic principles and  
> structure.

I agree to some extent, although given this is a hobby project it is  
expected that the interested reader invests *some* of their own time  
in understanding it!  The main focus for documentation will be on how  
to *use* the parser, not on its internal workings.

Cheers,
Neil
--
http://www.njohnson.co.uk





From neil.johnson97 at ntlworld.com  Tue Nov 16 21:08:12 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 16 Nov 2010 20:08:12 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
Message-ID: <D32AB4F2-7E3C-494A-8C19-A42FD3DFB683@ntlworld.com>

Olivier,

> I think it's just shifting the channel number from 1-16 (what's
> exposed to the user) to 0-15 values (what's used internally by MIDI).
>
> The HASH( ) is used to implement a lookup map from status byte to
> handler function, by observing that there are no two status byte with
> the same nibble checksum (they are either nx, with n between 8 and E
> and x for channel messages, or Fn, with n below 8 for system messages.

Spot on!

Neil
--
http://www.njohnson.co.uk





From jimp at pobox.com  Tue Nov 16 22:02:06 2010
From: jimp at pobox.com (jimp at pobox.com)
Date: Tue, 16 Nov 2010 15:02:06 -0600
Subject: [sdiy] MN3005/Time Machines?
In-Reply-To: <e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
	<BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
	<e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
Message-ID: <4CE2F14E.8000805@pobox.com>

mmmm i would love to make another time machine...

On 11/16/2010 1:41 PM, blacet at blacet.com wrote:
> I see a bunch of MN3005s for sale on ebay. Anyone bought any of these
> lately? Had any good ones or fraud?
>
> I guess the second part of the question is anyone up for some Time Machine
> bare boards?
>
> John Blacet
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From dingebre at 3dphysics.net  Tue Nov 16 22:42:44 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Tue, 16 Nov 2010 14:42:44 -0700
Subject: [sdiy] MN3005/Time Machines?
In-Reply-To: <e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>	<4CE1404E.5060403@pdp7.org>	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>	<4CE1872F.3060104@pdp7.org>	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>	<BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
	<e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
Message-ID: <001d01cb85d7$359b1590$a0d140b0$@net>

Yes, I've collected a bunch of MN3005s in anticipation of playing with delay
circuits and would love to have another Frac size Time Machine in my rack.

David


~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of blacet at blacet.com
~~ Sent: Tuesday, November 16, 2010 12:42 PM
~~ To: synth-diy at dropmix.xs4all.nl
~~ Subject: [sdiy] MN3005/Time Machines?
~~ 
~~ I see a bunch of MN3005s for sale on ebay. Anyone bought any of these
~~ lately? Had any good ones or fraud?
~~ 
~~ I guess the second part of the question is anyone up for some Time
Machine
~~ bare boards?
~~ 
~~ John Blacet
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From blacet at blacet.com  Tue Nov 16 22:49:29 2010
From: blacet at blacet.com (blacet at blacet.com)
Date: Tue, 16 Nov 2010 13:49:29 -0800
Subject: [sdiy] MN3005/Time Machines?
In-Reply-To: <e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
	<BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
	<e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
Message-ID: <cb8f5cc1cfe85d40610b5ef0ac7865cb.squirrel@webmail.blacet.com>

I should mention that these would be the regular frac boards. I did do a
run of 5U (MOTM) way back when but I won't be doing that again.

> I see a bunch of MN3005s for sale on ebay. Anyone bought any of these
> lately? Had any good ones or fraud?
>
> I guess the second part of the question is anyone up for some Time Machine
> bare boards?
>
> John Blacet
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From neil.johnson97 at ntlworld.com  Wed Nov 17 00:16:38 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 16 Nov 2010 23:16:38 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
Message-ID: <4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>

Hi Tom,

> The MIDI bytestream never shows you the channel values as displayed  
> to the user. Channel "One" is always '0x0'. In fact, aside from the  
> actual user display, there isn't anywhere that MIDI channel 16  
> actually exists, is there?

You're confusing a particular encoding of channel numbers, with the  
actual channel numbers.  MIDI has channels 1-16, while the encoding  
uses 0-15.  If anything, it would be more correct to say that MIDI  
channel 0 does not exist!

>> The HASH( ) is used to implement a lookup map from status byte to
>> handler function, by observing that there are no two status byte with
>> the same nibble checksum (they are either nx, with n between 8 and E
>> and x for channel messages, or Fn, with n below 8 for system  
>> messages.
>
> I'm not sure I get this. Ok, status bytes are unique, I get that.  
> And there are only certain values possible, I get that. And we have  
> a function to call for each type of message. So far so good.

Great!

> But what's the point of the hash? A lookup map, you say? So it maps  
> from status byte x to function y?

No, you don't seem to understand what a hash is.  A hash generates a  
value from a small set of values given a value from a large set.   
There are bound to be clashes (multiple input values hash to the same  
output value), but in this specific case the sparse input values do  
not cause clashes in the output values, so it all works out  
nicely :)  The end result is the values 0x80, 0x90, 0xA0, 0xB0, 0xC0,  
0xD0, 0xE0, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6 and 0xF7 are  
hashed, without clashing, onto the range 0-15.

> Why not use an array

Because for the set of input values, without any processing, you  
would need an array of size 0xF7 - 0x80 = 0x77, or 119, entries.

> a switch statement,

I could, but again given the sparse input values this would either be  
turned into a list of if--else or if the compiler is *really* smart  
it would work out the same hashing function in order to generate an  
index into a jump table.

> a long if/elseif,

Not very compact though is it?  And think of all those lines of source!

Also note that a long chain of if--else has different processing  
times depending on the order of tests - those early in the chain  
execute faster than those at the end of the chain.

> or any of the other possible constructions that would provide this  
> mapping?

You mean, like a hash function and a small function pointer table?   
Its a common idiom.

> If that is really what it's for, I still don't understand why you'd  
> do it like this.

It has many advantages, a few of which I've touched on here.

Cheers,
Neil
--
http://www.njohnson.co.uk





From neil.johnson97 at ntlworld.com  Wed Nov 17 00:18:52 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 16 Nov 2010 23:18:52 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
Message-ID: <52847935-104B-4A8E-8DC1-5BAA4FD83787@ntlworld.com>

Hi Olivier,

> When I mean user I really mean "user of the library". It looks like
> Neil's library exposes to the user of the library the channel numbers
> as 1-16. Just look here:
> http://code.google.com/p/miby/source/browse/trunk/src/miby.c#148

Yes indeed!

> Switch statements are likely to generate heavier code, because some
> compilers are unable to optimize them properly as jump tables - and
> they end up being compiled as a bunch of comparison / jump.

Even good compilers sometimes do poorly with switch statements.  And  
the quality of the generated code also depends on the underlaying  
instruction set support for jump tables.

> Given that
> this kind of code could very well be embedded on platforms with 2 or
> 4k of code memory with lousy compilers, this is a sane thing to do.

Thanks!

Neil
--
http://www.njohnson.co.uk





From neil.johnson97 at ntlworld.com  Wed Nov 17 00:24:53 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 16 Nov 2010 23:24:53 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
	<2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
Message-ID: <74969BC6-A066-4D00-ABF9-E48F3EB9829A@ntlworld.com>

Hi Tom,

> Ok, *now* I get it, thanks!

Great!

> It's a workaround for crap compilers to ensure that they produce  
> something that is a reasonable approximation to efficient code.

No, its simply a common programming method applied to processing MIDI  
messages.  Compilers and good and bad, and compilers are tuned for  
specific reasons.  It is certainly *not* a "workaround".

> Because although the point of higher level languages is the easy  
> readability and useful structures like switch, if you actually use  
> them you finish up with hideous bloatware that won't go in your  
> chip, let alone run fast and do the job in hand? Am I close?!

No, but this is an argument that has been raging on for years, and I  
don't think you really mean to open that can of worms!

> Grrr...not convinced by C. If that's the kind of stuff you have to  
> do to make things work, I'm going back to assembly language...

A pity -- there's so much to learn from studying high(er) level  
languages that would benefit programming in assembler.  But its your  
choice.  At the very least, remember that algorithms and code are not  
the same, although they are related.  If I was going to target a  
specific processor and write this in assembler, the structure and  
methods employed would look pretty similar to what I've written in  
C.  It would just be in a different representation, that's all.

Cheers,
Neil
--
http://www.njohnson.co.uk





From davebr at earthlink.net  Wed Nov 17 04:09:19 2010
From: davebr at earthlink.net (David Brown)
Date: Tue, 16 Nov 2010 19:09:19 -0800
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <74969BC6-A066-4D00-ABF9-E48F3EB9829A@ntlworld.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<AANLkTi=PmxN_ZLzUCynLD1ZCJ_TJ5ZiYsPBDDFNHHbpM@mail.gmail.com>
	<2C130658-E75D-4909-BA92-B8D767343452@electricdruid.net>
	<74969BC6-A066-4D00-ABF9-E48F3EB9829A@ntlworld.com>
Message-ID: <20101117030912.BB59910F817@relay02.roch.ny.frontiernet.net>

I've been following this thread so I thought I would share my 
experiences with MIDI processing.

I've implemented a midi parser in both assembly and basic.  I'm not 
sure of the end project in mind for this thread, but my work started 
out as programs for my ComputerVoltageSource 
http://modularsynthesis.com/cvs/cvs.htm

A lot of what I did was convert various MIDI messages to CV, or 
process the MIDI stream to change controllers, messages, or transpose 
keys or channels.  Some of the more fun programs are to reverse the 
keyboard from end to end. http://modularsynthesis.com/programs/programs.htm

I integrated that MIDI code into my bass pedals so I can scan the 
pedals, convert to MIDI notes or arpeggiation sequences, and merge 
the bass MIDI with an incoming MIDI stream from another synth.  To do 
that, I need to expand the running status so I can merge the messages 
correctly with their own MIDI channel. 
http://modularsynthesis.com/basspedals/basspedals.htm  All of my 
basic source code is found on the various project pages.

I've also implemented this code structure in AVR assembly using an 
ATTINY2313.  I've used it for a variety or projects including a sysex 
display driver (e.g. send messages to a LCD display as a sysex 
message) http://modularsynthesis.com/cvs/cvs2.htm, a MIDI keyboard 
split http://modularsynthesis.com/custom/custom.htm, a MIDI note 
transpose for my keyboard 
http://modularsynthesis.com/kurzweil/kurzweil.htm, and a MIDI-powered 
MIDI processor http://modularsynthesis.com/processor/processor.htm.

The latter is what I used for my MIDI keyboard split and I've done 
some custom versions for people.  One useful implementation was to 
remap MIDI volume and expression messages.  Roland tends to use 
expression messages and many other synths use volume messages.  If 
you are driving both kinds of synths from a single controller, the 
volume pedal won't interoperate with Roland.  That's an easy 
on-the-fly message transpose.  My AVR assembly source is on my MIDI 
processor page.

It would be interesting to benchmark the performance differences 
between my assembly and basic implementations.  I've never had an 
issue with being able to keep up with incoming MIDI messages, but my 
controllers tend to not use a lot of real-time messages.

Dave 



From davebr at earthlink.net  Wed Nov 17 04:12:53 2010
From: davebr at earthlink.net (David Brown)
Date: Tue, 16 Nov 2010 19:12:53 -0800
Subject: [sdiy] MN3005/Time Machines?
In-Reply-To: <cb8f5cc1cfe85d40610b5ef0ac7865cb.squirrel@webmail.blacet.c
 om>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<BLU0-SMTP122F576C7F09BBE18F4BF9FC8370@phx.gbl>
	<B156A86831A33949A0977840648802475DF3BF4F0A@S060VS20.kapsch.co.at>
	<BC623A6B90984C2B8F7469C21E5B80B7@galvanox01>
	<e8f827e1003260ef76056a8274111d40.squirrel@webmail.blacet.com>
	<cb8f5cc1cfe85d40610b5ef0ac7865cb.squirrel@webmail.blacet.com>
Message-ID: <20101117031245.E9E9618E362@relay04.roch.ny.frontiernet.net>

I'd probably go for another PCB.  It would be nice if the PCB came 
with the BBDs.

My application if 5U but the depth wasn't a problem.  I assume I had 
the Frac PCB.
http://modularsynthesis.com/blacet/timemachine/timemachine.htm

Dave

At 01:49 PM 11/16/2010, blacet at blacet.com wrote:
>I should mention that these would be the regular frac boards. I did do a
>run of 5U (MOTM) way back when but I won't be doing that again.
>
> > I see a bunch of MN3005s for sale on ebay. Anyone bought any of these
> > lately? Had any good ones or fraud?
> >
> > I guess the second part of the question is anyone up for some Time Machine
> > bare boards?
> >
> > John Blacet
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> >
>
>
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From dlmanley at sonic.net  Wed Nov 17 06:03:59 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Tue, 16 Nov 2010 21:03:59 -0800
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
Message-ID: <4CE3623F.4010109@sonic.net>

On 11/16/2010 3:16 PM, Neil Johnson wrote:

> A hash generates a value from a small set of values given a value
from a large set. There are bound to be clashes (multiple input values
hash to the same output value), but in this specific case the sparse
input values do not cause clashes in the output values, so it all works
out nicely :) The end result is the values 0x80, 0x90, 0xA0, 0xB0,
0xC0, 0xD0, 0xE0, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6 and 0xF7
are hashed, without clashing, onto the range 0-15.

Hi Neil,

But what if the output of the hash created collisions?

I suppose you could look for a different hash that was collision
free, or you could let the collision occur, and then sort it
out later.

I guess I answered my own question.  :-p

-Dave



From jason at redfish.net  Wed Nov 17 06:20:07 2010
From: jason at redfish.net (Jason Proctor)
Date: Tue, 16 Nov 2010 21:20:07 -0800
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <4CE3623F.4010109@sonic.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net>
Message-ID: <a06200745c9091528e24c@[192.168.1.64]>

>On 11/16/2010 3:16 PM, Neil Johnson wrote:
>
>>A hash generates a value from a small set of values given a value
>from a large set. There are bound to be clashes (multiple input values
>hash to the same output value), but in this specific case the sparse
>input values do not cause clashes in the output values, so it all works
>out nicely :) The end result is the values 0x80, 0x90, 0xA0, 0xB0,
>0xC0, 0xD0, 0xE0, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6 and 0xF7
>are hashed, without clashing, onto the range 0-15.
>
>Hi Neil,
>
>But what if the output of the hash created collisions?
>
>I suppose you could look for a different hash that was collision
>free, or you could let the collision occur, and then sort it
>out later.
>
>I guess I answered my own question.  :-p

another option might be a jumptable off (((byte - 0x80) >> 4) - 0x8), 
with a further jumptable for the selector off 0xf0.

first jumptable has 8 entries, the second has 16.

makes me less nervous than a hashtable, and faster too :-)



From oakleylist at btinternet.com  Wed Nov 17 08:41:16 2010
From: oakleylist at btinternet.com (Oakley Sound)
Date: Wed, 17 Nov 2010 07:41:16 +0000
Subject: [sdiy] Oakley stuff
Message-ID: <4CE3871C.3080604@btinternet.com>

PCBs for the new version of my noise and filter module are now available.

More information at the usual spot:

http://www.oakleysound.com/noise.htm

Documentation should be ready at the end of the week.

Tony

http://www.oakleysound.com


From Stromeko at nexgo.de  Wed Nov 17 09:05:15 2010
From: Stromeko at nexgo.de (ASSI)
Date: Wed, 17 Nov 2010 09:05:15 +0100
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <4CE3623F.4010109@sonic.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net>
Message-ID: <201011170905.15460.Stromeko@nexgo.de>

On Wednesday 17 November 2010, Dave Manley wrote:
> But what if the output of the hash created collisions?

What Neil uses there is called a "perfect hash".  By definition a perfect 
hash doesn't create collisions.  And yes, it is a common idiom for 
optimization or compaction of code - in fact so common that the problem of 
finding a perfect hash for a given set of data has been solved numerous 
times in different ways and implemented both into standalone programs and 
into compilers.

http://en.wikipedia.org/wiki/Perfect_hash_function


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

SD adaptations for KORG EX-800 and Poly-800MkII V0.9:
http://Synth.Stromeko.net/Downloads.html#KorgSDada


From neil.johnson97 at ntlworld.com  Wed Nov 17 09:07:22 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 17 Nov 2010 08:07:22 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <4CE3623F.4010109@sonic.net>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net>
Message-ID: <97B1C155-688C-4302-950F-8B80269764B6@ntlworld.com>

Hi Dave,

> But what if the output of the hash created collisions?

The one I'm using doesn't for the specific set of inputs in this  
application.

> I suppose you could look for a different hash that was collision
> free, or you could let the collision occur, and then sort it
> out later.
>
> I guess I answered my own question.  :-p

Yep :)

Cheers,
Neil
--
http://www.njohnson.co.uk





From neil.johnson97 at ntlworld.com  Wed Nov 17 09:08:48 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 17 Nov 2010 08:08:48 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <a06200745c9091528e24c@[192.168.1.64]>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<E7E75B2F-317D-4E88-9D2A-170A533B41F6@electricdruid.net>
	<AANLkTikLtPpGr51U+sr0tFNssGP+V2VG6FK7SOouFTji@mail.gmail.com>
	<3BAD5A28-0A1F-492C-88CC-ABD31E42B9D9@electricdruid.net>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net> <a06200745c9091528e24c@[192.168.1.64]>
Message-ID: <C2FA1560-94A1-4BCA-8FCC-C00F42A8AFDF@ntlworld.com>

Hi Jason,

> another option might be a jumptable off (((byte - 0x80) >> 4) -  
> 0x8), with a further jumptable for the selector off 0xf0.
>
> first jumptable has 8 entries, the second has 16.

Well, yes you could, but that's more code and more processing, when  
you can do it with a single jumptable.  Note that the system realtime  
messages are treated separately to minimise the processing time.

> makes me less nervous than a hashtable, and faster too :-)

Are you sure?

Neil
--
http://www.njohnson.co.uk





From neil.johnson97 at ntlworld.com  Wed Nov 17 09:40:33 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 17 Nov 2010 08:40:33 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <201011170905.15460.Stromeko@nexgo.de>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net> <201011170905.15460.Stromeko@nexgo.de>
Message-ID: <C7D9382B-F142-4D6B-A669-8F5CD49D040E@ntlworld.com>

Hi Achim,

> What Neil uses there is called a "perfect hash".  By definition a  
> perfect
> hash doesn't create collisions.

Yes indeed.  One more step and it could be a minimal perfect hash,  
but the extra code would not be any smaller than the one unused table  
entry.  As it stands I think the current hash function is quite small  
and fast, so I'm happy with it.

Cheers,
Neil
--
http://www.njohnson.co.uk





From 21pointy at tpg.com.au  Wed Nov 17 09:58:37 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Wed, 17 Nov 2010 18:58:37 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
	<643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>
Message-ID: <BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>

More tests today -
the negative going triggers from the latch chips do indeed manage to  
trigger the 77s voices, but only very quietly and without accent.
Unfortunately, the positive CVs from the envelope generators are  
unsuitable as trigger sources - I discovered any rapid sequence of  
notes causes a slurring of the envelope, especially with accent, so  
not all notes are reliably converted to triggers.



regards
Adam Inglis
http://www.adambaby.com

On 16/11/2010, at 9:42 PM, Adam Inglis wrote:

> er.. I'm not yet actually up to the chapters on logic in  
> Horowitz&Hill, ha ha!!
>
> You're right - there are negative triggers to be found in the 707  
> (+5 to ground) going to the bases of each transistor in each  
> envelope generator. The Accent line is a positive CV line going to  
> all the collectors of these transistors, can't remember the levels,  
> prob around 5 volts (there are two levels of accent).
> Not sure - does that sound like something I could AND??
>
> On 16/11/2010, at 6:11 PM, cheater cheater wrote:
>
>
>> Hi Adam,
>> can't you use the trigger that goes into the 707's envelopes? I
>> believe there's a separate accent line (as far as I remember the
>> schematics). You can AND that with a separate copy of the trigger
>> lines, and add it to the original trigger lines. That's probably one
>> AND array, together with just some logic buffers or whatevers (I'm  
>> not
>> that great with digital logic hardware, just software!)
>>
>> Maybe you can use those directly in the 77 without any conversion.
>>
>> Cheers,
>> D.
>>
>> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au>  
>> wrote:
>>
>>
>>> Cheers - I was hoping to avoid building a negative rail, the 77  
>>> manages
>>> without one (The negative-edge detector circuits that make up the  
>>> matrix
>>> generate a brief negative pulse on the falling edge of the square  
>>> waves from
>>> the multivibrator counters).
>>>
>>> Hanging a common-emitter amp off the 24 volt rail to invert the  
>>> signal, and
>>> running this into a similar edge-detector seems to work, but  
>>> thats a lot of
>>> parts if I have to make one for every voice.
>>>
>>> regards
>>> Adam Inglis
>>> http://www.adambaby.com
>>>
>>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>>
>>>
>>>
>>>> I'm thinking a voltage regulator to get you your -7 volts.. and  
>>>> then a
>>>> transistor for each voice. use the 707 CV to trip the transistor
>>>> letting the -7 through?  Probably a current limiting resistor on  
>>>> each
>>>> one?
>>>>
>>>> Of course, this is how I design my own stuff... and sometimes it
>>>> works.  I really have no idea of the "correct" way to do things.
>>>>
>>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis  
>>>> <21pointy at tpg.com.au> wrote:
>>>>
>>>>
>>>>
>>>>> Hi All
>>>>>
>>>>> First post - long time lurker and learner here for many years.
>>>>> Self-taught
>>>>> in analogue audio electronics thanks to a studio full of old  
>>>>> "junk" from
>>>>> the
>>>>> 70s and 80s, an oscilloscope from the 60s, and the first few  
>>>>> chapters of
>>>>> Horowitz and Hill!
>>>>>
>>>>> Question: Someone here mentioned not too long ago the idea of  
>>>>> using the
>>>>> voice trigger signals in a Roland TR707 to trigger external  
>>>>> instruments.
>>>>> It
>>>>> got me thinking, as I love the interface of this drum machine -  
>>>>> quick and
>>>>> fun.
>>>>>  I would like to be able to trigger the voices in my old preset  
>>>>> Roland
>>>>> Rhythm TR77. This uses passive LC voice circuits, which respond  
>>>>> fairly
>>>>> dynamically to voltage triggers of between -3 to -10 volts.  
>>>>> Looking at
>>>>> the
>>>>> 707, I found the voice group's envelope generators supplied a  
>>>>> positive
>>>>> envelope CV of varying decay times and amplitudes (about 2-5  
>>>>> volts)
>>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>>> programmable ACCENT, and so would appear to be a good source of
>>>>> triggering.
>>>>>
>>>>> Any suggestions as to a simple, low-parts-count circuit I could  
>>>>> install
>>>>> (several iterations of) into the 77 that would convert the  
>>>>> positive CVs
>>>>> from
>>>>> the 707 into brief negative pulses for the 77s voices?
>>>>> I should mention there is 0 - 12 - 24 volts available in the 77  
>>>>> with just
>>>>> basic filtering, no voltage regulators, so I was assuming it  
>>>>> would need a
>>>>> transistor rather than a chip based solution.
>>>>>
>>>>> Anyone interested in my crude investigations into the workings  
>>>>> of the
>>>>> TR77
>>>>> can have a look here...
>>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> regards
>>>>> Adam Inglis
>>>>> http://www.adambaby.com
>>>>>
>>>>>
>>>>>


From tim.parkhurst at gmail.com  Wed Nov 17 10:33:55 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Wed, 17 Nov 2010 01:33:55 -0800
Subject: [sdiy] MFOS gets a nod from Jameco
Message-ID: <AANLkTimQX7F+5OUXzL7=MDhfm1WQ0tRFCVqv2CuRXUgZ@mail.gmail.com>

Don't know if this has been mentioned before, but I just saw this link
pop up in my latest news from Jameco. Congrats, Ray!

http://www.jameco.com/Jameco/PressRoom/mfosdesign.html?CID=bbNOVEMBER3223920&sp_rid=MTgzNDUwMzg1MTYS1&sp_mid=3223920


Tim (reminds me, I have to go there and pick up some stuff tomorrow) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From dixon at interchange.ubc.ca  Wed Nov 17 10:42:26 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Wed, 17 Nov 2010 01:42:26 -0800
Subject: [sdiy] MFOS gets a nod from Jameco
In-Reply-To: <AANLkTimQX7F+5OUXzL7=MDhfm1WQ0tRFCVqv2CuRXUgZ@mail.gmail.com>
References: <AANLkTimQX7F+5OUXzL7=MDhfm1WQ0tRFCVqv2CuRXUgZ@mail.gmail.com>
Message-ID: <9B22E16BCA23448F93DF9CE5F7A41C7E@galvanox01>

> Don't know if this has been mentioned before, but I just saw this link
> pop up in my latest news from Jameco. Congrats, Ray!
> 
> http://www.jameco.com/Jameco/PressRoom/mfosdesign.html?CID=bbNOVEMBER32239
> 20&sp_rid=MTgzNDUwMzg1MTYS1&sp_mid=3223920

Ray's definitely the man!  And if you think this is impressive, you oughta
check out his rendition of Debussy's "Prelude to the Afternoon of a Faun" as
realized on his Ultimate Synth Lab.



From tom at electricdruid.net  Wed Nov 17 11:01:15 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Wed, 17 Nov 2010 10:01:15 +0000
Subject: [sdiy] Oakley stuff
In-Reply-To: <4CE3871C.3080604@btinternet.com>
References: <4CE3871C.3080604@btinternet.com>
Message-ID: <88436014-5328-444E-9C25-B333172FE915@electricdruid.net>

Looks like a interesting mutant of the Polyfusion noise source coupled with a couple of simple VCFs based on the THAT 2180.

Not y'typical ramp vco ladder filter thingy, and all the better for it.

Nice work Tony.

Regards,
Tom

On 17 Nov 2010, at 07:41, Oakley Sound wrote:

> PCBs for the new version of my noise and filter module are now available.
> 
> More information at the usual spot:
> 
> http://www.oakleysound.com/noise.htm
> 
> Documentation should be ready at the end of the week.
> 
> Tony
> 
> http://www.oakleysound.com
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From neil.johnson97 at ntlworld.com  Wed Nov 17 11:57:26 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 17 Nov 2010 10:57:26 +0000
Subject: [sdiy] MIDI bytestream parser
In-Reply-To: <C7D9382B-F142-4D6B-A669-8F5CD49D040E@ntlworld.com>
References: <3DC3DC08-8D23-4D63-A411-4E775DED642B@ntlworld.com>
	<4AEFBDC0-2CD6-406D-9BD1-1300DB0C2098@ntlworld.com>
	<4CE3623F.4010109@sonic.net> <201011170905.15460.Stromeko@nexgo.de>
	<C7D9382B-F142-4D6B-A669-8F5CD49D040E@ntlworld.com>
Message-ID: <AANLkTimT0wxs5iEPb0ksahDL8iLPsA+A0J8RForO1zZh@mail.gmail.com>

Hi,

Oh, yeah, the software diagram I uploaded yesterday is a little bit
out of date, in that it was originally drawn for the 'pull' model.  So
the START section is now in miby_init(), and the "get next byte" box
becomes the entry point for the miby_parse(), and any edge looping
back to "get next byte" now exits the function.

Other than that the overall structure is pretty much correct.

http://miby.googlecode.com/svn/trunk/doc/midi%20flowchart.pdf

Oh, and I got rid of "insysex" by adding the IDLE state.  If I get
time this weekend I'll update it.

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From jim at antsclimbtree.com  Wed Nov 17 20:28:03 2010
From: jim at antsclimbtree.com (Jim Coursey)
Date: Wed, 17 Nov 2010 11:28:03 -0800
Subject: [sdiy] =?utf-8?q?Stripboard/tripad_OS-X_layout_software=3F?=
Message-ID: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>

Hi,

I'm trying my hand at stripboard and tripad layouts and I'm wondering if
anyone can recommend a free or cheap OSX layout tool.  I tried a javascript
tool, DIY Layout Creator, but it is really slow, and it lacks a tripad
layout option.

Does anyone have recommendations for a Mac-compatible tool?

One of my first projects is stripboarding Tim Servo's 8k LFO -- thanks in
advance Tim, this looks cool.

-Jim


From jays at aracnet.com  Thu Nov 18 04:29:08 2010
From: jays at aracnet.com (jays at aracnet.com)
Date: Wed, 17 Nov 2010 19:29:08 -0800
Subject: [sdiy] =?utf-8?q?Aluminum_Thickness_for_Brake/Shear=3F?=
In-Reply-To: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
References: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
Message-ID: <de7e78fed6e98c10106d00cc24b5bf14@localhost>

I'm looking into getting one of those small, metal brake/shears to make
L "trays" to mount PCBs and front panels together.

So I was wondering what thickness of aluminum people are using to do
this?

Don't want to get anything that can't handle the thickness I need.

Also if someone could recommend a bench top hand brake/shear that
wouldn't be bad either.

Thanks for the help.
Jay S


From davebr at earthlink.net  Thu Nov 18 05:34:10 2010
From: davebr at earthlink.net (David Brown)
Date: Wed, 17 Nov 2010 20:34:10 -0800
Subject: [sdiy] Aluminum Thickness for Brake/Shear?
In-Reply-To: <de7e78fed6e98c10106d00cc24b5bf14@localhost>
References: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
	<de7e78fed6e98c10106d00cc24b5bf14@localhost>
Message-ID: <20101118043353.E134010259@relay03.roch.ny.frontiernet.net>

I use 0.050" aluminum.  I forget the exact alloy but have it written 
down somewhere.  The metal brake is not the issue, it will be the 
shear.  I've done quite a bit of researching and have not found a 
small one that will handle 0.050".  You need the equivalent of 16 
gauge steel.  They all stop a bit short of that.

I've gone to air shears which will work well on that 
thickness.  Straight lines are reasonable for brackets, but they are 
not exact so I wouldn't use it for a piece that shows.  I made a jig 
to help me shear that is on my page.
http://modularsynthesis.com/modules/parts/parts.htm

I used to use the foot shear at work and greatly miss it.

For a brake, I settled on the Grizzly, but haven't bought it 
yet.  They have a couple small ones that are nice.  For now, I have 
two steel I beams that I simply clamp together with the piece 
in-between, and then just bend it down.

Dave



At 07:29 PM 11/17/2010, jays at aracnet.com wrote:
>I'm looking into getting one of those small, metal brake/shears to make
>L "trays" to mount PCBs and front panels together.
>
>So I was wondering what thickness of aluminum people are using to do
>this?
>
>Don't want to get anything that can't handle the thickness I need.
>
>Also if someone could recommend a bench top hand brake/shear that
>wouldn't be bad either.
>
>Thanks for the help.
>Jay S
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From gil_we at yahoo.com  Thu Nov 18 07:41:04 2010
From: gil_we at yahoo.com (Gil W.)
Date: Wed, 17 Nov 2010 22:41:04 -0800 (PST)
Subject: [sdiy] How to lube sticky sliders ?
Message-ID: <405909.90405.qm@web58008.mail.re3.yahoo.com>

In old synth usually you would come across sticky sliders. I know it is not very good to use contact cleaners as they can make things worse. How do you make them slide smoothly as before ? any special lubricant for this ?

Thanks !


      


From juzowen at googlemail.com  Thu Nov 18 10:02:47 2010
From: juzowen at googlemail.com (Justin Owen)
Date: Thu, 18 Nov 2010 09:02:47 +0000
Subject: [sdiy] Best kept secret of amazing electronics books
Message-ID: <4ce4ebbb.10d0e30a.7ed3.0928@mx.google.com>

-----Original Message-----
From: Paul Perry [pfperry at melbpc.org.au]
Received: 16.11.2010 04:37:45

http://www.national.com/rap/Book/0,1565,0,00.html
"Troubleshooting Analog Circuits".

Thanks Paul - I just picked up a copy of this from my fave 2nd hand book store.

Cheers,

Justin



From cheater00 at gmail.com  Thu Nov 18 10:38:41 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 18 Nov 2010 10:38:41 +0100
Subject: [sdiy] Best kept secret of amazing electronics books
In-Reply-To: <20101116134604.4c3fb31f@vz127.worldserver.net>
References: <BLU0-SMTP1253963D58FE4AC17079C54C8360@phx.gbl>
	<4CE1404E.5060403@pdp7.org>
	<AANLkTim+H-aqUwFB62zbTTm-bP=dvZoOLD6zCDzgX0-S@mail.gmail.com>
	<4CE1872F.3060104@pdp7.org>
	<AANLkTi=3ZRFsYxc4Yscd1QpNNu9HtYO4gwguzkpa9CgJ@mail.gmail.com>
	<059DBADA73F44CAB8E38EC4D0BD911E1@ownerf0d9273f5>
	<20101116134604.4c3fb31f@vz127.worldserver.net>
Message-ID: <AANLkTi=eEo5GaUFBu9DWr1CBpe4CwMmXyt4GNcvrcbus@mail.gmail.com>

Ah yes, great advice. This brings me to the problem that I don't
really know where to get 2nd hand technical books in Munich :( Even
though it's a university city as you say!

D.

On Tue, Nov 16, 2010 at 13:46, Florian E. Teply <usenet at teply.info> wrote:
> On Tue, 16 Nov 2010 13:45:18 +1100
> "Paul Perry" <pfperry at melbpc.org.au> wrote:
>
>> >Tietze/Schenk - Halbleiterschaltungstechnik. It's certainly not
>> >ideal,
>> > but it covers a lot of ground including the maths involved, signal
>> > transmission, basic control theory, etc. Dunno about the English
>> > translation
>>
>> I've read the English translation, and it is very good.
>> But, the book is pretty scarce and very expensive.
>> I don't think I will ever own a copy.
>>
> Especially the English edition is hard to come by and damn expensive
> (usually north of 250 USD). I've seen only one for less than 100 EUR
> right now, and thats apparently from a library.
> It's not that bad with the german edition, where you can easily get
> older editions for about 25 EUR. The new ones are still way expensive
> and out of reach for the average student, but apart from the
> computer-related stuff (which basically isn't in there nowadays) the
> basics don't change by much. That's why you usually can find an older
> edition for said 25 bucks, use it in your studies and sell it again for
> the same price if you're in a university city ;-)
>
> HTH,
> Florian
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From cheater00 at gmail.com  Thu Nov 18 10:55:33 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 18 Nov 2010 10:55:33 +0100
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
	<643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>
	<BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>
Message-ID: <AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>

Hi Adam,
no sweat, I didn't read anything on digital electronics other than a
few wikipedia articles and I basically understand what's going on.

My suggestion is to make a standard output from those 707 triggers, so
that they have a positive-going pulse, of adequate voltage (+5V). Then
make standard inputs on your 77. This is a bit more complicated but
having a set of standardized inputs and outputs on things you own is a
very good idea and you'll thank yourself later.

You can have two separate inputs for the two separate levels of
accent. Then you can use those somehow in your 77, which could have
two separate inputs as well. How to lay out the usage of the accent on
the panel is a fairly creative process and you can do a lot of
interesting things with it.

Cheers,
D.

