From mr at analogue.org  Wed Feb  1 00:24:36 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 1 Feb 2012 00:24:36 +0100
Subject: [sdiy] Switched-mode power supply module in synths... good or
	bad?
In-Reply-To: <C673D509-2C41-4F27-AA41-B1110EB81A8F@merryfield.ca>
References: <CAP92RBXEo-a+mgx_XfztiBopWJ9G9uzcE3NQzYdSD5cmi8WxpQ@mail.gmail.com>
	<20BA2B7A-CBA7-4BEA-9C38-59AAB3E82311@gmail.com>
	<4F208849.705@smiffytech.com>
	<9FE1792B-E81D-45D2-AB86-A63667600CF5@merryfield.ca>
	<C673D509-2C41-4F27-AA41-B1110EB81A8F@merryfield.ca>
Message-ID: <CAP92RBVKVvEBj-q7tEm3dPk3YFBiO-5HCea=-BSE5ozoF8-tZA@mail.gmail.com>

Thanks for the many very good advice & answers to this question.
SMPSU is definitely an everyday technique by now, but in my case I
guess the potential (sic!) problems would come from the fact that the
SMPSU wasn't designed there from the start. I'll have to try it out I
guess. Twitching supply next to the mic preamp, this is gonna get
interesting... :-)

/mr  -  bzzzt!

On 26 January 2012 01:55, Veronica Merryfield <veronica at merryfield.ca> wrote:
> Thought I'd add my experience to the mix.
>
> For the last 2 years I have been working on contracts for pro-audio gear, mostly electronic percussion, and have a number of products powered by cheap wall wart SMPSU. FCC regs, as far as I can tell, don't do much below about 30Mhz or so, so one expect a ton of emissions from them. I sampled plenty and none were that great. In all cases the output noise and regulation was well outside of the spec but my clients did not want to bring the power supply inside the units (cost, time, FCC approval) and did not want to spend a large amount on better units.
>
> Each of the projects required multiple power rails requiring more power supplies on the boards. Typically these were a +Ve/-Ve pair for audio and a logic rail, although in one design I had 3 pairs of +Ve/-Ve rails and a couple of logic rails. I used SMPSUs for the bigger current rails and linear regs for the low current rails.
>
> The input noise had to be suppressed with inline inductors and capacitors. Taking a decent look at the noise on a scope and tinkering allowed me to use a mix of capacitors but basically 3 across three decades 0.5uF and up did the trick.
>
> The on board SMPSUs were laid out on double sided boards (cost driven) and by a careful choice of thru hole and SMT parts, I managed to have decent ground planes top and bottom. Part choice and location is key - it is worth putting money into low ESR caps for instance. In one incarnation, a mod wire was needed and depending on how this was fitted, the units were quiet or exceptionally noisy. There can be a lot of radiated energy and the current flow can be high. Grounding and path (route, size) are important. Locating the SMPSUs at one end of the board is extremely useful and being able to separate the PSUs from the audio with ground traces also helps. The audio nearest the PSUs in these cases is the low impedance part (output drivers, midi etc).
>
> Long and short, the units are quiet. In fact, the problem now is the delta-sigma DAC noise - this is on a unit that is bought in. The supplier did not think I would be able to produce a quiet enough audio and PSU board using two layers. Whilst 4 layers or more would certain make life easier, it is not the panacea.
>
> So, if the OP is thinking of a mix, buy in a wall wart and make up the other rails, it is possible and it can be very quiet, but it is not a simple proposition.
>
> For what it is worth, my on board SMPSUs include a mix or buck, flyback, continuos and discontinuous mode supplies, 120Khz to over 1Mhz, and a mix of manufacturers controllers. Discontinuous mode switchers ad noise way below their switching speed but sometime one has no real choice but to use them.
>
> In short - passive filtering, ground plane, proper attention to layout, and they are clean. Linear regs will not clean up a dirty rail. Current spikes can be huge therefore think about radiated emissions.
>
> Veronica
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From Stromeko at nexgo.de  Wed Feb  1 07:37:25 2012
From: Stromeko at nexgo.de (ASSI)
Date: Wed, 01 Feb 2012 07:37:25 +0100
Subject: [sdiy] PREH Potentiometers
In-Reply-To: <CB4D9D84.29A57%thx1138@earthlink.net>
References: <CB4D9D84.29A57%thx1138@earthlink.net>
Message-ID: <1549099.HINPAFsrbf@rainer>

On Tuesday 31 January 2012, 13:30:44, thx1138 wrote:
> I am running out of stock on my PREH Poti's and I would like to know if
> they are still in business or should I migrate to something easier to
> find.

They are still in business (you can find them on Google), but AFAIK they 
stopped production of potentiometers quite a while ago.


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

SD adaptation for Waldorf Blofeld V1.15B11:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada



From yo at VacoLoco.net  Wed Feb  1 08:16:57 2012
From: yo at VacoLoco.net (Paul Maddox)
Date: Wed, 1 Feb 2012 07:16:57 +0000
Subject: [sdiy] Push buttons with LED
In-Reply-To: <CAP92RBUCQ7YWZs8ERjTuiDi7vbtCjkenec24H4PNoHzEpEaavA@mail.gmail.com>
References: <A645BBDD-BAAE-474E-8478-399D907A9743@wintherstormer.no>
	<3325AD88-6317-42CD-BD60-184F9F8298F0@VacoLoco.net>
	<FF1A2FCA-45FD-42A6-B63F-AF8E2BC1C4CE@electricdruid.net>
	<CAP92RBUCQ7YWZs8ERjTuiDi7vbtCjkenec24H4PNoHzEpEaavA@mail.gmail.com>
Message-ID: <BB160623-D25E-4CAD-9256-CD9C20EFB66F@VacoLoco.net>

I buy mine from a company called "foremost" (http://www.4most.co.uk/).
I've always found them REALLY helpful and if I need a switch these are the first people I go to.

Paul


On 31 Jan 2012, at 20:58, Mattias Rickardsson wrote:

> Interesting, haven't heard of them. Where do you buy MEC switches?
> They seem to be made in Denmark... Ballerup... http://www.mec.dk
> 
> /mr  -  one short ferry trip away from Denmark
> 
> On 31 January 2012 20:44, Tom Wiltshire <tom at electricdruid.net> wrote:
>> +1 for MEC switches. I've used this same range and they've been reliable. They're not the cheapest ever, but they're good.
>> 
>> T.
>> 
>> On 31 Jan 2012, at 19:21, Paul Maddox wrote:
>> 
>>> Terje,
>>> 
>>>  For Gorf, Tron and Zira I use the MEC3FTL range, they're about 10mm and should be around $4.00 a go for an LED + cap, less if you buy them in quantity.
>>> 
>>> Paul
>>> 
>>> On 31 Jan 2012, at 17:35, Terje Winther wrote:
>>> 
>>>> I am looking for some on/off pushbuttons with a LED indicator showing the on/off status. The problem is that all I find are either too big or too expensive, like over 10 USD per button. I see that Moon modular has been able to find some very cool ones for their modules, but I guess they could buy like 10.000 of them, while I only need *slightly* fewer.
>>>> Has anyone come across som good and inexpensive pushbuttons with LEDs?
>>>> 
>>>> Terje Winther
>>>> terje.winther at wintherstormer.no
>>>> http://www.wintherstormer.no/
>>>> 
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at dropmix.xs4all.nl
>>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>> 
>>> ___________________________________
>>> VacoLoco
>>> http://VacoLoco.net
>>> 
>>> 
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> 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

___________________________________
VacoLoco
http://VacoLoco.net







From stevenpaulcook at tiscali.co.uk  Wed Feb  1 11:35:17 2012
From: stevenpaulcook at tiscali.co.uk (Steven Cook)
Date: Wed, 1 Feb 2012 10:35:17 -0000
Subject: [sdiy] Big Stumbling Block in Synth Project
In-Reply-To: <3F1A4D71-5E8B-4951-8A00-9E7E9D611138@t-online.de>
References: <4F261201.1020701@cox.net>
	<3F1A4D71-5E8B-4951-8A00-9E7E9D611138@t-online.de>
Message-ID: <60891E59E14249FB9F602C8452081981@pc>

Just in case no one has suggested: Try a different PDF reader - Acrobat is 
awful bloatware anyway - I use Foxit Reader but there are others available.

http://www.foxitsoftware.com/Secure_PDF_Reader/

http://blog.kowalczyk.info/software/sumatrapdf/free-pdf-reader.html

http://www.tracker-software.com/product/pdf-xchange-viewer

Steven Cook
http://www.spcplugins.com/ 



From subjectivity at hotmail.com  Wed Feb  1 15:15:04 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Wed, 1 Feb 2012 09:15:04 -0500
Subject: [sdiy] Pcb/parts contractor recommendations???
Message-ID: <BLU0-SMTP1564D7DE77A983EAB26B24CC8730@phx.gbl>

I am having some trouble with my pcb house. Can anyone recommend a place that can do parts and population from a bom and gerber?


Thanks

Sent from my iPhone

From jpdesroc at oricom.ca  Wed Feb  1 15:25:27 2012
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Wed, 01 Feb 2012 09:25:27 -0500
Subject: [sdiy] Pcb/parts contractor recommendations???
Message-ID: <56058.1328106327@oricom.ca>

Where are you located ? USA ?