On Wed, Nov 17, 2010 at 09:58, Adam Inglis <21pointy at tpg.com.au> wrote:
> More tests today -
> the negative going triggers from the latch chips do indeed manage to trigger
> the 77s voices, but only very quietly and without accent.
> Unfortunately, the positive CVs from the envelope generators are unsuitable
> as trigger sources - I discovered any rapid sequence of notes causes a
> slurring of the envelope, especially with accent, so not all notes are
> reliably converted to triggers.
>
>
>
> regards
> Adam Inglis
> http://www.adambaby.com
>
> On 16/11/2010, at 9:42 PM, Adam Inglis wrote:
>
>> er.. I'm not yet actually up to the chapters on logic in Horowitz&Hill, ha
>> ha!!
>>
>> You're right - there are negative triggers to be found in the 707 (+5 to
>> ground) going to the bases of each transistor in each envelope generator.
>> The Accent line is a positive CV line going to all the collectors of these
>> transistors, can't remember the levels, prob around 5 volts (there are two
>> levels of accent).
>> Not sure - does that sound like something I could AND??
>>
>> On 16/11/2010, at 6:11 PM, cheater cheater wrote:
>>
>>
>>> Hi Adam,
>>> can't you use the trigger that goes into the 707's envelopes? I
>>> believe there's a separate accent line (as far as I remember the
>>> schematics). You can AND that with a separate copy of the trigger
>>> lines, and add it to the original trigger lines. That's probably one
>>> AND array, together with just some logic buffers or whatevers (I'm not
>>> that great with digital logic hardware, just software!)
>>>
>>> Maybe you can use those directly in the 77 without any conversion.
>>>
>>> Cheers,
>>> D.
>>>
>>> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au> wrote:
>>>
>>>
>>>> Cheers - I was hoping to avoid building a negative rail, the 77 manages
>>>> without one (The negative-edge detector circuits that make up the matrix
>>>> generate a brief negative pulse on the falling edge of the square waves
>>>> from
>>>> the multivibrator counters).
>>>>
>>>> Hanging a common-emitter amp off the 24 volt rail to invert the signal,
>>>> and
>>>> running this into a similar edge-detector seems to work, but thats a lot
>>>> of
>>>> parts if I have to make one for every voice.
>>>>
>>>> regards
>>>> Adam Inglis
>>>> http://www.adambaby.com
>>>>
>>>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>>>
>>>>
>>>>
>>>>> I'm thinking a voltage regulator to get you your -7 volts.. and then a
>>>>> transistor for each voice. use the 707 CV to trip the transistor
>>>>> letting the -7 through? ?Probably a current limiting resistor on each
>>>>> one?
>>>>>
>>>>> Of course, this is how I design my own stuff... and sometimes it
>>>>> works. ?I really have no idea of the "correct" way to do things.
>>>>>
>>>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au>
>>>>> wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Hi All
>>>>>>
>>>>>> First post - long time lurker and learner here for many years.
>>>>>> Self-taught
>>>>>> in analogue audio electronics thanks to a studio full of old "junk"
>>>>>> from
>>>>>> the
>>>>>> 70s and 80s, an oscilloscope from the 60s, and the first few chapters
>>>>>> of
>>>>>> Horowitz and Hill!
>>>>>>
>>>>>> Question: Someone here mentioned not too long ago the idea of using
>>>>>> the
>>>>>> voice trigger signals in a Roland TR707 to trigger external
>>>>>> instruments.
>>>>>> It
>>>>>> got me thinking, as I love the interface of this drum machine - quick
>>>>>> and
>>>>>> fun.
>>>>>> ?I would like to be able to trigger the voices in my old preset Roland
>>>>>> Rhythm TR77. This uses passive LC voice circuits, which respond fairly
>>>>>> dynamically to voltage triggers of between -3 to -10 volts. Looking at
>>>>>> the
>>>>>> 707, I found the voice group's envelope generators supplied a positive
>>>>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>>>> programmable ACCENT, and so would appear to be a good source of
>>>>>> triggering.
>>>>>>
>>>>>> Any suggestions as to a simple, low-parts-count circuit I could
>>>>>> install
>>>>>> (several iterations of) into the 77 that would convert the positive
>>>>>> CVs
>>>>>> from
>>>>>> the 707 into brief negative pulses for the 77s voices?
>>>>>> I should mention there is 0 - 12 - 24 volts available in the 77 with
>>>>>> just
>>>>>> basic filtering, no voltage regulators, so I was assuming it would
>>>>>> need a
>>>>>> transistor rather than a chip based solution.
>>>>>>
>>>>>> Anyone interested in my crude investigations into the workings of the
>>>>>> TR77
>>>>>> can have a look here...
>>>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> regards
>>>>>> Adam Inglis
>>>>>> http://www.adambaby.com
>>>>>>
>>>>>>
>>>>>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From cheater00 at gmail.com  Thu Nov 18 11:20:45 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 18 Nov 2010 11:20:45 +0100
Subject: [sdiy] How to lube sticky sliders ?
In-Reply-To: <405909.90405.qm@web58008.mail.re3.yahoo.com>
References: <405909.90405.qm@web58008.mail.re3.yahoo.com>
Message-ID: <AANLkTimuYc01uLwLVN+ByvdoXC2=BTQ5VonAZF_X2TtW@mail.gmail.com>

Hi Gil,
wash it with water (just use the shower) until the grime stops coming
out, then dry it with a towel and blow-dry it immediately on cold.
Spray it with kontakt 60 (it's made for cleaning contacts), let it
work in for 24 hours, then clean it out with kontakt wl. right after
that wash it with water again and dry it out immediately like before.
let it rest for a day then spray kontakt 61 into it and let it work in
for 24 hours. then clean off the pins that you need to solder, and
you're ready to go.

Cheers,
D.

On Thu, Nov 18, 2010 at 07:41, Gil W. <gil_we at yahoo.com> wrote:
> In old synth usually you would come across sticky sliders. I know it is not very good to use contact cleaners as they can make things worse. How do you make them slide smoothly as before ? any special lubricant for this ?
>
> Thanks !
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From tom at electricdruid.net  Thu Nov 18 12:48:26 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Thu, 18 Nov 2010 11:48:26 +0000
Subject: [sdiy] Stripboard/tripad OS-X layout software?
In-Reply-To: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
References: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
Message-ID: <A5C79036-ED94-4316-851E-7775ED8619AB@electricdruid.net>

Hi Jim,

I'm not sure how good it'd be for stripboard, but I've been using Diptrace schematic and layout software for several years now and I'd recommend it highly.
It's way more modern-feeling and logically arranged compared to something like Eagle, which is just painful to use, IMHO.

Whilst it's not expensive compared to others (Orcad! Yikes!), they also have a free version with some limits, and have recently introduced a Mac OS X version.

Have a look and see what you think.

http://www.diptrace.com

HTH,
Tom

On 17 Nov 2010, at 19:28, Jim Coursey wrote:

> Hi,
> 
> I'm trying my hand at stripboard and tripad layouts and I'm wondering if
> anyone can recommend a free or cheap OSX layout tool.  I tried a javascript
> tool, DIY Layout Creator, but it is really slow, and it lacks a tripad
> layout option.
> 
> Does anyone have recommendations for a Mac-compatible tool?
> 
> One of my first projects is stripboarding Tim Servo's 8k LFO -- thanks in
> advance Tim, this looks cool.
> 
> -Jim
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Thu Nov 18 14:16:09 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 18 Nov 2010 14:16:09 +0100
Subject: [sdiy] Lots of tube books etc - public domain
Message-ID: <AANLkTimWocGz6AYJ+UNdLwNUuQjDaFqOXisVtq0YtdEH@mail.gmail.com>

Hi guys,
I have been looking for Zucconi's book "Probes" (about, yes, test
probes) and I have chanced upon this link:
http://www.pmillett.com/tubebooks/

According to the owner of the page, all those books are not copyrighted anymore.

Here's a list of contents:
* NEW 8/1/10 - Technical books -  Full image scans of old technical
books related to tube audio, radio, and pre-silicon electrical
engineering and technology
* NEW 8/1/10 - Vintage audio info and articles - Everything but books:
magazine articles, schematics, catalogs, brochures...
* McIntosh service data - Schematics and other service data for
classic McIntosh products
* Transformer data and schematics from Tango, UTC, Thordarson,
Acrosound, Chicago...
* NEW 8/1/10 - Tube Data, including some data from RCA, Western
Electric, GE, Tung-Sol, etc.
* RCA HB-3 Tube Data Manual
* 1951 and 1959 Sylvania tube manual

I must say I'm impressed. All available for free. The guy has done a great job!

Hope you guys enjoy it as much as I do

Cheers,
D.


From synth1 at airmail.net  Thu Nov 18 15:55:22 2010
From: synth1 at airmail.net (Paul Schreiber)
Date: Thu, 18 Nov 2010 08:55:22 -0600
Subject: [sdiy] E560 Deflector Shield: Come to NAMM
Message-ID: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>

http://www.youtube.com/watch?v=atBmDOAHBEw

Paul S.


From marr at lumin.us  Thu Nov 18 16:02:50 2010
From: marr at lumin.us (Mark Rivera)
Date: Thu, 18 Nov 2010 09:02:50 -0600
Subject: [sdiy] E560 Deflector Shield: Come to NAMM
In-Reply-To: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
References: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
Message-ID: <AANLkTims4SHcCydAOJGqe7_=JTqW-exVW3Z19SHhWuH3@mail.gmail.com>

academy award.

On Thu, Nov 18, 2010 at 8:55 AM, Paul Schreiber <synth1 at airmail.net> wrote:
> http://www.youtube.com/watch?v=atBmDOAHBEw
>
> Paul S.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From senso at vintageplanet.nl  Thu Nov 18 16:33:40 2010
From: senso at vintageplanet.nl (Senso)
Date: Thu, 18 Nov 2010 16:33:40 +0100
Subject: [sdiy] E560 Deflector Shield: Come to NAMM
In-Reply-To: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
References: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
Message-ID: <a06240800c90af74e85cf@[192.168.254.1]>

Best ad in decades of synth promo. :-)

Senso (still smiling)


>http://www.youtube.com/watch?v=atBmDOAHBEw
>
>Paul S.

-- 
----------------------------------------------
---------- VINTAGE PLANET ---------
----- Synthesizer Parts Service -----
---- http://www.vintageplanet.nl ----
----------------------------------------------


From subjectivity at hotmail.com  Thu Nov 18 17:28:53 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Thu, 18 Nov 2010 11:28:53 -0500
Subject: [sdiy] portable X/Y scope?
Message-ID: <BLU0-SMTP110F0F568B0D10AA0BA510AC8390@phx.gbl>

anyone know of a DUAL trace (X/Y capable) mini-scope that could be used to put inside a Module or for a portable box? I'd love to be able to have a portable instrument that had X/Y scope capabilities.

is there an LCD kit or anything out there?

thanks




From djservs at comcast.net  Thu Nov 18 18:37:17 2010
From: djservs at comcast.net (Nathan M. Reeves)
Date: Thu, 18 Nov 2010 12:37:17 -0500
Subject: [sdiy] mackie onyx service notes
Message-ID: <00CF7038-36D1-4850-8104-48C3BCAAFD8D@comcast.net>

any one have these?

  i have an onyx 16 channel power with a messed up P/S...

I guess i can just use the manual schematics but i thought i would try to see if there was any service information available...

cheers,

nathan



From dingebre at 3dphysics.net  Thu Nov 18 18:44:15 2010
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Thu, 18 Nov 2010 10:44:15 -0700
Subject: [sdiy] portable X/Y scope?
In-Reply-To: <BLU0-SMTP110F0F568B0D10AA0BA510AC8390@phx.gbl>
References: <BLU0-SMTP110F0F568B0D10AA0BA510AC8390@phx.gbl>
Message-ID: <001e01cb8748$37ef0f00$a7cd2d00$@net>

www.gabotronics.com


~~ -----Original Message-----
~~ From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
~~ bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
~~ Sent: Thursday, November 18, 2010 9:29 AM
~~ To: synth-diy DIY
~~ Subject: [sdiy] portable X/Y scope?
~~ 
~~ anyone know of a DUAL trace (X/Y capable) mini-scope that could be used
to
~~ put inside a Module or for a portable box? I'd love to be able to have a
~~ portable instrument that had X/Y scope capabilities.
~~ 
~~ is there an LCD kit or anything out there?
~~ 
~~ thanks
~~ 
~~ 
~~ _______________________________________________
~~ Synth-diy mailing list
~~ Synth-diy at dropmix.xs4all.nl
~~ http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From tim.parkhurst at gmail.com  Thu Nov 18 20:18:57 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Thu, 18 Nov 2010 11:18:57 -0800
Subject: [sdiy] E560 Deflector Shield: Come to NAMM
In-Reply-To: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
References: <6BA7B58E1F464FE5BF43BCAEB97E0BFD@optiplex>
Message-ID: <AANLkTike6ErZC5tQ7JZnhsSHpLRCgo9JKqSmKfAiV+Lo@mail.gmail.com>

Now THAT is freaking hilarious. Nice work, Paul.

I think people would like the names of your modules more if you put a
lower case "i" at the beginning. "iDeflector Shield" is much cooler.

Tim (iDiot) Servo



On Thu, Nov 18, 2010 at 6:55 AM, Paul Schreiber <synth1 at airmail.net> wrote:
> http://www.youtube.com/watch?v=atBmDOAHBEw
>
> Paul S.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From tim.parkhurst at gmail.com  Thu Nov 18 20:56:12 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Thu, 18 Nov 2010 11:56:12 -0800
Subject: [sdiy] Stripboard/tripad OS-X layout software?
In-Reply-To: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
References: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
Message-ID: <AANLkTinKm7t4PyacZYMU3crM3oLtLkA_LZwOjAd3O1T-@mail.gmail.com>

On Wed, Nov 17, 2010 at 11:28 AM, Jim Coursey <jim at antsclimbtree.com> wrote:
> Hi,
>
> I'm trying my hand at stripboard and tripad layouts and I'm wondering if
> anyone can recommend a free or cheap OSX layout tool. ?I tried a javascript
> tool, DIY Layout Creator, but it is really slow, and it lacks a tripad
> layout option.
>
> Does anyone have recommendations for a Mac-compatible tool?
>
> One of my first projects is stripboarding Tim Servo's 8k LFO -- thanks in
> advance Tim, this looks cool.
>
> -Jim
>

Hey Jim,

Thanks. I get a lot of use out of my 8k LFOs. The basic circuit is
very simple, so that's a good one to start with. Later on, you might
try the TSQ (Triangle to Square) and TSW (Triangle to Saw)
waveshapers. I've got another waveshaper that's just a combo of parts
of the TSQ and TSW, but it gives all sorts of non-standard (but fun)
waves. I'll have to post that soon. Hopefully you can find some good
layout software for your Mac.

Tim (mmm, wavey) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From music.maker at gte.net  Thu Nov 18 21:03:01 2010
From: music.maker at gte.net (Scott Gravenhorst)
Date: Thu, 18 Nov 2010 13:03:01 -0700
Subject: [sdiy] varactor/varicaps?
Message-ID: <201011182103.oAIL31ke025228@linux7.lan>

<lanterma at ece.gatech.edu> wrote:
>They're kind of useless for audio - there's not enough variation  
>available. They're really for radio frequencies.

Yes, years ago I'd seen one used in a Popular Electronics FM transmitter project
where the diode was used to modulate an RF oscillator.

>I had a student try to build a filter with them once, no success at  
>all. Rapidly switched to another project.
>
>Sent from my iPhone
>
>On Nov 18, 2010, at 3:40 PM, "dan snazelle" <subjectivity at hotmail.com>  
>wrote:
>
>> anybody know much about varicaps? they sound too good to be  
>> true...voltage variable capacitance up to 200pf?
>>
>>
>> of course a lot of them come in weird form-factors (sot-23,etc)
>>
>> anyway, wondered why i never see them in any projects.
>>
>> thanks
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.



From stewpye at optusnet.com.au  Thu Nov 18 21:03:53 2010
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Fri, 19 Nov 2010 06:03:53 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>	<643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>	<BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>
	<AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>
Message-ID: <4CE586A9.8000608@optusnet.com.au>

I agree that it would be more versatile to have positive going triggers 
coming out of the TR707, however I'd replicate ENV GEN circuit for each 
voice but leave out the decay capacitor. I think I'll layout a PCB to do 
this for my 707. It's only 2 x LM324, 8 transistors and 16 resistors.

Also, there's more than 2 levels of accent. 64 I think, but most are 
only accessed via MIDI.

Cheers,
Stew.

cheater cheater wrote:
> Hi Adam,
> no sweat, I didn't read anything on digital electronics other than a
> few wikipedia articles and I basically understand what's going on.
>
> My suggestion is to make a standard output from those 707 triggers, so
> that they have a positive-going pulse, of adequate voltage (+5V). Then
> make standard inputs on your 77. This is a bit more complicated but
> having a set of standardized inputs and outputs on things you own is a
> very good idea and you'll thank yourself later.
>
> You can have two separate inputs for the two separate levels of
> accent. Then you can use those somehow in your 77, which could have
> two separate inputs as well. How to lay out the usage of the accent on
> the panel is a fairly creative process and you can do a lot of
> interesting things with it.
>
> Cheers,
> D.
>
> On Wed, Nov 17, 2010 at 09:58, Adam Inglis <21pointy at tpg.com.au> wrote:
>   
>> More tests today -
>> the negative going triggers from the latch chips do indeed manage to trigger
>> the 77s voices, but only very quietly and without accent.
>> Unfortunately, the positive CVs from the envelope generators are unsuitable
>> as trigger sources - I discovered any rapid sequence of notes causes a
>> slurring of the envelope, especially with accent, so not all notes are
>> reliably converted to triggers.
>>
>>
>>
>> regards
>> Adam Inglis
>> http://www.adambaby.com
>>
>> On 16/11/2010, at 9:42 PM, Adam Inglis wrote:
>>
>>     
>>> er.. I'm not yet actually up to the chapters on logic in Horowitz&Hill, ha
>>> ha!!
>>>
>>> You're right - there are negative triggers to be found in the 707 (+5 to
>>> ground) going to the bases of each transistor in each envelope generator.
>>> The Accent line is a positive CV line going to all the collectors of these
>>> transistors, can't remember the levels, prob around 5 volts (there are two
>>> levels of accent).
>>> Not sure - does that sound like something I could AND??
>>>
>>> On 16/11/2010, at 6:11 PM, cheater cheater wrote:
>>>
>>>
>>>       
>>>> Hi Adam,
>>>> can't you use the trigger that goes into the 707's envelopes? I
>>>> believe there's a separate accent line (as far as I remember the
>>>> schematics). You can AND that with a separate copy of the trigger
>>>> lines, and add it to the original trigger lines. That's probably one
>>>> AND array, together with just some logic buffers or whatevers (I'm not
>>>> that great with digital logic hardware, just software!)
>>>>
>>>> Maybe you can use those directly in the 77 without any conversion.
>>>>
>>>> Cheers,
>>>> D.
>>>>
>>>> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au> wrote:
>>>>
>>>>
>>>>         
>>>>> Cheers - I was hoping to avoid building a negative rail, the 77 manages
>>>>> without one (The negative-edge detector circuits that make up the matrix
>>>>> generate a brief negative pulse on the falling edge of the square waves
>>>>> from
>>>>> the multivibrator counters).
>>>>>
>>>>> Hanging a common-emitter amp off the 24 volt rail to invert the signal,
>>>>> and
>>>>> running this into a similar edge-detector seems to work, but thats a lot
>>>>> of
>>>>> parts if I have to make one for every voice.
>>>>>
>>>>> regards
>>>>> Adam Inglis
>>>>> http://www.adambaby.com
>>>>>
>>>>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>>>>
>>>>>
>>>>>
>>>>>           
>>>>>> I'm thinking a voltage regulator to get you your -7 volts.. and then a
>>>>>> transistor for each voice. use the 707 CV to trip the transistor
>>>>>> letting the -7 through?  Probably a current limiting resistor on each
>>>>>> one?
>>>>>>
>>>>>> Of course, this is how I design my own stuff... and sometimes it
>>>>>> works.  I really have no idea of the "correct" way to do things.
>>>>>>
>>>>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au>
>>>>>> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>             
>>>>>>> Hi All
>>>>>>>
>>>>>>> First post - long time lurker and learner here for many years.
>>>>>>> Self-taught
>>>>>>> in analogue audio electronics thanks to a studio full of old "junk"
>>>>>>> from
>>>>>>> the
>>>>>>> 70s and 80s, an oscilloscope from the 60s, and the first few chapters
>>>>>>> of
>>>>>>> Horowitz and Hill!
>>>>>>>
>>>>>>> Question: Someone here mentioned not too long ago the idea of using
>>>>>>> the
>>>>>>> voice trigger signals in a Roland TR707 to trigger external
>>>>>>> instruments.
>>>>>>> It
>>>>>>> got me thinking, as I love the interface of this drum machine - quick
>>>>>>> and
>>>>>>> fun.
>>>>>>>  I would like to be able to trigger the voices in my old preset Roland
>>>>>>> Rhythm TR77. This uses passive LC voice circuits, which respond fairly
>>>>>>> dynamically to voltage triggers of between -3 to -10 volts. Looking at
>>>>>>> the
>>>>>>> 707, I found the voice group's envelope generators supplied a positive
>>>>>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>>>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>>>>> programmable ACCENT, and so would appear to be a good source of
>>>>>>> triggering.
>>>>>>>
>>>>>>> Any suggestions as to a simple, low-parts-count circuit I could
>>>>>>> install
>>>>>>> (several iterations of) into the 77 that would convert the positive
>>>>>>> CVs
>>>>>>> from
>>>>>>> the 707 into brief negative pulses for the 77s voices?
>>>>>>> I should mention there is 0 - 12 - 24 volts available in the 77 with
>>>>>>> just
>>>>>>> basic filtering, no voltage regulators, so I was assuming it would
>>>>>>> need a
>>>>>>> transistor rather than a chip based solution.
>>>>>>>
>>>>>>> Anyone interested in my crude investigations into the workings of the
>>>>>>> TR77
>>>>>>> can have a look here...
>>>>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> regards
>>>>>>> Adam Inglis
>>>>>>> http://www.adambaby.com
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>               
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>     
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
>   



From subjectivity at hotmail.com  Thu Nov 18 21:40:10 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Thu, 18 Nov 2010 15:40:10 -0500
Subject: [sdiy] varactor/varicaps?
Message-ID: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>

anybody know much about varicaps? they sound too good to be true...voltage variable capacitance up to 200pf?


of course a lot of them come in weird form-factors (sot-23,etc)

anyway, wondered why i never see them in any projects.

thanks





From lanterma at ece.gatech.edu  Thu Nov 18 21:56:03 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Thu, 18 Nov 2010 20:56:03 +0000
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
Message-ID: <C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>

They're kind of useless for audio - there's not enough variation  
available. They're really for radio frequencies.

I had a student try to build a filter with them once, no success at  
all. Rapidly switched to another project.

Sent from my iPhone

On Nov 18, 2010, at 3:40 PM, "dan snazelle" <subjectivity at hotmail.com>  
wrote:

> anybody know much about varicaps? they sound too good to be  
> true...voltage variable capacitance up to 200pf?
>
>
> of course a lot of them come in weird form-factors (sot-23,etc)
>
> anyway, wondered why i never see them in any projects.
>
> thanks
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From louis at dompselaar.org  Thu Nov 18 22:02:31 2010
From: louis at dompselaar.org (Louis van Dompselaar)
Date: Thu, 18 Nov 2010 22:02:31 +0100
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
	<C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>
Message-ID: <B6A37180-6D2E-4FD0-9497-D7C70FA1EF3A@dompselaar.org>

> The only time I have actually seen one used is in the clock circuit of an Elektor BBD delay, where it was controlled by an LFO. 


> 
> 
> Op 18 nov. 2010 om 21:56 heeft <lanterma at ece.gatech.edu> het volgende geschreven:
> 
>> They're kind of useless for audio - there's not enough variation  
>> available. They're really for radio frequencies.
>> 
>> I had a student try to build a filter with them once, no success at  
>> all. Rapidly switched to another project.


From synth at willacy.co.uk  Thu Nov 18 22:08:07 2010
From: synth at willacy.co.uk (Steve Carter)
Date: Thu, 18 Nov 2010 21:08:07 +0000
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
Message-ID: <67022179-E5A7-459A-9CB5-3425818F3720@willacy.co.uk>

They were used a lot in 70s/80s TV sets for voltage controlled push button tuning. These were smaller values being for VHF and UHF use. There is a 500pf Varicap intended for AM bands which is the BB112 - it comes in a TO92 type package.  I've often wondered too whether these can be put to synth use, maybe even used in a capacitance multiplier configuration to become useful in the audio range. 

Steve 

On 18 Nov 2010, at 20:40, dan snazelle wrote:

> anybody know much about varicaps? they sound too good to be true...voltage variable capacitance up to 200pf?
> 
> 
> of course a lot of them come in weird form-factors (sot-23,etc)
> 
> anyway, wondered why i never see them in any projects.
> 
> thanks
> 



From rdrake at data2action.com  Thu Nov 18 22:29:59 2010
From: rdrake at data2action.com (bbob)
Date: Thu, 18 Nov 2010 16:29:59 -0500
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
	<C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>
Message-ID: <AANLkTikC-AKVUEdc4TWbY+SEG=0bUosk3LwdKOY+Yruk@mail.gmail.com>

I did a VC radio, based on a Ramsey kit that used a varactor in the
tuning circuit.  worked, but not as useful as i'd hoped...



On Thu, Nov 18, 2010 at 3:56 PM,  <lanterma at ece.gatech.edu> wrote:
> They're kind of useless for audio - there's not enough variation
> available. They're really for radio frequencies.
>
> I had a student try to build a filter with them once, no success at
> all. Rapidly switched to another project.
>
> Sent from my iPhone
>
> On Nov 18, 2010, at 3:40 PM, "dan snazelle" <subjectivity at hotmail.com>
> wrote:
>
>> anybody know much about varicaps? they sound too good to be
>> true...voltage variable capacitance up to 200pf?
>>
>>
>> of course a lot of them come in weird form-factors (sot-23,etc)
>>
>> anyway, wondered why i never see them in any projects.
>>
>> thanks
>>
>>
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From dixon at interchange.ubc.ca  Thu Nov 18 23:00:02 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Thu, 18 Nov 2010 14:00:02 -0800
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>
Message-ID: <667CF26DD07947468A68365EFA6B359E@galvanox01>

> anybody know much about varicaps? they sound too good to be true...voltage
> variable capacitance up to 200pf?

Well, the value is right, because I use 205pF silvered mica caps in all of
my own filter designs.

However, the big problem I can see right off the bat is that this would give
linear control of filter cutoff, when what you really want is exponential
control.  It might be an interesting way to introduce linear FM to a filter,
but probably not worth it.



From obl64 at ix.netcom.com  Thu Nov 18 23:21:13 2010
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Thu, 18 Nov 2010 16:21:13 -0600
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <AANLkTikC-AKVUEdc4TWbY+SEG=0bUosk3LwdKOY+Yruk@mail.gmail.com>
References: <BLU0-SMTP1368EA3CB940F01356BDA70C8390@phx.gbl>	<C5703226-0960-4C09-BEF6-13BFEEC7D368@ece.gatech.edu>
	<AANLkTikC-AKVUEdc4TWbY+SEG=0bUosk3LwdKOY+Yruk@mail.gmail.com>
Message-ID: <4CE5A6D9.7050104@ix.netcom.com>



On 11/18/2010 3:29 PM, bbob wrote:
> I did a VC radio, based on a Ramsey kit that used a varactor in the
> tuning circuit.  worked, but not as useful as i'd hoped...
>
>
>

Musical application-wise, a varactor would work very well in a master 
oscillator for a top-octave generator or other 
divide-down/beat-frequency designs, although the voltage control range 
isn't very wide.
There is enough voltage-control for adjusting the tuning over several 
semitones and easily adding vibrato.
The master oscillator in the Eminent/Arp Solina (and probably the 
Eminent 310U) uses a varactor diode.

- Oren

> On Thu, Nov 18, 2010 at 3:56 PM,<lanterma at ece.gatech.edu>  wrote:
>> They're kind of useless for audio - there's not enough variation
>> available. They're really for radio frequencies.
>>
>> I had a student try to build a filter with them once, no success at
>> all. Rapidly switched to another project.
>>
>> Sent from my iPhone
>>
>> On Nov 18, 2010, at 3:40 PM, "dan snazelle"<subjectivity at hotmail.com>
>> wrote:
>>
>>> anybody know much about varicaps? they sound too good to be
>>> true...voltage variable capacitance up to 200pf?
>>>
>>>
>>> of course a lot of them come in weird form-factors (sot-23,etc)
>>>
>>> anyway, wondered why i never see them in any projects.
>>>
>>> thanks
>>>
>>>
>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From thx1138 at earthlink.net  Fri Nov 19 01:18:10 2010
From: thx1138 at earthlink.net (thx1138)
Date: Thu, 18 Nov 2010 16:18:10 -0800
Subject: [sdiy] Kinetis discount code for 50% discount
In-Reply-To: <4CE548CD.3020106@cox.net>
Message-ID: <C90B0242.213DB%thx1138@earthlink.net>



On 11/18/2010 05:34 AM, Shultz Terry-RVHA50 wrote:
> Hi Guys,
>
> I have a discount card you can use for the Kinetis platform.
>
> http://www.Freescale.com/TWR-K40X256
>
> http://www.Freescale.com/TWR-K60N512
>
> Promo Code: KING7JRE   Limit 1 per customer
>
> So basically the entire kit is $139.00 ? 50% discount. = $69.00
>
> Also check out http://www.TowerGeeks.org for more stuff related to the
> Tower platform.
>
> Best regards,
>
> Terry Shultz
>
> Freescale Inc.



From cheater00 at gmail.com  Fri Nov 19 13:58:51 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Fri, 19 Nov 2010 13:58:51 +0100
Subject: [sdiy] Kinetis discount code for 50% discount
In-Reply-To: <C90B0242.213DB%thx1138@earthlink.net>
References: <4CE548CD.3020106@cox.net> <C90B0242.213DB%thx1138@earthlink.net>
Message-ID: <AANLkTimk0YecADbc6YhK9Vh7aK3hfOkTm1sNrg65FHhJ@mail.gmail.com>

Thanks, Terry!

On Fri, Nov 19, 2010 at 01:18, thx1138 <thx1138 at earthlink.net> wrote:
>
>
> On 11/18/2010 05:34 AM, Shultz Terry-RVHA50 wrote:
>> Hi Guys,
>>
>> I have a discount card you can use for the Kinetis platform.
>>
>> http://www.Freescale.com/TWR-K40X256
>>
>> http://www.Freescale.com/TWR-K60N512
>>
>> Promo Code: KING7JRE ? Limit 1 per customer
>>
>> So basically the entire kit is $139.00 ? 50% discount. = $69.00
>>
>> Also check out http://www.TowerGeeks.org for more stuff related to the
>> Tower platform.
>>
>> Best regards,
>>
>> Terry Shultz
>>
>> Freescale Inc.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From harrybissell at wowway.com  Fri Nov 19 14:46:56 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 19 Nov 2010 08:46:56 -0500 (EST)
Subject: [sdiy] varactor/varicaps?
In-Reply-To: <667CF26DD07947468A68365EFA6B359E@galvanox01>
Message-ID: <306496984.514102.1290174416158.JavaMail.root@md01.wow.synacor.com>

seems that such a filter would have problems with CV feed-through
(like so many other diode-like technologies) unless you were willing
to make some form of balanced circuit.  Their limited range is
uhhhh.... "limited"   :^P

H^) harry



----- Original Message -----
From: David G. Dixon <dixon at interchange.ubc.ca>
To: 'dan snazelle' <subjectivity at hotmail.com>, 'synth-diy DIY' <synth-diy at dropmix.xs4all.nl>
Sent: Thu, 18 Nov 2010 17:00:02 -0500 (EST)
Subject: Re: [sdiy] varactor/varicaps?

> anybody know much about varicaps? they sound too good to be true...voltage
> variable capacitance up to 200pf?

Well, the value is right, because I use 205pF silvered mica caps in all of
my own filter designs.

However, the big problem I can see right off the bat is that this would give
linear control of filter cutoff, when what you really want is exponential
control.  It might be an interesting way to introduce linear FM to a filter,
but probably not worth it.

_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From subjectivity at hotmail.com  Fri Nov 19 17:02:04 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Fri, 19 Nov 2010 11:02:04 -0500
Subject: [sdiy] simple transistor buffers?
Message-ID: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>

So i am working on a circuit where there are a bunch of outputs. to save space/opamps I decided it would be nice to use transistor buffers (emitter followers)

however when i switched to what i THOUGHT was a usable buffer, the output gain (versus opamp followers) dropped drastically.

let me see if i understand this properly. ( i dont think i do)

if i want to buffer an lfo that is running between + and - 12 volts, I was putting the oscillator wave through a 1k resistor into BASE. I was then putting the collector to +v. What confuses me is what to do with the emitter other than
this is where i take the output and a resistor to ground or -v should connect here.

I am not sure if i should put emitter to GROUND or to -v through say a 10k resistor.


Also, do I need to put a cap before the input to the base?


any help and or links to schematics for reference highly appreciated




thanks!





From harrybissell at wowway.com  Fri Nov 19 17:08:26 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Fri, 19 Nov 2010 11:08:26 -0500 (EST)
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
Message-ID: <504213633.518299.1290182906292.JavaMail.root@md01.wow.synacor.com>

emitter follower always has about a .7V drop at the emitter
(the b-e drop).  Its good for increasing current but does not
preserve voltage levels.

Some J-fet followers do a bit better than this...

The op-amp follower is the standard if you need precise voltages.



----- Original Message -----
From: dan snazelle <subjectivity at hotmail.com>
To: synth-diy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Fri, 19 Nov 2010 11:02:04 -0500 (EST)
Subject: [sdiy] simple transistor buffers?

So i am working on a circuit where there are a bunch of outputs. to save space/opamps I decided it would be nice to use transistor buffers (emitter followers)

however when i switched to what i THOUGHT was a usable buffer, the output gain (versus opamp followers) dropped drastically.

let me see if i understand this properly. ( i dont think i do)

if i want to buffer an lfo that is running between + and - 12 volts, I was putting the oscillator wave through a 1k resistor into BASE. I was then putting the collector to +v. What confuses me is what to do with the emitter other than
this is where i take the output and a resistor to ground or -v should connect here.

I am not sure if i should put emitter to GROUND or to -v through say a 10k resistor.


Also, do I need to put a cap before the input to the base?


any help and or links to schematics for reference highly appreciated




thanks!



_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From John.Speth at coherent.com  Fri Nov 19 17:40:38 2010
From: John.Speth at coherent.com (Speth, John)
Date: Fri, 19 Nov 2010 08:40:38 -0800
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <504213633.518299.1290182906292.JavaMail.root@md01.wow.synacor.com>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<504213633.518299.1290182906292.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AB7F62BBA358E04FA919701B9703184AF2918154@DC1EXC2.na.coherentinc.com>

To continue Harry's thoughts,

When the tranny is configured as an emitter follower, the emitter will always be .7V less than the base voltage.  The BE junction must always be forward biased or the emitter voltage ceases to "follow" the input.  The base resistor limits the current through the junction.  The ensure the junction is always forward biased even with negative input voltages, you should connect the emitter to -v through a resistor.  The exact resistor values will depend on the transistor you pick and your supply and input voltages.  I've found typical trannies will give you a wide leeway on resistor values for audio frequencies.

If you AC couple the input, I think you'll need to bias the base voltage so that it won't float off to one of the rails (not sure which one).  There's not much point to AC coupling the input without AC coupling the output unless you find the DC offset on the output desirable.

The key to remember is that the transistor must be properly biased (operate within the "linear" region) all the time when it functions as an amplifier.

If I were you, I'd go with a FET and not a BJT.  I think an FET is a little simpler to apply.

John Speth
Coherent Molectron
mailto:john.speth at coherent.com


> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
> bounces at dropmix.xs4all.nl] On Behalf Of Harry Bissell
> Sent: Friday, November 19, 2010 8:08 AM
> To: dan snazelle
> Cc: synth-diy DIY
> Subject: Re: [sdiy] simple transistor buffers?
>
> emitter follower always has about a .7V drop at the emitter
> (the b-e drop).  Its good for increasing current but does not
> preserve voltage levels.
>
> Some J-fet followers do a bit better than this...
>
> The op-amp follower is the standard if you need precise voltages.
>
>
>
> ----- Original Message -----
> From: dan snazelle <subjectivity at hotmail.com>
> To: synth-diy DIY <synth-diy at dropmix.xs4all.nl>
> Sent: Fri, 19 Nov 2010 11:02:04 -0500 (EST)
> Subject: [sdiy] simple transistor buffers?
>
> So i am working on a circuit where there are a bunch of outputs.
> to save space/opamps I decided it would be nice to use transistor
> buffers (emitter followers)
>
> however when i switched to what i THOUGHT was a usable buffer, the
> output gain (versus opamp followers) dropped drastically.
>
> let me see if i understand this properly. ( i dont think i do)
>
> if i want to buffer an lfo that is running between + and - 12
> volts, I was putting the oscillator wave through a 1k resistor
> into BASE. I was then putting the collector to +v. What confuses
> me is what to do with the emitter other than
> this is where i take the output and a resistor to ground or -v
> should connect here.
>
> I am not sure if i should put emitter to GROUND or to -v through
> say a 10k resistor.
>
>
> Also, do I need to put a cap before the input to the base?
>
>
> any help and or links to schematics for reference highly
> appreciated
>
>
>
>
> thanks!
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

The information contained in this communication is confidential and may be legally privileged. It is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. If you are not the intended recipient you are hereby (a) notified that any disclosure, copying, distribution or taking any action with respect to the content of this information is strictly prohibited and may be unlawful, and (b) kindly requested to inform the sender immediately and delete any copies. Coherent is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.


From dixon at interchange.ubc.ca  Fri Nov 19 18:37:02 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Fri, 19 Nov 2010 09:37:02 -0800
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
Message-ID: <97676A73CC424D4794425C9C6E30B080@galvanox01>

> So i am working on a circuit where there are a bunch of outputs. to save
> space/opamps I decided it would be nice to use transistor buffers (emitter
> followers)

If they are precision CV outputs, then opamp followers are really the only
defensible option.  For audio circuits emanating from opamps (provided they
are not coming from a circuit which has compromised the normally very low
output impedance of the opamp, e.g. an ideal diode or rectifier, etc), the
output is already buffered.

> however when i switched to what i THOUGHT was a usable buffer, the output
> gain (versus opamp followers) dropped drastically.
> 
> let me see if i understand this properly. ( i dont think i do)
> 
> if i want to buffer an lfo that is running between + and - 12 volts, I was
> putting the oscillator wave through a 1k resistor into BASE. I was then
> putting the collector to +v. What confuses me is what to do with the
> emitter other than
> this is where i take the output and a resistor to ground or -v should
> connect here.
> 
> I am not sure if i should put emitter to GROUND or to -v through say a 10k
> resistor.

The emitter follower output will only go as low as whatever is connected to
the emitter resistor.  Hence, if you ground the emitter, then follower
output will not go below 0V.  This is because the transistor (presuming it
is NPN) can only source current, so the voltage at the emitter must always
be higher than whatever is connected on the other side of the emitter
resistor.  If you want the emitter follower to give output over the entire
range between the rails, then you must connect the emitter resistor to the
negative rail.  However, even then, the output will still ride 0.6V to 0.7V
below the input, which means that you will get clipping distortion if your
signal goes right to the negative rail.

Plus, if you take the base very negative (more than about -6V) while the
emitter is grounded, the breakdown voltage of the base-emitter diode is
exceeded, which degrades the transistor.  If you use grounded-emitter
followers (for positive-only signals), then you should probably put a diode
between emitter and base (pointing toward the base) to protect the
transistor from negative base swings.

(Ain't Horowitz and Hill grand?)



From marr at lumin.us  Fri Nov 19 18:50:45 2010
From: marr at lumin.us (Mark Rivera)
Date: Fri, 19 Nov 2010 11:50:45 -0600
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <97676A73CC424D4794425C9C6E30B080@galvanox01>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<97676A73CC424D4794425C9C6E30B080@galvanox01>
Message-ID: <AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>

Is there a particular book that has transistor information presented
like this.. practical rather than mathematical/theoretical?


On Fri, Nov 19, 2010 at 11:37 AM, David G. Dixon
<dixon at interchange.ubc.ca> wrote:
>> So i am working on a circuit where there are a bunch of outputs. to save
>> space/opamps I decided it would be nice to use transistor buffers (emitter
>> followers)
>
> If they are precision CV outputs, then opamp followers are really the only
> defensible option. ?For audio circuits emanating from opamps (provided they
> are not coming from a circuit which has compromised the normally very low
> output impedance of the opamp, e.g. an ideal diode or rectifier, etc), the
> output is already buffered.
>
>> however when i switched to what i THOUGHT was a usable buffer, the output
>> gain (versus opamp followers) dropped drastically.
>>
>> let me see if i understand this properly. ( i dont think i do)
>>
>> if i want to buffer an lfo that is running between + and - 12 volts, I was
>> putting the oscillator wave through a 1k resistor into BASE. I was then
>> putting the collector to +v. What confuses me is what to do with the
>> emitter other than
>> this is where i take the output and a resistor to ground or -v should
>> connect here.
>>
>> I am not sure if i should put emitter to GROUND or to -v through say a 10k
>> resistor.
>
> The emitter follower output will only go as low as whatever is connected to
> the emitter resistor. ?Hence, if you ground the emitter, then follower
> output will not go below 0V. ?This is because the transistor (presuming it
> is NPN) can only source current, so the voltage at the emitter must always
> be higher than whatever is connected on the other side of the emitter
> resistor. ?If you want the emitter follower to give output over the entire
> range between the rails, then you must connect the emitter resistor to the
> negative rail. ?However, even then, the output will still ride 0.6V to 0.7V
> below the input, which means that you will get clipping distortion if your
> signal goes right to the negative rail.
>
> Plus, if you take the base very negative (more than about -6V) while the
> emitter is grounded, the breakdown voltage of the base-emitter diode is
> exceeded, which degrades the transistor. ?If you use grounded-emitter
> followers (for positive-only signals), then you should probably put a diode
> between emitter and base (pointing toward the base) to protect the
> transistor from negative base swings.
>
> (Ain't Horowitz and Hill grand?)
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From Barry.L.Klein at wdc.com  Fri Nov 19 18:58:33 2010
From: Barry.L.Klein at wdc.com (Barry Klein)
Date: Fri, 19 Nov 2010 09:58:33 -0800
Subject: [sdiy] simple transistor buffers?
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl><97676A73CC424D4794425C9C6E30B080@galvanox01>
	<AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
Message-ID: <C651097094AAD54C846A5BAA28F7141D04008F@wdscexbe08.sc.wdc.com>

Perhaps if you experiment with a simulator like LTSpice or the one
recently described for the iPad (if you have one)?

Barry


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Mark Rivera
Sent: Friday, November 19, 2010 9:51 AM
To: synth-diy DIY
Subject: Re: [sdiy] simple transistor buffers?

Is there a particular book that has transistor information presented
like this.. practical rather than mathematical/theoretical?


On Fri, Nov 19, 2010 at 11:37 AM, David G. Dixon
<dixon at interchange.ubc.ca> wrote:
>> So i am working on a circuit where there are a bunch of outputs. to save
>> space/opamps I decided it would be nice to use transistor buffers
(emitter
>> followers)
>
> If they are precision CV outputs, then opamp followers are really the only
> defensible option. ?For audio circuits emanating from opamps (provided
they
> are not coming from a circuit which has compromised the normally very low
> output impedance of the opamp, e.g. an ideal diode or rectifier, etc), the
> output is already buffered.
>
>> however when i switched to what i THOUGHT was a usable buffer, the output
>> gain (versus opamp followers) dropped drastically.
>>
>> let me see if i understand this properly. ( i dont think i do)
>>
>> if i want to buffer an lfo that is running between + and - 12 volts, I
was
>> putting the oscillator wave through a 1k resistor into BASE. I was then
>> putting the collector to +v. What confuses me is what to do with the
>> emitter other than
>> this is where i take the output and a resistor to ground or -v should
>> connect here.
>>
>> I am not sure if i should put emitter to GROUND or to -v through say a
10k
>> resistor.
>
> The emitter follower output will only go as low as whatever is connected
to
> the emitter resistor. ?Hence, if you ground the emitter, then follower
> output will not go below 0V. ?This is because the transistor (presuming it
> is NPN) can only source current, so the voltage at the emitter must always
> be higher than whatever is connected on the other side of the emitter
> resistor. ?If you want the emitter follower to give output over the entire
> range between the rails, then you must connect the emitter resistor to the
> negative rail. ?However, even then, the output will still ride 0.6V to
0.7V
> below the input, which means that you will get clipping distortion if your
> signal goes right to the negative rail.
>
> Plus, if you take the base very negative (more than about -6V) while the
> emitter is grounded, the breakdown voltage of the base-emitter diode is
> exceeded, which degrades the transistor. ?If you use grounded-emitter
> followers (for positive-only signals), then you should probably put a
diode
> between emitter and base (pointing toward the base) to protect the
> transistor from negative base swings.
>
> (Ain't Horowitz and Hill grand?)
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From dixon at interchange.ubc.ca  Fri Nov 19 19:28:41 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Fri, 19 Nov 2010 10:28:41 -0800
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<97676A73CC424D4794425C9C6E30B080@galvanox01>
	<AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
Message-ID: <195A8723535548BF8BC7FCB5EA9D2C58@galvanox01>

> Is there a particular book that has transistor information presented
> like this.. practical rather than mathematical/theoretical?

I guess you missed my last comment from before:

> > (Ain't Horowitz and Hill grand?)



From lanterma at ece.gatech.edu  Fri Nov 19 22:38:11 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Fri, 19 Nov 2010 21:38:11 +0000
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<97676A73CC424D4794425C9C6E30B080@galvanox01>
	<AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
Message-ID: <90B0780B-416E-433F-870F-1BD2DB6FC6C2@ece.gatech.edu>

On Nov 19, 2010, at 12:50 PM, Mark Rivera wrote:

> Is there a particular book that has transistor information presented like this.. practical rather than mathematical/theoretical?

Horowitz and Hill (both the main book and the lab manual) RULES ALL!

- Aaron

From lanterma at ece.gatech.edu  Fri Nov 19 22:50:14 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Fri, 19 Nov 2010 21:50:14 +0000
Subject: [sdiy] simple transistor buffers?
In-Reply-To: <AB7F62BBA358E04FA919701B9703184AF2918154@DC1EXC2.na.coherentinc.com>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<504213633.518299.1290182906292.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF2918154@DC1EXC2.na.coherentinc.com>
Message-ID: <4E83B235-9B8C-4CAA-8C5D-45E95259508E@ece.gatech.edu>

On Nov 19, 2010, at 11:40 AM, Speth, John wrote:

> If I were you, I'd go with a FET and not a BJT.  I think an FET is a little simpler to apply.

With a FET you don't need to worry about the voltage drop; it also has much higher input impedance so it won't load down things before it so much.

The Polyfusion VCF shows examples of FET buffers:

http://www.experimentalistsanonymous.com/diy/Schematics/Filters%20Wahs%20and%20VCFs/Polyfusion%20VCF.jpg

The Buchla Music Easel VCF and and early version of the 292 (version B) use FET buffers, although it should be noted that later versions of the 292 use regular op amps. (Probably his earlier use of FETs had to do with the lack of availability of op amps with really high-impedance FET inputs).

The Buchla 291 has more sophisticated buffers made of FET pairs, although Mark Verbos showed that this worked fine when replaced with op-amp buffers (and one of my students built this as a project on the breadboard and confirmed this).

- Aaron

From blacet at blacet.com  Sat Nov 20 00:13:46 2010
From: blacet at blacet.com (blacet at blacet.com)
Date: Fri, 19 Nov 2010 15:13:46 -0800
Subject: [sdiy] Blacet Time Machine Bare PCBs
In-Reply-To: <C651097094AAD54C846A5BAA28F7141D04008F@wdscexbe08.sc.wdc.com>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl><97676A73CC424D4794425C9C6E30B080@galvanox01>
	<AANLkTimGPmjz6h0AiLX2r8F186TvDQVNkVdwcecNi==O@mail.gmail.com>
	<C651097094AAD54C846A5BAA28F7141D04008F@wdscexbe08.sc.wdc.com>
Message-ID: <81d7001b6f72b5913ea94888d514f542.squirrel@webmail.blacet.com>

Check the Bargain Basement page.

http://www.blacet.com/bargains.html

I may have some front panels but if so they are 400 miles away in a
storeroom. I'll check later this month.

John



From elektrodwarf at yahoo.se  Sat Nov 20 00:37:17 2010
From: elektrodwarf at yahoo.se (Karl Ekdahl)
Date: Fri, 19 Nov 2010 23:37:17 +0000 (GMT)
Subject: [sdiy] NIST calibration?
Message-ID: <989857.61996.qm@web26204.mail.ukl.yahoo.com>

So i'm on the hunt for a new multimeter and was looking through old threads in the archives, finding the Extech MM560A to be a good candidate. However there's two options, one that's NIST certified and one that is not - how important is this? Would the non-NIST basically be uncalibrated? It's a pretty big difference in price on the meters, $239 vs $314 so i'm wondering.. ..any help appreciated!

Thanks

Karl




From Barry.L.Klein at wdc.com  Sat Nov 20 01:16:43 2010
From: Barry.L.Klein at wdc.com (Barry Klein)
Date: Fri, 19 Nov 2010 16:16:43 -0800
Subject: [sdiy] NIST calibration?
References: <989857.61996.qm@web26204.mail.ukl.yahoo.com>
Message-ID: <C651097094AAD54C846A5BAA28F7141D040095@wdscexbe08.sc.wdc.com>

I have the 470 and it is extremely annoying to use as it shuts down too
quickly with no usage.  Let me know if you find a way to perhaps disable
this or lengthen the time.  Mine does pass calibration by local ANKO guys.

Barry


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Karl Ekdahl
Sent: Friday, November 19, 2010 3:37 PM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] NIST calibration?

So i'm on the hunt for a new multimeter and was looking through old threads
in the archives, finding the Extech MM560A to be a good candidate. However
there's two options, one that's NIST certified and one that is not - how
important is this? Would the non-NIST basically be uncalibrated? It's a
pretty big difference in price on the meters, $239 vs $314 so i'm
wondering.. ..any help appreciated!

Thanks

Karl


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From tom at electricdruid.net  Sat Nov 20 01:51:39 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sat, 20 Nov 2010 00:51:39 +0000
Subject: [sdiy] Polyfusion VCF was Re:  simple transistor buffers?
In-Reply-To: <4E83B235-9B8C-4CAA-8C5D-45E95259508E@ece.gatech.edu>
References: <BLU0-SMTP1072FF8BC601B904E406691C83A0@phx.gbl>
	<504213633.518299.1290182906292.JavaMail.root@md01.wow.synacor.com>
	<AB7F62BBA358E04FA919701B9703184AF2918154@DC1EXC2.na.coherentinc.com>
	<4E83B235-9B8C-4CAA-8C5D-45E95259508E@ece.gatech.edu>
Message-ID: <31DDC81F-BF71-4449-8350-CFA64F590167@electricdruid.net>

I've always loved that polyfusion VCF. So simple, so explicit.

T.


On 19 Nov 2010, at 21:50, <lanterma at ece.gatech.edu> <lanterma at ece.gatech.edu> wrote:

> On Nov 19, 2010, at 11:40 AM, Speth, John wrote:
> 
>> If I were you, I'd go with a FET and not a BJT.  I think an FET is a little simpler to apply.
> 
> With a FET you don't need to worry about the voltage drop; it also has much higher input impedance so it won't load down things before it so much.
> 
> The Polyfusion VCF shows examples of FET buffers:
> 
> http://www.experimentalistsanonymous.com/diy/Schematics/Filters%20Wahs%20and%20VCFs/Polyfusion%20VCF.jpg
> 
> The Buchla Music Easel VCF and and early version of the 292 (version B) use FET buffers, although it should be noted that later versions of the 292 use regular op amps. (Probably his earlier use of FETs had to do with the lack of availability of op amps with really high-impedance FET inputs).
> 
> The Buchla 291 has more sophisticated buffers made of FET pairs, although Mark Verbos showed that this worked fine when replaced with op-amp buffers (and one of my students built this as a project on the breadboard and confirmed this).
> 
> - Aaron
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From madhun2001 at yahoo.com  Sat Nov 20 01:53:31 2010
From: madhun2001 at yahoo.com (Tim Ressel)
Date: Fri, 19 Nov 2010 16:53:31 -0800 (PST)
Subject: [sdiy] NIST calibration?
In-Reply-To: <989857.61996.qm@web26204.mail.ukl.yahoo.com>
References: <989857.61996.qm@web26204.mail.ukl.yahoo.com>
Message-ID: <277958.75252.qm@web55301.mail.re4.yahoo.com>

NIST traceability in this context means they probably did everything correctly. 
It is not important unless your gig requires traceability. One thing you should 
look for on new gear that sez its calibrated is a certificate of calibration 
that shows the gear that was used was calibrated.

--tr




----- Original Message ----
From: Karl Ekdahl <elektrodwarf at yahoo.se>
To: synth-diy at dropmix.xs4all.nl
Sent: Fri, November 19, 2010 3:37:17 PM
Subject: [sdiy] NIST calibration?

So i'm on the hunt for a new multimeter and was looking through old threads in 
the archives, finding the Extech MM560A to be a good candidate. However there's 
two options, one that's NIST certified and one that is not - how important is 
this? Would the non-NIST basically be uncalibrated? It's a pretty big difference 
in price on the meters, $239 vs $314 so i'm wondering.. ..any help appreciated!

Thanks

Karl


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From 21pointy at tpg.com.au  Sat Nov 20 02:55:41 2010
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Sat, 20 Nov 2010 11:55:41 +1000
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
	<643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>
	<BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>
	<AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>
Message-ID: <6787D2B1-BD6B-42A4-8A97-A469AB86C567@tpg.com.au>


On 18/11/2010, at 7:55 PM, cheater cheater wrote:

> My suggestion is to make a standard output from those 707 triggers, so
> that they have a positive-going pulse, of adequate voltage (+5V). Then
> make standard inputs on your 77. This is a bit more complicated but
> having a set of standardized inputs and outputs on things you own is a
> very good idea and you'll thank yourself later.


I think you're right. My view of this needs to broaden a bit. It then  
can contribute to the whole studio, as in a "modular" system


> You can have two separate inputs for the two separate levels of
> accent. Then you can use those somehow in your 77, which could have
> two separate inputs as well.

That's an interesting idea I hadn't considered - having a global  
accent input for the 77s voices

Maybe implementing it like the envelope circuit in the 707 - i.e. as  
a common rail for the trigger transistors




>
> On Wed, Nov 17, 2010 at 09:58, Adam Inglis <21pointy at tpg.com.au>  
> wrote:
>
>> More tests today -
>> the negative going triggers from the latch chips do indeed manage  
>> to trigger
>> the 77s voices, but only very quietly and without accent.
>> Unfortunately, the positive CVs from the envelope generators are  
>> unsuitable
>> as trigger sources - I discovered any rapid sequence of notes  
>> causes a
>> slurring of the envelope, especially with accent, so not all notes  
>> are
>> reliably converted to triggers.
>>
>>
>>
>> regards
>> Adam Inglis
>> http://www.adambaby.com
>>
>> On 16/11/2010, at 9:42 PM, Adam Inglis wrote:
>>
>>
>>> er.. I'm not yet actually up to the chapters on logic in  
>>> Horowitz&Hill, ha
>>> ha!!
>>>
>>> You're right - there are negative triggers to be found in the 707  
>>> (+5 to
>>> ground) going to the bases of each transistor in each envelope  
>>> generator.
>>> The Accent line is a positive CV line going to all the collectors  
>>> of these
>>> transistors, can't remember the levels, prob around 5 volts  
>>> (there are two
>>> levels of accent).
>>> Not sure - does that sound like something I could AND??
>>>
>>> On 16/11/2010, at 6:11 PM, cheater cheater wrote:
>>>
>>>
>>>
>>>> Hi Adam,
>>>> can't you use the trigger that goes into the 707's envelopes? I
>>>> believe there's a separate accent line (as far as I remember the
>>>> schematics). You can AND that with a separate copy of the trigger
>>>> lines, and add it to the original trigger lines. That's probably  
>>>> one
>>>> AND array, together with just some logic buffers or whatevers  
>>>> (I'm not
>>>> that great with digital logic hardware, just software!)
>>>>
>>>> Maybe you can use those directly in the 77 without any conversion.
>>>>
>>>> Cheers,
>>>> D.
>>>>
>>>> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au>  
>>>> wrote:
>>>>
>>>>
>>>>
>>>>> Cheers - I was hoping to avoid building a negative rail, the 77  
>>>>> manages
>>>>> without one (The negative-edge detector circuits that make up  
>>>>> the matrix
>>>>> generate a brief negative pulse on the falling edge of the  
>>>>> square waves
>>>>> from
>>>>> the multivibrator counters).
>>>>>
>>>>> Hanging a common-emitter amp off the 24 volt rail to invert the  
>>>>> signal,
>>>>> and
>>>>> running this into a similar edge-detector seems to work, but  
>>>>> thats a lot
>>>>> of
>>>>> parts if I have to make one for every voice.
>>>>>
>>>>> regards
>>>>> Adam Inglis
>>>>> http://www.adambaby.com
>>>>>
>>>>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> I'm thinking a voltage regulator to get you your -7 volts..  
>>>>>> and then a
>>>>>> transistor for each voice. use the 707 CV to trip the transistor
>>>>>> letting the -7 through?  Probably a current limiting resistor  
>>>>>> on each
>>>>>> one?
>>>>>>
>>>>>> Of course, this is how I design my own stuff... and sometimes it
>>>>>> works.  I really have no idea of the "correct" way to do things.
>>>>>>
>>>>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis  
>>>>>> <21pointy at tpg.com.au>
>>>>>> wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> Hi All
>>>>>>>
>>>>>>> First post - long time lurker and learner here for many years.
>>>>>>> Self-taught
>>>>>>> in analogue audio electronics thanks to a studio full of old  
>>>>>>> "junk"
>>>>>>> from
>>>>>>> the
>>>>>>> 70s and 80s, an oscilloscope from the 60s, and the first few  
>>>>>>> chapters
>>>>>>> of
>>>>>>> Horowitz and Hill!
>>>>>>>
>>>>>>> Question: Someone here mentioned not too long ago the idea of  
>>>>>>> using
>>>>>>> the
>>>>>>> voice trigger signals in a Roland TR707 to trigger external
>>>>>>> instruments.
>>>>>>> It
>>>>>>> got me thinking, as I love the interface of this drum machine  
>>>>>>> - quick
>>>>>>> and
>>>>>>> fun.
>>>>>>>  I would like to be able to trigger the voices in my old  
>>>>>>> preset Roland
>>>>>>> Rhythm TR77. This uses passive LC voice circuits, which  
>>>>>>> respond fairly
>>>>>>> dynamically to voltage triggers of between -3 to -10 volts.  
>>>>>>> Looking at
>>>>>>> the
>>>>>>> 707, I found the voice group's envelope generators supplied a  
>>>>>>> positive
>>>>>>> envelope CV of varying decay times and amplitudes (about 2-5  
>>>>>>> volts)
>>>>>>> depending on instrument. These CVs also respond to the 2  
>>>>>>> levels of
>>>>>>> programmable ACCENT, and so would appear to be a good source of
>>>>>>> triggering.
>>>>>>>
>>>>>>> Any suggestions as to a simple, low-parts-count circuit I could
>>>>>>> install
>>>>>>> (several iterations of) into the 77 that would convert the  
>>>>>>> positive
>>>>>>> CVs
>>>>>>> from
>>>>>>> the 707 into brief negative pulses for the 77s voices?
>>>>>>> I should mention there is 0 - 12 - 24 volts available in the  
>>>>>>> 77 with
>>>>>>> just
>>>>>>> basic filtering, no voltage regulators, so I was assuming it  
>>>>>>> would
>>>>>>> need a
>>>>>>> transistor rather than a chip based solution.
>>>>>>>
>>>>>>> Anyone interested in my crude investigations into the  
>>>>>>> workings of the
>>>>>>> TR77
>>>>>>> can have a look here...
>>>>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> regards
>>>>>>> Adam Inglis
>>>>>>> http://www.adambaby.com
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>
>
>
>



From synth1 at airmail.net  Sat Nov 20 05:49:11 2010
From: synth1 at airmail.net (Paul Schreiber)
Date: Fri, 19 Nov 2010 22:49:11 -0600
Subject: [sdiy] 2nd Euro module to be shown at NAMM
Message-ID: <C4891AA19D4C44DF9A1CB43D3215E3FC@optiplex>

http://www.youtube.com/watch?v=UWGenLYGMq0

More details in early Jan. Hope to see you there!

Sorry for the non-USA block by YouTube, I have no idea why.

Paul S.


From cheater00 at gmail.com  Sat Nov 20 10:05:32 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sat, 20 Nov 2010 10:05:32 +0100
Subject: [sdiy] TR707 to TR77 voice triggering
In-Reply-To: <6787D2B1-BD6B-42A4-8A97-A469AB86C567@tpg.com.au>
References: <507AF6DE-38FB-44FF-8D5D-C39B85A4AF3A@tpg.com.au>
	<AANLkTi=yVcP1Zy37+aHj6cwtomd=KJ-iLFvqj9MYNiA_@mail.gmail.com>
	<E9C2C2E5-470A-43EA-B82A-11111AC03804@tpg.com.au>
	<AANLkTikm2T5SS+NJJrKsbCYf=AH_9ac4u7KBR0aBoi5v@mail.gmail.com>
	<643C9923-3ABA-491B-B86D-844D7C2D24DC@tpg.com.au>
	<BBEC955B-C381-4AAB-A964-A9F910E03429@tpg.com.au>
	<AANLkTimDfvGovGa3hdTbjsN5AitPRwri-EpKVFKP-MoU@mail.gmail.com>
	<6787D2B1-BD6B-42A4-8A97-A469AB86C567@tpg.com.au>
Message-ID: <AANLkTi=WWPtcVv1knAGpoOBy1qe9u4c6j1ggyMZxbC4+@mail.gmail.com>

On Sat, Nov 20, 2010 at 02:55, Adam Inglis <21pointy at tpg.com.au> wrote:
>
> On 18/11/2010, at 7:55 PM, cheater cheater wrote:
>
>> My suggestion is to make a standard output from those 707 triggers, so
>> that they have a positive-going pulse, of adequate voltage (+5V). Then
>> make standard inputs on your 77. This is a bit more complicated but
>> having a set of standardized inputs and outputs on things you own is a
>> very good idea and you'll thank yourself later.
>
>
> I think you're right. My view of this needs to broaden a bit. It then can
> contribute to the whole studio, as in a "modular" system
>
>
>> You can have two separate inputs for the two separate levels of
>> accent. Then you can use those somehow in your 77, which could have
>> two separate inputs as well.
>
> That's an interesting idea I hadn't considered - having a global accent
> input for the 77s voices
>
> Maybe implementing it like the envelope circuit in the 707 - i.e. as a
> common rail for the trigger transistors

yeah, that could probably work! I guess you want some sort of
buffering.. don't ask me, I'm no electronics wiz ;-)

Also, since there are 64 levels (thanks for pointing that out guys,
schematics show that there's actually a 6-bit DAC there..) I suggest
just one output.

Cheers,
D.

>>
>> On Wed, Nov 17, 2010 at 09:58, Adam Inglis <21pointy at tpg.com.au> wrote:
>>
>>> More tests today -
>>> the negative going triggers from the latch chips do indeed manage to
>>> trigger
>>> the 77s voices, but only very quietly and without accent.
>>> Unfortunately, the positive CVs from the envelope generators are
>>> unsuitable
>>> as trigger sources - I discovered any rapid sequence of notes causes a
>>> slurring of the envelope, especially with accent, so not all notes are
>>> reliably converted to triggers.
>>>
>>>
>>>
>>> regards
>>> Adam Inglis
>>> http://www.adambaby.com
>>>
>>> On 16/11/2010, at 9:42 PM, Adam Inglis wrote:
>>>
>>>
>>>> er.. I'm not yet actually up to the chapters on logic in Horowitz&Hill,
>>>> ha
>>>> ha!!
>>>>
>>>> You're right - there are negative triggers to be found in the 707 (+5 to
>>>> ground) going to the bases of each transistor in each envelope
>>>> generator.
>>>> The Accent line is a positive CV line going to all the collectors of
>>>> these
>>>> transistors, can't remember the levels, prob around 5 volts (there are
>>>> two
>>>> levels of accent).
>>>> Not sure - does that sound like something I could AND??
>>>>
>>>> On 16/11/2010, at 6:11 PM, cheater cheater wrote:
>>>>
>>>>
>>>>
>>>>> Hi Adam,
>>>>> can't you use the trigger that goes into the 707's envelopes? I
>>>>> believe there's a separate accent line (as far as I remember the
>>>>> schematics). You can AND that with a separate copy of the trigger
>>>>> lines, and add it to the original trigger lines. That's probably one
>>>>> AND array, together with just some logic buffers or whatevers (I'm not
>>>>> that great with digital logic hardware, just software!)
>>>>>
>>>>> Maybe you can use those directly in the 77 without any conversion.
>>>>>
>>>>> Cheers,
>>>>> D.
>>>>>
>>>>> On Tue, Nov 16, 2010 at 02:20, Adam Inglis <21pointy at tpg.com.au> wrote:
>>>>>
>>>>>
>>>>>
>>>>>> Cheers - I was hoping to avoid building a negative rail, the 77
>>>>>> manages
>>>>>> without one (The negative-edge detector circuits that make up the
>>>>>> matrix
>>>>>> generate a brief negative pulse on the falling edge of the square
>>>>>> waves
>>>>>> from
>>>>>> the multivibrator counters).
>>>>>>
>>>>>> Hanging a common-emitter amp off the 24 volt rail to invert the
>>>>>> signal,
>>>>>> and
>>>>>> running this into a similar edge-detector seems to work, but thats a
>>>>>> lot
>>>>>> of
>>>>>> parts if I have to make one for every voice.
>>>>>>
>>>>>> regards
>>>>>> Adam Inglis
>>>>>> http://www.adambaby.com
>>>>>>
>>>>>> On 15/11/2010, at 2:37 PM, Chromatest J. Pantsmaker wrote:
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>> I'm thinking a voltage regulator to get you your -7 volts.. and then
>>>>>>> a
>>>>>>> transistor for each voice. use the 707 CV to trip the transistor
>>>>>>> letting the -7 through? ?Probably a current limiting resistor on each
>>>>>>> one?
>>>>>>>
>>>>>>> Of course, this is how I design my own stuff... and sometimes it
>>>>>>> works. ?I really have no idea of the "correct" way to do things.
>>>>>>>
>>>>>>> On Sun, Nov 14, 2010 at 9:30 PM, Adam Inglis <21pointy at tpg.com.au>
>>>>>>> wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> Hi All
>>>>>>>>
>>>>>>>> First post - long time lurker and learner here for many years.
>>>>>>>> Self-taught
>>>>>>>> in analogue audio electronics thanks to a studio full of old "junk"
>>>>>>>> from
>>>>>>>> the
>>>>>>>> 70s and 80s, an oscilloscope from the 60s, and the first few
>>>>>>>> chapters
>>>>>>>> of
>>>>>>>> Horowitz and Hill!
>>>>>>>>
>>>>>>>> Question: Someone here mentioned not too long ago the idea of using
>>>>>>>> the
>>>>>>>> voice trigger signals in a Roland TR707 to trigger external
>>>>>>>> instruments.
>>>>>>>> It
>>>>>>>> got me thinking, as I love the interface of this drum machine -
>>>>>>>> quick
>>>>>>>> and
>>>>>>>> fun.
>>>>>>>> ?I would like to be able to trigger the voices in my old preset
>>>>>>>> Roland
>>>>>>>> Rhythm TR77. This uses passive LC voice circuits, which respond
>>>>>>>> fairly
>>>>>>>> dynamically to voltage triggers of between -3 to -10 volts. Looking
>>>>>>>> at
>>>>>>>> the
>>>>>>>> 707, I found the voice group's envelope generators supplied a
>>>>>>>> positive
>>>>>>>> envelope CV of varying decay times and amplitudes (about 2-5 volts)
>>>>>>>> depending on instrument. These CVs also respond to the 2 levels of
>>>>>>>> programmable ACCENT, and so would appear to be a good source of
>>>>>>>> triggering.
>>>>>>>>
>>>>>>>> Any suggestions as to a simple, low-parts-count circuit I could
>>>>>>>> install
>>>>>>>> (several iterations of) into the 77 that would convert the positive
>>>>>>>> CVs
>>>>>>>> from
>>>>>>>> the 707 into brief negative pulses for the 77s voices?
>>>>>>>> I should mention there is 0 - 12 - 24 volts available in the 77 with
>>>>>>>> just
>>>>>>>> basic filtering, no voltage regulators, so I was assuming it would
>>>>>>>> need a
>>>>>>>> transistor rather than a chip based solution.
>>>>>>>>
>>>>>>>> Anyone interested in my crude investigations into the workings of
>>>>>>>> the
>>>>>>>> TR77
>>>>>>>> can have a look here...
>>>>>>>> http://www.adambaby.com/studiotech_TR-77.html
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> regards
>>>>>>>> Adam Inglis
>>>>>>>> http://www.adambaby.com
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>>
>>
>>
>>
>
>


From synth1 at airmail.net  Sat Nov 20 16:37:03 2010
From: synth1 at airmail.net (Paul Schreiber)
Date: Sat, 20 Nov 2010 09:37:03 -0600
Subject: [sdiy] E580 teaser should work everywhere
Message-ID: <80E0477E520D492895FC6C302DB91965@optiplex>

http://www.xtranormal.com/watch/7743377

I have no idea why ComCast has 'visual content'. It's exactly the same as 
the first one. It's not even the Neil Young reference (I took that out and 
reloaded, was still rejected. So I left it in).

Paul S. 



From juzowen at googlemail.com  Sat Nov 20 17:57:16 2010
From: juzowen at googlemail.com (Justin Owen)
Date: Sat, 20 Nov 2010 16:57:16 +0000
Subject: [sdiy] Bare-bones, stand-alone MIDI I/O modules?
Message-ID: <4ce7fdee.eaecd80a.7b97.ffff81c6@mx.google.com>

Hey all,

Reading through the posts about Neil Johnson's MIDI parser and dusting off my Arduino board [yeah, yeah - all you hardcore coder types can stop giggling ;) ] got me wondering what stand-alone MIDI I/O modules are out there?

Not (necessarily) looking to buy one so I don't really have a preference for language or platform - I'm  more interested in trying to gauge what features they had.

I'd prefer to see examples of ready made or kits rather than "here's some code" - but I'm open to whatever. I'm looking at this from the perspective of someone who is designing things that might be controlled via MIDI rather than someone who wants to code MIDI - if that makes sense.

For example - Sparkfun has this for MIDI to USB in:

http://www.sparkfun.com/products/9108

I know there's loads of others - what are they?

Thanks much,

Justin





From cheater00 at gmail.com  Sat Nov 20 17:59:03 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sat, 20 Nov 2010 17:59:03 +0100
Subject: [sdiy]  Bell System Technical Journal again
Message-ID: <AANLkTi=FUSfg2D_RZJQ6sas-bAy=7ifVhOO-h+mDH3g4@mail.gmail.com>

Hi guys,
I have been trying to mirror the BSTJ on my hard drive lately, but
sadly the server is super slow (around 3 KB/s with max 10 transfers or
so..). Turns out some nice fellas have created a torrent the nearly 40
gigabytes of journal data:

http://thepiratebay.org/torrent/5946997/Bell_Systems_Technical_Journals_%28Full_Site_Rip%29

enjoy!

Cheers,
D.


From ol.gillet at gmail.com  Sat Nov 20 18:10:37 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Sat, 20 Nov 2010 18:10:37 +0100
Subject: [sdiy] Bare-bones, stand-alone MIDI I/O modules?
In-Reply-To: <4ce7fdee.eaecd80a.7b97.ffff81c6@mx.google.com>
References: <4ce7fdee.eaecd80a.7b97.ffff81c6@mx.google.com>
Message-ID: <AANLkTimOMxO9H-EEJ8XszOx136pvP85bot8d8cnHofgW@mail.gmail.com>

Hi,

> I'd prefer to see examples of ready made or kits rather than "here's some code" - but I'm open to whatever. I'm looking at this from the perspective of someone who is designing things that might be controlled via MIDI rather than someone who wants to code MIDI - if that makes sense.

You'd probably get that by cobbling together bits of the MIDIbox
project. In particular they have the AOUT module with 8 CV outputs.
http://www.ucapps.de/mbhp_aout.html. Combined with their "core"
module, you have a good platform for building a MIDI and patch
storage/edition interface around analog circuits.

There are many more products in the "connect your pots/sensors to this
board to make your MIDI controller" department: the doepfer pocket
electronic, the MIDI CPU from highly liquid... just like the sparkfun
product you mentioned. But then it doesn't really look like what you
are looking for.

Olivier


From subjectivity at hotmail.com  Sat Nov 20 20:21:07 2010
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Sat, 20 Nov 2010 14:21:07 -0500
Subject: [sdiy] Bell System Technical Journal again
In-Reply-To: <AANLkTi=FUSfg2D_RZJQ6sas-bAy=7ifVhOO-h+mDH3g4@mail.gmail.com>
References: <AANLkTi=FUSfg2D_RZJQ6sas-bAy=7ifVhOO-h+mDH3g4@mail.gmail.com>
Message-ID: <BLU0-SMTP146916AD6DF4FEFA0837617C83B0@phx.gbl>

How big is the torrent compressed?

Thanks

Sent from my iPhone

On Nov 20, 2010, at 11:59 AM, cheater cheater <cheater00 at gmail.com> wrote:

> Hi guys,
> I have been trying to mirror the BSTJ on my hard drive lately, but
> sadly the server is super slow (around 3 KB/s with max 10 transfers or
> so..). Turns out some nice fellas have created a torrent the nearly 40
> gigabytes of journal data:
> 
> http://thepiratebay.org/torrent/5946997/Bell_Systems_Technical_Journals_%28Full_Site_Rip%29
> 
> enjoy!
> 
> Cheers,
> D.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From cheater00 at gmail.com  Sat Nov 20 20:43:10 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sat, 20 Nov 2010 20:43:10 +0100
Subject: [sdiy] Bell System Technical Journal again
In-Reply-To: <BLU0-SMTP146916AD6DF4FEFA0837617C83B0@phx.gbl>
References: <AANLkTi=FUSfg2D_RZJQ6sas-bAy=7ifVhOO-h+mDH3g4@mail.gmail.com>
	<BLU0-SMTP146916AD6DF4FEFA0837617C83B0@phx.gbl>
Message-ID: <AANLkTikyQjhz=xd5f0rHkp=vWMK3wQUmvCLEOt8FhYfu@mail.gmail.com>

Hi Dan,
I have to disappoint you - I hadn't downloaded it yet. I assume you
won't gain much, since it's all just JPG's embedded in PDF's.

Cheers,
D.

On Sat, Nov 20, 2010 at 20:21, Dan Snazelle <subjectivity at hotmail.com> wrote:
> How big is the torrent compressed?
>
> Thanks
>
> Sent from my iPhone
>
> On Nov 20, 2010, at 11:59 AM, cheater cheater <cheater00 at gmail.com> wrote:
>
>> Hi guys,
>> I have been trying to mirror the BSTJ on my hard drive lately, but
>> sadly the server is super slow (around 3 KB/s with max 10 transfers or
>> so..). Turns out some nice fellas have created a torrent the nearly 40
>> gigabytes of journal data:
>>
>> http://thepiratebay.org/torrent/5946997/Bell_Systems_Technical_Journals_%28Full_Site_Rip%29
>>
>> enjoy!
>>
>> Cheers,
>> D.
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>


From xyzzy at sysabend.org  Sat Nov 20 21:02:02 2010
From: xyzzy at sysabend.org (Tom Arnold)
Date: Sat, 20 Nov 2010 12:02:02 -0800
Subject: [sdiy] Aluminum Thickness for Brake/Shear?
In-Reply-To: <de7e78fed6e98c10106d00cc24b5bf14@localhost>
References: <ac2f1fb6fa44e64489fd61ba454ceb22@localhost>
	<de7e78fed6e98c10106d00cc24b5bf14@localhost>
Message-ID: <20101120200201.GQ9110@moo.sysabend.org>

On Wed, Nov 17, 2010 at 07:29:08PM -0800, jays at aracnet.com wrote:
> I'm looking into getting one of those small, metal brake/shears to make
> L "trays" to mount PCBs and front panels together.
> 
> So I was wondering what thickness of aluminum people are using to do
> this?
> 
> Don't want to get anything that can't handle the thickness I need.

The 8" brake/shear that I have ( commonly available from Harbor Freight,
Grizzley, etc ) can handle .050 however I also wanted to do PCBoards which
are closer to 0.063 so I shimmed the shear just a little.  If yo uhave a
narrow (1") piece of 0.063 6061-T6 aluminum, it'll handle it, but honestly even
0.050 is tricky if its more then 4" wide or so.

I use 5052-H16 in 0.050 for my brackets and it cuts/forms fine.  6061 is a
bit harder and doesn't cut/form as well.

-- 
 -----------------------------------------------------------------
 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -
 - BBD Fanatic      -  "...is it a virus, a drug, or a religion?" 
 - echo evho wjxo   -    Juanita Shrugs. "What's the difference?" 
 --------------------  



From cheater00 at gmail.com  Sun Nov 21 12:14:01 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 21 Nov 2010 12:14:01 +0100
Subject: [sdiy]  Polyphase transformers
Message-ID: <AANLkTim+Pr3ObVTNd65MHOGTADYGyu=xefbfjyy2v3Yj@mail.gmail.com>

Hi,
I have been reading up on directional couplers lately and saw mention
of polyphase transformers. Supposedly they can output copies the
signal that is input, rotated in pi/4 steps. Sounds like a fairly fun
way to do a phaser. Anyone ever use one of those? Are there any
circuits that use this specifically?