Here in Quebec City, Canada.. **Circuits imprim?s de la Capitale inc.**
(Capital's Printed Circuits) have VERY competitive prices
in big or small quantities..
Here is the link 
http://www.pcbcic.com/
They do board manufacturing, assembly & rapid prototyping..

Good luck!

 On Wed 01/02/12 09:15 , Dan Snazelle subjectivity at hotmail.com sent:
> I am having some trouble with my pcb house. Can anyone recommend a place
> that can do parts and population from a bom and gerber?
> 
> Thanks
> 
> Sent from my iPhone
> _______________________________________________
> Synth-diy mailing list
> S
> ynth-diy at dropmix.xs4all.nlhttp://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 


From jpdesroc at oricom.ca  Wed Feb  1 20:43:43 2012
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Wed, 01 Feb 2012 14:43:43 -0500
Subject: [sdiy] Reliable web site for capacitor packages & types
Message-ID: <45447.1328125423@oricom.ca>


Does anybody know a good web site that shows
good pictures of ALL the actual standard capacitor types
(ex: Polystyrene, Polyester, Metalized Polyester, etc..)
with their real packages ?
For an example:
On the net I saw a lot of false pictures of capacitors
named as Polystyrene type but they were actually
Polyester or something else..
This is very confusing when you sneak in your drawers
to find a specific type of capacitor and you are messed up
with the real package it should be in..

Any web site ?
JP
 


From harrybissell at wowway.com  Wed Feb  1 20:48:48 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 1 Feb 2012 14:48:48 -0500 (EST)
Subject: [sdiy] Reliable web site for capacitor packages & types
In-Reply-To: <45447.1328125423@oricom.ca>
Message-ID: <1999687527.63711.1328125728827.JavaMail.root@md01.wow.synacor.com>

I don't know that you could tell the dielectric from a picture of the package.

You'd need to know the manufacturer and get their data sheet to be sure...

But such a web site might be useful to tell (lets say) a ceramic disk from
an aluminum electrolytic... good for newbies only

H^) harry

----- Original Message -----
From: Jean-Pierre Desrochers <jpdesroc at oricom.ca>
To: Synth-diy at dropmix.xs4all.nl
Sent: Wed, 01 Feb 2012 14:43:43 -0500 (EST)
Subject: [sdiy] Reliable web site for capacitor packages & types


Does anybody know a good web site that shows
good pictures of ALL the actual standard capacitor types
(ex: Polystyrene, Polyester, Metalized Polyester, etc..)
with their real packages ?
For an example:
On the net I saw a lot of false pictures of capacitors
named as Polystyrene type but they were actually
Polyester or something else..
This is very confusing when you sneak in your drawers
to find a specific type of capacitor and you are messed up
with the real package it should be in..

Any web site ?
JP
 
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From nitro2k01 at gmail.com  Thu Feb  2 03:44:53 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Thu, 2 Feb 2012 03:44:53 +0100
Subject: [sdiy] Reliable web site for capacitor packages & types
In-Reply-To: <45447.1328125423@oricom.ca>
References: <45447.1328125423@oricom.ca>
Message-ID: <CABacs=DNqAN9WYF-Yvw-k-7AR_0THiwJ1PeJGEYWe0J9=fGwKQ@mail.gmail.com>

On 1 February 2012 20:43, Jean-Pierre Desrochers <jpdesroc at oricom.ca> wrote:
> Does anybody know a good web site that shows
> good pictures of ALL the actual standard capacitor types
> (ex: Polystyrene, Polyester, Metalized Polyester, etc..)
> with their real packages ?
> For an example:
> On the net I saw a lot of false pictures of capacitors
> named as Polystyrene type but they were actually
> Polyester or something else..
> This is very confusing when you sneak in your drawers
> to find a specific type of capacitor and you are messed up
> with the real package it should be in..

This is not a trivial task. You can of course easily distinguish
certain types of caps, say electrolytic ones vs ceramic disc caps, but
when it comes to different plastic types, you have to rely on
markings, which can be vendor-specific.

Here's what the bottom looks on four capacitors I have lying around:
<http://www.flickr.com/photos/gameboygenius/6804489847/in/photostream>
Three of them are potted with an opaque resin, whereas one is potted
with a transparent resin, interestingly enough. Just from seeing this,
you never be able to figure out the dielectric.

Like I said, you have to rely on the markings:
<http://www.flickr.com/photos/gameboygenius/6804492645/in/photostream>
The blue and green ones are ERO brand. You have the value and the
voltage rating, but the other thing of note is the MKP and MKT
designators. Google has an interesting tidbit of knowledge there:

# Metallized plastic polypropylene (German: Metallisierter Kunststoff
Polypropylen), a type of plastic-film capacitors (see also: Types of
capacitors)
# Metallized plastic polyester (German: metallisierter kunststoff
polyester), a type of plastic-film capacitors (the last ?T? is due to
?P? been already used for ?polypropylene? ? see MKP). See also: Types
of capacitors

That's on the "disambiguation pages" for MKT and MKP.

I have no clue which dielectric the gray one is using, but on the
other side it says Rifa FS-capacitor PFE210GF. Googling for PFE210
capacitor leads me to.
http://www.evoxrifa.fi/aust_nz/obsolete_caps.htm
There's a table that says:

Old Type 	Modern Replacement
...
PFE210 (Note 1) 	PFR, PHE426

What does note 1 say?
"Note 1: These types were made in polystyrene film which is no longer
available from any source. Replacement types are made with
polypropylene and have different electrical and physical
characteristics."

Since this is an official information source (Evox Rifa) I'm pretty
confident that this is indeed a polystyrene cap.

Then there's the orange one, I'm pretty sure this is a tantalum cap.
After the F on the top, there's a line, indicating polarity. There's
also a line on the right side of the orange one in the picture, which
for some reason doesn't show up very well in the picture. Another
giveaway from experience that this is a tantalum is the tall height
and the orange color. From my biased experience, capacitors in a tall
package like that and/or capacitors in a plastic package that are
orange are often tantalum/electrolytes.

If you can provide pictures of a few of your caps, I can try to do
similar detective work for you.

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From nitro2k01 at gmail.com  Thu Feb  2 03:49:34 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Thu, 2 Feb 2012 03:49:34 +0100
Subject: [sdiy] Reliable web site for capacitor packages & types
In-Reply-To: <CABacs=DNqAN9WYF-Yvw-k-7AR_0THiwJ1PeJGEYWe0J9=fGwKQ@mail.gmail.com>
References: <45447.1328125423@oricom.ca>
	<CABacs=DNqAN9WYF-Yvw-k-7AR_0THiwJ1PeJGEYWe0J9=fGwKQ@mail.gmail.com>
Message-ID: <CABacs=DDkoaAQa-do-GzRisMC=0_-m4g1CjNv_0wq1aNWgGptQ@mail.gmail.com>

On 2 February 2012 03:44, Ove Rid? <nitro2k01 at gmail.com> wrote:
> On 1 February 2012 20:43, Jean-Pierre Desrochers <jpdesroc at oricom.ca> wrote:
>> Does anybody know a good web site that shows
>> good pictures of ALL the actual standard capacitor types
>> (ex: Polystyrene, Polyester, Metalized Polyester, etc..)
>> with their real packages ?
>> For an example:
>> On the net I saw a lot of false pictures of capacitors
>> named as Polystyrene type but they were actually
>> Polyester or something else..
>> This is very confusing when you sneak in your drawers
>> to find a specific type of capacitor and you are messed up
>> with the real package it should be in..
>
> This is not a trivial task. You can of course easily distinguish
> certain types of caps, say electrolytic ones vs ceramic disc caps, but
> when it comes to different plastic types, you have to rely on
> markings, which can be vendor-specific.
>
> Here's what the bottom looks on four capacitors I have lying around:
> <http://www.flickr.com/photos/gameboygenius/6804489847/in/photostream>
> Three of them are potted with an opaque resin, whereas one is potted
> with a transparent resin, interestingly enough. Just from seeing this,
> you never be able to figure out the dielectric.
>
> Like I said, you have to rely on the markings:
> <http://www.flickr.com/photos/gameboygenius/6804492645/in/photostream>
> The blue and green ones are ERO brand. You have the value and the
> voltage rating, but the other thing of note is the MKP and MKT
> designators. Google has an interesting tidbit of knowledge there:
>
> # Metallized plastic polypropylene (German: Metallisierter Kunststoff
> Polypropylen), a type of plastic-film capacitors (see also: Types of
> capacitors)
> # Metallized plastic polyester (German: metallisierter kunststoff
> polyester), a type of plastic-film capacitors (the last ?T? is due to
> ?P? been already used for ?polypropylene? ? see MKP). See also: Types
> of capacitors
>
> That's on the "disambiguation pages" for MKT and MKP.
>
> I have no clue which dielectric the gray one is using, but on the
> other side it says Rifa FS-capacitor PFE210GF. Googling for PFE210
> capacitor leads me to.
> http://www.evoxrifa.fi/aust_nz/obsolete_caps.htm
> There's a table that says:
>
> Old Type ? ? ? ?Modern Replacement
> ...
> PFE210 (Note 1) ? ? ? ? PFR, PHE426
>
> What does note 1 say?
> "Note 1: These types were made in polystyrene film which is no longer
> available from any source. Replacement types are made with
> polypropylene and have different electrical and physical
> characteristics."
>
> Since this is an official information source (Evox Rifa) I'm pretty
> confident that this is indeed a polystyrene cap.
>
> Then there's the orange one, I'm pretty sure this is a tantalum cap.
> After the F on the top, there's a line, indicating polarity. There's
> also a line on the right side of the orange one in the picture, which
> for some reason doesn't show up very well in the picture. Another
> giveaway from experience that this is a tantalum is the tall height
> and the orange color. From my biased experience, capacitors in a tall
> package like that and/or capacitors in a plastic package that are
> orange are often tantalum/electrolytes.
>
> If you can provide pictures of a few of your caps, I can try to do
> similar detective work for you.
>
> --
> /Ove