Quote from wikipedia:
For three-phase supplies, a bank of three individual single-phase
transformers can be used, or all three phases can be incorporated as a
single three-phase transformer. In this case, the magnetic circuits
are connected together, the core thus containing a three-phase flow of
flux.[49] A number of winding configurations are possible, giving rise
to different attributes and phase shifts.[50] One particular polyphase
configuration is the zigzag transformer, used for grounding and in the
suppression of harmonic currents.[51]

Cheers,
D.


From gatkins at blueyonder.co.uk  Sun Nov 21 12:28:33 2010
From: gatkins at blueyonder.co.uk (Graham Atkins)
Date: Sun, 21 Nov 2010 11:28:33 +0000
Subject: [sdiy] Polyphase transformers
In-Reply-To: <AANLkTim+Pr3ObVTNd65MHOGTADYGyu=xefbfjyy2v3Yj@mail.gmail.com>
References: <AANLkTim+Pr3ObVTNd65MHOGTADYGyu=xefbfjyy2v3Yj@mail.gmail.com>
Message-ID: <5E01E051-C192-42DC-A055-66516F6695C1@blueyonder.co.uk>

Sounds like a description of an industrial supply transformer. What  
use is that
in audio gear ?

Graham

On 21 Nov 2010, at 11:14, cheater cheater wrote:

> Hi,
> I have been reading up on directional couplers lately and saw mention
> of polyphase transformers. Supposedly they can output copies the
> signal that is input, rotated in pi/4 steps. Sounds like a fairly fun
> way to do a phaser. Anyone ever use one of those? Are there any
> circuits that use this specifically?
>
> Quote from wikipedia:
> For three-phase supplies, a bank of three individual single-phase
> transformers can be used, or all three phases can be incorporated as a
> single three-phase transformer. In this case, the magnetic circuits
> are connected together, the core thus containing a three-phase flow of
> flux.[49] A number of winding configurations are possible, giving rise
> to different attributes and phase shifts.[50] One particular polyphase
> configuration is the zigzag transformer, used for grounding and in the
> suppression of harmonic currents.[51]
>
> Cheers,
> D.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From rburnett at richieburnett.co.uk  Sun Nov 21 12:32:14 2010
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Sun, 21 Nov 2010 11:32:14 -0000
Subject: [sdiy] Polyphase transformers
Message-ID: <FC0D40B5E7D341F6A3A2652EC1A5C2FB@homepc002>

Polyphase transformers just perform vector additions of the waveforms 
applied to them...  So they can be used to play tricks with the relative 
phases of 3-phase sinusoidal voltages applied to them in power distribution 
systems.  (E.g. Look up the "24-pulse rectifier" for an example of how 
something called a "star-delta transformer" is used to generate 3 additional 
phases with offsets of 30 degrees from each of the existing 3-phase supply 
line voltages.)

Unfortunately a polyphase transformer doesn't impart any time delay to 
signals passing through it like you would need to implement something like 
an audio phaser.  Effectively it is just a mixer performing vector addition 
of the multiple input phases.

3-phase transformers also tend to weigh 300lbs and need a flatbed truck to 
move, so probably not ideal for Synth DIY !?!?!?

-Richie, 



From tom at electricdruid.net  Sun Nov 21 14:31:15 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 21 Nov 2010 13:31:15 +0000
Subject: [sdiy] Quick C query
Message-ID: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>

Hi there,

Not directly synth-related, but I'm learning C in order to write code for my synth's main processor board!

What's the best way to deal with booleans in C? I see that we don't have a Boolean type explicitly.
Presumably there's a standard practice for this, since I'm not the first person to need a boolean.

If it makes any odds, I'm using Microchip's C Lite on dsPIC.

Thanks,
Tom

PS: Neil - frustrations aside, I'll stick at it!

From thomas at pdp7.org  Sun Nov 21 14:37:14 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Sun, 21 Nov 2010 14:37:14 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
Message-ID: <4CE9208A.7060805@pdp7.org>

On 11/21/10 14:31 , Tom Wiltshire wrote:
> What's the best way to deal with booleans in C? I see that we don't have a Boolean type explicitly.
> Presumably there's a standard practice for this, since I'm not the first person to need a boolean.

If you just need one or two boolean variables use something like char 
which has only 8 bits usually. If you need whole arrays of boolean 
variables you'll want to look into bit manipulation to adress each bit 
individually or try out what the compiler does with bit fields.

I think http://en.wikipedia.org/wiki/Bit_field has a fairly good discussion.

	Thomas


From tom at electricdruid.net  Sun Nov 21 14:53:10 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 21 Nov 2010 13:53:10 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <4CE9208A.7060805@pdp7.org>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<4CE9208A.7060805@pdp7.org>
Message-ID: <3F1F6620-E4A3-4B05-86A7-BB0A5E61E75C@electricdruid.net>

Thanks. I usually use bit fields in assembly, and wondered if that was the way to go in C. I think I'd better look at what I get out of the compiler too - I can see potential for something that's intended to be efficient actually making the situation much worse.

T.

On 21 Nov 2010, at 13:37, Thomas Strathmann wrote:

> On 11/21/10 14:31 , Tom Wiltshire wrote:
>> What's the best way to deal with booleans in C? I see that we don't have a Boolean type explicitly.
>> Presumably there's a standard practice for this, since I'm not the first person to need a boolean.
> 
> If you just need one or two boolean variables use something like char which has only 8 bits usually. If you need whole arrays of boolean variables you'll want to look into bit manipulation to adress each bit individually or try out what the compiler does with bit fields.
> 
> I think http://en.wikipedia.org/wiki/Bit_field has a fairly good discussion.
> 
> 	Thomas
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From cheater00 at gmail.com  Sun Nov 21 15:52:13 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 21 Nov 2010 15:52:13 +0100
Subject: [sdiy] Polyphase transformers
In-Reply-To: <FC0D40B5E7D341F6A3A2652EC1A5C2FB@homepc002>
References: <FC0D40B5E7D341F6A3A2652EC1A5C2FB@homepc002>
Message-ID: <AANLkTi=G-bED0uxDYquM+0B5m6fPfVuOx4iqX_bYFovX@mail.gmail.com>

Hi guys,
thanks for the replies :-)

On Sun, Nov 21, 2010 at 12:32, Richie Burnett
<rburnett at richieburnett.co.uk> wrote:
> Polyphase transformers just perform vector additions of the waveforms
> applied to them...

ok, I understand you mean when the waveforms are sinusoids? I don't
know "vector addition of waveforms" other than when you take a vector
with the phase of the sinusoid and the magnitude being the amplitude
and add them like that. Is there some form of generalization to
arbitrary waveforms? If so, how does it look? Got me curious there :-)

>?So they can be used to play tricks with the relative
> phases of 3-phase sinusoidal voltages applied to them in power distribution
> systems. ?(E.g. Look up the "24-pulse rectifier" for an example of how
> something called a "star-delta transformer" is used to generate 3 additional
> phases with offsets of 30 degrees from each of the existing 3-phase supply
> line voltages.)

I have looked it up but have been confronted with super-technical
stuff that went way over my head :-) I've seen star-delta transformers
in tri-phase generators, though, I think? Am I right to think they're
the same thing you are referring to?

> Unfortunately a polyphase transformer doesn't impart any time delay to
> signals passing through it like you would need to implement something like
> an audio phaser. ?Effectively it is just a mixer performing vector addition
> of the multiple input phases.

Yes, but it does impart phase delay, doesn't it? And phase delay is
just frequency-dependent time delay. I've experimented a bit with
phase-delay and it sounds just like a normal "opto" phaser would - I
can only recommend that - a bbd-based phaser can't compete

> 3-phase transformers also tend to weigh 300lbs and need a flatbed truck to
> move, so probably not ideal for Synth DIY !?!?!?

Haha, yes, fully aware of that! However, an inclined person might wind
their own low-voltage transformer...

Thanks,
D.


From aym-htnys at teaser.fr  Sun Nov 21 16:04:22 2010
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Sun, 21 Nov 2010 16:04:22 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
Message-ID: <20101121150422.GA3341@aym.net2.nerim.net>

On 2010-11-21 13:31 +0000, Tom Wiltshire wrote:

> What's the best way to deal with booleans in C? I see that we don't
> have a Boolean type explicitly.
> Presumably there's a standard practice for this, since I'm not the
> first person to need a boolean.

Zero is false, non-zero is true. Any signed or unsigned integral
type will do. The default integral type in C is "int" but you
can use "char" or individual bits if you're tight on memory.

Some feel better after

  typedef sometype bool_t;
  #define TRUE 1
  #define FALSE 0

but that's really not necessary. It leads to code like

  if (b == TRUE)

which is not only pleonastic but also incorrect because if b
ever happens to be non-zero but different from 1, this test
would consider it false even though it's really true.

-- 
Andr? Majorel http://www.teaser.fr/~amajorel/


From neil.johnson97 at ntlworld.com  Sun Nov 21 17:17:51 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Sun, 21 Nov 2010 16:17:51 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
Message-ID: <CCF83A9D-669C-4CF3-9314-27E5BBBBE5DE@ntlworld.com>

Hi Tom,

> What's the best way to deal with booleans in C?

What is it that you are trying to do?  Do you have individual boolean  
values that you are looking for efficient storage?  Do you have  
complicated expressions that you want to simplify?

Some example code would help.

Thing is with C, there are so many ways to do things it all really  
depends on the specific application.

> I see that we don't have a Boolean type explicitly.

Indeed not, as the original machines that C was designed for did not  
have boolean operators (other than conditional branching and the Zero  
flag).

> Presumably there's a standard practice for this, since I'm not the  
> first person to need a boolean.

The are *standards* - plural.  As I say it really depends on what you  
want to achieve.

> If it makes any odds, I'm using Microchip's C Lite on dsPIC.

Does that have any target-specific or vendor-specific extensions?

> PS: Neil - frustrations aside, I'll stick at it!

Once you see the light you'll wonder why you never jumped before!!!

Cheers,
Neil
--
http://www.njohnson.co.uk





From steff at steff.name  Sun Nov 21 17:41:01 2010
From: steff at steff.name (Steff)
Date: Sun, 21 Nov 2010 16:41:01 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
Message-ID: <AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>

On 21 November 2010 13:31, Tom Wiltshire <tom at electricdruid.net> wrote:
> Hi there,
>
> Not directly synth-related, but I'm learning C in order to write code for my synth's main processor board!
>
> What's the best way to deal with booleans in C? I see that we don't have a Boolean type explicitly.
> Presumably there's a standard practice for this, since I'm not the first person to need a boolean.
>
> If it makes any odds, I'm using Microchip's C Lite on dsPIC.

If your specific compiler implements C99, you should find there's a
header stdbool.h which introduces a type "bool". It's just an int
really, though, so bitfields may make more sense if memory's tight.

Traditionally, one sees quite of a lot of this sort of thing:

[in a header file somewhere]
#define FOO 1
#define BAR 2
#define BAZ 4
#define BLARP 8

followed by:

[in code somewhere]
if(flags == (BLARP | BAR)) { /* do stuff here */ }

Regards,

Steff

Disclaimer: I'm a sysadmin who occasionally has to read or write C,
not a C language scientist.


From mikas.paukstis at gmail.com  Sun Nov 21 17:43:01 2010
From: mikas.paukstis at gmail.com (Mykolas)
Date: Sun, 21 Nov 2010 18:43:01 +0200
Subject: [sdiy] VCO voltage summer question?
Message-ID: <AANLkTikU9=5Dk32kxjiD=fB8XoxHq1N6ANdAb9yS-9P+@mail.gmail.com>

Hi all,

I'm breadboarding this VCO:
http://www.analogas.uzrasai.lt/wp-content/uploads/2010/11/VCO_v1.jpg
Many thanks to Jarek Ziembicki.

I'd like to have a two pots for "tune" (drift in 5 volts) and "fine
tune" instead of R2 and R12 (drift in 1 volt) and change R6 to 100k
trimpot for seting initial frequency.

How to calculate R1 and R2?

Or http://www.analogas.uzrasai.lt/wp-content/uploads/2010/11/potres.jpg

A) should I change R1 and R2 to 100K and add 15k resistors to each end
of P1 (change P1 to 50k too)? and have 5V drift and add 180k resistors
to each end of R12 for 1V drift;

B) add 30k resistor to +8V end of P1 for 0-5V and 350k for R12 0-1V?

Many thanks.



-- 

Mykolas
+370 67626261
www.analogas.uzrasai.lt


From tom at electricdruid.net  Sun Nov 21 17:57:20 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 21 Nov 2010 16:57:20 +0000
Subject: [sdiy] Quick C query
Message-ID: <59FD3FD8-A5BE-4CA0-ACCB-0889C5EBE784@electricdruid.net>

Neil,

>> What's the best way to deal with booleans in C?
> 
> What is it that you are trying to do?  Do you have individual boolean values that you are looking for efficient storage?  Do you have complicated expressions that you want to simplify?

I have individual booleans and I'm looking for efficient storage. Using a whole byte for each one makes me go "ugh!". But if it makes doing conditional tests on those booleans horrible, I'm willing to swallow the frog and use a byte per boolean.

> Some example code would help.

Well, in assembly, I'd have something like this:

	MainFlags:		.space 2		; 2 bytes, enough for 16 flags

	.equiv	EDIT_MODE, 0
	.equiv	RELEASE_DELAY, 1
	.equiv	BUTTON_PRESSED, 2
	etc etc

Then I can do things like;
	btfss	MainFlags, #EDIT_MODE		;  Test the flag, skip if set
	goto	NotEditMode					; Flag not set - jump off elsewhere
	.EditMode							; Flag set code follows

I've copied this fairly directly into C like this (howl if this is a really bad idea...):

	struct MainFlags {
		unsigned	EditMode :1
		unsigned	ReleaseDelay :1
		unsigned	ButtonPressed:1

	} MainFlags;

	// I can then set these up
	MainFlags.EditMode = 0;
	MainFlags.ReleaseDelay = 0;
	MainFlags.ButtonPressed = 0;

My reason for doing this was that it's how Microchip have chosen to expose many bitfield settings in various dsPIC registers, so it follows their example. Whether it's right in my case, I don't know.

For instance, setting up the Clock pre-division:

	CLKDIVbits.PLLPRE = 0;

Their header files define CLKDIVbits and the individual bits within it. I just copied their structure.

> Thing is with C, there are so many ways to do things it all really depends on the specific application.

That's usually the way it goes. However, what makes programming interesting is that if you ask n programmers which is the best way for a specific application, you can be guaranteed to get at least n different answers!

>> If it makes any odds, I'm using Microchip's C Lite on dsPIC.
> 
> Does that have any target-specific or vendor-specific extensions?

I have no idea currently. I don't even know what size short or long ints I've got, although I could have a good guess. These are early days.

> Once you see the light you'll wonder why you never jumped before!!!

I sincerely hope so! It'd be nice to work in something that produced results quicker than assembly. I doubt I'll ever leave "hand-tweaked" behind for audio-rate stuff though.

Thanks,
Tom


From music.maker at gte.net  Sun Nov 21 18:23:27 2010
From: music.maker at gte.net (Scott Gravenhorst)
Date: Sun, 21 Nov 2010 10:23:27 -0700
Subject: [sdiy] Quick C query
Message-ID: <201011211823.oALINRLB010562@linux7.lan>

Tom Wiltshire <tom at electricdruid.net> wrote:
>
>On 21 Nov 2010, at 18:05, Steff wrote:
>
>> On 21 November 2010 17:45, cheater cheater <cheater00 at gmail.com> wrote:
>>> 
>>>> if(flags == (BLARP | BAR)) { /* do stuff here */ }
>>> 
>>> I think you mean:
>>> 
>>> if(flags & (A | B) == (A | B)) {
>>>  ...
>>> }
>
>I've seen this written as:
>
>	if (flags & (A | B)) {
>	 ...
>	}
>
>Which would be the following for a single flag:
>
>	if (flags & mask) {
>	 ...
>	}
>
>There's no need for the part with the "==(etc)", since C is just 
>looking for a non-zero result to indicate true (simply processor 
>zero flag clear, I hope). 
>
>Or have I got the stick by the sticky end?

Looks correct to me.  I use that kind of structure regulary in C (that is, "if"
statements without any comparison operator).

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.



From cheater00 at gmail.com  Sun Nov 21 18:45:31 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 21 Nov 2010 18:45:31 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
Message-ID: <AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>

On Sun, Nov 21, 2010 at 17:41, Steff <steff at steff.name> wrote:
> On 21 November 2010 13:31, Tom Wiltshire <tom at electricdruid.net> wrote:
>> Hi there,
>>
>> Not directly synth-related, but I'm learning C in order to write code for my synth's main processor board!
>>
>> What's the best way to deal with booleans in C? I see that we don't have a Boolean type explicitly.
>> Presumably there's a standard practice for this, since I'm not the first person to need a boolean.
>>
>> If it makes any odds, I'm using Microchip's C Lite on dsPIC.
>
> If your specific compiler implements C99, you should find there's a
> header stdbool.h which introduces a type "bool". It's just an int
> really, though, so bitfields may make more sense if memory's tight.
>
> Traditionally, one sees quite of a lot of this sort of thing:
>
> [in a header file somewhere]
> #define FOO 1
> #define BAR 2
> #define BAZ 4
> #define BLARP 8
>
> followed by:
>
> [in code somewhere]
> if(flags == (BLARP | BAR)) { /* do stuff here */ }

I think you mean:

if(flags & (A | B) == (A | B)) {
 ...
}

Doing it the way you have mentioned is bad because it necessitates a
check of the other bit fields. So, a very good compiler could end up
having to do much less work if only two fields are compared. So you're
not only checking for those two flags to be on, you're also checking
for all the other flags to be off.

Additionally, you disable code reuse and code expandability, because
if you suddenly have new flags that you hadn't had before, they
disable this branch - even if the branch has nothing to do with those
new flags (and almost certainly doesn't, because how could it be using
the value of things that didn't exist when you were making it work the
first time)

Tom: if you want to have a look at how C performs in the critical
places, get good with a disassembler. Also learn how to inline
assembly code.

There's little shame in copying asm code step by step over to C, since
C is a low-level language itself. They really aren't that far apart,
especially in the situation given by the application you're using C
for.

Cheers,
D.

>
> Regards,
>
> Steff
>
> Disclaimer: I'm a sysadmin who occasionally has to read or write C,
> not a C language scientist.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From dixon at interchange.ubc.ca  Sun Nov 21 18:59:04 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Sun, 21 Nov 2010 09:59:04 -0800
Subject: [sdiy] Polyphase transformers
In-Reply-To: <FC0D40B5E7D341F6A3A2652EC1A5C2FB@homepc002>
References: <FC0D40B5E7D341F6A3A2652EC1A5C2FB@homepc002>
Message-ID: <1CCEF2F0A0E64197B7469C0FF5DDD355@galvanox01>

> 3-phase transformers also tend to weigh 300lbs and need a flatbed truck to
> move, so probably not ideal for Synth DIY !?!?!?

Sounds like the ideal phaser for your Teleharmonium!



From steff at steff.name  Sun Nov 21 19:05:40 2010
From: steff at steff.name (Steff)
Date: Sun, 21 Nov 2010 18:05:40 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
Message-ID: <AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>

On 21 November 2010 17:45, cheater cheater <cheater00 at gmail.com> wrote:
>
>> if(flags == (BLARP | BAR)) { /* do stuff here */ }
>
> I think you mean:
>
> if(flags & (A | B) == (A | B)) {
> ?...
> }

You're quite right about later expansion, though I'm not sure about
the optimisation point. The former should compile to a simple
comparison and the latter to a logic op and a comparison, I think.
Been a while since I did much of this, though.

S


From tom at electricdruid.net  Sun Nov 21 19:13:56 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 21 Nov 2010 18:13:56 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
Message-ID: <8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>


On 21 Nov 2010, at 18:05, Steff wrote:

> On 21 November 2010 17:45, cheater cheater <cheater00 at gmail.com> wrote:
>> 
>>> if(flags == (BLARP | BAR)) { /* do stuff here */ }
>> 
>> I think you mean:
>> 
>> if(flags & (A | B) == (A | B)) {
>>  ...
>> }

I've seen this written as:

	if (flags & (A | B)) {
	 ...
	}

Which would be the following for a single flag:

	if (flags & mask) {
	 ...
	}

There's no need for the part with the "==(etc)", since C is just looking for a non-zero result to indicate true (simply processor zero flag clear, I hope).

Or have I got the stick by the sticky end?

T.



From steff at steff.name  Sun Nov 21 19:18:38 2010
From: steff at steff.name (Steff)
Date: Sun, 21 Nov 2010 18:18:38 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
Message-ID: <AANLkTikkh=JpNqm2jh40G5fPhyQPZZQRMT3tSHBv0n7E@mail.gmail.com>

On 21 November 2010 18:13, Tom Wiltshire <tom at electricdruid.net> wrote:
>
> There's no need for the part with the "==(etc)", since C is just looking for a non-zero result to indicate true (simply processor zero flag clear, I hope).

You're quite right of course (and cheater cheater too, if I re-read
his paragraph on optimisation in the right light, I think). I blame
rustiness.

S


From ebrombaugh1 at cox.net  Sun Nov 21 19:18:52 2010
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Sun, 21 Nov 2010 11:18:52 -0700
Subject: [sdiy] Quick C query
In-Reply-To: <59FD3FD8-A5BE-4CA0-ACCB-0889C5EBE784@electricdruid.net>
References: <59FD3FD8-A5BE-4CA0-ACCB-0889C5EBE784@electricdruid.net>
Message-ID: <4CE9628C.9010000@cox.net>

On 11/21/2010 09:57 AM, Tom Wiltshire wrote:
>> Once you see the light you'll wonder why you never jumped before!!!
>
> I sincerely hope so! It'd be nice to work in something that produced results quicker than assembly. I doubt I'll ever leave "hand-tweaked" behind for audio-rate stuff though.

I've been coding dsPIC in a combination of C & assembly for the last few 
years. It works pretty nicely - using the C mainly for low-priority 
setup & background processing, as well as complex conditional stuff 
that's harder to keep track of in assembly when all you've got is branch 
instructions. Amazing how much using braces {} and whitespace helps to 
clarify the flow.

High-priority & DSP stuff that the C compiler doesn't deal with 
efficiently then goes into hand-coded assembly subroutines. I've also 
been using their DSP library, as well as extending it with my own 
functions that use the same API.

This approach also makes it more practical to incorporate some of the 
other libraries that are available, like MCHP's SD card access code. 
Makes it easy to use huge filesystems for waveform storage, FPGA code, etc.

There was some talk a while back of using dsPIC DMA to handle 
buffer-oriented processing of audio samples. I started a project along 
this line recently and it's been working nicely. There are some pretty 
easy-to-use examples in the DCI documentation that can get you going 
without a lot of effort. Most of the executive code in this project is 
in C with a number of hand-tuned DSP subroutines to handle buffer 
processing. It's seems to be pretty efficient, even with the C calling 
overhead.

Recommended.

Eric


From cheater00 at gmail.com  Sun Nov 21 19:38:52 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 21 Nov 2010 19:38:52 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
Message-ID: <AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>

On Sun, Nov 21, 2010 at 19:13, Tom Wiltshire <tom at electricdruid.net> wrote:
>
> On 21 Nov 2010, at 18:05, Steff wrote:
>
>> On 21 November 2010 17:45, cheater cheater <cheater00 at gmail.com> wrote:
>>>
>>>> if(flags == (BLARP | BAR)) { /* do stuff here */ }
>>>
>>> I think you mean:
>>>
>>> if(flags & (A | B) == (A | B)) {
>>> ?...
>>> }
>
> I've seen this written as:
>
> ? ? ? ?if (flags & (A | B)) {
> ? ? ? ? ...
> ? ? ? ?}
>
> Which would be the following for a single flag:
>
> ? ? ? ?if (flags & mask) {
> ? ? ? ? ...
> ? ? ? ?}
>
> There's no need for the part with the "==(etc)", since C is just looking for a non-zero result to indicate true (simply processor zero flag clear, I hope).
>
> Or have I got the stick by the sticky end?

if(flags & (A | B))

is different from

if(flags & (A | B) == (A | B))

in that the first will be active when either A or B are set in flags,
whereas the second will trigger only when A and B are set in the
flags. This is what Steff's original post did. So I guess you got the
sticky end this time, but not to worry! ;-)

If you're unhappy about the maintainability of your assembler code,
try using a high level assembler such as something like this:
http://web.mac.com/randyhyde/HighLevelAsm/WinDownload.html

"HLA can operate in one of several modes. In the standard mode (under
Windows) it converts an HLA source file directly into an object file
like most assemblers. In other modes, it has the ability to translate
HLA source code into another source form that is compatible with
several other assemblers, such as MASM, TASM, FASM, and Gas."

Whether or not it will support your architecture I don't know - maybe
- but it's a starting point.

One other option is to use the wealth of Haskell DSL's (domain
specific languages) that put out assembly. Haskell is fairly easy to
learn due to the wealth of very good books around
(learnyouahaskell.com is one you can access for free) and a very
strong community which includes some of the core developers.

Cheers,
D.

> T.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From jason at redfish.net  Sun Nov 21 19:43:51 2010
From: jason at redfish.net (Jason Proctor)
Date: Sun, 21 Nov 2010 10:43:51 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTikkh=JpNqm2jh40G5fPhyQPZZQRMT3tSHBv0n7E@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTikkh=JpNqm2jh40G5fPhyQPZZQRMT3tSHBv0n7E@mail.gmail.com>
Message-ID: <a0620077ac90f17de82a6@[192.168.1.64]>

>On 21 November 2010 18:13, Tom Wiltshire <tom at electricdruid.net> wrote:
>>
>>  There's no need for the part with the "==(etc)", since C is just 
>>looking for a non-zero result to indicate true (simply processor 
>>zero flag clear, I hope).
>
>You're quite right of course (and cheater cheater too, if I re-read
>his paragraph on optimisation in the right light, I think). I blame
>rustiness.

with the provisor that you are actually testing for A *or* B. if 
you're testing for A *and* B, then you have to test that the masked 
result is equal to  A *or * B.

(i *think* this is what Tom means by "for a single flag" but i'm not sure.)



From tom at electricdruid.net  Sun Nov 21 20:11:07 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 21 Nov 2010 19:11:07 +0000
Subject: [sdiy] dsPIC DMA buffered audio Re:  Quick C query
In-Reply-To: <4CE9628C.9010000@cox.net>
References: <59FD3FD8-A5BE-4CA0-ACCB-0889C5EBE784@electricdruid.net>
	<4CE9628C.9010000@cox.net>
Message-ID: <50E6106D-304E-4765-842B-0FDA6CE76B7F@electricdruid.net>


On 21 Nov 2010, at 18:18, Eric Brombaugh wrote:

> There was some talk a while back of using dsPIC DMA to handle buffer-oriented processing of audio samples. I started a project along this line recently and it's been working nicely.

I've had a crack at this too, and I agree entirely. You can get a couple of buffers set up, and get the DMA to read samples out of one whilst you fill the other. If your buffer is (say) 16 samples long, that gives you a good chunk of time to generate samples without being interrupted. When the DMA finishes the buffer, it sets a flag to tell the main code that the buffer is empty and then starts on the other buffer. The main code just has to poll the two flags and fill whichever buffer has just been emptied.

I had this running with a 89KHz sample rate, with modulations at the block rate (eg generated once after all the audio samples are done) which gives a modulation rate of 89/16 = 5.5KHz. It's pretty good, and if I run out of time I'll push it to a block size of 32 samples and use a mod rate of 2.75KHz. Prophet 08 allegedly uses around 1KHz mod rate, so if I'm going twice as fast as Dave Smith, I'm still happy!

On a separate note, thanks everyone for all the help with C. I know it's not entirely synthy, but I knew there'd be loads of people here who would know and who would have tried similar things to where I'm heading. And so it proved.

T.



From blincoln at eventualdecline.com  Sun Nov 21 20:47:32 2010
From: blincoln at eventualdecline.com (Ben Lincoln)
Date: Sun, 21 Nov 2010 11:47:32 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
Message-ID: <4CE97754.3070503@eventualdecline.com>

On 11/21/2010 10:38 AM, cheater cheater wrote:
> if(flags&  (A | B))
>
> is different from
>
> if(flags&  (A | B) == (A | B))
>
> in that the first will be active when either A or B are set in flags,
> whereas the second will trigger only when A and B are set in the
> flags.

This is one of the main reasons I avoid "programming shorthand". It 
takes a little longer to type out the full statement, but I'm a lot less 
likely to end up with something that behaves subtly differently than 
what I expect, and it's a lot easier to determine my original intent if 
I'm looking at the code again after a long time.

FWIW, I'm not a professional developer either, but I've coded in a lot 
of languages over the years, and when I use flag arrays, I tend to use 
this method rather than a struct (although in higher-level languages 
like C#, I would use a struct or class with boolean values because it's 
easier to read IMO).

On the subject of this type of hardware, is hand-tuned assembly still 
necessary these days? I know in the world of general-purpose PC 
hardware, the threshold was passed long ago, and it's generally 
considered not worth the trade-off in terms of the code becoming less 
-portable and less-maintainable by non-specialists (as well as the 
compiler being able to out-perform human optimization in most cases). 
I'm not familiar enough with embedded/programmable hardware to have an 
informed understanding of that side of things, though.

Obviously even if it's not strictly necessary, there's nothing wrong 
with enthusiasts doing it to squeeze the last possible drop of 
performance out of the hardware (which e.g. demo scene coders still do 
in the PC world).


From cheater00 at gmail.com  Sun Nov 21 20:56:47 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 21 Nov 2010 20:56:47 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <4CE97754.3070503@eventualdecline.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
Message-ID: <AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>

high performance programs (simulations, audio applications, computer
games) where execution speed is critical - as opposed to desktop
applications where it doesn't matter if calculating a spreadsheet will
take 2x longer - do use hand-coded assembly in the high-performance
parts (so, for example, 8 VCF's executing in an interleaved mode). On
the other hand sometimes there are things that are inaccessible with
higher level languages and you have to break out to assembler (be it
use of SIMD, or atomic changes to data)

There is a real demand for this kind of work being performed.


With MCU's you're dealing with something that's slower than a 386.
Most applications for the 386 were written in pure assembler.

Cheers,
D.

On Sun, Nov 21, 2010 at 20:47, Ben Lincoln <blincoln at eventualdecline.com> wrote:
> On 11/21/2010 10:38 AM, cheater cheater wrote:
>>
>> if(flags& ?(A | B))
>>
>> is different from
>>
>> if(flags& ?(A | B) == (A | B))
>>
>> in that the first will be active when either A or B are set in flags,
>> whereas the second will trigger only when A and B are set in the
>> flags.
>
> This is one of the main reasons I avoid "programming shorthand". It takes a
> little longer to type out the full statement, but I'm a lot less likely to
> end up with something that behaves subtly differently than what I expect,
> and it's a lot easier to determine my original intent if I'm looking at the
> code again after a long time.
>
> FWIW, I'm not a professional developer either, but I've coded in a lot of
> languages over the years, and when I use flag arrays, I tend to use this
> method rather than a struct (although in higher-level languages like C#, I
> would use a struct or class with boolean values because it's easier to read
> IMO).
>
> On the subject of this type of hardware, is hand-tuned assembly still
> necessary these days? I know in the world of general-purpose PC hardware,
> the threshold was passed long ago, and it's generally considered not worth
> the trade-off in terms of the code becoming less -portable and
> less-maintainable by non-specialists (as well as the compiler being able to
> out-perform human optimization in most cases). I'm not familiar enough with
> embedded/programmable hardware to have an informed understanding of that
> side of things, though.
>
> Obviously even if it's not strictly necessary, there's nothing wrong with
> enthusiasts doing it to squeeze the last possible drop of performance out of
> the hardware (which e.g. demo scene coders still do in the PC world).
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From veronica.merryfield at shaw.ca  Sun Nov 21 21:24:41 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Sun, 21 Nov 2010 12:24:41 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
Message-ID: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>


On 2010-11-21, at 11:56 AM, cheater cheater wrote:

> higher level languages and you have to break out to assembler (be it
> use of SIMD, or atomic changes to data)
> 
> There is a real demand for this kind of work being performed.

You'd be surprised how much you can hand assemble in C if you understand what the compiler is doing. Most embedded application projects do not change the tools during the life of the project so tuning the C to the output is not the heinous sin it would first appear.

> With MCU's you're dealing with something that's slower than a 386.
> Most applications for the 386 were written in pure assembler.

I doubt that somehow even if by virtue of the compiler wars between Borland and Microsoft.

Going back to the OP, single logic flags are normally instantiated as ints, being the most natural size for the under lying architecture and therefore normally the most efficient. One should check the flag against 0, i.e. equal to or not equal to. Some define FALSE as 0 and TRUE as 1, but one should stick to checking against 0. THe underlying assembler to this on most machines is similar.

Whilst some compilers support bitfields, it is not universal - check the tools set text for this. Those that do support it are often expensive in code size and execution speed although some architectures offer bitfield support that the compiler writers can use. In PIC land, the register definition headers often use unions of structures that include a bitfield definition and a non-bitfield overlay.

It is common to find the bits defined in binary powers of two with defined meanings and use the | and & operators to combine and test. This is great for packing but can lead to lengthy chains of if elseif else code which can get cumbersome and expensive depending on the compiler. 

Which gets me back to knowing what the compiler does with code. Output to a listing file and look can get you a very long way before having to goto assembly. 

>> Obviously even if it's not strictly necessary, there's nothing wrong with
>> enthusiasts doing it to squeeze the last possible drop of performance out of
>> the hardware (which e.g. demo scene coders still do in the PC world).

Many professionals do it all the time although an equal number seem to think that buying a faster machine is a reasonable solution too. 

Veronica



From jason at redfish.net  Sun Nov 21 21:31:00 2010
From: jason at redfish.net (Jason Proctor)
Date: Sun, 21 Nov 2010 12:31:00 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
Message-ID: <a0620077dc90f317481db@[192.168.1.64]>

>Which gets me back to knowing what the compiler does with code. 
>Output to a listing file and look can get you a very long way before 
>having to goto assembly.

seconded. i wrote gobs of C before i did any assembler, hence i 
learned a lot by having the compiler compile, but not assemble or 
link. studying the assembler output can be very enlightening indeed, 
especially while varying the optimisation settings.



From thomas at pdp7.org  Sun Nov 21 21:35:58 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Sun, 21 Nov 2010 21:35:58 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>	<4CE97754.3070503@eventualdecline.com>	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
Message-ID: <4CE982AE.9090707@pdp7.org>

On 11/21/10 21:24 , Veronica Merryfield wrote:
>>> Obviously even if it's not strictly necessary, there's nothing wrong with
>>> enthusiasts doing it to squeeze the last possible drop of performance out of
>>> the hardware (which e.g. demo scene coders still do in the PC world).
>
> Many professionals do it all the time although an equal number seem to think that buying a faster machine is a reasonable solution too.

In demo scene productions assembly is used mostly to cut down on the 
size although tools that compress the binary before release are more 
efficient. If assembly is needed for SIMD stuff they tend to use 
compiler intrinsics. Anyway, most of the time it's about faster GPUs 
with more memory and bigger memory bandwidth than about the CPU. And GPU 
programs are usually written in high level languages like HLSL and GLSL. 
Some people may cling to hand coding assembly but it's more a 
sentimental thing (or rather doing what one excells at instead of going 
through learning the intricate interplay between C/C++ code, the 
compiler, runtime system, binary format, and compression tools). On a 
related note: Design and being convenient for artists to work with 
usually trumps squeezing out the last drop of performance. In 4k and 64k 
productions size is more important than performance.

	Thomas


From ol.gillet at gmail.com  Sun Nov 21 21:40:50 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Sun, 21 Nov 2010 21:40:50 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
Message-ID: <AANLkTi=NOtRruwC04U-wTAXf6sBjsUTiuzQ-NZtiHs-1@mail.gmail.com>

> You'd be surprised how much you can hand assemble in C if you understand what the compiler is doing. Most embedded application projects do not change the tools during the life of the project so tuning the C to the output is not the heinous sin it would first appear.

Oh, I was going to write exactly that! What I was going to suggest Tom
was to take some time with a disassembler to study carefully the
generated code for all the C constructs, multiplications / shifts
between various datatypes, function calls, ISR preludes/postludes + to
check if there's some overhead with inlined assembly ; and to get a
rough idea of the effects of compiler optimization flags, etc. Then
make some educated choices with the constructs used in his code. This
breaks the "portability/machine independence" purpose of C since it
bends the code towards a target of choice (but then it doesn't make it
totally unportable). This absolutely won't break the readability and
"wide angle" view on the code C offers - and those last two are
absolutely valid reasons for using a high-level language.

What I learned by doing this on avr-gcc is that there are few blind
spots - and those are not due to compiler weakness but to the fact
that it's hard to express in C things about data sizes - "this 16x16
multiplication is indeed 8.4 x 8.4 and I will only care about the 16
highest bits of the result" etc.