Forgot one little detail. The orange cap has a little SH logo, which I
looked up on the following page and it turned out to be a Siemens
brand cap.
<http://www.advanced-tech.com/ic_logos/ic_logos.htm>

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From stewpye at optusnet.com.au  Thu Feb  2 10:05:14 2012
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Thu, 02 Feb 2012 19:05:14 +1000
Subject: [sdiy] Snubber Capacitors
Message-ID: <4F2A51CA.6000609@optusnet.com.au>

Hi,

I'm designing a power supply for my synth. I want to put snubber caps 
for the bridge rectifier on the PCB in case I find a need for them, but 
am not sure whether to have one across each diode, or just one across 
the bridge. Also sometimes a series RC circuit is used. Would it be best 
to include room for a resistor as well?



Regards,
Stewart.


From rburnett at richieburnett.co.uk  Thu Feb  2 10:19:20 2012
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Thu, 2 Feb 2012 09:19:20 -0000 (GMT)
Subject: [sdiy] Snubber Capacitors
In-Reply-To: <4F2A51CA.6000609@optusnet.com.au>
References: <4F2A51CA.6000609@optusnet.com.au>
Message-ID: <51854.128.240.229.68.1328174360.squirrel@www.richieburnett.co.uk>

Snubbers across bridge rectifier diodes in 50/60Hz supplies are there to damp HF
ringing that occurs when the rectifier diodes abruptly switch large currents. 
You really should include some series resistance too, as adding capacitance
alone just lowers the ringing frequency but does little to damp it.

This document explains how they work and how to design them:

http://www.hagtech.com/pdf/snubber.pdf

Page 7 onwards deals with low-frequency "conventional" power supplies.

-Richie,

> Hi,
>
> I'm designing a power supply for my synth. I want to put snubber caps
> for the bridge rectifier on the PCB in case I find a need for them, but
> am not sure whether to have one across each diode, or just one across
> the bridge. Also sometimes a series RC circuit is used. Would it be best
> to include room for a resistor as well?
>
>
>
> Regards,
> Stewart.
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From Gergo_Palatinszky at epam.com  Thu Feb  2 10:24:37 2012
From: Gergo_Palatinszky at epam.com (Gergo Palatinszky)
Date: Thu, 2 Feb 2012 09:24:37 +0000
Subject: [sdiy] Snubber Capacitors
In-Reply-To: <4F2A51CA.6000609@optusnet.com.au>
References: <4F2A51CA.6000609@optusnet.com.au>
Message-ID: <174DD44EDEBA224ABA06E172DC2D8FC802EC2227@EPHUBUDSA0036.epam.com>

Hi,

In my BIG PSU (~10A) I used caps only (100nF or so)  ... might overkill to deal too much with it...

Br,
         Pala

-----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, February 02, 2012 10:05 AM
To: Synth DIY
Subject: [sdiy] Snubber Capacitors

Hi,

I'm designing a power supply for my synth. I want to put snubber caps for the bridge rectifier on the PCB in case I find a need for them, but am not sure whether to have one across each diode, or just one across the bridge. Also sometimes a series RC circuit is used. Would it be best to include room for a resistor as well?



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


From Gergo_Palatinszky at epam.com  Thu Feb  2 10:31:52 2012
From: Gergo_Palatinszky at epam.com (Gergo Palatinszky)
Date: Thu, 2 Feb 2012 09:31:52 +0000
Subject: [sdiy] Snubber Capacitors
In-Reply-To: <174DD44EDEBA224ABA06E172DC2D8FC802EC2227@EPHUBUDSA0036.epam.com>
References: <4F2A51CA.6000609@optusnet.com.au>
	<174DD44EDEBA224ABA06E172DC2D8FC802EC2227@EPHUBUDSA0036.epam.com>
Message-ID: <174DD44EDEBA224ABA06E172DC2D8FC802EC225A@EPHUBUDSA0036.epam.com>

Yep four... over each diode in the bridge ... and as many big capacitor X * 1000-4700uF you have after the bridge to smooth more the wave as many small cap (100nF) next to the big caps...


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Gergo Palatinszky
Sent: Thursday, February 02, 2012 10:25 AM
To: Stewart Pye; Synth DIY
Subject: Re: [sdiy] Snubber Capacitors

Hi,

In my BIG PSU (~10A) I used caps only (100nF or so)  ... might overkill to deal too much with it...

Br,
         Pala

-----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, February 02, 2012 10:05 AM
To: Synth DIY
Subject: [sdiy] Snubber Capacitors

Hi,

I'm designing a power supply for my synth. I want to put snubber caps for the bridge rectifier on the PCB in case I find a need for them, but am not sure whether to have one across each diode, or just one across the bridge. Also sometimes a series RC circuit is used. Would it be best to include room for a resistor as well?



Regards,
Stewart.
_______________________________________________
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 goaqihai at yahoo.co.uk  Thu Feb  2 20:59:46 2012
From: goaqihai at yahoo.co.uk (ganesha)
Date: Thu, 2 Feb 2012 19:59:46 +0000 (GMT)
Subject: [sdiy] unstable Korg MS 50 vco
In-Reply-To: <348371927.608231.1327159182455.JavaMail.root@md01.wow.synacor.com>
References: <1327147660.68811.YahooMailNeo@web25708.mail.ukl.yahoo.com>
	<348371927.608231.1327159182455.JavaMail.root@md01.wow.synacor.com>
Message-ID: <1328212786.5290.YahooMailNeo@web171412.mail.ir2.yahoo.com>

Hi,

I recently bought a Korg MS 50 but I noticed that the VCO is very unstable for the first 10 minutes after I turn it on. It's not just detuning but it really jumps from high to low notes and vice versa.

This is the case with both the HZ/V and OCT/V inputs. After 10 minutes, there is no problem anymore.

I've checked the schematics. Could it be the 2SC1583 that is causing this?


http://www.korganalogue.net/korgms/service/ms50/ms50schemos.pdf

Thanks.



From kingravine at comcast.net  Thu Feb  2 21:51:40 2012
From: kingravine at comcast.net (Dave Magnuson)
Date: Thu, 2 Feb 2012 15:51:40 -0500
Subject: [sdiy] unstable Korg MS 50 vco
In-Reply-To: <1328212786.5290.YahooMailNeo@web171412.mail.ir2.yahoo.com>
References: <1327147660.68811.YahooMailNeo@web25708.mail.ukl.yahoo.com>	<348371927.608231.1327159182455.JavaMail.root@md01.wow.synacor.com>
	<1328212786.5290.YahooMailNeo@web171412.mail.ir2.yahoo.com>
Message-ID: <002101cce1ec$76afb5a0$640f20e0$@comcast.net>



-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of ganesha
Sent: Thursday, February 02, 2012 3:00 PM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] unstable Korg MS 50 vco

Hi,

I recently bought a Korg MS 50 but I noticed that the VCO is very unstable
for the first 10 minutes after I turn it on. It's not just detuning but it
really jumps from high to low notes and vice versa.

This is the case with both the HZ/V and OCT/V inputs. After 10 minutes,
there is no problem anymore.

I've checked the schematics. Could it be the 2SC1583 that is causing this?


http://www.korganalogue.net/korgms/service/ms50/ms50schemos.pdf

Thanks.

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


Since your problem goes away after warm-up, I'd suspect a "thermal" related
problem.  Something could be warming up, expanding, and making better
contact.

So the first thing to look for is cracked/cold solder joints near the VCO,
loose wiring harnesses, etc.  It could also be a hairline crack in one of
the circuit board traces

Sometimes I'll just re-touch all of the solder joints on the board in that
region with a tiny dab of new solder, making sure the old solder melts and
re-flows

Dave Magnuson



From sempini at gmail.com  Thu Feb  2 21:52:41 2012
From: sempini at gmail.com (paulo semprini)
Date: Thu, 2 Feb 2012 12:52:41 -0800
Subject: [sdiy] SSM2040 replacement
Message-ID: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>

Just wanted to notify anyone who didn't know that Hearn/Morley is
selling a replacement for the SSM2040 quad VCF --
http://sites.google.com/site/hearnmorley/products/hm2040

It's an odd size, and not directly pin-compatible; ?but I wired up a
simple adapter socket & plugged one into a rev2 Prophet 5 -- the
customer couldn't tell the difference between the new one & the
originals.