From veronica.merryfield at shaw.ca  Sun Nov 21 21:48:54 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Sun, 21 Nov 2010 12:48:54 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <4CE982AE.9090707@pdp7.org>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<4CE982AE.9090707@pdp7.org>
Message-ID: <BD1A3266-DAF1-4C9E-BC83-97F9008A3116@shaw.ca>


On 2010-11-21, at 12:35 PM, Thomas Strathmann wrote:

> On 11/21/10 21:24 , Veronica Merryfield wrote:
>>>> Obviously even if it's not strictly necessary, there's nothing wrong with
>>>> enthusiasts doing it to squeeze the last possible drop of performance out of
>>>> the hardware (which e.g. demo scene coders still do in the PC world).
>> 
>> Many professionals do it all the time although an equal number seem to think that buying a faster machine is a reasonable solution too.
> 
> In demo scene productions assembly is used mostly to cut down on the size although tools that compress the binary before release are more efficient. If assembly is needed for SIMD stuff they tend to use compiler intrinsics. Anyway, most of the time it's about faster GPUs with more memory and bigger memory bandwidth than about the CPU. And GPU programs are usually written in high level languages like HLSL and GLSL. Some people may cling to hand coding assembly but it's more a sentimental thing (or rather doing what one excells at instead of going through learning the intricate interplay between C/C++ code, the compiler, runtime system, binary format, and compression tools). On a related note: Design and being convenient for artists to work with usually trumps squeezing out the last drop of performance. In 4k and 64k productions size is more important than performance.


Once you start having systems with cache and memory that is slower than the processor, different schemes come into play - algorithms that can fit in cache operating on data in cache become important but then you can also get hit by OS cache flushes. Horses for course but any half decent software engineer should know what is going on and work accordingly, but many just churn out code and scratch their heads after.



From veronica.merryfield at shaw.ca  Sun Nov 21 22:04:26 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Sun, 21 Nov 2010 13:04:26 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <a0620077dc90f317481db@[192.168.1.64]>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<a0620077dc90f317481db@[192.168.1.64]>
Message-ID: <1798D19B-5F52-4C0B-B8DA-A77E56D12A40@shaw.ca>


On 2010-11-21, at 12:31 PM, Jason Proctor wrote:

>> Which gets me back to knowing what the compiler does with code. Output to a listing file and look can get you a very long way before having to goto assembly.
> 
> seconded. i wrote gobs of C before i did any assembler, hence i learned a lot by having the compiler compile, but not assemble or link. studying the assembler output can be very enlightening indeed, especially while varying the optimisation settings.

A few years into my career in embedded software I found that one can not rely on optimisations. The typical pattern is to write code and debug it and switch optimisation to get it to run faster, often leading to code was very hard to debug and could lead to unexpected side effects which were now hard to debug. I learnt to write code that gained little by changing options which meant I had debuggable code with decent performance.

I know some will say that there are somethings that a compiler can optimise that you can't write in the C, but if you find out what it does and learn from it, there is a lot you can do that will get your code very close.

About 14/15 years back I was working on IR video streaming to disk and live on windows 95. My colleague and I had the same ideas on this and we were doing things in windows that our competitors thought we must be cheating on in some way, but it was all written in C with no optimisation - very slick.

From jason at redfish.net  Sun Nov 21 22:10:36 2010
From: jason at redfish.net (Jason Proctor)
Date: Sun, 21 Nov 2010 13:10:36 -0800
Subject: [sdiy] Quick C query
In-Reply-To: <1798D19B-5F52-4C0B-B8DA-A77E56D12A40@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<a0620077dc90f317481db@[192.168.1.64]>
	<1798D19B-5F52-4C0B-B8DA-A77E56D12A40@shaw.ca>
Message-ID: <a06200780c90f3a4e94e6@[192.168.1.64]>

>On 2010-11-21, at 12:31 PM, Jason Proctor wrote:
>
>>>  Which gets me back to knowing what the compiler does with code. 
>>>Output to a listing file and look can get you a very long way 
>>>before having to goto assembly.
>>
>>  seconded. i wrote gobs of C before i did any assembler, hence i 
>>learned a lot by having the compiler compile, but not assemble or 
>>link. studying the assembler output can be very enlightening 
>>indeed, especially while varying the optimisation settings.
>
>A few years into my career in embedded software I found that one can 
>not rely on optimisations. The typical pattern is to write code and 
>debug it and switch optimisation to get it to run faster, often 
>leading to code was very hard to debug and could lead to unexpected 
>side effects which were now hard to debug. I learnt to write code 
>that gained little by changing options which meant I had debuggable 
>code with decent performance.

i agree on optimisation in general - in fact the strategy now seems 
to be to make code only 70-80% as fast as it needs to be, assuming 
that the optimiser will pick up the rest. but in this case i'm 
referring to learning different assembler techniques from looking at 
how the compiler does it. and with different optimisation settings, 
little chunks of C can have dramatically different resulting 
assembler code.

i found for example without optimisation GCC for 68k wouldn't even 
bother to try to save instructions on some situations (long time ago, 
no example sorry) whereas passing even a regular -O would result in 
collapsing a calculation down to one combo instruction. which is in 
fact how i learned to apply that particular instruction :-)



From alvitar at xavax.com  Sun Nov 21 22:10:45 2010
From: alvitar at xavax.com (Phillip Harbison)
Date: Sun, 21 Nov 2010 16:10:45 -0500
Subject: [sdiy] Quick C query
In-Reply-To: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>	<4CE97754.3070503@eventualdecline.com>	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
Message-ID: <4CE98AD5.3070305@xavax.com>

Dealing with booleans is a tradeoff between code size and data
size. It's important to know the architecture of your CPU. For
example, in C it is tradition that integer types (including
char) be signed values. After loading a char (byte) the value
is sign-extended to a normal int. The 68000 had instructions
to extend a byte to a word (EXTB) and extend a word to a long,
but no instruction to extend a byte to a long. Many compilers
used a 32-bit "long word" as their basic "int" type. If you
used a char to store a boolean, thinking you were saving 3
bytes, you just wasted 4 bytes (2 instructions) extending the
sign. That's fine if you have lots of ROM and very little RAM.
If your memory is homogeneous, it's a false economy.

Using an unsigned char for booleans is a bit more efficient,
especially if your architecture automatically zeroes out the
upper byte(s) of the register. If not, then you'll need one
extra instruction to clear the register. If that instruction
is only one byte, it's still a win. On a typical RISC CPU, an
instruction is 4 bytes, so it's another false economy unless
RAM is a precious resource and you have ROM to burn.

The code size really starts to mount when you use bit fields
in C. The compiler cannot guess your intent, so it is going
to load the register, mask out the other bits, shift what is
left to the least significant bits of the register, and then
possibly sign extend the result. If you're mapping a bit field
to a device register, that's probably OK. If you're just using
bit fields to store booleans, it's a false economy on almost
any architecture.

Most compilers for x86 and RISC architectures make use of
optimization techniques such as loop invariant analysis and
common subexpression analysis. In my experience, compilers
for embedded processors are not quite so advanced, but that
may have changed since I did embedded work many years ago.
If you want to help the compiler out, the best things you
can do is apply the aforementioned techniques yourself. That
way the compiler doesn't have to deduce your intentions. If
you have a common subexpression, calculate it once and put
the result in a temporary variable. Avoid array indexing in
loops. Instead create a pointer to the first array element
and increment the pointer each time through the loop. This
made a huge difference in code size for old compilers for
the Z80 and 6800/6809. It may not be true for modern micro-
processors. As always, your mileage may vary.

Now back to lurking mode. :-)

-- 
Phil Harbison



From cheater00 at gmail.com  Mon Nov 22 09:17:39 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 22 Nov 2010 09:17:39 +0100
Subject: [sdiy] Quick C query
In-Reply-To: <632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
Message-ID: <AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>

Hi guys,
Phillip, thanks for a very interesting post. Regarding optimizations,
isn't Tom's MCU supported by some sort of gcc-based toolchain?

Veronica,

On Sun, Nov 21, 2010 at 21:24, Veronica Merryfield
<veronica.merryfield at shaw.ca> wrote:
>
> On 2010-11-21, at 11:56 AM, cheater cheater wrote:
>
>> higher level languages and you have to break out to assembler (be it
>> use of SIMD, or atomic changes to data)
>>
>> There is a real demand for this kind of work being performed.
>
> You'd be surprised how much you can hand assemble in C if you understand what the compiler is doing. Most embedded application projects do not change the tools during the life of the project so tuning the C to the output is not the heinous sin it would first appear.

yes, but then if you want a piece of code to fit exactly into cache
then it's much easier to do with ASM. But this discussion diverges
very far from Tom Wiltshire's original questions.

>> With MCU's you're dealing with something that's slower than a 386.
>> Most applications for the 386 were written in pure assembler.
>
> I doubt that somehow even if by virtue of the compiler wars between Borland and Microsoft.

I think you're more right than I am, given that you must be viewing
the computer based on where it was intended to go - i.e. companies and
scientific usage. Where I come from, computerization of businesses
hadn't happened until around the windows 95 days, and that was pretty
much the end of the 386. So the 386 was mostly used for things like
computer games, "having a computer to learn how to program it", and
heavyweight scientific calculations, especially given that many 386's
were second-hand at that point.

> Going back to the OP, single logic flags are normally instantiated as ints, being the most natural size for the under lying architecture and therefore normally the most efficient. One should check the flag against 0, i.e. equal to or not equal to. Some define FALSE as 0 and TRUE as 1, but one should stick to checking against 0. THe underlying assembler to this on most machines is similar.

that's also a good design pattern for hardware that's e.g. used for
extended periods of time (decades) or used in radio-active
environments. Bits can flip on their own.

> Whilst some compilers support bitfields, it is not universal - check the tools set text for this. Those that do support it are often expensive in code size and execution speed although some architectures offer bitfield support that the compiler writers can use. In PIC land, the register definition headers often use unions of structures that include a bitfield definition and a non-bitfield overlay.
>
> It is common to find the bits defined in binary powers of two with defined meanings and use the | and & operators to combine and test. This is great for packing but can lead to lengthy chains of if elseif else code which can get cumbersome and expensive depending on the compiler.
>
> Which gets me back to knowing what the compiler does with code. Output to a listing file and look can get you a very long way before having to goto assembly.

same reason why I have suggested a disassembler!

>>> Obviously even if it's not strictly necessary, there's nothing wrong with
>>> enthusiasts doing it to squeeze the last possible drop of performance out of
>>> the hardware (which e.g. demo scene coders still do in the PC world).
>
> Many professionals do it all the time although an equal number seem to think that buying a faster machine is a reasonable solution too.

Premature optimization is one thing, but writing dumb idiot-code is
another. You don't want to do either, unfortunately the latter group
you mentioned seems to correlate well with the latter group I mention.
It's much easier for newbies to say "buy a faster computer" than for
them to learn how to do things right.

Cheers,
D.


From neil.johnson97 at ntlworld.com  Mon Nov 22 11:17:46 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Mon, 22 Nov 2010 10:17:46 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>
Message-ID: <AANLkTikfeM-yRTbD9ywJ94Qe=kMEePv27XUGy6c_zF=P@mail.gmail.com>

Hi,

> Phillip, thanks for a very interesting post. Regarding optimizations,
> isn't Tom's MCU supported by some sort of gcc-based toolchain?

GCC is pretty good these days.  Since they moved over to SSA for the
internal representation there are many many more optimisations that
are possible.

>>> With MCU's you're dealing with something that's slower than a 386.
>>> Most applications for the 386 were written in pure assembler.
>>
>> I doubt that somehow even if by virtue of the compiler wars between Borland and Microsoft.
>
> I think you're more right than I am, given that you must be viewing
> the computer based on where it was intended to go - i.e. companies and
> scientific usage.

Ahhh, fond memories - the first PC I used for serious engineering use
was a Tandon 386/20, with a HUGE (!!!!) 1MB of RAM.  And OrCad SDT
worked well on it too.  Was it really only 20 years ago???

>> Which gets me back to knowing what the compiler does with code. Output to a listing file and look can get you a very long way before having to goto assembly.
>
> same reason why I have suggested a disassembler!

One advantage of a listing file is that you get source interspersed
with the assembler so you get a clear connection between C and asm.

> Premature optimization is one thing, but writing dumb idiot-code is
> another. You don't want to do either, unfortunately the latter group
> you mentioned seems to correlate well with the latter group I mention.
> It's much easier for newbies to say "buy a faster computer" than for
> them to learn how to do things right.

Using a language like C gives you, I think, the best of both worlds:
it handles all the drudgery of local and global variables, if-trees,
math expressions, and so on, and yet it is sufficiently low-level that
if you know what the compiler is going to do you can code pretty close
to assembler.  PLUS the benefit of the optimizer to do some funky
stuff with your code to give you improvements in execution speed or
size.

The whole issue about the optimiser is quite interesting.  If you want
the optimizer to work for you then write simple CORRECT code, and then
it will be able to do a better job.  The optimiser has to *try* to
work out what you want your program to do, not necessarily what you
coded.  A quick example: if GCC sees you writing a trivial loop that
looks like doing a memcpy it will optimise out that code with a call
to memcpy, which will usually be smaller (reuse of library code) and
faster (a good memcpy will be handed coded to be fast on the target
platform).

I've seen instances of where some "clever" programmer wrote some
horribly contorted and difficult to understand code because they
thought it would be smaller/faster, and then the optimiser found it
too difficult to understand so it didn't bother optimising it.
Rewritten in simple steps and the optimiser ended up doing a better
job than the original contorted code.

But then I did a PhD in optimising compilers so I guess I'm biased :)

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From lanterma at ece.gatech.edu  Mon Nov 22 12:07:50 2010
From: lanterma at ece.gatech.edu (lanterma at ece.gatech.edu)
Date: Mon, 22 Nov 2010 11:07:50 +0000
Subject: [sdiy] Sad news
Message-ID: <8C39BFC1-81F6-4073-A00B-964ABD793F10@ece.gatech.edu>

My colleague Prof. Marshall Leach passed away yesterday. He was an exemplary teacher, and a mentor to students and faculty alike. You would be hard pressed to find faculty in my department who cared more about students than Marshall. (I sat in on Marshall Leach's ECE3050 Analog Electronics class last year; his mastery of the subject and how to teach it well was inspiring.) I often went to him for advice in figuring out various synthesizer circuits; much of what I learned from him went into my Electronics for Music Synthesis class. 

Some of you might know his work on the "Leach amp" - other might know his work on loudspeaker modeling. In any case, he left quite a legacy:

http://users.ece.gatech.edu/mleach

- Aaron

From gil_we at yahoo.com  Mon Nov 22 13:27:59 2010
From: gil_we at yahoo.com (Gil W.)
Date: Mon, 22 Nov 2010 04:27:59 -0800 (PST)
Subject: [sdiy] Looking for plastic bender and slider cap for Juno 60
Message-ID: <919609.32668.qm@web58004.mail.re3.yahoo.com>

please email me.

Thanks


      


From ebrombaugh1 at cox.net  Mon Nov 22 15:44:22 2010
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Mon, 22 Nov 2010 07:44:22 -0700
Subject: [sdiy] Quick C query
In-Reply-To: <AANLkTikfeM-yRTbD9ywJ94Qe=kMEePv27XUGy6c_zF=P@mail.gmail.com>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>
	<AANLkTikfeM-yRTbD9ywJ94Qe=kMEePv27XUGy6c_zF=P@mail.gmail.com>
Message-ID: <A31357F0-EEE7-4393-B0F3-6E7D60D5C4AF@cox.net>


On Nov 22, 2010, at 3:17 AM, Neil Johnson wrote:
>> Phillip, thanks for a very interesting post. Regarding optimizations,
>> isn't Tom's MCU supported by some sort of gcc-based toolchain?
> 
> GCC is pretty good these days.  Since they moved over to SSA for the
> internal representation there are many many more optimisations that
> are possible.

The C compiler for the dsPIC (Tom's MCU in this case) is based on GCC with some proprietary optimizations added on. Unfortunately, MCHP has intertwined GCC with their own non-free material to such an extent that it's very difficult to create an OSS/Free distribution of dsPIC GCC. Tom Sailer did this a few years ago and posted the build instructions here:

http://www.baycom.org/~tom/dspic/

but it's a fairly complex process, and extremely dated at this point. The upshot of course is that unless you're willing to fork out ~$1k for MCHP's version you won't have access to the highest levels of optimization (they do allow -O1 for free), and the optimizations that are available in the OSS/Free versions of GCC are out of the question unless you're a compiler geek and capable of updating the dsPIC GCC sources yourself.

The good news is that for most stuff the free 1st-level optimization is fairly good. I've tried the higher levels during the 60-day trial period and they haven't provided a significant reduction in code size or speed on my test cases.

Eric

From tom at electricdruid.net  Mon Nov 22 16:16:59 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 22 Nov 2010 15:16:59 +0000
Subject: [sdiy] Quick C query
In-Reply-To: <A31357F0-EEE7-4393-B0F3-6E7D60D5C4AF@cox.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>
	<AANLkTikfeM-yRTbD9ywJ94Qe=kMEePv27XUGy6c_zF=P@mail.gmail.com>
	<A31357F0-EEE7-4393-B0F3-6E7D60D5C4AF@cox.net>
Message-ID: <2E3F99F1-C2B3-4DFD-B7AA-57C09BBA681A@electricdruid.net>


On 22 Nov 2010, at 14:44, Eric Brombaugh wrote:

> The C compiler for the dsPIC (Tom's MCU in this case) is based on GCC with some proprietary optimizations added on. Unfortunately, MCHP has intertwined GCC with their own non-free material to such an extent that it's very difficult to create an OSS/Free distribution of dsPIC GCC. Tom Sailer did this a few years ago and posted the build instructions here:
> 
> http://www.baycom.org/~tom/dspic/
> 
> but it's a fairly complex process, and extremely dated at this point. The upshot of course is that unless you're willing to fork out ~$1k for MCHP's version you won't have access to the highest levels of optimization (they do allow -O1 for free), and the optimizations that are available in the OSS/Free versions of GCC are out of the question unless you're a compiler geek and capable of updating the dsPIC GCC sources yourself.
> 
> The good news is that for most stuff the free 1st-level optimization is fairly good. I've tried the higher levels during the 60-day trial period and they haven't provided a significant reduction in code size or speed on my test cases.
> 
> Eric


Further good news (from my point of view) is that having tested various methods of dealing with booleans, it looks like Microchip have optimized the compiler for their preferred "struct" bitfield way of doing things.

Doing something like this:

 struct MainFlags {
               unsigned        EditMode :1;
               unsigned        ReleaseDelay :1;
               unsigned        ButtonPressed:1;

       } MainFlags;

..gives you three flags in sequential bits in one byte, and setting the flags:

       // I can then set these up
       MainFlags.EditMode = 0;
       MainFlags.ReleaseDelay = 0;
       MainFlags.ButtonPressed = 0;

..is done using the bclr (bit clear) instruction, which is exactly what I've have done in assembly. So I'm a happy bunny.

Thanks,
Tom





From harrybissell at wowway.com  Mon Nov 22 16:56:58 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 22 Nov 2010 10:56:58 -0500 (EST)
Subject: [sdiy] VCO voltage summer question?
In-Reply-To: <AANLkTikU9=5Dk32kxjiD=fB8XoxHq1N6ANdAb9yS-9P+@mail.gmail.com>
Message-ID: <206425820.576697.1290441418879.JavaMail.root@md01.wow.synacor.com>

I'm not sure I understood the question...

I'd leave POT1 circuit the  way it is, and add a second
POT (same as POT1) but with R1 increased in value to maybe
2.2M ohm. This will make the second pot have much less
range.  You can change the value if needed...

I would avoid adding resistors to the ends of the pots
to limit the range. This will make the loading on the
wiper affect the linear operation of the pot.

H^) harry


----- Original Message -----
From: Mykolas <mikas.paukstis at gmail.com>
To: synth-diy at dropmix.xs4all.nl
Sent: Sun, 21 Nov 2010 11:43:01 -0500 (EST)
Subject: [sdiy] VCO voltage summer question?

Hi all,

I'm breadboarding this VCO:
http://www.analogas.uzrasai.lt/wp-content/uploads/2010/11/VCO_v1.jpg
Many thanks to Jarek Ziembicki.

I'd like to have a two pots for "tune" (drift in 5 volts) and "fine
tune" instead of R2 and R12 (drift in 1 volt) and change R6 to 100k
trimpot for seting initial frequency.

How to calculate R1 and R2?

Or http://www.analogas.uzrasai.lt/wp-content/uploads/2010/11/potres.jpg

A) should I change R1 and R2 to 100K and add 15k resistors to each end
of P1 (change P1 to 50k too)? and have 5V drift and add 180k resistors
to each end of R12 for 1V drift;

B) add 30k resistor to +8V end of P1 for 0-5V and 350k for R12 0-1V?

Many thanks.



-- 

Mykolas
+370 67626261
www.analogas.uzrasai.lt
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From ebrombaugh1 at cox.net  Mon Nov 22 17:13:35 2010
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Mon, 22 Nov 2010 09:13:35 -0700
Subject: [sdiy] Quick C query
In-Reply-To: <2E3F99F1-C2B3-4DFD-B7AA-57C09BBA681A@electricdruid.net>
References: <44EFF9BF-9964-4DCC-97A4-83F293067BEB@electricdruid.net>
	<AANLkTinkVdHVqniTCgcGioHqFRQo69EywFM6J3vA6D-2@mail.gmail.com>
	<AANLkTimrfXOhrefRktPkc_q-Ywn3LKKWinSEU67E=4b4@mail.gmail.com>
	<AANLkTinBR7SXH0=V5aEwocrBvbtOVSR5=Vw44mjPWuQz@mail.gmail.com>
	<8756B51A-47B0-45B5-AC4B-5230053E7970@electricdruid.net>
	<AANLkTin+-q5Q8sdfwwyYAcuvnvReku0Mb9fjGTru2qvs@mail.gmail.com>
	<4CE97754.3070503@eventualdecline.com>
	<AANLkTimVFeenqZg_R=b8n4OxsWSfZHk334q3MwP0PpOx@mail.gmail.com>
	<632D3E36-F1E8-4E66-B9A0-AB943DDE966C@shaw.ca>
	<AANLkTik0UvS3adgB9Sb4fw0Pwa_Vqn7k-BzN1fBMG_gj@mail.gmail.com>
	<AANLkTikfeM-yRTbD9ywJ94Qe=kMEePv27XUGy6c_zF=P@mail.gmail.com>
	<A31357F0-EEE7-4393-B0F3-6E7D60D5C4AF@cox.net>
	<2E3F99F1-C2B3-4DFD-B7AA-57C09BBA681A@electricdruid.net>
Message-ID: <4CEA96AF.7080107@cox.net>

On 11/22/2010 08:16 AM, Tom Wiltshire wrote:
> Further good news (from my point of view) is that having tested various methods of dealing with booleans, it looks like Microchip have optimized the compiler for their preferred "struct" bitfield way of doing things.

That is nice to know. I had suspected as much but never checked the 
disassembly listing closely to verify. It makes sense that they would do 
this given how heavily bit operations are represented in the dsPIC 
instruction set.

Eric


From tom at electricdruid.net  Mon Nov 22 17:29:27 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 22 Nov 2010 16:29:27 +0000
Subject: [sdiy] Organisation of tasks in synth's main uP
Message-ID: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>

Hi all,

Having got started with C, I'm thinking about what I'm trying to do with it - Write code for the main uP in my synth.
This uP has to accomplish the following tasks, which are common to many synths:

* Scan the keyboard and calculate velocity, note on, etc.
* Update the LCD screens
* Update panel LEDs
* Scan panel buttons and controls
* Read several ADC channels
* Process incoming MIDI
* Send outgoing MIDI
* Deal with voice assignment
* Send instructions to the voices over a serial comms link

Most of these things I've done at one time or another, so I'm not too worried about the nuts and bolts of each part. What I haven't done before is deal with a system that does so many different things at once. It needs to do each in a timely manner.

Some of these tasks are quite slow and will delay other things appreciably if not handled correctly. One example is the LCD. LCDs are dog slow to respond, so sending a screenful of information to one will hang up my uP for a considerable time. To prevent this should I buffer outgoing bytes to the LCD? I could then throw LCD data into a buffer and then feed bytes from there to the LCD at a slower rate.

Other tasks are slow, but require fairly swift attention. For example, I could buffer MIDI information coming in, and then deal with it in quite large chunks (say 16 or 32 bytes), but this would entail a considerable MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the MIDI parser each time a status byte arrives. This would mean that the previous message was now complete and could be processed, or that a system realtime message had just arrived, in which case it could be processed.

I can see that interrupts are going to be crucial, but the question is where to focus scarce resources? I know some people here have broken the job down by having a separate uP doing control panel scanning. Whilst that has some benefits, it also implies another set of inter-uP comms which has costs.
Your thoughts please?

Thanks,
Tom

From ebrombaugh1 at cox.net  Mon Nov 22 17:38:48 2010
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Mon, 22 Nov 2010 09:38:48 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
Message-ID: <4CEA9C98.7030106@cox.net>

On 11/22/2010 09:29 AM, Tom Wiltshire wrote:
> Most of these things I've done at one time or another, so I'm not too worried about the nuts and bolts of each part. What I haven't done before is deal with a system that does so many different things at once. It needs to do each in a timely manner.

One word for you: RTOS

You'll either end up coding your own, or using an existing one. There 
are some free ones available. FreeRTOS seems to be pretty well regarded 
and is used on a lot of architectures so you won't be painting yourself 
into a corner with it. It's available for dsPIC/PIC24 too.

http://www.freertos.org

Eric


From marr at lumin.us  Mon Nov 22 17:52:57 2010
From: marr at lumin.us (Mark Rivera)
Date: Mon, 22 Nov 2010 10:52:57 -0600
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
Message-ID: <AANLkTinjAeCB4bK=0jUKMeZXiVUh_tau-VeOLcKZiKtw@mail.gmail.com>

You might start with a rough calculation of how many cycles each task
will take by looking at datasheets.. e.g., the LCD's, ADC's, etc.
Usually there's enough time to do everything without breaking a
sweat... what I've done in the past (with sequencers) is use the
natural PPQN division of the MIDI clock ticks as my schedule windows.
This seems to work out fine for me at 10MHz (PIC18F). You might find
some natural division of duties like this depending on the tasks of
your synth.

The other important thing is which functions will be on interrupts
and/or timers and what levels of priority your MCU(s) have. The PIC18
only has high and low, for instance.


On Mon, Nov 22, 2010 at 10:29 AM, Tom Wiltshire <tom at electricdruid.net> wrote:
> Hi all,
>
> Having got started with C, I'm thinking about what I'm trying to do with it - Write code for the main uP in my synth.
> This uP has to accomplish the following tasks, which are common to many synths:
>
> * Scan the keyboard and calculate velocity, note on, etc.
> * Update the LCD screens
> * Update panel LEDs
> * Scan panel buttons and controls
> * Read several ADC channels
> * Process incoming MIDI
> * Send outgoing MIDI
> * Deal with voice assignment
> * Send instructions to the voices over a serial comms link
>
> Most of these things I've done at one time or another, so I'm not too worried about the nuts and bolts of each part. What I haven't done before is deal with a system that does so many different things at once. It needs to do each in a timely manner.
>
> Some of these tasks are quite slow and will delay other things appreciably if not handled correctly. One example is the LCD. LCDs are dog slow to respond, so sending a screenful of information to one will hang up my uP for a considerable time. To prevent this should I buffer outgoing bytes to the LCD? I could then throw LCD data into a buffer and then feed bytes from there to the LCD at a slower rate.
>
> Other tasks are slow, but require fairly swift attention. For example, I could buffer MIDI information coming in, and then deal with it in quite large chunks (say 16 or 32 bytes), but this would entail a considerable MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the MIDI parser each time a status byte arrives. This would mean that the previous message was now complete and could be processed, or that a system realtime message had just arrived, in which case it could be processed.
>
> I can see that interrupts are going to be crucial, but the question is where to focus scarce resources? I know some people here have broken the job down by having a separate uP doing control panel scanning. Whilst that has some benefits, it also implies another set of inter-uP comms which has costs.
> Your thoughts please?
>
> Thanks,
> Tom
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From grant at musictechnologiesgroup.com  Mon Nov 22 18:12:41 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Mon, 22 Nov 2010 10:12:41 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
Message-ID: <20101122101241.c16e921f9c8655b42ea149fc1daa3492.c3e162bfed.wbe@email04.secureserver.net>

There are so many good books and magazines about this it will make your
head spin.  Back issues of Embedded Systems Programming from the 90's
are great in this respect.  Lots of good microcontroller textbooks are
good too.  There was an article series describing MCX11 that was killer.
 Also uCOS is similar (and it has it's own books too).  But it is larger
and more generic RTOS-like. 

I ported MCX11 to the 6809 and later taught courses using both MCX11 and
"MCX09". So there must be docs on it somewhere.  Reading how that works
would be very useful and fun.

Commercial RTOS's work too of course, but the overhead can be high. 
Smaller "executives" can be very efficient.  I use a variation on the
"super loop" with both hard and soft timers. Main loop checks flags to
see what functions (tasks) need to run. Flags (similar to semaphores)
can be set by timers, hardware or other tasks.

A "timer" thing is very easy to do. Have one hardware timer that runs
every ms or 10ms or whatever. When it's ISR runs it evaluates soft
timers for tasks. Once a soft timer counts to zero then it resets the
timer to full value and sets the flag/semaphore. Note that this is
useful primarily for low priority stuff (scanning panel switches or
updating LEDs).  But once you build a framework it gets very manageable.

GB

> -------- Original Message --------
> Subject: [sdiy] Organisation of tasks in synth's main uP
> From: Tom Wiltshire <tom at electricdruid.net>
> Date: Mon, November 22, 2010 8:29 am
> To: Synth DIY <synth-diy at dropmix.xs4all.nl>
> 
> 
> Hi all,
> 
> Having got started with C, I'm thinking about what I'm trying to do with it - Write code for the main uP in my synth.
> This uP has to accomplish the following tasks, which are common to many synths:
> 
> * Scan the keyboard and calculate velocity, note on, etc.
> * Update the LCD screens
> * Update panel LEDs
> * Scan panel buttons and controls
> * Read several ADC channels
> * Process incoming MIDI
> * Send outgoing MIDI
> * Deal with voice assignment
> * Send instructions to the voices over a serial comms link
> 
> Most of these things I've done at one time or another, so I'm not too worried about the nuts and bolts of each part. What I haven't done before is deal with a system that does so many different things at once. It needs to do each in a timely manner.
> 
> Some of these tasks are quite slow and will delay other things appreciably if not handled correctly. One example is the LCD. LCDs are dog slow to respond, so sending a screenful of information to one will hang up my uP for a considerable time. To prevent this should I buffer outgoing bytes to the LCD? I could then throw LCD data into a buffer and then feed bytes from there to the LCD at a slower rate.
> 
> Other tasks are slow, but require fairly swift attention. For example, I could buffer MIDI information coming in, and then deal with it in quite large chunks (say 16 or 32 bytes), but this would entail a considerable MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the MIDI parser each time a status byte arrives. This would mean that the previous message was now complete and could be processed, or that a system realtime message had just arrived, in which case it could be processed.
> 
> I can see that interrupts are going to be crucial, but the question is where to focus scarce resources? I know some people here have broken the job down by having a separate uP doing control panel scanning. Whilst that has some benefits, it also implies another set of inter-uP comms which has costs.
> Your thoughts please?
> 
> Thanks,
> Tom
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From ol.gillet at gmail.com  Mon Nov 22 18:12:51 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Mon, 22 Nov 2010 18:12:51 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
Message-ID: <AANLkTi=avVCGg2v5hM2VDd+AXJ6mKMFC5bdwj3uSE2EZ@mail.gmail.com>

Hi Tom,

It's probably best illustrated by code
(https://github.com/pichenettes/shruthi-1/blob/master/hardware/shruthi/shruthi.cc),
but I can summarize here what I did for the Shruthi:

ISR land:

* Incoming MIDI data is pushed onto a ring buffer whenever the UART RX
interrupt is raised.
* There's a 39kHz timer interrupt which does the following:
 - pop samples from a ring buffer and write them to the audio output.
The path from the interrupt prolog to the actual write is
constant-time to avoid jitter.
 - every 16th clock tick (2.5 kHz):
    - send a nibble from a ring-buffer to the LCD (The LCD is thus
never polled - we are sure a write is complete because there's a
guarantee delay between calls).
    - step through the switches/encoder debouncing routine
    - flush bytes from a ring-buffer to the MIDI out
 - every 32th clock tick, update a ms system clock which is used in a
few places.


mainland:

Besides that, everything is in non-blocking, rate-independent,
cooperative "tasks". The core of the program is a loop that calls the
tasks in sequence, with some tasks being called more often than
others. All the tasks are polling something, so they return
immediately if there's nothing for them to do:
- poll debounced switches values.
- poll the ADC's end of conversion flag to read pots values / CV inputs.
- poll the MIDI input buffer and parse MIDI.
- poll the text buffer to detect changes on the LCD text and push
bytes to LCD commands ring buffer.
- poll the output buffer and if empty, render 32 samples of audio + 1
sample of modulations.

All the tasks do small chunks of processing which take less than the
allowed 32 buffered samples. At one exception, none of those tasks
have a heavy state, so there's not much cost switching from one task
to another. The "context-switch" is simply a function
prelude/postlude. I find the following idiom particularly useful:
http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html

Indeed, there's only one bit in the code which is blocking: writes to
eeprom when saving patches - I block during the 5ms or so of write
time between each eeprom block.

I did not consider a RTOS but will do when switching to a platform on
which I can tolerate the overhead.

Olivier


From igg.debus at t-online.de  Mon Nov 22 18:20:10 2010
From: igg.debus at t-online.de (Ingo Debus)
Date: Mon, 22 Nov 2010 18:20:10 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
Message-ID: <87996D7D-7E8B-490E-83C4-D56F2774B5AC@t-online.de>


Am 22.11.2010 um 17:29 schrieb Tom Wiltshire:

> Other tasks are slow, but require fairly swift attention. For  
> example, I could buffer MIDI information coming in, and then deal  
> with it in quite large chunks (say 16 or 32 bytes), but this would  
> entail a considerable MIDI lag, which I'd like to avoid. Instead,  
> I'd thought of calling the MIDI parser each time a status byte  
> arrives. This would mean that the previous message was now complete  
> and could be processed, or that a system realtime message had just  
> arrived, in which case it could be processed.

In all my projects I'm using a MIDI input ring buffer. When the UART  
receives a MIDI byte, an interrupt routine puts it just to the ring  
buffer and increnets the write pointer. The MIDI data are parsed in  
the main program. The main program gets aware of received MIDI data  
by comparing the read and the write pointers. If they're not equal,  
the main program grabs the MIDI byte off the ring buffer and  
increments the read pointer. This way the data are not processed in  
larger chunks, still no data are lost even if the main program is  
busy with other things for a while (unless the ring buffer is too  
small).

Ingo


From grant at musictechnologiesgroup.com  Mon Nov 22 18:23:35 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Mon, 22 Nov 2010 10:23:35 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
Message-ID: <20101122102335.c16e921f9c8655b42ea149fc1daa3492.c591928143.wbe@email04.secureserver.net>

> Some of these tasks are quite slow and will delay other things appreciably if not handled correctly. One example is the LCD. LCDs are dog slow to respond, so sending a screenful of information to one will hang up my uP for a considerable time. To prevent this should I buffer outgoing bytes to the LCD? I could then throw LCD data into a buffer and then feed bytes from there to the LCD at a slower rate.

Totally. I write data to a virtual LCD buffer which takes zero time.
Then a low priority task moves the data from the buffer to the LCD
continually. Very easy and efficient. And of course the user can't tell.
Never check the LCD busy flag *after*. No spin waits. Ever. Pet Peeve of
mine. If you do this correctly you can move data and never see the busy
flag set. Therefore no lost time. 

> Other tasks are slow, but require fairly swift attention. For example, I could buffer MIDI information coming in, and then deal with it in quite large chunks (say 16 or 32 bytes), but this would entail a considerable MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the MIDI parser each time a status byte arrives. This would mean that the previous message was now complete and could be processed, or that a system realtime message had just arrived, in which case it could be processed.

I haven't read the MIDI parser thread, but there might be some gems in
there. Serial data is SLOW. Many uS between bytes. It is an easy enough
matter to build a state machine that evaluates the data as each byte
arrives and moves the machine along until a message is completely
decoded. Then again you set a flag and/or call the routine as you see
fit. Now you also need to decide on adding another layer or not. You can
buffer the incoming midi data from the Uart into a buffer and decode the
buffer content in the main loop (ie. a task) or you can do it in the
ISR. Flame wars erupt over such things so I won't recommend one or the
other.

> I can see that interrupts are going to be crucial, but the question is where to focus scarce resources? I know some people here have broken the job down by having a separate uP doing control panel scanning. Whilst that has some benefits, it also implies another set of inter-uP comms which has costs.

I would not add a second uC unless you really have to.  Certainly not at
the stage you are talking about now.   Later on maybe.  Small micros are
cheap for sure.

GB



From obl64 at ix.netcom.com  Mon Nov 22 20:01:04 2010
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Mon, 22 Nov 2010 13:01:04 -0600
Subject: [sdiy] Sad news
In-Reply-To: <8C39BFC1-81F6-4073-A00B-964ABD793F10@ece.gatech.edu>
References: <8C39BFC1-81F6-4073-A00B-964ABD793F10@ece.gatech.edu>
Message-ID: <4CEABDF0.5020608@ix.netcom.com>

On 11/22/2010 5:07 AM, lanterma at ece.gatech.edu wrote:
> My colleague Prof. Marshall Leach passed away yesterday. He was an exemplary teacher, and a mentor to students and faculty alike. You would be hard pressed to find faculty in my department who cared more about students than Marshall. (I sat in on Marshall Leach's ECE3050 Analog Electronics class last year; his mastery of the subject and how to teach it well was inspiring.) I often went to him for advice in figuring out various synthesizer circuits; much of what I learned from him went into my Electronics for Music Synthesis class.
>
> Some of you might know his work on the "Leach amp" - other might know his work on loudspeaker modeling. In any case, he left quite a legacy:
>
> http://users.ece.gatech.edu/mleach
>
> - Aaron


Aaron, I am very sorry to hear of Prof. Marshall Leach's passing.
I have been well aware of his "Leach amp" power amplifier design.

- Oren


From cheater00 at gmail.com  Mon Nov 22 21:20:27 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Mon, 22 Nov 2010 21:20:27 +0100
Subject: [sdiy] Sad news
In-Reply-To: <4CEABDF0.5020608@ix.netcom.com>
References: <8C39BFC1-81F6-4073-A00B-964ABD793F10@ece.gatech.edu>
	<4CEABDF0.5020608@ix.netcom.com>
Message-ID: <AANLkTims38jVtJGpc2BO=7FSfxqZCBPfXSGDoo1P+DvP@mail.gmail.com>

Aaron, I'm terribly sorry to hear that. I hope you guys are holding
up. It's a terrible loss and I'm sure it shook the whole university.
Even someone who doesn't know electronics at all, like me, recognizes
the name Leach. I think I've even read up on the Leach amplifier
once..

My sincere condolences.
D.

On Mon, Nov 22, 2010 at 20:01, Oren Leavitt <obl64 at ix.netcom.com> wrote:
> On 11/22/2010 5:07 AM, lanterma at ece.gatech.edu wrote:
>>
>> My colleague Prof. Marshall Leach passed away yesterday. He was an
>> exemplary teacher, and a mentor to students and faculty alike. You would be
>> hard pressed to find faculty in my department who cared more about students
>> than Marshall. (I sat in on Marshall Leach's ECE3050 Analog Electronics
>> class last year; his mastery of the subject and how to teach it well was
>> inspiring.) I often went to him for advice in figuring out various
>> synthesizer circuits; much of what I learned from him went into my
>> Electronics for Music Synthesis class.
>>
>> Some of you might know his work on the "Leach amp" - other might know his
>> work on loudspeaker modeling. In any case, he left quite a legacy:
>>
>> http://users.ece.gatech.edu/mleach
>>
>> - Aaron
>
>
> Aaron, I am very sorry to hear of Prof. Marshall Leach's passing.
> I have been well aware of his "Leach amp" power amplifier design.
>
> - Oren
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From paul at fitvideo.co.uk  Mon Nov 22 21:47:54 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Mon, 22 Nov 2010 20:47:54 -0000
Subject: [sdiy] And you want to study electrical engineering?
Message-ID: <002601cb8a86$90992f00$b1cb8d00$@co.uk>

How was your day ?

http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/
player_config.php?token=07b_1284580365%26embed=1


cheers

Paul



From tim.parkhurst at gmail.com  Mon Nov 22 22:14:28 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Mon, 22 Nov 2010 13:14:28 -0800
Subject: [sdiy] And you want to study electrical engineering?
In-Reply-To: <002601cb8a86$90992f00$b1cb8d00$@co.uk>
References: <002601cb8a86$90992f00$b1cb8d00$@co.uk>
Message-ID: <AANLkTim6cpbn24pP8jVTW51o9jcCqON_0S7D1txPXhbs@mail.gmail.com>

On Mon, Nov 22, 2010 at 12:47 PM, Paul Burns <paul at fitvideo.co.uk> wrote:
> How was your day ?
>
> http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/
> player_config.php?token=07b_1284580365%26embed=1
>
> cheers
>
> Paul
>

Oh sh*t, that gave me vertigo just watching it! Respect for the guys
and gals who do that stuff.

Tim (it also gave me The Birds, Psycho, and Rear Window, but I digress) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From paul at fitvideo.co.uk  Mon Nov 22 22:25:43 2010
From: paul at fitvideo.co.uk (Paul Burns)
Date: Mon, 22 Nov 2010 21:25:43 -0000
Subject: [sdiy]  And you want to study electrical engineering?
Message-ID: <003201cb8a8b$d36722b0$7a356810$@co.uk>

I suppose if you are really hard you base jump to get home from work ...

Regards Paul

From: Tim Parkhurst [mailto:tim.parkhurst at gmail.com] 
Sent: 22 November 2010 21:14
To: Paul Burns
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] And you want to study electrical engineering?

On Mon, Nov 22, 2010 at 12:47 PM, Paul Burns <paul at fitvideo.co.uk> wrote:
> How was your day ?
>
>
http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/
> player_config.php?token=07b_1284580365%26embed=1
>
> cheers
>
> Paul
>

Oh sh*t, that gave me vertigo just watching it! Respect for the guys
and gals who do that stuff.

Tim (it also gave me The Birds, Psycho, and Rear Window, but I digress)
Servo
--
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings



From jdec at mindspring.com  Mon Nov 22 22:31:30 2010
From: jdec at mindspring.com (BrightBoy)
Date: Mon, 22 Nov 2010 16:31:30 -0500 (GMT-05:00)
Subject: [sdiy] And you want to study electrical engineering?
Message-ID: <25858877.1290461490760.JavaMail.root@mswamui-swiss.atl.sa.earthlink.net>

Here's a smaller link that doesn't break because it's too long:

http://www.liveleak.com/view?i=07b_1284580365

Jeff

-----Original Message-----
>From: Tim Parkhurst <tim.parkhurst at gmail.com>
>Sent: Nov 22, 2010 4:14 PM
>To: Paul Burns <paul at fitvideo.co.uk>
>Cc: synth-diy at dropmix.xs4all.nl
>Subject: Re: [sdiy] And you want to study electrical engineering?
>
>On Mon, Nov 22, 2010 at 12:47 PM, Paul Burns <paul at fitvideo.co.uk> wrote:
>> How was your day ?
>>
>> http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/
>> player_config.php?token=07b_1284580365%26embed=1
>>
>> cheers
>>
>> Paul
>>
>
>Oh sh*t, that gave me vertigo just watching it! Respect for the guys
>and gals who do that stuff.
>
>Tim (it also gave me The Birds, Psycho, and Rear Window, but I digress) Servo
>-- 
>"Sire, the church of God is an anvil that has worn out many hammers."
>- H.L. Hastings
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy





From obl64 at ix.netcom.com  Mon Nov 22 22:34:56 2010
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Mon, 22 Nov 2010 15:34:56 -0600
Subject: [sdiy] And you want to study electrical engineering?
In-Reply-To: <003201cb8a8b$d36722b0$7a356810$@co.uk>
References: <003201cb8a8b$d36722b0$7a356810$@co.uk>
Message-ID: <4CEAE200.4020102@ix.netcom.com>



On 11/22/2010 3:25 PM, Paul Burns wrote:
> I suppose if you are really hard you base jump to get home from work ...
>
> Regards Paul
>


...or ride a zip line home :-)



> From: Tim Parkhurst [mailto:tim.parkhurst at gmail.com]
> Sent: 22 November 2010 21:14
> To: Paul Burns
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] And you want to study electrical engineering?
>
> On Mon, Nov 22, 2010 at 12:47 PM, Paul Burns<paul at fitvideo.co.uk>  wrote:
>> How was your day ?
>>
>>
> http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/
>> player_config.php?token=07b_1284580365%26embed=1
>>
>> cheers
>>
>> Paul
>>
>
> Oh sh*t, that gave me vertigo just watching it! Respect for the guys
> and gals who do that stuff.
>
> Tim (it also gave me The Birds, Psycho, and Rear Window, but I digress)
> Servo
> --
> "Sire, the church of God is an anvil that has worn out many hammers."
> - H.L. Hastings
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From magnus at rubidium.dyndns.org  Tue Nov 23 01:33:51 2010
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Tue, 23 Nov 2010 01:33:51 +0100
Subject: [sdiy] NIST calibration?
In-Reply-To: <989857.61996.qm@web26204.mail.ukl.yahoo.com>
References: <989857.61996.qm@web26204.mail.ukl.yahoo.com>
Message-ID: <4CEB0BEF.7080102@rubidium.dyndns.org>

Karl,

On 11/20/2010 12:37 AM, Karl Ekdahl wrote:
> So i'm on the hunt for a new multimeter and was looking through old threads in the archives, finding the Extech MM560A to be a good candidate. However there's two options, one that's NIST certified and one that is not - how important is this? Would the non-NIST basically be uncalibrated? It's a pretty big difference in price on the meters, $239 vs $314 so i'm wondering.. ..any help appreciated!

If you buy it for a company needing ISO 9000 stuff or similar Quality 
fluff, then traceability is the way to go. Otherwise - don't waste your 
money on it.

Traceability is a mine-field, and a confusing one too.

Cheers,
Magnus


From sounddoctorin at imt.net  Tue Nov 23 05:28:26 2010
From: sounddoctorin at imt.net (Bob Weigel)
Date: Mon, 22 Nov 2010 21:28:26 -0700
Subject: [sdiy] And you want to study electrical engineering?
In-Reply-To: <4CEAE200.4020102@ix.netcom.com>
References: <003201cb8a8b$d36722b0$7a356810$@co.uk>
	<4CEAE200.4020102@ix.netcom.com>
Message-ID: <4CEB42EA.9010109@imt.net>

On 11/22/2010 2:34 PM, Oren Leavitt wrote:
>
>
> On 11/22/2010 3:25 PM, Paul Burns wrote:
>> I suppose if you are really hard you base jump to get home from work ...
>>
>> Regards Paul
>>
>
>
> ...or ride a zip line home :-)
>
>
>
>> From: Tim Parkhurst [mailto:tim.parkhurst at gmail.com]
>> Sent: 22 November 2010 21:14
>> To: Paul Burns
>> Cc: synth-diy at dropmix.xs4all.nl
>> Subject: Re: [sdiy] And you want to study electrical engineering?
>>
>> On Mon, Nov 22, 2010 at 12:47 PM, Paul Burns<paul at fitvideo.co.uk>  
>> wrote:
>>> How was your day ?
>>>
>>>
>> http://www.liveleak.com/mp53/player.swf?config=http://www.liveleak.com/mp53/ 
>>
>>> player_config.php?token=07b_1284580365%26embed=1
>>>
>>> cheers
>>>
>>> Paul
>>>
>>
>> Oh sh*t, that gave me vertigo just watching it! Respect for the guys
>> and gals who do that stuff.
>>
>> Tim (it also gave me The Birds, Psycho, and Rear Window, but I digress)
>> Servo
>> -- 
>> "Sire, the church of God is an anvil that has worn out many hammers."
>> - H.L. Hastings
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
Really amazes me how they don't...ya know..invest an extra few hundred 
bucks in ...ya know... maybe a little extra platform space on the top 
and... ohh I dunno maybe a..pulley and cable?  Well 1000 foot of cable 
might cost a bit... and a winch...  course a hand crank with someone at 
the bottom maybe would save a winch.  not that I'm saying do away with 
the hand grips in case the guy cranking decides he's had enough of your 
bad jokes or something....

-- 
Check out sounddoctorin.com for songs, a studio tour, help
repairing old synthesizers and parts or thought provoking
articles that could help make your eternity!



From carsten at analog-monster.de  Tue Nov 23 08:46:46 2010
From: carsten at analog-monster.de (Carsten Toensmann)
Date: Tue, 23 Nov 2010 08:46:46 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
Message-ID: <7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>


Hi Tom,

I don't know the real overhead using C or any other languages but it might 
be better to use assembler instead of C. Modern controller offer a quite 
comfortable assembler, and my experiences with an 8mhz controller 
(ATmega8535) were good. My ?Net keyboard module uses an 8mhz ATmega8535 
scanning a 5 Octave keyboard, creating MIDI messages for 10 voices including 
key velocity, handling an LCD display, scans an analogue joystick (two axis) 
and two digital potentiometers, reading MIDI just with a simple scheduler, 
see also

http://www.analog-monster.de/un_kbd_en.html

Time control of MIDI input or output can be handled by USART interrupts, the 
rest of the tasks below can be handled in a simple program loop. HD44780 
compatible LCDs are not the fastest, I know, but not as slow that I needed 
an asynchronous scheduler / buffer for that.

To cut a long story short: I prefer a rather simple solution: one 
controller, language without overhead, no operating system, just a simple 
program loop.

Regards

Carsten

----- Original Message ----- 
From: "Tom Wiltshire" <tom at electricdruid.net>
To: "Synth DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Monday, November 22, 2010 5:29 PM
Subject: [sdiy] Organisation of tasks in synth's main uP


> Hi all,
>
> Having got started with C, I'm thinking about what I'm trying to do with 
> it - Write code for the main uP in my synth.
> This uP has to accomplish the following tasks, which are common to many 
> synths:
>
> * Scan the keyboard and calculate velocity, note on, etc.
> * Update the LCD screens
> * Update panel LEDs
> * Scan panel buttons and controls
> * Read several ADC channels
> * Process incoming MIDI
> * Send outgoing MIDI
> * Deal with voice assignment
> * Send instructions to the voices over a serial comms link
>
> Most of these things I've done at one time or another, so I'm not too 
> worried about the nuts and bolts of each part. What I haven't done before 
> is deal with a system that does so many different things at once. It needs 
> to do each in a timely manner.
>
> Some of these tasks are quite slow and will delay other things appreciably 
> if not handled correctly. One example is the LCD. LCDs are dog slow to 
> respond, so sending a screenful of information to one will hang up my uP 
> for a considerable time. To prevent this should I buffer outgoing bytes to 
> the LCD? I could then throw LCD data into a buffer and then feed bytes 
> from there to the LCD at a slower rate.
>
> Other tasks are slow, but require fairly swift attention. For example, I 
> could buffer MIDI information coming in, and then deal with it in quite 
> large chunks (say 16 or 32 bytes), but this would entail a considerable 
> MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the 
> MIDI parser each time a status byte arrives. This would mean that the 
> previous message was now complete and could be processed, or that a system 
> realtime message had just arrived, in which case it could be processed.
>
> I can see that interrupts are going to be crucial, but the question is 
> where to focus scarce resources? I know some people here have broken the 
> job down by having a separate uP doing control panel scanning. Whilst that 
> has some benefits, it also implies another set of inter-uP comms which has 
> costs.
> Your thoughts please?
>
> Thanks,
> Tom
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 



From jdm at synthcom.com  Tue Nov 23 12:07:35 2010
From: jdm at synthcom.com (J.D. McEachin)
Date: Tue, 23 Nov 2010 03:07:35 -0800
Subject: [sdiy] Sad news
In-Reply-To: <8C39BFC1-81F6-4073-A00B-964ABD793F10@ece.gatech.edu>
Message-ID: <3.0.6.32.20101123030735.022991f0@synthcom.com>

At 11:07 AM 11/22/2010 +0000, lanterma at ece.gatech.edu wrote:

>My colleague Prof. Marshall Leach passed away yesterday. He was an
exemplary teacher, and a mentor to students and faculty alike. You would be
hard pressed to find faculty in my department who cared more about students
than Marshall. 

I'm very sorry to hear that.  He was one of the best professors I had at
Tech, a natural teacher whose classes everybody wanted to attend.  The man
loved Bode plots, and I can't tell you how many packs of log-ruled paper I
went through in his classes. :)

My favorite moment with Dr. Leach - one time, at the annual EE picnic, I
told him "you have a very interesting skull."  Dr. Leach replied, "I'm not
sure how to take that."  I said, "you should take it as it's intended - as
a complement!"  He then smiled.  Yes, I may have had a few beers at the
time.  ;)

Jeffrey



From veronica.merryfield at shaw.ca  Tue Nov 23 12:27:25 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Tue, 23 Nov 2010 03:27:25 -0800
Subject: [sdiy] OT: Wisdom
Message-ID: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>

I wonder if the collected masses, who seem to have a decent handle on this sort of stuff, could take a quick look at the below ASCII art schematic. 

Assuming all the resistors are the same, what would the output be of the two op-amps?

Thanks

3.3v-----
	|
	\
	/
	\
	/    ---/\/\/\---
	|   |            |
	|-----|+         |
	|     |opamp  -----
	\  0v-|-
	/   
	\
	/
	|
	|
	|
	\
	/
	\
	/
	|   ---/\/\/\---
	|  |            |
	 ----|+         |
             |opamp ------ ????
          0v-|-

From pata at ieee.org  Tue Nov 23 12:44:27 2010
From: pata at ieee.org (KATAYAMA)
Date: Tue, 23 Nov 2010 20:44:27 +0900
Subject: [sdiy] OT: Wisdom
In-Reply-To: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>
References: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>
Message-ID: <4CEBA91B.3010508@ieee.org>

Hi Velonica and the lists

I think all the outputs are high-rail saturation voltage, because each 
OPamp has positive feedback and positive voltage is fed to non-inverting 
input terminal.

...Or, did you mistake that input terminal?

Taku

(2010/11/23 20:27), Veronica Merryfield wrote:
> I wonder if the collected masses, who seem to have a decent handle on this sort of stuff, could take a quick look at the below ASCII art schematic.
>
> Assuming all tOhe resistors are the same, what would the output be of the two op-amps?
>
> Thanks
>
> 3.3v-----
> 	|
> 	\
> 	/
> 	\
> 	/    ---/\/\/\---
> 	|   |            |
> 	|-----|+         |
> 	|     |opamp  -----
> 	\  0v-|-
> 	/
> 	\
> 	/
> 	|
> 	|
> 	|
> 	\
> 	/
> 	\
> 	/
> 	|   ---/\/\/\---
> 	|  |            |
> 	 ----|+         |
>               |opamp ------ ????
>            0v-|-
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


-- 
=========================================
KATAYAMA, Takuya
Muse Music Synthesizer Laboratory, Japan


From neil.johnson97 at ntlworld.com  Tue Nov 23 13:18:44 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 23 Nov 2010 12:18:44 +0000
Subject: [sdiy] OT: Wisdom
In-Reply-To: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>
References: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>
Message-ID: <AANLkTik4Qj0RsKtygD0KJkbr_X8QBCJbrzc9mZ-G_PXN@mail.gmail.com>

Well, assuming Taku is right and we swap the inputs to the opamps,
then the top op-amp outputs -3V3, and the bottom op-amp output sits at
0V.

Assuming of course that your op-amps are wired across bipolar supplies, etc.

Neil

On 23 November 2010 11:27, Veronica Merryfield
<veronica.merryfield at shaw.ca> wrote:
> I wonder if the collected masses, who seem to have a decent handle on this sort of stuff, could take a quick look at the below ASCII art schematic.
>
> Assuming all the resistors are the same, what would the output be of the two op-amps?
>
> Thanks
>
> 3.3v-----
> ? ? ? ?|
> ? ? ? ?\
> ? ? ? ?/
> ? ? ? ?\
> ? ? ? ?/ ? ?---/\/\/\---
> ? ? ? ?| ? | ? ? ? ? ? ?|
> ? ? ? ?|-----|+ ? ? ? ? |
> ? ? ? ?| ? ? |opamp ?-----
> ? ? ? ?\ ?0v-|-
> ? ? ? ?/
> ? ? ? ?\
> ? ? ? ?/
> ? ? ? ?|
> ? ? ? ?|
> ? ? ? ?|
> ? ? ? ?\
> ? ? ? ?/
> ? ? ? ?\
> ? ? ? ?/
> ? ? ? ?| ? ---/\/\/\---
> ? ? ? ?| ?| ? ? ? ? ? ?|
> ? ? ? ? ----|+ ? ? ? ? |
> ? ? ? ? ? ? |opamp ------ ????
> ? ? ? ? ?0v-|-
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



-- 
http://www.njohnson.co.uk


From neil.johnson97 at ntlworld.com  Tue Nov 23 13:19:59 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 23 Nov 2010 12:19:59 +0000
Subject: [sdiy] OT: Wisdom
In-Reply-To: <AANLkTik4Qj0RsKtygD0KJkbr_X8QBCJbrzc9mZ-G_PXN@mail.gmail.com>
References: <67071D62-49EF-4CE9-BD29-E60C065361D0@shaw.ca>
	<AANLkTik4Qj0RsKtygD0KJkbr_X8QBCJbrzc9mZ-G_PXN@mail.gmail.com>
Message-ID: <AANLkTim3c34Rt41E4wvyst0Hxb3wRZ=vn7G9n0nx__oO@mail.gmail.com>

(Oops! Sorry about the top-posting)

-- 
http://www.njohnson.co.uk


From thomas at pdp7.org  Tue Nov 23 13:34:26 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Tue, 23 Nov 2010 13:34:26 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
Message-ID: <4CEBB4D2.9070107@pdp7.org>

On 11/23/10 08:46 , Carsten Toensmann wrote:
> I don't know the real overhead using C or any other languages but it
> might be better to use assembler instead of C.

How is it possible to compare something you say you don't know with 
something that I assume you know and derive a recommendation from that?

> To cut a long story short: I prefer a rather simple solution: one
> controller, language without overhead, no operating system, just a
> simple program loop.

Nothing stops anyone from just writing a simple program loop in just 
about any language. Overhead is not primarily a language issue: If you 
compare C and assembler (assuming reasonable C compilers) you'll notice 
that you can write the same algorithm in any number of moronic ways in 
both languages. If you know what your target architecture does best 
you'll be well off regardless of clinging to assembler or C instead of C++.

	Thomas


From tom at electricdruid.net  Tue Nov 23 13:46:57 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 23 Nov 2010 12:46:57 +0000
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <4CEBB4D2.9070107@pdp7.org>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
Message-ID: <E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>


On 11/23/10 08:46 , Carsten Toensmann wrote:
> I don't know the real overhead using C or any other languages but it
> might be better to use assembler instead of C.


Don't worry, Carsten, I've seriously considered it, even for a job of this size. However, I think ultimately C is the better choice because it offers you more in the way of structure (without having to put it there yourself) and makes the conditional logic lot easier to read and debug.

On 23 Nov 2010, at 12:34, Thomas Strathmann wrote:
> Nothing stops anyone from just writing a simple program loop in just about any language. Overhead is not primarily a language issue: If you compare C and assembler (assuming reasonable C compilers) you'll notice that you can write the same algorithm in any number of moronic ways in both languages. If you know what your target architecture does best you'll be well off regardless of clinging to assembler or C instead of C++.

I quite agree that you can write a simple program loop or hideous code in any language. One advantage of coming to this from assembly is that I do have a clear understanding of what the target architecture looks like since I've been dealing with nothing else for the last goodwhile. I hope that this will enable me (in time) to write C that compiles down to something neat and fast. For now I just have to get up to speed with my C.

As to C++, I learned it at Uni but haven't done any since, and anyway, are there compilers for C++ and dsPIC?

Thanks,
Tom



From neil.johnson97 at ntlworld.com  Tue Nov 23 14:37:58 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 23 Nov 2010 13:37:58 +0000
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
Message-ID: <AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>

Hi,

Tom Wiltshire wrote:
> Don't worry, Carsten, I've seriously considered it, even for a job of this size. However, I think ultimately C is the better choice because it offers you more in the way of structure (without having to put it there yourself) and makes the conditional logic lot easier to read and debug.

Yes indeed.  Once you reach a certain level of competence with C you
can treat it as a high-level assembler, with the compiler doing a lot
of the tedious house-keeping stuff that you'd otherwise have to do in
bare assembler.  For example: local variables, stack management,
pointer arithmetic/table indexing, etc.  And then there are all those
wonderful optimisations which speed up your code or make it smaller,
but if you did them in assembler you'd end up with almost
unmaintainable code.

Most compilers aimed at embedded systems, including GCC, usually have
some way to place native assembler instructions in your C code
("inline assembler") and have the compiler sort out all the other
stuff (function prologue and epilogue, etc) for you.  However  I don't
generally recommend it for large functions (it tends to block any
optimisations in that function, same with longjmp/setjmp) so best to
hide it away in utility functions.

Cheers,
Neil
-- 
http://www.njohnson.co.uk


From ol.gillet at gmail.com  Tue Nov 23 14:54:06 2010
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Tue, 23 Nov 2010 14:54:06 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
	<AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>
Message-ID: <AANLkTi=rxVXr8ozRf7CzjpY-ifkGKUMYKK1iPAz5DUsy@mail.gmail.com>

> Most compilers aimed at embedded systems, including GCC, usually have
> some way to place native assembler instructions in your C code
> ("inline assembler") and have the compiler sort out all the other
> stuff (function prologue and epilogue, etc) for you. ?However ?I don't
> generally recommend it for large functions (it tends to block any
> optimisations in that function, same with longjmp/setjmp) so best to
> hide it away in utility functions.

Same experience here... I found that avr-gcc did the "right" register
allocation in code surrounding inlined assembly only when the assembly
code was kept small and didn't touch too many variables. So it seems
better (and also good from a readability and code reuse point of view)
to keep in C the "glue" between small inlined assembly functions.


From jgrisso at det3.net  Tue Nov 23 15:14:11 2010
From: jgrisso at det3.net (Joe Grisso)
Date: Tue, 23 Nov 2010 07:14:11 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
Message-ID: <AANLkTikG7StvtYHWr=pfqJEKt+FRG6K7Mvxz14NwtAZT@mail.gmail.com>

Tom,

     I'm currently working on a sequencer which is quite timing
dependent. I'm using bare metal, meaning that I haven't chosen a
particular RTOS, and I'm using an AVR with GCC. One thing I do to
enforce soft real-time capacity is set up a timer interrupt for all of
the time critical tasks I need to do. The timer is usually firing
every 500uS or 1ms depending on the required resolution. For a synth
engine, this might not be acceptable, but it is definitely faster than
responding to MIDI. You might be able to do something like that as
well. There are other techniques you can investigate to maximize
efficiency like slimming down your interrupt routines so they only
shuttle data from the peripheral to main memory, and foist off the
heavy lifting of the ISR into user-space. This is sometimes described
as top-half/bottom-half interrupt routines.
     The decision tree in the master timer-tick interrupt is fed with
data from the main loop and its associated subroutines, which is
passed only after data has been completely updated by whatever process
is handling this. This includes front panel management, sequencer
parameter changes, and processing of ADC/DAC data for things like CV
and quantization. The main routine handles things at the high level -
manipulating data structures which are then read by the interrupt to
do the physical updating. I have a bunch of inline functions to break
up the craziness of this interrupt, and those functions are also quite
small. Using an inline keyword basically removes the function as an
independent piece of code that can be called, and inserts it into the
ISR as an 'in-line' piece of assembly code. This eliminates calling
another subroutine during an interrupt at the expense of code size -
if you call the function elsewhere then the entire code for that
function will be duplicated. So, I make sure that the ISR is the only
routine using that function. :-)
     One other thing to note about languages to write in, I personally
choose C because I move between architectures and OSes so much - AVR,
PIC, ARM, ColdFire, etc. It's easier to port when the language is
somewhat processor-neutral. Also, back when I worked at E-Mu, I
remember good swaths of EOS, the Sampler O/S for the Emulator, being
written in C++. Language is somewhat unimportant given a bare minimum
of appropriate resources and applying the proper programming
techniques. I remember many discussions about function tables,
ctor/dtor caching and other C++ ugliness the firmware guys experienced
when starting to port EOS to ColdFire from 68K.
     I always try to find open-source projects as design examples for
programming. Some of them are good, some of them not so good.
Specifically, I've looked at AVR-X, the x0xb0x project, MIDIbox,
MIDIduino and a bunch of Paul Maddox' code he's open sourced. The bits
of information that can be gleaned are very useful with respect to
program structure, handling timing and processing data in a way that
doesn't gum the processor up too bad.

Best,

-- 
Joe Grisso
Detachment 3, Ltd.

On Tue, Nov 23, 2010 at 5:46 AM, Tom Wiltshire <tom at electricdruid.net> wrote:
>
> On 11/23/10 08:46 , Carsten Toensmann wrote:
>> I don't know the real overhead using C or any other languages but it
>> might be better to use assembler instead of C.
>
>
> Don't worry, Carsten, I've seriously considered it, even for a job of this size. However, I think ultimately C is the better choice because it offers you more in the way of structure (without having to put it there yourself) and makes the conditional logic lot easier to read and debug.
>
> On 23 Nov 2010, at 12:34, Thomas Strathmann wrote:
>> Nothing stops anyone from just writing a simple program loop in just about any language. Overhead is not primarily a language issue: If you compare C and assembler (assuming reasonable C compilers) you'll notice that you can write the same algorithm in any number of moronic ways in both languages. If you know what your target architecture does best you'll be well off regardless of clinging to assembler or C instead of C++.
>
> I quite agree that you can write a simple program loop or hideous code in any language. One advantage of coming to this from assembly is that I do have a clear understanding of what the target architecture looks like since I've been dealing with nothing else for the last goodwhile. I hope that this will enable me (in time) to write C that compiles down to something neat and fast. For now I just have to get up to speed with my C.
>
> As to C++, I learned it at Uni but haven't done any since, and anyway, are there compilers for C++ and dsPIC?
>
> Thanks,
> Tom
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From paul at cometway.com  Tue Nov 23 15:47:08 2010
From: paul at cometway.com (Paul Cunningham)
Date: Tue, 23 Nov 2010 09:47:08 -0500
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
Message-ID: <0DCEC3B0-4ABC-4117-9F6A-C1C7CA512511@cometway.com>

You guys might go back and read the recent discussion regarding C. I didn't follow the entire thread, but there's lots of the typical arguments for using C vs assembler on an embedded circuit. Modern optimizing C compilers yield tight object code, and anything else that carries weight can be analyzed and hand-assembled inline. -pc

On Nov 23, 2010, at 2:46 AM, Carsten Toensmann wrote:

> 
> Hi Tom,
> 
> I don't know the real overhead using C or any other languages but it might be better to use assembler instead of C. Modern controller offer a quite comfortable assembler, and my experiences with an 8mhz controller (ATmega8535) were good. My ?Net keyboard module uses an 8mhz ATmega8535 scanning a 5 Octave keyboard, creating MIDI messages for 10 voices including key velocity, handling an LCD display, scans an analogue joystick (two axis) and two digital potentiometers, reading MIDI just with a simple scheduler, see also
> 
> http://www.analog-monster.de/un_kbd_en.html
> 
> Time control of MIDI input or output can be handled by USART interrupts, the rest of the tasks below can be handled in a simple program loop. HD44780 compatible LCDs are not the fastest, I know, but not as slow that I needed an asynchronous scheduler / buffer for that.
> 
> To cut a long story short: I prefer a rather simple solution: one controller, language without overhead, no operating system, just a simple program loop.
> 
> Regards
> 
> Carsten
> 
> ----- Original Message ----- From: "Tom Wiltshire" <tom at electricdruid.net>
> To: "Synth DIY" <synth-diy at dropmix.xs4all.nl>
> Sent: Monday, November 22, 2010 5:29 PM
> Subject: [sdiy] Organisation of tasks in synth's main uP
> 
> 
>> Hi all,
>> 
>> Having got started with C, I'm thinking about what I'm trying to do with it - Write code for the main uP in my synth.
>> This uP has to accomplish the following tasks, which are common to many synths:
>> 
>> * Scan the keyboard and calculate velocity, note on, etc.
>> * Update the LCD screens
>> * Update panel LEDs
>> * Scan panel buttons and controls
>> * Read several ADC channels
>> * Process incoming MIDI
>> * Send outgoing MIDI
>> * Deal with voice assignment
>> * Send instructions to the voices over a serial comms link
>> 
>> Most of these things I've done at one time or another, so I'm not too worried about the nuts and bolts of each part. What I haven't done before is deal with a system that does so many different things at once. It needs to do each in a timely manner.
>> 
>> Some of these tasks are quite slow and will delay other things appreciably if not handled correctly. One example is the LCD. LCDs are dog slow to respond, so sending a screenful of information to one will hang up my uP for a considerable time. To prevent this should I buffer outgoing bytes to the LCD? I could then throw LCD data into a buffer and then feed bytes from there to the LCD at a slower rate.
>> 
>> Other tasks are slow, but require fairly swift attention. For example, I could buffer MIDI information coming in, and then deal with it in quite large chunks (say 16 or 32 bytes), but this would entail a considerable MIDI lag, which I'd like to avoid. Instead, I'd thought of calling the MIDI parser each time a status byte arrives. This would mean that the previous message was now complete and could be processed, or that a system realtime message had just arrived, in which case it could be processed.
>> 
>> I can see that interrupts are going to be crucial, but the question is where to focus scarce resources? I know some people here have broken the job down by having a separate uP doing control panel scanning. Whilst that has some benefits, it also implies another set of inter-uP comms which has costs.
>> Your thoughts please?
>> 
>> Thanks,
>> Tom
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From nvawter at media.mit.edu  Tue Nov 23 17:50:42 2010
From: nvawter at media.mit.edu (Noah Vawter)
Date: Tue, 23 Nov 2010 11:50:42 -0500
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <AANLkTi=rxVXr8ozRf7CzjpY-ifkGKUMYKK1iPAz5DUsy@mail.gmail.com>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
	<AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>
	<AANLkTi=rxVXr8ozRf7CzjpY-ifkGKUMYKK1iPAz5DUsy@mail.gmail.com>
Message-ID: <4A2FB51F-3C8D-4928-838B-A14DB8883173@media.mit.edu>


pro-question time: in assembly, I rely heavily on the overflow bit  
being set to detect wrap-around, e.g. in 8-bit registers.  But these  
days I program mainly in C and I can't figure out how to access that  
overflow bit.
I have gone so far as to use 7-bit numbers and treat the MSB as an  
overflow, but does anyone know how to read the CPU's overflow bit from  
C?

thank you,
-N


On Nov 23, 2010, at 8:54 AM, Olivier Gillet wrote:

>> Most compilers aimed at embedded systems, including GCC, usually have
>> some way to place native assembler instructions in your C code
>> ("inline assembler") and have the compiler sort out all the other
>> stuff (function prologue and epilogue, etc) for you.  However  I  
>> don't
>> generally recommend it for large functions (it tends to block any
>> optimisations in that function, same with longjmp/setjmp) so best to
>> hide it away in utility functions.
>
> Same experience here... I found that avr-gcc did the "right" register
> allocation in code surrounding inlined assembly only when the assembly
> code was kept small and didn't touch too many variables. So it seems
> better (and also good from a readability and code reuse point of view)
> to keep in C the "glue" between small inlined assembly functions.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From John.Speth at coherent.com  Tue Nov 23 18:10:52 2010
From: John.Speth at coherent.com (Speth, John)
Date: Tue, 23 Nov 2010 09:10:52 -0800
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <4A2FB51F-3C8D-4928-838B-A14DB8883173@media.mit.edu>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
	<AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>
	<AANLkTi=rxVXr8ozRf7CzjpY-ifkGKUMYKK1iPAz5DUsy@mail.gmail.com>
	<4A2FB51F-3C8D-4928-838B-A14DB8883173@media.mit.edu>
Message-ID: <AB7F62BBA358E04FA919701B9703184AF29189D6@DC1EXC2.na.coherentinc.com>

> pro-question time: in assembly, I rely heavily on the overflow bit
> being set to detect wrap-around, e.g. in 8-bit registers.  But
> these
> days I program mainly in C and I can't figure out how to access
> that
> overflow bit.
> I have gone so far as to use 7-bit numbers and treat the MSB as an
> overflow, but does anyone know how to read the CPU's overflow bit
> from
> C?

There's no in-built way in C to test for overflow.  You, as the designer, must build enough dynamic range into your variables by sizing them adequately to avoid overflow.  Or you must build a mechanism into your code that will allow you to test.

There is a simple way to test for overflow that works as long as you don't need all bits in your storage.  For example, if you want to detect overflow on adding 12 bits and you are storing in 16 bits, you know you have overflow when bit 12 is high after the addition.  Even simpler, testing for a negative number after adding to a C int will give you overflow indication if your usable range is 0 to [(2^N-1)-1].

JJS


The information contained in this communication is confidential and may be legally privileged. It is intended solely for the use of the individual or entity to whom it is addressed and others authorized to receive it. If you are not the intended recipient you are hereby (a) notified that any disclosure, copying, distribution or taking any action with respect to the content of this information is strictly prohibited and may be unlawful, and (b) kindly requested to inform the sender immediately and delete any copies. Coherent is neither liable for the proper and complete transmission of the information contained in this communication nor for any delay in its receipt.


From tom at electricdruid.net  Tue Nov 23 18:31:35 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Tue, 23 Nov 2010 17:31:35 +0000
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <4A2FB51F-3C8D-4928-838B-A14DB8883173@media.mit.edu>
References: <69ED6A7A-EFB9-40ED-93FF-2F788F8005F2@electricdruid.net>
	<7099C962C0244983B317B9E21EFB8ED8@ww901.siemens.net>
	<4CEBB4D2.9070107@pdp7.org>
	<E365A56D-158F-44A9-82F7-5F7D4247BED9@electricdruid.net>
	<AANLkTimoeA7LXtjMk0vv8rDpK6aCLc-Y7QYL7CG-Q_f6@mail.gmail.com>
	<AANLkTi=rxVXr8ozRf7CzjpY-ifkGKUMYKK1iPAz5DUsy@mail.gmail.com>
	<4A2FB51F-3C8D-4928-838B-A14DB8883173@media.mit.edu>
Message-ID: <8DC5A4E0-698B-498A-9F75-15BF425D262E@electricdruid.net>

The device header files for the dsPIC (and presumably PIC too, but I haven't checked) make all the bits of the status register available using MCHPs favoured 'struct' approach.

This means the following is legal:

int x = SRbits.OV;

You can also do tests and comparisons with it, or any of the other status register bits:

if (SRbits.OV) {
	// Overflow!

} else {
	// No overflow!
}

I've just tried this, and the compiler throws no error. YPMV (Your platform may vary?).

T.