Some differences might show up in other applications; but it's nice to
know there's a chip available for that 2040 sound.


From matt at smiffytech.com  Fri Feb  3 06:07:15 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Fri, 03 Feb 2012 15:37:15 +1030
Subject: [sdiy] Performance control - processing a control voltage
In-Reply-To: <D1E87D9F-7B9C-405B-865B-F46146D38F0F@electricdruid.net>
References: <4F248E79.7070100@smiffytech.com>
	<D1E87D9F-7B9C-405B-865B-F46146D38F0F@electricdruid.net>
Message-ID: <4F2B6B83.4030603@smiffytech.com>

Harry, Tom, many thanks for your input on this.

The main thing that has come out of this, both from your comments and my 
muddling around on paper, is that I'm not going to get it out of a 
single 5V supply, at least not without having an on-board boost 
regulator and then creating a virtual ground. [My original design, from 
which this is an offshoot, uses a digital output sensor - going analogue 
to make the whole thing more "organic."]

One of my design criteria for just about everything is that it should 
run off a wall-wart, so that whatever plugs into the mains can be fully 
compliant with local regulations, and the apparatus as a whole not 
require certfication. (I just ain't going there.)

So - I'll see if I can get my hands on a 24V wall-wart (possibly an 
after-market laptop power supply) and use a rail-splitter and buffer 
(it's a Burr Brown part, can't remember the number, ditto the rail 
splitter) to give a virtual ground. If that turns out to be unavailable 
or too expensive, I'll probably use a closed-frame MeanWell Supply that 
gives me +12V/-12V/+5V straight up. Element14 (Farnell) carries such as 
these, and I can generally screw them down on price pretty well.

Tom - what's the basis of 14 x lowest resistance - is this a hard and 
fast rule (of thumb)? Just for information, the LDRs I have go from (and 
I'll have to test and trim them individually) 8k-24k light resistance to 
at least half a Meg dark resistance.

But Tom's schematic wraps up what I really couldn't figure out, which 
was do the offset first, or do the gain first - or do come magic and get 
them in a single stage.

I'll have a fiddle based on this schematic, and actually nut out the 
details experimentally, in hardware.

---- Now for the boring bit ----

What this is actually doing.

The unit I'm designing is a multi-sensory sculpture; in essence, a synth 
and a light show in a single (Perspex) box.

Light source is a set of RGB LEDs, mounted in various positions in the 
box.  A set of mirrors, some moving (stepper motors) and some static, 
combined with some surplus optics from Electronic Goldmine make up the 
visual side. Synth bits are hidden underneath. The LDRs are (tastefully) 
mounted in various locations within the box, so get illumination from 
the LEDs, or reflected light thereof. CVs go to a patch panel which then 
routes to the synth controls and also to the ADC inputs of a 
microcontroller which drives the steppers and the LEDs. It's not a 
totally closed loop, as ambient light will also affect the inputs.  The 
result should be chaotic - a constantly evolving pattern of lights and 
tones.

Well, that's the idea, anyway!

Now I've just got to figure out how to make a mirror drum entirely out 
of Perspex.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy


From neil.johnson97 at ntlworld.com  Fri Feb  3 10:30:22 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Fri, 3 Feb 2012 09:30:22 +0000
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
Message-ID: <CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>

Hi,

paulo semprini wrote:
> Just wanted to notify anyone who didn't know that Hearn/Morley is
> selling a replacement for the SSM2040 quad VCF --
> http://sites.google.com/site/hearnmorley/products/hm2040
>
> It's an odd size, and not directly pin-compatible; ?but I wired up a
> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
> customer couldn't tell the difference between the new one & the
> originals.

You can see pictures of George's polysynth using these modules when he
brought it along to synth-diy UK in 2008:

http://www.diy.synth.net/glry/main.php?g2_itemId=1032

Cheers,
Neil
-- 
Modules and more: http://www.cesyg.com
Homepage: http://www.njohnson.co.uk


From goaqihai at yahoo.co.uk  Fri Feb  3 11:15:05 2012
From: goaqihai at yahoo.co.uk (ganesha)
Date: Fri, 3 Feb 2012 10:15:05 +0000 (GMT)
Subject: [sdiy] unstable Korg MS 50 vco
In-Reply-To: <002101cce1ec$76afb5a0$640f20e0$@comcast.net>
References: <1327147660.68811.YahooMailNeo@web25708.mail.ukl.yahoo.com>
	<348371927.608231.1327159182455.JavaMail.root@md01.wow.synacor.com>
	<1328212786.5290.YahooMailNeo@web171412.mail.ir2.yahoo.com>
	<002101cce1ec$76afb5a0$640f20e0$@comcast.net>
Message-ID: <1328264105.47129.YahooMailNeo@web171406.mail.ir2.yahoo.com>



Thanks to everyone for the advice. 

I'm going to open it this weekend to check for any problems in the exponential converter area.

I'll let you know if I find anything.



----- Original Message -----
From: Dave Magnuson <kingravine at comcast.net>
To: 'ganesha' <goaqihai at yahoo.co.uk>; synth-diy at dropmix.xs4all.nl
Cc: 
Sent: Thursday, 2 February 2012, 21:51
Subject: RE: [sdiy] unstable Korg MS 50 vco



-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of ganesha
Sent: Thursday, February 02, 2012 3:00 PM
To: synth-diy at dropmix.xs4all.nl
Subject: [sdiy] unstable Korg MS 50 vco

Hi,

I recently bought a Korg MS 50 but I noticed that the VCO is very unstable
for the first 10 minutes after I turn it on. It's not just detuning but it
really jumps from high to low notes and vice versa.

This is the case with both the HZ/V and OCT/V inputs. After 10 minutes,
there is no problem anymore.

I've checked the schematics. Could it be the 2SC1583 that is causing this?


http://www.korganalogue.net/korgms/service/ms50/ms50schemos.pdf

Thanks.

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


Since your problem goes away after warm-up, I'd suspect a "thermal" related
problem.? Something could be warming up, expanding, and making better
contact.

So the first thing to look for is cracked/cold solder joints near the VCO,
loose wiring harnesses, etc.? It could also be a hairline crack in one of
the circuit board traces

Sometimes I'll just re-touch all of the solder joints on the board in that
region with a tiny dab of new solder, making sure the old solder melts and
re-flows

Dave Magnuson


From admin at bugbrand.co.uk  Fri Feb  3 11:40:28 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Fri, 03 Feb 2012 10:40:28 +0000
Subject: [sdiy] Tama TS206 Schematics anyone
Message-ID: <4F2BB99C.2000105@bugbrand.co.uk>

Hi all,

Does anyone happen to have scans of schematics for the Tama TS-206 dual 
drum synth rack (2 x tom).
I'm just about to receive one and am always interested to see whether 
mods may be possible and how the insides work.
The only online versions seem to be the TS305 via Florian's website - 
they're likely to be quite similar design, but obviously not quite the same.

Any help would be greatly appreciated.
Cheers & best,
Tom

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From yo at VacoLoco.net  Fri Feb  3 13:48:25 2012
From: yo at VacoLoco.net (Paul Maddox)
Date: Fri, 3 Feb 2012 12:48:25 +0000
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
Message-ID: <3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>

Yeah, and I have to say, it sounded REAL nice too!

I have one of his HM2040 modules, I just don't have much time right now :(

I might knock up some eagle parts for them this weekend, in between house hold DIY. Maybe that'll spur me into making something.

Paul

On 3 Feb 2012, at 09:30, Neil Johnson wrote:

> Hi,
> 
> paulo semprini wrote:
>> Just wanted to notify anyone who didn't know that Hearn/Morley is
>> selling a replacement for the SSM2040 quad VCF --
>> http://sites.google.com/site/hearnmorley/products/hm2040
>> 
>> It's an odd size, and not directly pin-compatible;  but I wired up a
>> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
>> customer couldn't tell the difference between the new one & the
>> originals.
> 
> You can see pictures of George's polysynth using these modules when he
> brought it along to synth-diy UK in 2008:
> 
> http://www.diy.synth.net/glry/main.php?g2_itemId=1032
> 
> Cheers,
> Neil
> -- 
> Modules and more: http://www.cesyg.com
> Homepage: http://www.njohnson.co.uk
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

___________________________________
VacoLoco
http://VacoLoco.net







From mr at analogue.org  Fri Feb  3 14:17:55 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 3 Feb 2012 14:17:55 +0100
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
	<3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
Message-ID: <CAP92RBUXJBW_bTuV11mg1=VKArzx=MsSN+um-dpp2T7XVWs-7Q@mail.gmail.com>

The SSM2040 must be the filter chip that most people regard the
highest, but early Prophet~5 is the only synth where the majority of
people have heard it. Other filter favourites are often situated in
monophonic synths, where the filter is often used more radically.

Would you say that the sound of the SSM2040 is primarily a "good
polysynth filter sound" or does it fight with the top ones in
monophonic applications too?

/mr  -  with a spare good old SSM2040 that needs some love :-)

On 3 February 2012 13:48, Paul Maddox <yo at vacoloco.net> wrote:
> Yeah, and I have to say, it sounded REAL nice too!
>
> I have one of his HM2040 modules, I just don't have much time right now :(
>
> I might knock up some eagle parts for them this weekend, in between house hold DIY. Maybe that'll spur me into making something.
>
> Paul
>
> On 3 Feb 2012, at 09:30, Neil Johnson wrote:
>
>> Hi,
>>
>> paulo semprini wrote:
>>> Just wanted to notify anyone who didn't know that Hearn/Morley is
>>> selling a replacement for the SSM2040 quad VCF --
>>> http://sites.google.com/site/hearnmorley/products/hm2040
>>>
>>> It's an odd size, and not directly pin-compatible; ?but I wired up a
>>> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
>>> customer couldn't tell the difference between the new one & the
>>> originals.
>>
>> You can see pictures of George's polysynth using these modules when he
>> brought it along to synth-diy UK in 2008:
>>
>> http://www.diy.synth.net/glry/main.php?g2_itemId=1032
>>
>> Cheers,
>> Neil
>> --
>> Modules and more: http://www.cesyg.com
>> Homepage: http://www.njohnson.co.uk
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
> ___________________________________
> VacoLoco
> http://VacoLoco.net
>
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From jpdesroc at oricom.ca  Fri Feb  3 14:20:40 2012
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Fri, 03 Feb 2012 08:20:40 -0500
Subject: [sdiy] Some genuine National semi LM3080N available cheap...
Message-ID: <37748.1328275240@oricom.ca>


Is anybody looking for LM3080N's ?
Some IC's left here..

http://www.alltronics.com/cgi-bin/item/LM3080N/search/LM3080N-Linear-IC



From modular at gmail.com  Fri Feb  3 14:50:44 2012
From: modular at gmail.com (Dennis Verschoor)
Date: Fri, 3 Feb 2012 14:50:44 +0100
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <CAP92RBUXJBW_bTuV11mg1=VKArzx=MsSN+um-dpp2T7XVWs-7Q@mail.gmail.com>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
	<3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
	<CAP92RBUXJBW_bTuV11mg1=VKArzx=MsSN+um-dpp2T7XVWs-7Q@mail.gmail.com>
Message-ID: <D9958943-64A6-4AF5-9102-D8B05EAA01C3@gmail.com>

Don't forget it is the filter what makes the RSF Kobol sounds great.

Cheers,

Dennis

http://www.mono-poly.nl


On Feb 3, 2012, at 14:17, Mattias Rickardsson <mr at analogue.org> wrote:

> The SSM2040 must be the filter chip that most people regard the
> highest, but early Prophet~5 is the only synth where the majority of
> people have heard it. Other filter favourites are often situated in
> monophonic synths, where the filter is often used more radically.
> 
> Would you say that the sound of the SSM2040 is primarily a "good
> polysynth filter sound" or does it fight with the top ones in
> monophonic applications too?
> 
> /mr  -  with a spare good old SSM2040 that needs some love :-)
> 
> On 3 February 2012 13:48, Paul Maddox <yo at vacoloco.net> wrote:
>> Yeah, and I have to say, it sounded REAL nice too!
>> 
>> I have one of his HM2040 modules, I just don't have much time right now :(
>> 
>> I might knock up some eagle parts for them this weekend, in between house hold DIY. Maybe that'll spur me into making something.
>> 
>> Paul
>> 
>> On 3 Feb 2012, at 09:30, Neil Johnson wrote:
>> 
>>> Hi,
>>> 
>>> paulo semprini wrote:
>>>> Just wanted to notify anyone who didn't know that Hearn/Morley is
>>>> selling a replacement for the SSM2040 quad VCF --
>>>> http://sites.google.com/site/hearnmorley/products/hm2040
>>>> 
>>>> It's an odd size, and not directly pin-compatible;  but I wired up a
>>>> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
>>>> customer couldn't tell the difference between the new one & the
>>>> originals.
>>> 
>>> You can see pictures of George's polysynth using these modules when he
>>> brought it along to synth-diy UK in 2008:
>>> 
>>> http://www.diy.synth.net/glry/main.php?g2_itemId=1032
>>> 
>>> Cheers,
>>> Neil
>>> --
>>> Modules and more: http://www.cesyg.com
>>> Homepage: http://www.njohnson.co.uk
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>> 
>> ___________________________________
>> VacoLoco
>> http://VacoLoco.net
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> 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 mr at analogue.org  Fri Feb  3 15:49:29 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 3 Feb 2012 15:49:29 +0100
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <D9958943-64A6-4AF5-9102-D8B05EAA01C3@gmail.com>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
	<3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
	<CAP92RBUXJBW_bTuV11mg1=VKArzx=MsSN+um-dpp2T7XVWs-7Q@mail.gmail.com>
	<D9958943-64A6-4AF5-9102-D8B05EAA01C3@gmail.com>
Message-ID: <CAP92RBWwdNcKZGA1TAd+aRh3MEg66e0uhWau73SXQdsNw4we-A@mail.gmail.com>

I don't forget it, but how many have ever played (or even heard (or
even seen)) an RSF Kobol? ;-)

/mr

On 3 February 2012 14:50, Dennis Verschoor <modular at gmail.com> wrote:
> Don't forget it is the filter what makes the RSF Kobol sounds great.
>
> Cheers,
>
> Dennis
>
> http://www.mono-poly.nl
>
>
> On Feb 3, 2012, at 14:17, Mattias Rickardsson <mr at analogue.org> wrote:
>
>> The SSM2040 must be the filter chip that most people regard the
>> highest, but early Prophet~5 is the only synth where the majority of
>> people have heard it. Other filter favourites are often situated in
>> monophonic synths, where the filter is often used more radically.
>>
>> Would you say that the sound of the SSM2040 is primarily a "good
>> polysynth filter sound" or does it fight with the top ones in
>> monophonic applications too?
>>
>> /mr ?- ?with a spare good old SSM2040 that needs some love :-)
>>
>> On 3 February 2012 13:48, Paul Maddox <yo at vacoloco.net> wrote:
>>> Yeah, and I have to say, it sounded REAL nice too!
>>>
>>> I have one of his HM2040 modules, I just don't have much time right now :(
>>>
>>> I might knock up some eagle parts for them this weekend, in between house hold DIY. Maybe that'll spur me into making something.
>>>
>>> Paul
>>>
>>> On 3 Feb 2012, at 09:30, Neil Johnson wrote:
>>>
>>>> Hi,
>>>>
>>>> paulo semprini wrote:
>>>>> Just wanted to notify anyone who didn't know that Hearn/Morley is
>>>>> selling a replacement for the SSM2040 quad VCF --
>>>>> http://sites.google.com/site/hearnmorley/products/hm2040
>>>>>
>>>>> It's an odd size, and not directly pin-compatible; ?but I wired up a
>>>>> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
>>>>> customer couldn't tell the difference between the new one & the
>>>>> originals.
>>>>
>>>> You can see pictures of George's polysynth using these modules when he
>>>> brought it along to synth-diy UK in 2008:
>>>>
>>>> http://www.diy.synth.net/glry/main.php?g2_itemId=1032
>>>>
>>>> Cheers,
>>>> Neil
>>>> --
>>>> Modules and more: http://www.cesyg.com
>>>> Homepage: http://www.njohnson.co.uk
>>>> _______________________________________________
>>>> Synth-diy mailing list
>>>> Synth-diy at dropmix.xs4all.nl
>>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>>
>>> ___________________________________
>>> VacoLoco
>>> http://VacoLoco.net
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> 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 fanwander at mnet-online.de  Fri Feb  3 16:27:33 2012
From: fanwander at mnet-online.de (Florian Anwander)
Date: Fri, 03 Feb 2012 16:27:33 +0100
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <CAP92RBWwdNcKZGA1TAd+aRh3MEg66e0uhWau73SXQdsNw4we-A@mail.gmail.com>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>	<3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>	<CAP92RBUXJBW_bTuV11mg1=VKArzx=MsSN+um-dpp2T7XVWs-7Q@mail.gmail.com>	<D9958943-64A6-4AF5-9102-D8B05EAA01C3@gmail.com>
	<CAP92RBWwdNcKZGA1TAd+aRh3MEg66e0uhWau73SXQdsNw4we-A@mail.gmail.com>
Message-ID: <4F2BFCE5.1040809@mnet-online.de>

Am 03.02.2012 15:49, schrieb Mattias Rickardsson:
>> Don't forget it is the filter what makes the RSF Kobol sounds great.
 > I don't forget it, but how many have ever played (or even heard (or
 > even seen)) an RSF Kobol? ;-)

But _if_ you ever have heard and RSF Kobol, then you won't forget it.