On 23 Nov 2010, at 16:50, Noah Vawter wrote:

> 
> pro-question time: in assembly, I rely heavily on the overflow bit being set to detect wrap-around, e.g. in 8-bit registers.  But these days I program mainly in C and I can't figure out how to access that overflow bit.
> I have gone so far as to use 7-bit numbers and treat the MSB as an overflow, but does anyone know how to read the CPU's overflow bit from C?
> 
> thank you,
> -N
> 
> 
> On Nov 23, 2010, at 8:54 AM, Olivier Gillet wrote:
> 
>>> Most compilers aimed at embedded systems, including GCC, usually have
>>> some way to place native assembler instructions in your C code
>>> ("inline assembler") and have the compiler sort out all the other
>>> stuff (function prologue and epilogue, etc) for you.  However  I don't
>>> generally recommend it for large functions (it tends to block any
>>> optimisations in that function, same with longjmp/setjmp) so best to
>>> hide it away in utility functions.
>> 
>> Same experience here... I found that avr-gcc did the "right" register
>> allocation in code surrounding inlined assembly only when the assembly
>> code was kept small and didn't touch too many variables. So it seems
>> better (and also good from a readability and code reuse point of view)
>> to keep in C the "glue" between small inlined assembly functions.
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From Alan.Needham at centrica.com  Tue Nov 23 18:46:59 2010
From: Alan.Needham at centrica.com (Needham, Alan)
Date: Tue, 23 Nov 2010 17:46:59 -0000
Subject: [sdiy] OT: Wisdom
In-Reply-To: <AANLkTik4Qj0RsKtygD0KJkbr_X8QBCJbrzc9mZ-G_PXN@mail.gmail.com>
Message-ID: <7481C6264DDFF94AB1A0A96930BED3D802907E11@WC000043A.uk.centricaplc.com>

| On 23 November 2010 11:27, Veronica Merryfield
| <veronica.merryfield at shaw.ca> wrote:
| > I wonder if the collected masses, who seem to have a decent handle on
| this sort of stuff, could take a quick look at the below ASCII art
| schematic.
| >
| > Assuming all the resistors are the same, what would the output be of the
| two op-amps?
| >
| > Thanks
| >
| > 3.3v-----
| > ? ? ? ?|
| > ? ? ? ?\
| > ? ? ? ?/
| > ? ? ? ?\
| > ? ? ? ?/ ? ?---/\/\/\---
| > ? ? ? ?| ? | ? ? ? ? ? ?|
| > ? ? ? ?|-----|+ ? ? ? ? |
| > ? ? ? ?| ? ? |opamp ?-----
| > ? ? ? ?\ ?0v-|-
| > ? ? ? ?/
| > ? ? ? ?\
| > ? ? ? ?/
| > ? ? ? ?|
| > ? ? ? ?|
| > ? ? ? ?|
| > ? ? ? ?\
| > ? ? ? ?/
| > ? ? ? ?\
| > ? ? ? ?/
| > ? ? ? ?| ? ---/\/\/\---
| > ? ? ? ?| ?| ? ? ? ? ? ?|
| > ? ? ? ? ----|+ ? ? ? ? |
| > ? ? ? ? ? ? |opamp ------ ????
| > ? ? ? ? ?0v-|-
| > _______________________________________________

All the resistors are the same,
assuming the op-amps are both reversed (as per Taku's suggestion),
Will the bottom op-amp not drive to match the + and - inputs?
3.3v through 3 resistors = 1.1v each so the bottom out will be -1.1v
The upper op-amp will be +2.2v
This gives the same current through each of the 4 'current path' resistors

Or am I missing something?
	Alan


_____________________________________________________________________
The information contained in or attached to this email is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are not authorised to and must not disclose, copy,distribute, or retain this message or any part of it. It may contain information which is confidential and/or covered by legal professional or other privilege (or other rules or laws with similar effect in jurisdictions outside England and Wales).

The views expressed in this email are not necessarily the views of Centrica plc, and the company, its directors, officers or employees make no representation or accept any liability for its accuracy or completeness unless expressly stated to the contrary.

A Centrica business British Gas Services Limited is authorised and regulated by the Financial Services Authority for its insurance mediation activities.

Registered office: Millstream, Maidenhead Road, Windsor, Berkshire SL4 5GD

Registered in England No 3141243.  

Centrica plc

Registered office: Millstream, Maidenhead Road, Windsor, Berkshire SL4 5GD

Registered in England and Wales No 3033654


From grant at musictechnologiesgroup.com  Tue Nov 23 18:54:57 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Tue, 23 Nov 2010 10:54:57 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
Message-ID: <20101123105457.c16e921f9c8655b42ea149fc1daa3492.e1d32301ad.wbe@email04.secureserver.net>

> pro-question time: in assembly, I rely heavily on the overflow bit  
> being set to detect wrap-around, e.g. in 8-bit registers.  But these  
> days I program mainly in C and I can't figure out how to access that  
> overflow bit.
> I have gone so far as to use 7-bit numbers and treat the MSB as an  
> overflow, but does anyone know how to read the CPU's overflow bit from  
> C?

Admittedly it hurts at first moving to C (and procedural methods). I
don't think you want to look at the overflow bit. It's too hardware and
compiler dependent. The nice thing about C, when used "properly" is that
the code really is quite portable.  I think in order to really benefit
from C you need to allow yourself to accept the spirit of it. Same goes
for C++ -- if you don't adopt the spirit you just keep writing C and
missing out on the great benefits.  So I would say to try and think at a
slightly higher level. "There are no CPU flags". The penalty is minimal
and the benefits huge. Just use a for or while loop and get creative
with the start and/or end conditions. If that's not intuitive try moving
up to an unsigned int or doing an extra C statement before or after the
loop.  Using an unsigned int now and then shouldn't be a barrier. If
it's a local variable the compiler will recapture the variable space and
the difference in execution speed probably one uS. I also try to avoid
being "too clever".  If it's hard to understand now, it will be way hard
later when you go back to revisit that code.

GB




From controlvoltage at gmail.com  Tue Nov 23 19:27:48 2010
From: controlvoltage at gmail.com (Amos)
Date: Tue, 23 Nov 2010 13:27:48 -0500
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <20101123105457.c16e921f9c8655b42ea149fc1daa3492.e1d32301ad.wbe@email04.secureserver.net>
References: <20101123105457.c16e921f9c8655b42ea149fc1daa3492.e1d32301ad.wbe@email04.secureserver.net>
Message-ID: <AANLkTimOzH=YB44aUBVzmS_qbvezKfXj93t8Xm22JROW@mail.gmail.com>

I love writing really "clever-looking" c code that works a whole
complex branching operation into a single (on-screen) line of source.

My compiler thinks I'm not so hot though, and seldom/never does as
well with this kind of input as when I think about opcodes and write c
in a more lined-out way, where each c statement only "says" one or two
lines-of-code.  I'm learning not to be so fancy as a result.

Back to the original question, I'm a big fan of RTOS for synths. Fits
very well and allows a lot of flexibility.  There are some challenges
merging run-loop and interrupt-driven approaches to resource use; I
use flags and simple state machines to make sure everyone is playing
nicely.


On 11/23/10, grant at musictechnologiesgroup.com
<grant at musictechnologiesgroup.com> wrote:
>> pro-question time: in assembly, I rely heavily on the overflow bit
>> being set to detect wrap-around, e.g. in 8-bit registers.  But these
>> days I program mainly in C and I can't figure out how to access that
>> overflow bit.
>> I have gone so far as to use 7-bit numbers and treat the MSB as an
>> overflow, but does anyone know how to read the CPU's overflow bit from
>> C?
>
> Admittedly it hurts at first moving to C (and procedural methods). I
> don't think you want to look at the overflow bit. It's too hardware and
> compiler dependent. The nice thing about C, when used "properly" is that
> the code really is quite portable.  I think in order to really benefit
> from C you need to allow yourself to accept the spirit of it. Same goes
> for C++ -- if you don't adopt the spirit you just keep writing C and
> missing out on the great benefits.  So I would say to try and think at a
> slightly higher level. "There are no CPU flags". The penalty is minimal
> and the benefits huge. Just use a for or while loop and get creative
> with the start and/or end conditions. If that's not intuitive try moving
> up to an unsigned int or doing an extra C statement before or after the
> loop.  Using an unsigned int now and then shouldn't be a barrier. If
> it's a local variable the compiler will recapture the variable space and
> the difference in execution speed probably one uS. I also try to avoid
> being "too clever".  If it's hard to understand now, it will be way hard
> later when you go back to revisit that code.
>
> GB
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>

-- 
Sent from my mobile device


From grant at musictechnologiesgroup.com  Tue Nov 23 20:07:39 2010
From: grant at musictechnologiesgroup.com (grant at musictechnologiesgroup.com)
Date: Tue, 23 Nov 2010 12:07:39 -0700
Subject: [sdiy] Organisation of tasks in synth's main uP
Message-ID: <20101123120739.c16e921f9c8655b42ea149fc1daa3492.db02fab668.wbe@email04.secureserver.net>

> I love writing really "clever-looking" c code that works a whole
> complex branching operation into a single (on-screen) line of source.

Aweseome! I'm not saying there aren't brilliant things that can be done
in C. ;-)

One of the things I like (and perhaps that's what you mean above) is
using a function pointer to call user interface code depending on the
user's context. Great for eliminating huge switch statements like you'd
encounter when doing front panel code.  

And there is a great book by Niall Murphy called Front Panel if anyone
is interested...

I would like to hear more about your RTOS experience. Especially w.r.t.
to your current project(s) Amos.

GB




From neil.johnson97 at ntlworld.com  Tue Nov 23 20:11:06 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 23 Nov 2010 19:11:06 +0000
Subject: [sdiy] OT: Wisdom
In-Reply-To: <7481C6264DDFF94AB1A0A96930BED3D802907E11@WC000043A.uk.centricaplc.com>
References: <7481C6264DDFF94AB1A0A96930BED3D802907E11@WC000043A.uk.centricaplc.com>
Message-ID: <A4B8F807-C66F-49C1-B27A-D938450A7DB3@ntlworld.com>

Alan,

Needham, Alan wrote:

> | On 23 November 2010 11:27, Veronica Merryfield
> | <veronica.merryfield at shaw.ca> wrote:
> | > I wonder if the collected masses, who seem to have a decent  
> handle on
> | this sort of stuff, could take a quick look at the below ASCII art
> | schematic.
> | >
> | > Assuming all the resistors are the same, what would the output  
> be of the
> | two op-amps?
> | >
> | > Thanks
> | >
> | > 3.3v-----
> | >        |
> | >        \
> | >        /
> | >        \
> | >        /    ---/\/\/\---
> | >        |   |            |
> | >        |-----|+         |
> | >        |     |opamp  -----
> | >        \  0v-|-
> | >        /
> | >        \
> | >        /
> | >        |
> | >        |
> | >        |
> | >        \
> | >        /
> | >        \
> | >        /
> | >        |   ---/\/\/\---
> | >        |  |            |
> | >         ----|+         |
> | >             |opamp ------ ????
> | >          0v-|-
> | > _______________________________________________
>
> All the resistors are the same,
> assuming the op-amps are both reversed (as per Taku's suggestion),
> Will the bottom op-amp not drive to match the + and - inputs?
> 3.3v through 3 resistors = 1.1v each so the bottom out will be -1.1v
> The upper op-amp will be +2.2v
> This gives the same current through each of the 4 'current path'  
> resistors
>
> Or am I missing something?
> 	Alan
>

(assuming the "Taku correction")

The top op-amp will servo its output so that the -ve input is at 0V.   
This forces the bottom of the top resistor to 0V.  As the feedback  
resistor is the same value this gives an output of -1 x Vinput = -3V3.

Now the bottom op-amp has an input resistor of 2R.  But the voltage  
at the top of the middle resistor is now 0V, so there is no current  
flowing into the summing node, so the output is 0V.

Neil
--
http://www.njohnson.co.uk





From jason at redfish.net  Tue Nov 23 20:15:06 2010
From: jason at redfish.net (Jason Proctor)
Date: Tue, 23 Nov 2010 11:15:06 -0800
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <AANLkTimOzH=YB44aUBVzmS_qbvezKfXj93t8Xm22JROW@mail.gmail.com>
References: <20101123105457.c16e921f9c8655b42ea149fc1daa3492.e1d32301ad.wbe@email04.se
	cureserver.net>
	<AANLkTimOzH=YB44aUBVzmS_qbvezKfXj93t8Xm22JROW@mail.gmail.com>
Message-ID: <a062007b3c911bc280037@[192.168.1.69]>

>On 11/23/10, grant at musictechnologiesgroup.com
><grant at musictechnologiesgroup.com> wrote:
>>>  pro-question time: in assembly, I rely heavily on the overflow bit
>>>  being set to detect wrap-around, e.g. in 8-bit registers.  But these
>>>  days I program mainly in C and I can't figure out how to access that
>>>  overflow bit.
>>>  I have gone so far as to use 7-bit numbers and treat the MSB as an
>>>  overflow, but does anyone know how to read the CPU's overflow bit from
>>>  C?
>>
>>  Admittedly it hurts at first moving to C (and procedural methods). I
>>  don't think you want to look at the overflow bit. It's too hardware and
>>  compiler dependent. The nice thing about C, when used "properly" is that
>>  the code really is quite portable.  I think in order to really benefit
>>  from C you need to allow yourself to accept the spirit of it. Same goes
>>  for C++ -- if you don't adopt the spirit you just keep writing C and
>>  missing out on the great benefits.  So I would say to try and think at a
>>  slightly higher level. "There are no CPU flags". The penalty is minimal
>>  and the benefits huge. Just use a for or while loop and get creative
>>  with the start and/or end conditions. If that's not intuitive try moving
>>  up to an unsigned int or doing an extra C statement before or after the
>>  loop.  Using an unsigned int now and then shouldn't be a barrier. If
>>  it's a local variable the compiler will recapture the variable space and
>>  the difference in execution speed probably one uS. I also try to avoid
>>  being "too clever".  If it's hard to understand now, it will be way hard
>>  later when you go back to revisit that code.
>>
>  > GB


At 1:27 PM -0500 11/23/10, Amos wrote:
>I love writing really "clever-looking" c code that works a whole
>complex branching operation into a single (on-screen) line of source.
>
>My compiler thinks I'm not so hot though, and seldom/never does as
>well with this kind of input as when I think about opcodes and write c
>in a more lined-out way, where each c statement only "says" one or two
>lines-of-code.  I'm learning not to be so fancy as a result.
>
>Back to the original question, I'm a big fan of RTOS for synths. Fits
>very well and allows a lot of flexibility.  There are some challenges
>merging run-loop and interrupt-driven approaches to resource use; I
>use flags and simple state machines to make sure everyone is playing
>nicely.
>

#pragma convert_to_posting_style(bottom)

clever-looking code == hard to read, rarely clever-working code, 
often written in such a way to ensure job security ;-)



From thomas at pdp7.org  Tue Nov 23 20:30:15 2010
From: thomas at pdp7.org (Thomas Strathmann)
Date: Tue, 23 Nov 2010 20:30:15 +0100
Subject: [sdiy] Organisation of tasks in synth's main uP
In-Reply-To: <20101123120739.c16e921f9c8655b42ea149fc1daa3492.db02fab668.wbe@email04.secureserver.net>
References: <20101123120739.c16e921f9c8655b42ea149fc1daa3492.db02fab668.wbe@email04.secureserver.net>
Message-ID: <4CEC1647.5080308@pdp7.org>

On 11/23/10 20:07 , grant at musictechnologiesgroup.com wrote:
> And there is a great book by Niall Murphy called Front Panel if anyone
> is interested...

Interesting. The parts that are in the Amazon preview for the most part 
look well rounded. I may have missed it, but I have not seen a detailed 
discussion of scheduling algorithms. When you use an RTOS, you'll want 
to make sure that tasks meat their deadlines and that ultimately leads 
to using some theory (or appropriate tools). I think the book could also 
benefit from a discussion of state charts for modelling the behaviour of 
systems. Using Mealy or Moore automata is all good and fine, but you may 
find that you'll want to have hierarchical models (supported by tools 
like Statemate or Stateflow). Live sequence charts might also be of 
interest (with tools like the Play-Engine). Using models with a formal 
theory to them might seem at first like academic over-indulgence but 
once your systems become non-trivial (with a few recurring tasks, 
dependencies between them, priorities, tight deadlines for some and 
looser deadlines for others etc.) you'll derive much value from a 
comprehensive model (even if it's drawn on paper). You'll find 
conceptual errors much faster (or at all) that might otherwise be quite 
elusive.

	Thomas


From veronica.merryfield at shaw.ca  Wed Nov 24 04:56:24 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Tue, 23 Nov 2010 19:56:24 -0800
Subject: [sdiy] OT: Wisdom
In-Reply-To: <C651097094AAD54C846A5BAA28F7141D0400AC@wdscexbe08.sc.wdc.com>
References: <7481C6264DDFF94AB1A0A96930BED3D802907E11@WC000043A.uk.centricaplc.com>
	<A4B8F807-C66F-49C1-B27A-D938450A7DB3@ntlworld.com>
	<C651097094AAD54C846A5BAA28F7141D0400AC@wdscexbe08.sc.wdc.com>
Message-ID: <04479438-76A1-468F-A9EC-E9538AB7362E@shaw.ca>

Thanks everyone. I needed a quick confirmation that I wasn't going mad. Client has bought in a team to review my stuff who disagreed with a scheme and proposed something else that boiled down to the diagram. My view is as the respondents. I sent the reviewers off to re-evaluate.

Thanks everyone.



From carsten at analog-monster.de  Wed Nov 24 09:02:14 2010
From: carsten at analog-monster.de (Carsten Toensmann)
Date: Wed, 24 Nov 2010 09:02:14 +0100
Subject: [sdiy] Moog System 55 PSU (930)
References: <7481C6264DDFF94AB1A0A96930BED3D802907E11@WC000043A.uk.centricaplc.com><A4B8F807-C66F-49C1-B27A-D938450A7DB3@ntlworld.com><C651097094AAD54C846A5BAA28F7141D0400AC@wdscexbe08.sc.wdc.com>
	<04479438-76A1-468F-A9EC-E9538AB7362E@shaw.ca>
Message-ID: <933EA8876099475B9CED4212D6039288@ww901.siemens.net>

Hi,

reading the service manual I asked myself which event triggered the 
'inhibit' function of the 930 PSU? Does anybody know that?

Regards

Carsten 



From neil.johnson97 at ntlworld.com  Wed Nov 24 13:21:29 2010
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 24 Nov 2010 12:21:29 +0000
Subject: [sdiy] OT: Wisdom
Message-ID: <1949011897-1290601284-cardhu_decombobulator_blackberry.rim.net-38584862-@b28.c12.bise7.blackberry>


> Client has bought in a team to review my stuff

So we're doing your work for you?  Excellent - next time you're in Cambridge mine's a pint of Old Speckled Hen then!

:-)

Seriously, that team needs sacking, or your company needs to stop outsourcing to the local kindergarten.

Cheers,
Neil


From sdiy-mz01 at blauwurf.info  Wed Nov 24 13:44:25 2010
From: sdiy-mz01 at blauwurf.info (Michael Zacherl.)
Date: Wed, 24 Nov 2010 13:44:25 +0100
Subject: [sdiy] [OT] first steps with audio transformers
Message-ID: <2EF9F63A-A135-428A-8BF7-707DB2B96E69@blauwurf.info>

Hello,

    I'm about to do my first steps with audio transformers and the more I read the more I  become uncertain about many points. :-(

First application will be an analogue input/output and monitoring stage for some laptops (different brands) in order to interface with a synth and/or mixer.

Admittedly I'm not sure about impedance, dc-resistance and if it's feasible to connect windings.

Looking at a data sheet overview like this 
http://docs-europe.origin.electrocomponents.com/webdocs/008d/0900766b8008d64a.pdf

I find this one pretty attractive (also moneywise)
http://docs-europe.electrocomponents.com/webdocs/00bb/0900766b800bbc2c.pdf

How to handle this low dc-resistance?
Could I connect the primary windings?
Input impedance appears to be pretty low as well, bad?

Thanks a lot, Michael. 

--
noise chasers: http://blauwurf.at 
http://facebook.com/noiseconformist





From harrybissell at wowway.com  Wed Nov 24 18:33:23 2010
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 24 Nov 2010 12:33:23 -0500 (EST)
Subject: [sdiy] [OT] first steps with audio transformers
In-Reply-To: <2EF9F63A-A135-428A-8BF7-707DB2B96E69@blauwurf.info>
Message-ID: <1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>

You can connect windings in series if you like... (or parallel but you probably don't want to do that...)

Low DC resistance should not be an issue, you need to keep DC out of a transformer anyway.

Probably you want to have some opamp buffer to drive the transformer. You'll need to keep signal
levels pretty low to avoid saturation at low frequencies (approaching DC, which is bad...).  That's
why the distortion chart takes such a steep curve up at the low end...

Try http://www.jensen-transformers.com/ for some good reading

H^) harry


----- Original Message -----
From: Michael Zacherl. <sdiy-mz01 at blauwurf.info>
To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
Sent: Wed, 24 Nov 2010 07:44:25 -0500 (EST)
Subject: [sdiy] [OT] first steps with audio transformers

Hello,

    I'm about to do my first steps with audio transformers and the more I read the more I  become uncertain about many points. :-(

First application will be an analogue input/output and monitoring stage for some laptops (different brands) in order to interface with a synth and/or mixer.

Admittedly I'm not sure about impedance, dc-resistance and if it's feasible to connect windings.

Looking at a data sheet overview like this 
http://docs-europe.origin.electrocomponents.com/webdocs/008d/0900766b8008d64a.pdf

I find this one pretty attractive (also moneywise)
http://docs-europe.electrocomponents.com/webdocs/00bb/0900766b800bbc2c.pdf

How to handle this low dc-resistance?
Could I connect the primary windings?
Input impedance appears to be pretty low as well, bad?

Thanks a lot, Michael. 

--
noise chasers: http://blauwurf.at 
http://facebook.com/noiseconformist



_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From Barry.L.Klein at wdc.com  Wed Nov 24 18:49:07 2010
From: Barry.L.Klein at wdc.com (Barry Klein)
Date: Wed, 24 Nov 2010 09:49:07 -0800
Subject: [sdiy] [OT] Need a job?
References: <20101101154202.c16e921f9c8655b42ea149fc1daa3492.4cca5893c6.wbe@email04.secureserver.net>
Message-ID: <C651097094AAD54C846A5BAA28F7141D0400B1@wdscexbe08.sc.wdc.com>

Hi all,
I work in the Branded Products group of Western Digital.
We are hiring people like crazy.  Most of our company just
relocated close to the OC airport, but our division remains 
in Lake Forest for another year or so.  My manager is harassing
us to find good applicants for open positions.  Thing is, when
you work at a place for 20 years you don't make many acquaintances
in outside companies...  So if you are out of a job or just
may be interested in a new one here take a look.  We have spots in 
management, software/hardware engineering, and test.  Linux,
Windows, Apple applications.  Products are storage-centric but
who knows, get in management and let's start a synth division.
Send me your resume if interested.
In the link below, enter California and Lake Forest for state/city.

http://www.westerndigital.apply2jobs.com/ProfExt/index.cfm?fuseaction=mExter
nal.showSearchInterface


Barry



From veronica.merryfield at shaw.ca  Wed Nov 24 19:06:58 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Wed, 24 Nov 2010 10:06:58 -0800
Subject: [sdiy] OT: Wisdom
In-Reply-To: <1949011897-1290601284-cardhu_decombobulator_blackberry.rim.net-38584862-@b28.c12.bise7.blackberry>
References: <1949011897-1290601284-cardhu_decombobulator_blackberry.rim.net-38584862-@b28.c12.bise7.blackberry>
Message-ID: <6C0E070C-84BC-4108-B310-662556936233@shaw.ca>


On 2010-11-24, at 4:21 AM, Neil Johnson wrote:

>> Client has bought in a team to review my stuff
> 
> So we're doing your work for you?  Excellent - next time you're in Cambridge mine's a pint of Old Speckled Hen then!

When you get run ragged by other people, the self doubt and madness need to be checked.

> Seriously, that team needs sacking, or your company needs to stop outsourcing to the local kindergarten.

I work alone. The client bought them in and they both play in the same sandbox.

From cheater00 at gmail.com  Wed Nov 24 19:27:41 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Wed, 24 Nov 2010 19:27:41 +0100
Subject: [sdiy] OT: Wisdom
In-Reply-To: <6C0E070C-84BC-4108-B310-662556936233@shaw.ca>
References: <1949011897-1290601284-cardhu_decombobulator_blackberry.rim.net-38584862-@b28.c12.bise7.blackberry>
	<6C0E070C-84BC-4108-B310-662556936233@shaw.ca>
Message-ID: <AANLkTinJyKMn=intOBgrR6=P2T6QVCrLxufCf27CKnox@mail.gmail.com>

Veronica, I think Neil was mostly being funny :-) Nothing bad about
asking about stuff here and using it in your own work. Actually, this
has been asked about explicitly and answered in full, in a thread
started by David Dixon.

D.

On Wed, Nov 24, 2010 at 19:06, Veronica Merryfield
<veronica.merryfield at shaw.ca> wrote:
>
> On 2010-11-24, at 4:21 AM, Neil Johnson wrote:
>
>>> Client has bought in a team to review my stuff
>>
>> So we're doing your work for you? ?Excellent - next time you're in Cambridge mine's a pint of Old Speckled Hen then!
>
> When you get run ragged by other people, the self doubt and madness need to be checked.
>
>> Seriously, that team needs sacking, or your company needs to stop outsourcing to the local kindergarten.
>
> I work alone. The client bought them in and they both play in the same sandbox.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From veronica.merryfield at shaw.ca  Wed Nov 24 19:34:37 2010
From: veronica.merryfield at shaw.ca (Veronica Merryfield)
Date: Wed, 24 Nov 2010 10:34:37 -0800
Subject: [sdiy] OT: Wisdom
In-Reply-To: <AANLkTinJyKMn=intOBgrR6=P2T6QVCrLxufCf27CKnox@mail.gmail.com>
References: <1949011897-1290601284-cardhu_decombobulator_blackberry.rim.net-38584862-@b28.c12.bise7.blackberry>
	<6C0E070C-84BC-4108-B310-662556936233@shaw.ca>
	<AANLkTinJyKMn=intOBgrR6=P2T6QVCrLxufCf27CKnox@mail.gmail.com>
Message-ID: <83BDFA7C-748C-4926-A6EF-3E64A376B4C0@shaw.ca>


On 2010-11-24, at 10:27 AM, cheater cheater wrote:

> Veronica, I think Neil was mostly being funny :-) Nothing bad about
> asking about stuff here and using it in your own work. Actually, this
> has been asked about explicitly and answered in full, in a thread
> started by David Dixon.

I know, but I thought some would appreciate the why's and wherefores.




From cheater00 at gmail.com  Thu Nov 25 02:00:15 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Thu, 25 Nov 2010 02:00:15 +0100
Subject: [sdiy] [OT] first steps with audio transformers
In-Reply-To: <1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>
References: <2EF9F63A-A135-428A-8BF7-707DB2B96E69@blauwurf.info>
	<1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>
Message-ID: <AANLkTi=pyHGsj55OJJcpBnFayLMYmKpWWUQagLgytTMS@mail.gmail.com>

On Wed, Nov 24, 2010 at 18:33, Harry Bissell <harrybissell at wowway.com> wrote:
> You can connect windings in series if you like... (or parallel but you probably don't want to do that...)
>
> Low DC resistance should not be an issue, you need to keep DC out of a transformer anyway.
>
> Probably you want to have some opamp buffer to drive the transformer. You'll need to keep signal
> levels pretty low

> to avoid saturation at low frequencies

Why would you want *that*?

:^)

D.

> (approaching DC, which is bad...). ?That's
> why the distortion chart takes such a steep curve up at the low end...
>
> Try http://www.jensen-transformers.com/ for some good reading
>
> H^) harry
>
>
> ----- Original Message -----
> From: Michael Zacherl. <sdiy-mz01 at blauwurf.info>
> To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
> Sent: Wed, 24 Nov 2010 07:44:25 -0500 (EST)
> Subject: [sdiy] [OT] first steps with audio transformers
>
> Hello,
>
> ? ?I'm about to do my first steps with audio transformers and the more I read the more I ?become uncertain about many points. :-(
>
> First application will be an analogue input/output and monitoring stage for some laptops (different brands) in order to interface with a synth and/or mixer.
>
> Admittedly I'm not sure about impedance, dc-resistance and if it's feasible to connect windings.
>
> Looking at a data sheet overview like this
> http://docs-europe.origin.electrocomponents.com/webdocs/008d/0900766b8008d64a.pdf
>
> I find this one pretty attractive (also moneywise)
> http://docs-europe.electrocomponents.com/webdocs/00bb/0900766b800bbc2c.pdf
>
> How to handle this low dc-resistance?
> Could I connect the primary windings?
> Input impedance appears to be pretty low as well, bad?
>
> Thanks a lot, Michael.
>
> --
> noise chasers: http://blauwurf.at
> http://facebook.com/noiseconformist
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> --
> Harry Bissell & Nora Abdullah 4eva
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From sdiy-mz01 at blauwurf.info  Thu Nov 25 02:44:15 2010
From: sdiy-mz01 at blauwurf.info (Michael Zacherl.)
Date: Thu, 25 Nov 2010 02:44:15 +0100
Subject: [sdiy] [OT] first steps with audio transformers
In-Reply-To: <1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>
References: <1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>
Message-ID: <533FE8A2-13C2-40FF-A35D-9C8C8D723D4E@blauwurf.info>

ah, thanks Harry - "Jensen" rings bells, I think it was mentioned here quite some while ago.  ;-)

 Michael.  (off to read)

On Nov24, 2010, at 18:33 , Harry Bissell wrote:

> You can connect windings in series if you like... (or parallel but you probably don't want to do that...)
> 
> Low DC resistance should not be an issue, you need to keep DC out of a transformer anyway.
> 
> Probably you want to have some opamp buffer to drive the transformer. You'll need to keep signal
> levels pretty low to avoid saturation at low frequencies (approaching DC, which is bad...).  That's
> why the distortion chart takes such a steep curve up at the low end...
> 
> Try http://www.jensen-transformers.com/ for some good reading
> 
> H^) harry
> 
> 
> ----- Original Message -----
> From: Michael Zacherl. <sdiy-mz01 at blauwurf.info>
> To: sdiy DIY <synth-diy at dropmix.xs4all.nl>
> Sent: Wed, 24 Nov 2010 07:44:25 -0500 (EST)
> Subject: [sdiy] [OT] first steps with audio transformers
> 
> Hello,
> 
>   I'm about to do my first steps with audio transformers and the more I read the more I  become uncertain about many points. :-(
> 
> First application will be an analogue input/output and monitoring stage for some laptops (different brands) in order to interface with a synth and/or mixer.
> 
> Admittedly I'm not sure about impedance, dc-resistance and if it's feasible to connect windings.
> 
> Looking at a data sheet overview like this 
> http://docs-europe.origin.electrocomponents.com/webdocs/008d/0900766b8008d64a.pdf
> 
> I find this one pretty attractive (also moneywise)
> http://docs-europe.electrocomponents.com/webdocs/00bb/0900766b800bbc2c.pdf
> 
> How to handle this low dc-resistance?
> Could I connect the primary windings?
> Input impedance appears to be pretty low as well, bad?
> 
> Thanks a lot, Michael. 



--
keep your ears open: http://blauwurf.at
http://facebook.com/noiseconformist





From sdiy-mz01 at blauwurf.info  Thu Nov 25 02:49:18 2010
From: sdiy-mz01 at blauwurf.info (Michael Zacherl.)
Date: Thu, 25 Nov 2010 02:49:18 +0100
Subject: [sdiy] [OT] first steps with audio transformers
In-Reply-To: <AANLkTi=pyHGsj55OJJcpBnFayLMYmKpWWUQagLgytTMS@mail.gmail.com>
References: <2EF9F63A-A135-428A-8BF7-707DB2B96E69@blauwurf.info>
	<1422884630.631577.1290620003620.JavaMail.root@md01.wow.synacor.com>
	<AANLkTi=pyHGsj55OJJcpBnFayLMYmKpWWUQagLgytTMS@mail.gmail.com>
Message-ID: <89189CC5-76A9-4577-B350-62BCC1E569A6@blauwurf.info>


On Nov25, 2010, at 02:00 , cheater cheater wrote:

> On Wed, Nov 24, 2010 at 18:33, Harry Bissell <harrybissell at wowway.com> wrote:
>> You can connect windings in series if you like... (or parallel but you probably don't want to do that...)
>> 
>> Low DC resistance should not be an issue, you need to keep DC out of a transformer anyway.
>> 
>> Probably you want to have some opamp buffer to drive the transformer. You'll need to keep signal
>> levels pretty low
> 
>> to avoid saturation at low frequencies
> 
> Why would you want *that*?

well, as always, that entirely depends on your application.
I'm considering saturation as well (trimable, as part of the output stage) - but since I have no experience 
with audio transformers  it's hard to tell  what products behave how when driving them hard.

;-)  m.

>> (approaching DC, which is bad...).  That's
>> why the distortion chart takes such a steep curve up at the low end...
>> 
>> Try http://www.jensen-transformers.com/ for some good reading
>> 
>> H^) harry


--
nonconform? noiseconform: http://blauwurf.at
http://facebook.com/noiseconformist





From sdiy-mz01 at blauwurf.info  Thu Nov 25 12:54:56 2010
From: sdiy-mz01 at blauwurf.info (Michael Zacherl.)
Date: Thu, 25 Nov 2010 12:54:56 +0100
Subject: [sdiy] favourite transformer companies,
	was: [OT] first steps with audio transformers
In-Reply-To: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
References: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
Message-ID: <BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>


On Nov25, 2010, at 11:00 , cheater cheater wrote:

> what other companies make worthwhile transformers? Both new
> and vintage. I guess there needs to be a distinction because new
> transformers can actually come with warranty, better documentation,
> support, ...

I know of Neutrik, Oxford Electrical Products, Hammond, Triad Magnetics.

http://www.neutrik.com/fl/en/audio/204_174211/%C3%9Cbertrager_productlist.aspx
http://www.oep.co.uk/
http://www.hammondmfg.com/5caud.htm
http://www.triadmagnetics.com/catalog_template.php?productCategoryId=48

Michael.

--
hear the colours of noise: http://blauwurf.at
http://facebook.com/noiseconformist




From sdiy-mz01 at blauwurf.info  Thu Nov 25 13:33:07 2010
From: sdiy-mz01 at blauwurf.info (Michael Zacherl.)
Date: Thu, 25 Nov 2010 13:33:07 +0100
Subject: [sdiy] favourite transformer companies,
	was: [OT] first steps with audio transformers
In-Reply-To: <BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
References: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
	<BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
Message-ID: <2168CB1A-DE6C-4DA7-89B9-B061CABE6AD3@blauwurf.info>

... just found out that Palmer also sell their transformers:
http://www.palmer-germany.com/35-1-components.html

m.

> On Nov25, 2010, at 11:00 , cheater cheater wrote:
> 
>> what other companies make worthwhile transformers? Both new
>> and vintage. I guess there needs to be a distinction because new
>> transformers can actually come with warranty, better documentation,
>> support, ...
> 
> I know of Neutrik, Oxford Electrical Products, Hammond, Triad Magnetics.
> 
> http://www.neutrik.com/fl/en/audio/204_174211/%C3%9Cbertrager_productlist.aspx
> http://www.oep.co.uk/
> http://www.hammondmfg.com/5caud.htm
> http://www.triadmagnetics.com/catalog_template.php?productCategoryId=48
> 
> Michael.


--
nonconform? noiseconform: http://blauwurf.at
http://facebook.com/noiseconformist





From altitude at optrand.com  Thu Nov 25 13:38:13 2010
From: altitude at optrand.com (Altitude)
Date: Thu, 25 Nov 2010 07:38:13 -0500
Subject: [sdiy] favourite transformer companies,
	was: [OT] first steps with audio transformers
In-Reply-To: <BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
References: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
	<BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
Message-ID: <000001cb8c9d$a04435d0$e0cca170$@com>

I have used some of the Alphamag PCB mount torroids from digikey and they
are fine..

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Michael Zacherl.
Sent: Thursday, November 25, 2010 6:55 AM
To: sdiy DIY
Subject: Re: [sdiy] favourite transformer companies, was: [OT] first steps
with audio transformers


On Nov25, 2010, at 11:00 , cheater cheater wrote:

> what other companies make worthwhile transformers? Both new
> and vintage. I guess there needs to be a distinction because new
> transformers can actually come with warranty, better documentation,
> support, ...

I know of Neutrik, Oxford Electrical Products, Hammond, Triad Magnetics.

http://www.neutrik.com/fl/en/audio/204_174211/%C3%9Cbertrager_productlist.as
px
http://www.oep.co.uk/
http://www.hammondmfg.com/5caud.htm
http://www.triadmagnetics.com/catalog_template.php?productCategoryId=48

Michael.