Florian


From yo at VacoLoco.net  Fri Feb  3 19:44:30 2012
From: yo at VacoLoco.net (Paul Maddox)
Date: Fri, 3 Feb 2012 18:44:30 +0000
Subject: [sdiy] SSM2040 replacement
In-Reply-To: <3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
References: <CAMB77sxhdTBeDOKcDEnYY38dgR1dfay5nbpx9BfyzgNF2DJdQA@mail.gmail.com>
	<CAEaByMTDxfpKGW006r22gVkGUzvnJF3=h9ZmBHr8NXHEHKuy5Q@mail.gmail.com>
	<3E1C2BCE-A6D8-4D6F-83C5-9A3F8A141CCE@VacoLoco.net>
Message-ID: <81CC1889-8024-439F-80D3-A6509A933A3D@VacoLoco.net>

Forgot to add,

 here it was the next year with four voices of polyphony.
http://www.diy.synth.net/glry/main.php?g2_itemId=1192

Paul

On 3 Feb 2012, at 12:48, Paul Maddox wrote:

> Yeah, and I have to say, it sounded REAL nice too!
> 
> I have one of his HM2040 modules, I just don't have much time right now :(
> 
> I might knock up some eagle parts for them this weekend, in between house hold DIY. Maybe that'll spur me into making something.
> 
> Paul
> 
> On 3 Feb 2012, at 09:30, Neil Johnson wrote:
> 
>> Hi,
>> 
>> paulo semprini wrote:
>>> Just wanted to notify anyone who didn't know that Hearn/Morley is
>>> selling a replacement for the SSM2040 quad VCF --
>>> http://sites.google.com/site/hearnmorley/products/hm2040
>>> 
>>> It's an odd size, and not directly pin-compatible;  but I wired up a
>>> simple adapter socket & plugged one into a rev2 Prophet 5 -- the
>>> customer couldn't tell the difference between the new one & the
>>> originals.
>> 
>> You can see pictures of George's polysynth using these modules when he
>> brought it along to synth-diy UK in 2008:
>> 
>> http://www.diy.synth.net/glry/main.php?g2_itemId=1032
>> 
>> Cheers,
>> Neil
>> -- 
>> Modules and more: http://www.cesyg.com
>> Homepage: http://www.njohnson.co.uk
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> ___________________________________
> VacoLoco
> http://VacoLoco.net
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

___________________________________
VacoLoco
http://VacoLoco.net







From stewpye at optusnet.com.au  Fri Feb  3 22:49:24 2012
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Sat, 04 Feb 2012 07:49:24 +1000
Subject: [sdiy] Snubber Capacitors
In-Reply-To: <51854.128.240.229.68.1328174360.squirrel@www.richieburnett.co.uk>
References: <4F2A51CA.6000609@optusnet.com.au>
	<51854.128.240.229.68.1328174360.squirrel@www.richieburnett.co.uk>
Message-ID: <4F2C5664.3040200@optusnet.com.au>

Thanks to all for the replies. I'll see if I can do some calculations...

Regards,
Stewart.


Richie Burnett wrote:
> Snubbers across bridge rectifier diodes in 50/60Hz supplies are there to damp HF
> ringing that occurs when the rectifier diodes abruptly switch large currents. 
> You really should include some series resistance too, as adding capacitance
> alone just lowers the ringing frequency but does little to damp it.
>
> This document explains how they work and how to design them:
>
> http://www.hagtech.com/pdf/snubber.pdf
>
> Page 7 onwards deals with low-frequency "conventional" power supplies.
>
> -Richie,
>
>   
>> Hi,
>>
>> I'm designing a power supply for my synth. I want to put snubber caps
>> for the bridge rectifier on the PCB in case I find a need for them, but
>> am not sure whether to have one across each diode, or just one across
>> the bridge. Also sometimes a series RC circuit is used. Would it be best
>> to include room for a resistor as well?
>>
>>
>>
>> Regards,
>> Stewart.
>> _______________________________________________
>> 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 Stromeko at nexgo.de  Sat Feb  4 08:17:27 2012
From: Stromeko at nexgo.de (ASSI)
Date: Sat, 04 Feb 2012 08:17:27 +0100
Subject: [sdiy] Snubber Capacitors
In-Reply-To: <4F2A51CA.6000609@optusnet.com.au>
References: <4F2A51CA.6000609@optusnet.com.au>
Message-ID: <1344754.10pWO1WbHc@rainer>

On Thursday 02 February 2012, 19:05:14, Stewart Pye wrote:
> I'm designing a power supply for my synth. I want to put snubber caps
> for the bridge rectifier on the PCB in case I find a need for them, but
> am not sure whether to have one across each diode, or just one across
> the bridge. Also sometimes a series RC circuit is used. Would it be best
> to include room for a resistor as well?

If you do need a snubber, it has to be RC to be effective, each diode will 
need one and you will have to take into account that the smoothing 
capacitance will reduce over the lifetime off the supply (by 30% is a good 
guess).

You didn't say how much current and voltage you are designing it for, but it 
would probably be better to select rectifier diodes and dimension the 
transformer and smoothing caps correctly so that you don't need a snubber in 
the first place.  Excessive ringing at current levels below some 10A is 
usually a sign of misguidedly overdimensioned components (resulting in too 
high quality factor of the LC tank) and a harbinger of more problems with 
that design.  BTW, the smoothing caps after a rectifier bridge are one of 
those places where too low ESR is counterproductive.


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

Samples for the Waldorf Blofeld:
http://Synth.Stromeko.net/Downloads.html#BlofeldSamplesExtra



From djthomaswhite at yahoo.com  Sat Feb  4 17:35:00 2012
From: djthomaswhite at yahoo.com (Thomas White)
Date: Sat, 4 Feb 2012 08:35:00 -0800
Subject: [sdiy] RLPG Board Orders: Shipping Next Week
Message-ID: <422671EA-C8E8-4CDF-825C-5A53BBB5A76D@yahoo.com>

Hi all,

The Resonant Lopass Gate boards are in and will be shipping next week. I happen to have about 40 extra boards. If you want some, email me and I'll pull some aside for you. They are $15 each, shipping included. Thanks gang!

Thomas White
Natural Rhythm Music
www.naturalrhythmmusic.com

From music.maker at gte.net  Sun Feb  5 18:57:25 2012
From: music.maker at gte.net (Scott Gravenhorst)
Date: Sun, 05 Feb 2012 10:57:25 -0700
Subject: [sdiy] TEST - PLEASE IGNORE
Message-ID: <201202051857.q15IvPnR013145@linux7.lan>


I've not seen traffic in some days.  I tried to email Rick Jansen, but the
server rejected my address, so I'm just testing to see if the list is up or
down.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
-- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
-- Some Random Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/
-- When the going gets tough, the tough use the command line.



From nitro2k01 at gmail.com  Sun Feb  5 20:06:44 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Sun, 5 Feb 2012 20:06:44 +0100
Subject: [sdiy] TEST - PLEASE IGNORE
In-Reply-To: <201202051857.q15IvPnR013145@linux7.lan>
References: <201202051857.q15IvPnR013145@linux7.lan>
Message-ID: <CABacs=Dm_Fbsfgp+7_JZajObVpjoBohRTErO=Z=TpYtMHFQFAw@mail.gmail.com>

On 5 February 2012 18:57, Scott Gravenhorst <music.maker at gte.net> wrote:
> I've not seen traffic in some days. ?I tried to email Rick Jansen, but the
> server rejected my address, so I'm just testing to see if the list is up or
> down.

If you simply want to ping the server, you can send an empty e-mail to
<synth-diy-request at dropmix.xs4all.nl>, which will give you a response
within a minute if the server is up and working. This is true for all
MailMan lists; you can simply add -request at the end of the list
address to talk to the server interface. (You can also give the list
robot the command help, in the title or body of the message, which
makes it tell you what it can do to serve you.)

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From jpdesroc at oricom.ca  Sun Feb  5 21:25:44 2012
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Sun, 05 Feb 2012 15:25:44 -0500
Subject: [sdiy] Low-Key transpose on a MIDI2CV interface..
Message-ID: <62908.1328473544@oricom.ca>


Hi list,
PAIA midi2cv8 user's guide stipulates the following:
Most 61 keys digital keyboards assign the midi note number #36 to their lowest 'C' key..
So that means 3 octaves higher than the lowest MIDI note number #0.
That would give 3.00vdc on the CV output for the first left C note (number#36)..
PAIA has a way to drop to 0.00vdc the first C note of MIDI keyboards..

Did anybody acknowledge the MIDI note#36 for the first C key
of most 61 keys digital keyboards ? 

JP

 


From aym-htnys at teaser.fr  Sun Feb  5 23:18:58 2012
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Sun, 5 Feb 2012 23:18:58 +0100
Subject: [sdiy] Low-Key transpose on a MIDI2CV interface..
In-Reply-To: <62908.1328473544@oricom.ca>
References: <62908.1328473544@oricom.ca>
Message-ID: <20120205221857.GB9197@aym.net2.nerim.net>

On 2012-02-05 15:25 -0500, Jean-Pierre Desrochers wrote:
> 
> PAIA midi2cv8 user's guide stipulates the following:
> Most 61 keys digital keyboards assign the midi note number #36
> to their lowest 'C' key..
> So that means 3 octaves higher than the lowest MIDI note number #0.
> That would give 3.00vdc on the CV output for the first left C
> note (number#36).. PAIA has a way to drop to 0.00vdc the first
> C note of MIDI keyboards..
> 
> Did anybody acknowledge the MIDI note#36 for the first C key
> of most 61 keys digital keyboards ? 

Without transposition, i.e. on the 8' stop, the middle A of a
keyboard is supposed to play at 440 Hz. So it must be MIDI note
69. If it's a five-octave keyboard, the low C must be therefore
be MIDI note 36.

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


From tom at electricdruid.net  Mon Feb  6 00:10:16 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 5 Feb 2012 23:10:16 +0000
Subject: [sdiy] Low-Key transpose on a MIDI2CV interface..
In-Reply-To: <20120205221857.GB9197@aym.net2.nerim.net>
References: <62908.1328473544@oricom.ca>
	<20120205221857.GB9197@aym.net2.nerim.net>
Message-ID: <72B9ABB1-1B43-49E7-A3BE-0AD796085057@electricdruid.net>


On 5 Feb 2012, at 22:18, Andre Majorel wrote:

> On 2012-02-05 15:25 -0500, Jean-Pierre Desrochers wrote:
>> 
>> PAIA midi2cv8 user's guide stipulates the following:
>> Most 61 keys digital keyboards assign the midi note number #36
>> to their lowest 'C' key..
>> So that means 3 octaves higher than the lowest MIDI note number #0.
>> That would give 3.00vdc on the CV output for the first left C
>> note (number#36).. PAIA has a way to drop to 0.00vdc the first
>> C note of MIDI keyboards..
>> 
>> Did anybody acknowledge the MIDI note#36 for the first C key
>> of most 61 keys digital keyboards ? 
> 
> Without transposition, i.e. on the 8' stop, the middle A of a
> keyboard is supposed to play at 440 Hz. So it must be MIDI note
> 69. If it's a five-octave keyboard, the low C must be therefore
> be MIDI note 36.

I agree. I've aways used Concert A 440Hz = MIDI note 69 too.

(Usual disclaimers apply: The value of the opinions of a lunatic on the internet may go down as well as up, etc.)

T.



From davekendall at ntlworld.com  Mon Feb  6 16:31:23 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Mon, 6 Feb 2012 15:31:23 +0000
Subject: [sdiy] LM358 datasheet VCO on spilt rails
Message-ID: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>

Hi All.

Wondering if any of you have tried the VCO on page 1 of the National 
semiconductor LM358 datasheet, and if it could run on a spilt rail 
instead of a single rail.
http://www.hebertech.com/view/1448-national-semiconductor-lm358.pdf
As it has V+ /2 going to the + input of the right hand opamp, could 
that be replaced by GND, and all GND signals connected to -V?

Am most interested in using it as a simple voltage controlled TRI wave 
LFO.

Any thoughts anyone?

cheers,
Dave



From ebrombaugh1 at cox.net  Mon Feb  6 17:52:02 2012
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Mon, 06 Feb 2012 09:52:02 -0700
Subject: [sdiy] EOL notice on dsPIC30F601x
Message-ID: <4F300532.1050707@cox.net>

Just a heads up - I got a notice from MCHP that the dsPIC30F6010-6014 
parts are end-of-life. These are pretty old parts (been around since '05 
or so) and are being superseded by the 'A' versions, so there are 
pin-compatible replacements.

These were used in a number of older synth applications - I think Seb 
Francis used the '6014A parts in his 4xD delay project and I may have 
one or two floating around from the early days of prototyping some 
oscillators. Lately most dsPIC synth projects are based on the 
dsPIC33FJxxGP802 or '804 which have built-in audio DACs, faster clocks 
and much lower power consumption.

Eric


From eric at ericframpton.com  Mon Feb  6 19:13:58 2012
From: eric at ericframpton.com (Eric Frampton)
Date: Mon, 6 Feb 2012 13:13:58 -0500
Subject: [sdiy] Oberheim DMX wackiness
Message-ID: <B48BA303-020F-437F-90BE-79E8D7D38975@ericframpton.com>

Hey y'all -

So I've just acquired a DMX that I'm bringing back from the dead. I've got it making the proper noises, and the computer seems to be working, battery is swapped out, corroded sockets, etc. But it's got two weird problems that I'm hoping you guys can help me with.

1. the first few characters of the display are prone to show incorrect - but not random - characters. It looks like the display is hanging off the same data bus as everybody else, and since the rest of the machine seems to be OK, I'm not sure where the trouble is. I've tried swapping out the 74LS42 driving it to no avail.

2. The hi-hat card is working, and the Tom 1 card is working, but only in any slot except the one they're supposed to go it. As in, the hi-hat doesn't work in hi-hat but does work in tom/snare/bass/etc, and the same for the Tom 1 card. Ideas?

Also, the battery in this thing leaked. It didn't actually spill its guts on to the motherboard, but the gasses corroded a bunch of things in the surrounding area - luckily all the traces are intact. It seems like whatever those gasses are really do the whammy to any solder, such that it makes it really difficult to melt. Is there some chemical I should try, or a trick that any of you can recommend, for making the corroded bits easier to remove? I've been very fortunate to not have had to deal with this problem (to this degree, at least) before.

Thanks a bunch,
Eric



From patchell at cox.net  Mon Feb  6 21:33:08 2012
From: patchell at cox.net (James Patchell)
Date: Mon, 06 Feb 2012 12:33:08 -0800
Subject: [sdiy] LM358 datasheet VCO on spilt rails
In-Reply-To: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>
References: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>
Message-ID: <4F303904.1090005@cox.net>

Yes, you can run it on split rails, BUT, and it is a big BUT...

Because of the nature of the LM358/LM324, you may find that this causes 
more problems that it may solve.  The common mode input range of the 
LM358 includes ground, and the designer of this VCO took advantage of 
this fact.  Also, you will note, that the control voltage range is from 
0 to 2 * VCC - <some amount>.  If you were to run it from +/- 15 V, 
well, you can see the problem.

I used this VCO in the first synth I built, which was the circuits for 
the Paia 2700.  I did not like the VCO circuit that was in the magazine 
(Paia later made some major improvements on it), and when I built it 
discovered it worked a lot better.  The supply rails in t6he 2700 were 
+18, +9 and -9 volts.  I ran the VCO on 0 to +9, and with the 18 volt 
rail, I was able to provide the VCO with all the voltage it needed to go 
through its tuning range.

     My recommendation is to use it in the single supply mode.  If need 
be, use level shifters to get the signal swings (using op-amps running 
on split supply rails) to get what you need.

     Oh, yes, and this VCO is a true VCO.  That, of course, has it's own 
problems.  This VCO will never be anything more than a linear control VCO.

     -Jim

On 2/6/2012 7:31 AM, Dave Kendall wrote:
> Hi All.
>
> Wondering if any of you have tried the VCO on page 1 of the National 
> semiconductor LM358 datasheet, and if it could run on a spilt rail 
> instead of a single rail.
> http://www.hebertech.com/view/1448-national-semiconductor-lm358.pdf
> As it has V+ /2 going to the + input of the right hand opamp, could 
> that be replaced by GND, and all GND signals connected to -V?
>
> Am most interested in using it as a simple voltage controlled TRI wave 
> LFO.
>
> Any thoughts anyone?
>
> cheers,
> Dave
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From dixon at mail.ubc.ca  Mon Feb  6 21:47:39 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 6 Feb 2012 12:47:39 -0800
Subject: [sdiy] current conveyor?
Message-ID: <D367111DF35543A9B291A8F9CB84B333@galvanox01>

Do any gurus here know of a circuit to convey a current from a virtual
ground point to another point at any voltage?  Essentially, I'm trying to
feed the current output from a 2164 (which must feed to virtual ground) to
an integrator with a voltage of -5V at its + input.  I want to convey the
2164's current precisely to that integrator.  I know I can convert the
current to a voltage, and then send it back to the integrator through
another resistor while also summing in a current from -10V through the same
resistor.  However, notwithstanding the fact that this arrangement will also
invert my current, input offset voltages are going to wreak havoc with
precision.  I guess what I'm asking is, is there any way to do this without
first converting the current to a voltage?  The current needs to be able to
flow in both directions.  Any help most appreciated.



From marzacdev at gmail.com  Mon Feb  6 22:04:09 2012
From: marzacdev at gmail.com (=?iso-8859-15?Q?Fr=E9d=E9ric_Meslin_=28Gmail=29?=)
Date: Mon, 06 Feb 2012 22:04:09 +0100
Subject: [sdiy] SMD capacitors : choosing dielectric type
Message-ID: <op.v89zg7yt1ee36r@fred-pad.res.insa>

Hi everybody,

I am planning to order a bulk of SMD capacitors from Farnell for my synth
project but I have a question related to dielectric qualities.

For bypassing caps, I am going to take X7R ceramic capacitors but for
coupling audio signal and for filters I am thinking of buying polycarbonate
caps but they are costly in SMD package. In through hole versions, I use
MKP or MKT film capacitors which I find very good and not very expensive.

What would be a good choice for replacing these MKP/T caps in a SMD design
according to your experience ?