--
hear the colours of noise: http://blauwurf.at
http://facebook.com/noiseconformist


_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From lenham at clara.co.uk  Thu Nov 25 14:00:56 2010
From: lenham at clara.co.uk (Steve Lenham)
Date: Thu, 25 Nov 2010 13:00:56 -0000
Subject: [sdiy] favourite transformer companies,
	was: [OT] first steps with audio transformers
References: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
	<BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
Message-ID: <8A03290C8A894355A50AA115639E9769@DELL>

----- Original Message ----- 
From: "Michael Zacherl." <sdiy-mz01 at blauwurf.info>
>> what other companies make worthwhile transformers?
> I know of Neutrik, Oxford Electrical Products, Hammond, Triad Magnetics.
>
> http://www.neutrik.com/fl/en/audio/204_174211/%C3%9Cbertrager_productlist.aspx
> http://www.oep.co.uk/
> http://www.hammondmfg.com/5caud.htm
> http://www.triadmagnetics.com/catalog_template.php?productCategoryId=48

>From the UK, two long-established companies are Sowter and Stevens &
Billington:

http://www.sowter.co.uk/
http://www.stevens-billington.co.uk/

Steve L.
Benden Sound Technology
www.bendensound 



From tu at alphalink.com.au  Thu Nov 25 14:12:54 2010
From: tu at alphalink.com.au (tu at alphalink.com.au)
Date: Fri, 26 Nov 2010 00:12:54 +1100
Subject: [sdiy] favourite transformer companies,
	was: [OT] first steps with audio transformers
In-Reply-To: <8A03290C8A894355A50AA115639E9769@DELL>
References: <AANLkTi=Z5NLD0MFpxPamOVaaU8Bh4PKPQFeuO9OPxyk4@mail.gmail.com>
	<BFA3BF75-7269-4BA9-A441-1DE90DAD5B26@blauwurf.info>
	<8A03290C8A894355A50AA115639E9769@DELL>
Message-ID: <1290690774.4cee60d641a07@webmail.chariot.com.au>

Lundahl and Jensen are manufacturers of high quality audio transformers

http://www.lundahl.se/
http://www.jensen-transformers.com/

-Tristan

On Fri, Nov 26th, 2010 at 12:00 AM, Steve Lenham <lenham at clara.co.uk> wrote:

> ----- Original Message ----- 
> From: "Michael Zacherl." <sdiy-mz01 at blauwurf.info>
> >> what other companies make worthwhile transformers?
> > I know of Neutrik, Oxford Electrical Products, Hammond, Triad
> Magnetics.
> >
> >
> http://www.neutrik.com/fl/en/audio/204_174211/%C3%9Cbertrager_productlist.aspx
> > http://www.oep.co.uk/
> > http://www.hammondmfg.com/5caud.htm
> > http://www.triadmagnetics.com/catalog_template.php?productCategoryId=48
> 
> From the UK, two long-established companies are Sowter and Stevens &
> Billington:
> 
> http://www.sowter.co.uk/
> http://www.stevens-billington.co.uk/
> 
> Steve L.
> Benden Sound Technology
> www.bendensound 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 
> 





From Synthmanic at aol.com  Thu Nov 25 14:32:48 2010
From: Synthmanic at aol.com (Synthmanic at aol.com)
Date: Thu, 25 Nov 2010 08:32:48 EST
Subject: [sdiy] Test
Message-ID: <2881a0.5f5c9790.3a1fbf80@aol.com>

Sorry, I am checking to see if posts are getting  through.


From cary.roberts at retrosynth.net  Thu Nov 25 19:26:53 2010
From: cary.roberts at retrosynth.net (Cary Roberts)
Date: Thu, 25 Nov 2010 10:26:53 -0800
Subject: [sdiy] favourite transformer companies,
Message-ID: <7F4978F0B25440699E09DF2E33A2ABD6@onlive.corp>

> what other companies make worthwhile transformers? Both new
> and vintage. I guess there needs to be a distinction because new
> transformers can actually come with warranty, better documentation,
> support, ...

What I consider to be better sounding transformers aren't necessarily
available off the shelf and their construction documentation is usually
regarded as trade secret.  A couple of the larger audio equipment
manufacturers have twisted the arm of their suppliers to stop selling
popular transformer configurations to DIYers.  To be fair some DIYers cloned
equipment that was still in producion by the original manufacturer (or some
form thereof) and made boards, enclosures, and part kits available in
reasonably large quantity.

But back to the subject matter at hand.  Here's a list of transformer
manufacturers I'd suggest looking at:

http://www.lundahl.se/

http://www.jensen-transformers.com/

http://www.carnhill.co.uk/

http://www.cinemag.biz/

http://www.profileelectronics.com/

http://www.oep.co.uk/

http://classicapi.com/catalog/index.php?cPath=21

http://www.jlmaudio.com/shop/index.php?_a=viewCat&catId=18



Your transformer questions are probably best answered on the audio DIY forum
at http://www.prodigy-pro.com/diy/ and more specifically, here:

http://www.prodigy-pro.com/diy/index.php?PHPSESSID=it2srosa9r82hr50ndtopeo9n
3&topic=467



From stewpye at optusnet.com.au  Thu Nov 25 21:26:25 2010
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Fri, 26 Nov 2010 06:26:25 +1000
Subject: [sdiy] favourite transformer companies,
In-Reply-To: <7F4978F0B25440699E09DF2E33A2ABD6@onlive.corp>
References: <7F4978F0B25440699E09DF2E33A2ABD6@onlive.corp>
Message-ID: <4CEEC671.8030307@optusnet.com.au>

In Australia we have Harbuch Electronics...
http://www.harbuch.com.au/audio_9.html

Regards,
Stewart.

Cary Roberts wrote:
>> what other companies make worthwhile transformers? Both new
>> and vintage. I guess there needs to be a distinction because new
>> transformers can actually come with warranty, better documentation,
>> support, ...
>>     
>
> What I consider to be better sounding transformers aren't necessarily
> available off the shelf and their construction documentation is usually
> regarded as trade secret.  A couple of the larger audio equipment
> manufacturers have twisted the arm of their suppliers to stop selling
> popular transformer configurations to DIYers.  To be fair some DIYers cloned
> equipment that was still in producion by the original manufacturer (or some
> form thereof) and made boards, enclosures, and part kits available in
> reasonably large quantity.
>
> But back to the subject matter at hand.  Here's a list of transformer
> manufacturers I'd suggest looking at:
>
> http://www.lundahl.se/
>
> http://www.jensen-transformers.com/
>
> http://www.carnhill.co.uk/
>
> http://www.cinemag.biz/
>
> http://www.profileelectronics.com/
>
> http://www.oep.co.uk/
>
> http://classicapi.com/catalog/index.php?cPath=21
>
> http://www.jlmaudio.com/shop/index.php?_a=viewCat&catId=18
>
>
>
> Your transformer questions are probably best answered on the audio DIY forum
> at http://www.prodigy-pro.com/diy/ and more specifically, here:
>
> http://www.prodigy-pro.com/diy/index.php?PHPSESSID=it2srosa9r82hr50ndtopeo9n
> 3&topic=467
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>   



From juzowen at googlemail.com  Fri Nov 26 18:09:47 2010
From: juzowen at googlemail.com (Justin Owen)
Date: Fri, 26 Nov 2010 17:09:47 +0000
Subject: [sdiy] Adding a fuse to a circuit
Message-ID: <4cefe9dc.57edd80a.04ab.629f@mx.google.com>

Hey all,

I'm mocking up a Eurorack power supply breakout panel so I can power my breadboard from my Eurorack via 3mm stackable plugs.

For a little extra safety I wanted to add a 1A fuse on the PCB for each of the rails (+12V/-12V/+5V).

Is it just a matter of putting a fuse holder in series with each rail?

For the more er, 'experimental' stuff - I'll keep my breadboard plugged into my bench power supply - which can take the abuse, I was more worried about trying to be nice to my existing modules.

Thanks,

Justin



From blacet at blacet.com  Fri Nov 26 18:16:09 2010
From: blacet at blacet.com (blacet at blacet.com)
Date: Fri, 26 Nov 2010 09:16:09 -0800
Subject: [sdiy] Adding a fuse to a circuit
In-Reply-To: <4cefe9dc.57edd80a.04ab.629f@mx.google.com>
References: <4cefe9dc.57edd80a.04ab.629f@mx.google.com>
Message-ID: <b6ec0d1ebcf997a402ac16abdac77cbb.squirrel@webmail.blacet.com>

You could also use a couple polyfuses and reverse IN4001 diodes to common.
These are resettable and a better choice to protect ICs.


> Hey all,
>
> I'm mocking up a Eurorack power supply breakout panel so I can power my
> breadboard from my Eurorack via 3mm stackable plugs.
>
> For a little extra safety I wanted to add a 1A fuse on the PCB for each of
> the rails (+12V/-12V/+5V).
>
> Is it just a matter of putting a fuse holder in series with each rail?
>
> For the more er, 'experimental' stuff - I'll keep my breadboard plugged
> into my bench power supply - which can take the abuse, I was more worried
> about trying to be nice to my existing modules.
>
> Thanks,
>
> Justin
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>




From cheater00 at gmail.com  Fri Nov 26 21:32:53 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Fri, 26 Nov 2010 21:32:53 +0100
Subject: [sdiy]  use pc psu's as EMI chassis for synth modules
Message-ID: <AANLkTikiuNCwV0gjJDcNffYVwDd3UoaeVKQ+qjsZ1GDL@mail.gmail.com>

Hi guys,
I've had a look at those old broken power supplies that will never
come to life, and I have had the perfect idea - you can use the
chassis for something nice! It's much shorter than one dotcom unit,
and a bit wider. More like 1 1/2 dotcom unit wide, or just under 2U of
MOTM. Still, most of the modules could probably fit in very easily.

Pro's:
- the module is nicely shielded from others and from outside interference
- the module gets some nice thermal stability
- if the module gets very hot, you can mount a Noctua P12 fan
(inaudible) and cool it
- the module is sturdier. It can sit on a shelf without you fearing
that the fragile PCBs will be destroyed.
- the module doesn't have wires sticking out! Installing new modules
and messing about inside a synth while it's turned on is not a problem
anymore
- generally, electrical safety is a big plus.
- you get a nice, sturdy frame for your module.
- the metal is usually just thick enough to be sturdy, but it's thin
enough to be easily punched.

Cons:
none


OK, those things are big, but then you don't have to use em for every module.

Regarding panel size etc: you can have one of several options:

1. use this size as your modular's panel size. Easy.
2. Dotcom: Use a cheap plastic panel and mount it to the chassis
stand-offs of about 1". This does two things: it gives you space to
mount front-panel controls; and additionally, if your module
front-panel is not as wide as the ex-powersupply chassis, you can
mount another, shallow, module next to it
3. Dotcom: use a cheap plastic panel and simply screw it onto the chassis.
4. Dotcom: take one row of your Dotcom chassis, and fill it with
modules of exactly this height. Use the remaining space for mults etc.
5. Eurorack: The side plate is slightly higher than eurorack. It's
also exactly 8 cm wide. Use the thing as a portable 4U eurorack synth.
Or, if your modules are not deep at all, then you can use it as 7U.
There's enough space there to house a small PSU as well, based off
e.g. a couple laptop power supplies (they have very flat toroids).
Even better, you get an IEC plug, and usually a fuse holder, so that
you don't need to take care of that.
6. Fracrack: same as Eurorack. Houses 1U of a deep module, or nearly
2U of fairly shallow modules. Having a tiny amount of overhang
(0.125") on the side shouldn't bother anyone.

Happy hacking!
D.


From mverbos at earthlink.net  Sat Nov 27 22:42:42 2010
From: mverbos at earthlink.net (mark verbos)
Date: Sat, 27 Nov 2010 16:42:42 -0500
Subject: [sdiy] AKG BX-10 II
Message-ID: <DE27FAEA-10D5-439A-8AE4-7C17E2B4E9D3@earthlink.net>

Hi there,

I have an AKG BX-10 II spring reverb unit that I am trying to overhaul. I can't find a schematic anywhere. 
The two sides are totally different volumes. I see several trim pots, so maybe all it needs is to be trimmed up. I assume the electrolytics and tantalums on here are not up to spec either.

Does anyone have the schematic for this thing? I guess I could reverse engineer it, but I'd rather not.  

Thanks!

Mark




From megaohm1 at gmail.com  Sun Nov 28 00:47:48 2010
From: megaohm1 at gmail.com (megaohm)
Date: Sat, 27 Nov 2010 17:47:48 -0600
Subject: [sdiy] use pc psu's as EMI chassis for synth modules
In-Reply-To: <AANLkTikiuNCwV0gjJDcNffYVwDd3UoaeVKQ+qjsZ1GDL@mail.gmail.com>
References: <AANLkTikiuNCwV0gjJDcNffYVwDd3UoaeVKQ+qjsZ1GDL@mail.gmail.com>
Message-ID: <AANLkTinnRY3_Z5V2vbPMmPkM4i_YVa=0zUdcBduWXtca@mail.gmail.com>

Good ideas!

I have an armful of these empty shells. I've been using them for power
supply pieces. I keep the IEC and switch, throw a fuse in and it acts
as the front end to my PSU's. I run wires out of the back hole and
hook those to the actual supply. I like my power supplies outside the
cab. I put them in old computer towers (metal towers) and stick them
under the table the cabs sit on.
  I have one of the PSU shells with an entire Power One +5V supply inside.
Definitely useful pieces to have around.

p.


On Fri, Nov 26, 2010 at 2:32 PM, cheater cheater <cheater00 at gmail.com> wrote:
> Hi guys,
> I've had a look at those old broken power supplies that will never
> come to life, and I have had the perfect idea - you can use the
> chassis for something nice! It's much shorter than one dotcom unit,
> and a bit wider. More like 1 1/2 dotcom unit wide, or just under 2U of
> MOTM. Still, most of the modules could probably fit in very easily.
>
> Pro's:
> - the module is nicely shielded from others and from outside interference
> - the module gets some nice thermal stability
> - if the module gets very hot, you can mount a Noctua P12 fan
> (inaudible) and cool it
> - the module is sturdier. It can sit on a shelf without you fearing
> that the fragile PCBs will be destroyed.
> - the module doesn't have wires sticking out! Installing new modules
> and messing about inside a synth while it's turned on is not a problem
> anymore
> - generally, electrical safety is a big plus.
> - you get a nice, sturdy frame for your module.
> - the metal is usually just thick enough to be sturdy, but it's thin
> enough to be easily punched.
>
> Cons:
> none
>
>
> OK, those things are big, but then you don't have to use em for every module.
>
> Regarding panel size etc: you can have one of several options:
>
> 1. use this size as your modular's panel size. Easy.
> 2. Dotcom: Use a cheap plastic panel and mount it to the chassis
> stand-offs of about 1". This does two things: it gives you space to
> mount front-panel controls; and additionally, if your module
> front-panel is not as wide as the ex-powersupply chassis, you can
> mount another, shallow, module next to it
> 3. Dotcom: use a cheap plastic panel and simply screw it onto the chassis.
> 4. Dotcom: take one row of your Dotcom chassis, and fill it with
> modules of exactly this height. Use the remaining space for mults etc.
> 5. Eurorack: The side plate is slightly higher than eurorack. It's
> also exactly 8 cm wide. Use the thing as a portable 4U eurorack synth.
> Or, if your modules are not deep at all, then you can use it as 7U.
> There's enough space there to house a small PSU as well, based off
> e.g. a couple laptop power supplies (they have very flat toroids).
> Even better, you get an IEC plug, and usually a fuse holder, so that
> you don't need to take care of that.
> 6. Fracrack: same as Eurorack. Houses 1U of a deep module, or nearly
> 2U of fairly shallow modules. Having a tiny amount of overhang
> (0.125") on the side shouldn't bother anyone.
>
> Happy hacking!
> D.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From subjectivity at hotmail.com  Sun Nov 28 04:43:44 2010
From: subjectivity at hotmail.com (dan snazelle)
Date: Sat, 27 Nov 2010 22:43:44 -0500
Subject: [sdiy] gyrator calculator
Message-ID: <BLU0-SMTP1806373D8C65A569EE698C2C8230@phx.gbl>

sounds like  a bad new wave band....anyone know a quick way to turn a desired inductor value into gyrator values?

thanks


From dixon at interchange.ubc.ca  Sun Nov 28 06:37:22 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Sat, 27 Nov 2010 21:37:22 -0800
Subject: [sdiy] gyrator calculator
In-Reply-To: <BLU0-SMTP1806373D8C65A569EE698C2C8230@phx.gbl>
References: <BLU0-SMTP1806373D8C65A569EE698C2C8230@phx.gbl>
Message-ID: <FCB6650BC68D4686B7331A4748636851@galvanox01>

> sounds like  a bad new wave band....anyone know a quick way to turn a
> desired inductor value into gyrator values?

Assuming all resistors R and capacitors C, the effective inductance is CR^2.



From cheater00 at gmail.com  Sun Nov 28 10:00:37 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Sun, 28 Nov 2010 10:00:37 +0100
Subject: [sdiy] use pc psu's as EMI chassis for synth modules
In-Reply-To: <AANLkTinnRY3_Z5V2vbPMmPkM4i_YVa=0zUdcBduWXtca@mail.gmail.com>
References: <AANLkTikiuNCwV0gjJDcNffYVwDd3UoaeVKQ+qjsZ1GDL@mail.gmail.com>
	<AANLkTinnRY3_Z5V2vbPMmPkM4i_YVa=0zUdcBduWXtca@mail.gmail.com>
Message-ID: <AANLkTimQRO=2foN+UEj6BNHay=YxyViYxZr-rCoY2nwy@mail.gmail.com>

also very simple to acquire... go to any pc repairs or refurbs shop,
they're bound to have zillions of them. Wonder what else you can use
for synth purposes that there is in the typical SMPS.

Cheers,
D.

On 28/11/2010, megaohm <megaohm1 at gmail.com> wrote:
> Good ideas!
>
> I have an armful of these empty shells. I've been using them for power
> supply pieces. I keep the IEC and switch, throw a fuse in and it acts
> as the front end to my PSU's. I run wires out of the back hole and
> hook those to the actual supply. I like my power supplies outside the
> cab. I put them in old computer towers (metal towers) and stick them
> under the table the cabs sit on.
>   I have one of the PSU shells with an entire Power One +5V supply inside.
> Definitely useful pieces to have around.
>
> p.
>
>
> On Fri, Nov 26, 2010 at 2:32 PM, cheater cheater <cheater00 at gmail.com>
> wrote:
>> Hi guys,
>> I've had a look at those old broken power supplies that will never
>> come to life, and I have had the perfect idea - you can use the
>> chassis for something nice! It's much shorter than one dotcom unit,
>> and a bit wider. More like 1 1/2 dotcom unit wide, or just under 2U of
>> MOTM. Still, most of the modules could probably fit in very easily.
>>
>> Pro's:
>> - the module is nicely shielded from others and from outside interference
>> - the module gets some nice thermal stability
>> - if the module gets very hot, you can mount a Noctua P12 fan
>> (inaudible) and cool it
>> - the module is sturdier. It can sit on a shelf without you fearing
>> that the fragile PCBs will be destroyed.
>> - the module doesn't have wires sticking out! Installing new modules
>> and messing about inside a synth while it's turned on is not a problem
>> anymore
>> - generally, electrical safety is a big plus.
>> - you get a nice, sturdy frame for your module.
>> - the metal is usually just thick enough to be sturdy, but it's thin
>> enough to be easily punched.
>>
>> Cons:
>> none
>>
>>
>> OK, those things are big, but then you don't have to use em for every
>> module.
>>
>> Regarding panel size etc: you can have one of several options:
>>
>> 1. use this size as your modular's panel size. Easy.
>> 2. Dotcom: Use a cheap plastic panel and mount it to the chassis
>> stand-offs of about 1". This does two things: it gives you space to
>> mount front-panel controls; and additionally, if your module
>> front-panel is not as wide as the ex-powersupply chassis, you can
>> mount another, shallow, module next to it
>> 3. Dotcom: use a cheap plastic panel and simply screw it onto the chassis.
>> 4. Dotcom: take one row of your Dotcom chassis, and fill it with
>> modules of exactly this height. Use the remaining space for mults etc.
>> 5. Eurorack: The side plate is slightly higher than eurorack. It's
>> also exactly 8 cm wide. Use the thing as a portable 4U eurorack synth.
>> Or, if your modules are not deep at all, then you can use it as 7U.
>> There's enough space there to house a small PSU as well, based off
>> e.g. a couple laptop power supplies (they have very flat toroids).
>> Even better, you get an IEC plug, and usually a fuse holder, so that
>> you don't need to take care of that.
>> 6. Fracrack: same as Eurorack. Houses 1U of a deep module, or nearly
>> 2U of fairly shallow modules. Having a tiny amount of overhang
>> (0.125") on the side shouldn't bother anyone.
>>
>> Happy hacking!
>> D.
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>


From subjectivity at hotmail.com  Sun Nov 28 14:07:07 2010
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Sun, 28 Nov 2010 08:07:07 -0500
Subject: [sdiy] gyrator calculator
In-Reply-To: <FCB6650BC68D4686B7331A4748636851@galvanox01>
References: <BLU0-SMTP1806373D8C65A569EE698C2C8230@phx.gbl>
	<FCB6650BC68D4686B7331A4748636851@galvanox01>
Message-ID: <BLU0-SMTP4E54C1FB632077D41416AC8230@phx.gbl>

Thanks! 

Sent from my iPhone

On Nov 28, 2010, at 12:37 AM, "David G. Dixon" <dixon at interchange.ubc.ca> wrote:

>> sounds like  a bad new wave band....anyone know a quick way to turn a
>> desired inductor value into gyrator values?
> 
> Assuming all resistors R and capacitors C, the effective inductance is CR^2.
> 
> 


From dalenkarl at yahoo.se  Sun Nov 28 22:08:45 2010
From: dalenkarl at yahoo.se (karl dalen)
Date: Sun, 28 Nov 2010 21:08:45 +0000 (GMT)
Subject: [sdiy] dsPIC USB?
In-Reply-To: <1A3C53FD-4BB2-4661-BC62-88320EA210BA@electricdruid.net>
Message-ID: <141960.38174.qm@web27602.mail.ukl.yahoo.com>

Just heard that M-chip have finally released a number of 16bit devices
with USB, PIC24FJ64GB002 but does anyone know if they will make a dsSPIC
with USB in the near future?

Regards
KD




From antoniotuzzi at gmail.com  Sun Nov 28 22:13:56 2010
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Sun, 28 Nov 2010 22:13:56 +0100
Subject: [sdiy] Roland SH101 pieces
Message-ID: <704A90C8-8CBC-4A5C-8898-0CB48ED921DC@gmail.com>

Hello,

I need some extra pieces for a Gray SH101

the portamento pot: 2MA
the pwm slider: 100kB
and possibly the battery door...

Technologytransplant won't ship to Italy, 
and maybe you have overbought in the past
maybe you want to resell some of the sh101 pieces to me!

Thank you for your help

at



From matt at smiffytech.com  Sun Nov 28 22:15:24 2010
From: matt at smiffytech.com (Matthew Smith)
Date: Mon, 29 Nov 2010 07:45:24 +1030
Subject: [sdiy] dsPIC USB?
In-Reply-To: <141960.38174.qm@web27602.mail.ukl.yahoo.com>
References: <141960.38174.qm@web27602.mail.ukl.yahoo.com>
Message-ID: <4CF2C66C.5060902@smiffytech.com>

Quoth karl dalen at 2010-11-29 07:38...
> Just heard that M-chip have finally released a number of 16bit devices
> with USB, PIC24FJ64GB002 but does anyone know if they will make a dsSPIC
> with USB in the near future?

I can't answer that but, unless you are really tight on space, you can
get USB to TTL serial modules (includes connector) for as little as $5
USD now.

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business:      http://www.smiffytech.com/
Blog/personal: http://www.smiffysplace.com/
LinkedIn:      http://www.linkedin.com/in/smiffy
Skype:         msmiffy
Twitter:       @smiffy



From dalenkarl at yahoo.se  Mon Nov 29 02:05:11 2010
From: dalenkarl at yahoo.se (karl dalen)
Date: Mon, 29 Nov 2010 01:05:11 +0000 (GMT)
Subject: [sdiy] Endless pots?
In-Reply-To: <141960.38174.qm@web27602.mail.ukl.yahoo.com>
Message-ID: <147091.33946.qm@web27603.mail.ukl.yahoo.com>

Regarding past pots and decoder discussions, i wonder why there are
are no pots that turns endlessly with a small dead zone around 360 deg?
Could be neat!

Regards
KD





From dixon at interchange.ubc.ca  Mon Nov 29 10:04:41 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 29 Nov 2010 01:04:41 -0800
Subject: [sdiy] serge wave multilplier
Message-ID: <852665E8C8454B148E2B81F0294F489E@galvanox01>

Hey Team,

Can anyone here please direct me to a weblink (or something else) where I
can find scope shots of the Serge (or perhaps the CGS) wave multiplier in
action, particularly the fabled "middle section"?

Thanks in advance!



From martin at martinfay.com  Mon Nov 29 10:29:29 2010
From: martin at martinfay.com (Martin Fay)
Date: Mon, 29 Nov 2010 09:29:29 +0000
Subject: [sdiy] serge wave multilplier
In-Reply-To: <852665E8C8454B148E2B81F0294F489E@galvanox01>
References: <852665E8C8454B148E2B81F0294F489E@galvanox01>
Message-ID: <AB849C1C-854A-4D58-8500-FB0AF6E9D0A2@martinfay.com>

Grant Richter has a page with some scope shots:

http://www.musicsynthesizer.com/Circuitry/nlt.htm

Martin

Sent from my iPhone

On 29 Nov 2010, at 09:04, "David G. Dixon" <dixon at interchange.ubc.ca>  
wrote:

> Hey Team,
>
> Can anyone here please direct me to a weblink (or something else)  
> where I
> can find scope shots of the Serge (or perhaps the CGS) wave  
> multiplier in
> action, particularly the fabled "middle section"?
>
> Thanks in advance!
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From tom at electricdruid.net  Mon Nov 29 11:56:16 2010
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 29 Nov 2010 10:56:16 +0000
Subject: [sdiy] serge wave multilplier
In-Reply-To: <AB849C1C-854A-4D58-8500-FB0AF6E9D0A2@martinfay.com>
References: <852665E8C8454B148E2B81F0294F489E@galvanox01>
	<AB849C1C-854A-4D58-8500-FB0AF6E9D0A2@martinfay.com>
Message-ID: <72CFB6F3-DDC8-4324-ADDA-096519B2C363@electricdruid.net>

It's interesting to consider those functions as Chebyshev polynomials. There's a mixture of odd and even functions, and by mixing them up a bit, I bet you can get all sorts of sounds.

My own experiments with waveshaping weren't that convincing, but it's still something that I'd like to try again.

T.


On 29 Nov 2010, at 09:29, Martin Fay wrote:

> Grant Richter has a page with some scope shots:
> 
> http://www.musicsynthesizer.com/Circuitry/nlt.htm
> 
> Martin
> 
> Sent from my iPhone
> 
> On 29 Nov 2010, at 09:04, "David G. Dixon" <dixon at interchange.ubc.ca> wrote:
> 
>> Hey Team,
>> 
>> Can anyone here please direct me to a weblink (or something else) where I
>> can find scope shots of the Serge (or perhaps the CGS) wave multiplier in
>> action, particularly the fabled "middle section"?
>> 
>> Thanks in advance!
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From jpdesroc at oricom.ca  Mon Nov 29 13:30:13 2010
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Mon, 29 Nov 2010 07:30:13 -0500
Subject: [sdiy] Endless pots?
References: <147091.33946.qm@web27603.mail.ukl.yahoo.com>
Message-ID: <688FAC1259EB4A999F4723606DADB20B@HPLYNE>

There are pots that turns endlessly with a small dead zone around 360 deg.
They mostly have very precise linearity (normaly used for servo controls)
Look at this one..
I used it for my Moog921A clone module.
It has 2% linearity:
http://parts.digikey.ca/1/1/862222-pot-100k-ohm-ww-bush-mnt-157b104mxb10.html

or this ended auction:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=290410301030&si=NKzIs3p8Y8k%252BgEygVwE%252BRRoeq3Q%253D&viewitem=

Very smooth action, 360deg. rotation, very good tracking linearity,
very small dead zone around 360deg.
I know they are not cheap but... nothing for nothing.
Hope this helps.
JP

----- Original Message ----- 
From: "karl dalen" <dalenkarl at yahoo.se>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, November 28, 2010 8:05 PM
Subject: [sdiy] Endless pots?


> Regarding past pots and decoder discussions, i wonder why there are
> are no pots that turns endlessly with a small dead zone around 360 deg?
> Could be neat!
>
> Regards
> KD
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 



From tu at alphalink.com.au  Mon Nov 29 14:32:52 2010
From: tu at alphalink.com.au (tu at alphalink.com.au)
Date: Tue, 30 Nov 2010 00:32:52 +1100
Subject: [sdiy] Endless pots?
In-Reply-To: <688FAC1259EB4A999F4723606DADB20B@HPLYNE>
References: <147091.33946.qm@web27603.mail.ukl.yahoo.com>
	<688FAC1259EB4A999F4723606DADB20B@HPLYNE>
Message-ID: <1291037572.4cf3ab84c4dab@webmail.chariot.com.au>

There are also 360deg rotation pots with dual wipers and no dead zone. These could be used for 
sensing direction using quadrature decoding.

http://www.taiwanalpha.com/english/p_e_80-1.htm

Pinout at the bottom of this page.

http://www.taiwanalpha.com/english/p_e_31.htm

/Tristan

On Mon, Nov 29th, 2010 at 11:30 PM, Jean-Pierre Desrochers <jpdesroc at oricom.ca> wrote:

> There are pots that turns endlessly with a small dead zone around 360
> deg.
> They mostly have very precise linearity (normaly used for servo controls)
> Look at this one..
> I used it for my Moog921A clone module.
> It has 2% linearity:
> http://parts.digikey.ca/1/1/862222-pot-100k-ohm-ww-bush-mnt-157b104mxb10.html
> 
> or this ended auction:
> http://cgi.ebay.com/ws/eBayISAPI.dll?
ViewItem&rt=nc&nma=true&item=290410301030&si=NKzIs3p8Y8k%252BgEygVwE%252BRRoeq3Q
%253D&viewitem=
> 
> Very smooth action, 360deg. rotation, very good tracking linearity,
> very small dead zone around 360deg.
> I know they are not cheap but... nothing for nothing.
> Hope this helps.
> JP
> 
> ----- Original Message ----- 
> From: "karl dalen" <dalenkarl at yahoo.se>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Sunday, November 28, 2010 8:05 PM
> Subject: [sdiy] Endless pots?
> 
> 
> > Regarding past pots and decoder discussions, i wonder why there are
> > are no pots that turns endlessly with a small dead zone around 360 deg?
> > Could be neat!
> >
> > Regards
> > KD
> >
> >
> >
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 
> 





From dixon at interchange.ubc.ca  Mon Nov 29 18:07:18 2010
From: dixon at interchange.ubc.ca (David G. Dixon)
Date: Mon, 29 Nov 2010 09:07:18 -0800
Subject: [sdiy] serge wave multilplier
In-Reply-To: <AB849C1C-854A-4D58-8500-FB0AF6E9D0A2@martinfay.com>
References: <852665E8C8454B148E2B81F0294F489E@galvanox01>
	<AB849C1C-854A-4D58-8500-FB0AF6E9D0A2@martinfay.com>
Message-ID: <7EDEA0B5AFA84F6587561A52520D4334@galvanox01>

> Grant Richter has a page with some scope shots:
> 
> http://www.musicsynthesizer.com/Circuitry/nlt.htm

Thanks, Martin!  I wanted some inspiration for my own designs, and that's
exactly what I was looking for.




From davebr at earthlink.net  Tue Nov 30 00:45:13 2010
From: davebr at earthlink.net (David Brown)
Date: Mon, 29 Nov 2010 15:45:13 -0800
Subject: [sdiy] plastic serrated edging
Message-ID: <20101129234514.7FE2E10FA7A@relay02.roch.ny.frontiernet.net>

I need several feet of plastic / nylon serrated edging that I can put 
on the edge of thin sheet metal, 0.050" or less in thickness.  I need 
it pretty flexible to go around the inside corners of some irregular 
holes to protect wiring that goes through them.

I can find this in 100' spools but I don't need that much.  Does 
anyone know where I can get this in smaller lengths?  Even single 
foot lengths would work.  I am located in the USA.

Dave

David Brown
davebr at earthlink.net
http://modularsynthesis.com 



From tim.parkhurst at gmail.com  Tue Nov 30 01:06:59 2010
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Mon, 29 Nov 2010 16:06:59 -0800
Subject: [sdiy] plastic serrated edging
In-Reply-To: <20101129234514.7FE2E10FA7A@relay02.roch.ny.frontiernet.net>
References: <20101129234514.7FE2E10FA7A@relay02.roch.ny.frontiernet.net>
Message-ID: <AANLkTi=81LiuQVL3vUPKrfek2hM1He_xL8vQMLEFyRaN@mail.gmail.com>

On Mon, Nov 29, 2010 at 3:45 PM, David Brown <davebr at earthlink.net> wrote:
> I need several feet of plastic / nylon serrated edging that I can put on the
> edge of thin sheet metal, 0.050" or less in thickness. ?I need it pretty
> flexible to go around the inside corners of some irregular holes to protect
> wiring that goes through them.

Hey Dave,

Have you checked local hardware stores? I've also seen this stuff at
Orchard Supply or (if you're brave) Home Depot. I looked for a few
different items at McMaster-Carr, but couldn't turn up anything.


Tim ('edging your bets) Servo
-- 
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From dlmanley at sonic.net  Tue Nov 30 04:51:24 2010
From: dlmanley at sonic.net (Dave Manley)
Date: Mon, 29 Nov 2010 19:51:24 -0800
Subject: [sdiy] plastic serrated edging
In-Reply-To: <AANLkTi=81LiuQVL3vUPKrfek2hM1He_xL8vQMLEFyRaN@mail.gmail.com>
References: <20101129234514.7FE2E10FA7A@relay02.roch.ny.frontiernet.net>
	<AANLkTi=81LiuQVL3vUPKrfek2hM1He_xL8vQMLEFyRaN@mail.gmail.com>
Message-ID: <4CF474BC.1090701@sonic.net>

On 11/29/2010 4:06 PM, Tim Parkhurst wrote:
> On Mon, Nov 29, 2010 at 3:45 PM, David Brown<davebr at earthlink.net>  wrote:
>> I need several feet of plastic / nylon serrated edging that I can put on the
>> edge of thin sheet metal, 0.050" or less in thickness.  I need it pretty
>> flexible to go around the inside corners of some irregular holes to protect
>> wiring that goes through them.

How about tubing of the correct diameter that you've slit with a razor?

Cheap, flexible, and available, but might require some adhesive.

If I went that route I'd be tempted to build a small wood fixture
with a hole drilled to guide the tubing against the blade - controls
the cut and makes it less likely to slit your finger :-0!

-Dave


From Synthmanic at aol.com  Tue Nov 30 14:33:59 2010
From: Synthmanic at aol.com (Synthmanic at aol.com)
Date: Tue, 30 Nov 2010 08:33:59 EST
Subject: [sdiy] FS: Moog Service Manuals
Message-ID: <68231.7c69623.3a265747@aol.com>


I have original Moog service manuals  for sale:

Micromoog/Multimoog
Modular
Opus  3
Prodigy
Source
Taurus
Rogue/Taurus 2
Accessories

$150 +  shipping for the whole set. E-mail me if interested. USA only  
please.

Dave  



From techman at synth.net  Tue Nov 30 14:53:38 2010
From: techman at synth.net (Andy Wilson)
Date: Tue, 30 Nov 2010 13:53:38 -0000
Subject: [sdiy] Moog Taurus Parts
Message-ID: <4CF501E2.25126.FCF320@techman.synth.net>


Does anyone know where I might get hold of replacement knobs and 
slider caps for a Moog Taurus 1?

Thanks

Andy


---

Andy Wilson
www.techman.synth.net


From julian at port23.co.uk  Tue Nov 30 19:45:17 2010
From: julian at port23.co.uk (Julian)
Date: Tue, 30 Nov 2010 18:45:17 -0000
Subject: [sdiy] looking for a 19" JH String Ensemble / Triple Chorus panel
	design?
Message-ID: <3A709F0947A24529BCF41A6186660284@legba>

A friend wants me to build him one of these.

I would rather not have to consider / design the panel, and i know that others have made 19" units, but, try as i might, i cant 
actally find any panel files about.

Has anyone got any pointers as to where i might find one?

Failing that, i think i should probably just go with the bridechamber design, but work it as a 19" - probably no issue with that, 
right?

Thanks, Julian

 



From cheater00 at gmail.com  Tue Nov 30 22:24:46 2010
From: cheater00 at gmail.com (cheater cheater)
Date: Tue, 30 Nov 2010 22:24:46 +0100
Subject: [sdiy] plastic serrated edging
In-Reply-To: <4CF474BC.1090701@sonic.net>
References: <20101129234514.7FE2E10FA7A@relay02.roch.ny.frontiernet.net>
	<AANLkTi=81LiuQVL3vUPKrfek2hM1He_xL8vQMLEFyRaN@mail.gmail.com>
	<4CF474BC.1090701@sonic.net>
Message-ID: <AANLkTikTtDTpT7t0pkCpNDkDtVq-CvSLgaqXsf7PnSMc@mail.gmail.com>

> How about tubing of the correct diameter that you've slit with a razor?

That was exactly my idea.

With some types of PVC tubing you can also bake it onto metal, making
it assume the shape and stay there.


> If I went that route I'd be tempted to build a small wood fixture
> with a hole drilled to guide the tubing against the blade - controls
> the cut and makes it less likely to slit your finger :-0!

If you just use a hole and a small razor, the cut won't be even - the
elasticity of the tubing may make the cut "drift" to the sides.
However if you use something like say a plastic knife after the razor,
with the plastic knife going into the cut in the tubing and making
sure the tubing doesn't twist, then you will have much better cuts.

Alternative: don't use plastic, use metal. Also good. You can get the
right kind of metal bits in metal shops. Metal tubing will not hurt
the cables any more than plastic tubing would, and it will also be
stronger and will stay put.

HTH,
D.

(Stay-Put monster! Don't cross the cables!)

On Tue, Nov 30, 2010 at 04:51, Dave Manley <dlmanley at sonic.net> wrote:
> On 11/29/2010 4:06 PM, Tim Parkhurst wrote:
>>
>> On Mon, Nov 29, 2010 at 3:45 PM, David Brown<davebr at earthlink.net> ?wrote:
>>>
>>> I need several feet of plastic / nylon serrated edging that I can put on
>>> the
>>> edge of thin sheet metal, 0.050" or less in thickness. ?I need it pretty
>>> flexible to go around the inside corners of some irregular holes to
>>> protect
>>> wiring that goes through them.
>
> How about tubing of the correct diameter that you've slit with a razor?
>
> Cheap, flexible, and available, but might require some adhesive.
>
> If I went that route I'd be tempted to build a small wood fixture
> with a hole drilled to guide the tubing against the blade - controls
> the cut and makes it less likely to slit your finger :-0!
>
> -Dave
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