Thank you by advance,
Fr?d?ric


-- 
Utilisant le logiciel de courrier r?volutionnaire d'Opera :  
http://www.opera.com/mail/


From stewpye at optusnet.com.au  Mon Feb  6 22:17:27 2012
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Tue, 07 Feb 2012 07:17:27 +1000
Subject: [sdiy] current conveyor?
In-Reply-To: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
Message-ID: <4F304367.3050906@optusnet.com.au>

Hi David,

This is probably too obvious to be an option, but can you resign the 
integrator part of the circuit so that the + input of the op amp is at 
ground?
Alternatively return the ground pin of the 2164 to +5V and level shift 
the control circuitry and input signal.

Regards,
Stewart.


On 2/7/2012 6:47 AM, David G Dixon wrote:
> Do any gurus here know of a circuit to convey a current from a virtual
> ground point to another point at any voltage?  Essentially, I'm trying to
> feed the current output from a 2164 (which must feed to virtual ground) to
> an integrator with a voltage of -5V at its + input.  I want to convey the
> 2164's current precisely to that integrator.  I know I can convert the
> current to a voltage, and then send it back to the integrator through
> another resistor while also summing in a current from -10V through the same
> resistor.  However, notwithstanding the fact that this arrangement will also
> invert my current, input offset voltages are going to wreak havoc with
> precision.  I guess what I'm asking is, is there any way to do this without
> first converting the current to a voltage?  The current needs to be able to
> flow in both directions.  Any help most appreciated.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From lightburnx at yahoo.com  Mon Feb  6 22:29:25 2012
From: lightburnx at yahoo.com (Kyle Stephens)
Date: Mon, 6 Feb 2012 13:29:25 -0800 (PST)
Subject: [sdiy] current conveyor?
In-Reply-To: <4F304367.3050906@optusnet.com.au>
Message-ID: <1328563765.61289.YahooMailClassic@web33904.mail.mud.yahoo.com>

Semi-edjamacated guess: current mirror?

Iirc, you may either need to worry about beta-matching or thermal drift depending on type, if it's discrete at least.


_Kyle

--- On Mon, 2/6/12, Stewart Pye <stewpye at optusnet.com.au> wrote:

> From: Stewart Pye <stewpye at optusnet.com.au>
> Subject: Re: [sdiy] current conveyor?
> To: synth-diy at dropmix.xs4all.nl
> Date: Monday, February 6, 2012, 1:17 PM
> Hi David,
> 
> This is probably too obvious to be an option, but can you
> resign the integrator part of the circuit so that the +
> input of the op amp is at ground?
> Alternatively return the ground pin of the 2164 to +5V and
> level shift the control circuitry and input signal.
> 
> Regards,
> Stewart.
> 
> 
> On 2/7/2012 6:47 AM, David G Dixon wrote:
> > Do any gurus here know of a circuit to convey a current
> from a virtual
> > ground point to another point at any voltage??
> Essentially, I'm trying to
> > feed the current output from a 2164 (which must feed to
> virtual ground) to
> > an integrator with a voltage of -5V at its +
> input.? I want to convey the
> > 2164's current precisely to that integrator.? I
> know I can convert the
> > current to a voltage, and then send it back to the
> integrator through
> > another resistor while also summing in a current from
> -10V through the same
> > resistor.? However, notwithstanding the fact that
> this arrangement will also
> > invert my current, input offset voltages are going to
> wreak havoc with
> > precision.? I guess what I'm asking is, is there
> any way to do this without
> > first converting the current to a voltage?? The
> current needs to be able to
> > flow in both directions.? Any help most
> appreciated.
> > 
> > _______________________________________________
> > 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 jays at aracnet.com  Mon Feb  6 22:38:20 2012
From: jays at aracnet.com (jays at aracnet.com)
Date: Mon, 06 Feb 2012 13:38:20 -0800
Subject: [sdiy] SMD capacitors : choosing dielectric type
In-Reply-To: <op.v89zg7yt1ee36r@fred-pad.res.insa>
References: <op.v89zg7yt1ee36r@fred-pad.res.insa>
Message-ID: <6821021244fda38c039ee067d81c5294@mail.spiritone.com>

Fr?d?ric,

I don't know which caps you are looking at or how you plan on soldering
them.

But one issue with plastic SMD caps is they can be very temperature
sensitive. There are some that you can melt quite easily soldering with
a soldering iron. So check your specs about soldering them before you
buy.

Good luck!
Jay S.

On Mon, 06 Feb 2012 22:04:09 +0100, Fr?d?ric Meslin (Gmail)
<marzacdev at gmail.com> wrote:
> Hi everybody,
> 
> I am planning to order a bulk of SMD capacitors from Farnell for my synth
> project but I have a question related to dielectric qualities.
> 
> For bypassing caps, I am going to take X7R ceramic capacitors but for
> coupling audio signal and for filters I am thinking of buying polycarbonate
> caps but they are costly in SMD package. In through hole versions, I use
> MKP or MKT film capacitors which I find very good and not very expensive.
> 
> What would be a good choice for replacing these MKP/T caps in a SMD design
> according to your experience ?
> 
> Thank you by advance,
> Fr?d?ric




From Stromeko at nexgo.de  Mon Feb  6 22:51:27 2012
From: Stromeko at nexgo.de (ASSI)
Date: Mon, 06 Feb 2012 22:51:27 +0100
Subject: [sdiy] current conveyor?
In-Reply-To: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
Message-ID: <4402262.gr3M1kYqgO@rainer>

On Monday 06 February 2012, 12:47:39, David G Dixon wrote:
> Do any gurus here know of a circuit to convey a current from a virtual
> ground point to another point at any voltage?

Not claiming guru status, but these things are indeed called current 
conveyors... they come in several types and generations.  While they are 
convenient to synthesize network functions with, their implementation can be 
fantastically complicated.  The "diamond transistor" from Burr-Brown 
actually can be used as a current conveyor.

> Essentially, I'm trying to
> feed the current output from a 2164 (which must feed to virtual ground) to
> an integrator with a voltage of -5V at its + input.

That's actually an easier thing to do, since you simply want to level shift 
that current signal from 0V down to -5V ? use a FET cascode transistor.  For 
an nMOS (enhancement, not JFET), the gate would be kept one Vth above -5V 
and everything else takes care of itself.  Now, Vth changes with temperature 
and is different for each transistor, so you'll have to put on a regulator 
that keeps the drain side at 0V to keep the 2164 happy.

Since the compliance of the 2164 does in fact goes slightly above and below 
0V, a crude but effective solution might be to level shift with a 5V 
(selected) Zener diode.  These have nearly no temperature coefficient, so 
this might actually work if the current range is not too large.


Regards,
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 marzacdev at gmail.com  Mon Feb  6 22:56:48 2012
From: marzacdev at gmail.com (=?iso-8859-15?Q?Fr=E9d=E9ric_Meslin_=28Gmail=29?=)
Date: Mon, 06 Feb 2012 22:56:48 +0100
Subject: [sdiy] SMD capacitors : choosing dielectric type
In-Reply-To: <6821021244fda38c039ee067d81c5294@mail.spiritone.com>
References: <op.v89zg7yt1ee36r@fred-pad.res.insa>
	<6821021244fda38c039ee067d81c5294@mail.spiritone.com>
Message-ID: <op.v891wysg1ee36r@fred-pad.res.insa>

Hi Jay S.

Thank you for your answer but soldering issues with 1206 or 805 SMD
caps are not big problems for me. I have the tools for soldering
this kind of components.

I think PPS caps are rather good according to this article :
http://www2.electronicproducts.com/PPS_stands_in_for_polycarbonate_in_film_capacitors-article-NOVDEA1-nov2000-html.aspx

Do you think so ?

Thank you by advance,
Fr?d?ric.


> I don't know which caps you are looking at or how you plan on soldering
> them.
>
> But one issue with plastic SMD caps is they can be very temperature
> sensitive. There are some that you can melt quite easily soldering with
> a soldering iron. So check your specs about soldering them before you
> buy.
>
> Good luck!
> Jay S.

-- 
Utilisant le logiciel de courrier r?volutionnaire d'Opera :  
http://www.opera.com/mail/


From matt at smiffytech.com  Mon Feb  6 23:19:23 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Tue, 07 Feb 2012 08:49:23 +1030
Subject: [sdiy] LM358 datasheet VCO on spilt rails
In-Reply-To: <4F303904.1090005@cox.net>
References: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>
	<4F303904.1090005@cox.net>
Message-ID: <4F3051EB.9040806@smiffytech.com>

Just out of curiosity, is the V+/2 shown on the schematic simply the 
supply voltage split with a potential divider, or does it require buffering?

Jim - what was your actual control range - 0V to +18V, or -9V to +18V? 
(Assuming the first, wanted to be clear.)

Given me an idea. Excluding PCB cost, a VCO for about $0.25. 4 for a 
dollar. Hmm.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From Stromeko at nexgo.de  Mon Feb  6 23:32:22 2012
From: Stromeko at nexgo.de (ASSI)
Date: Mon, 06 Feb 2012 23:32:22 +0100
Subject: [sdiy] current conveyor?
In-Reply-To: <4402262.gr3M1kYqgO@rainer>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
	<4402262.gr3M1kYqgO@rainer>
Message-ID: <2572803.ZcjtAJvjuU@rainer>

On Monday 06 February 2012, 22:51:27, ASSI wrote:
> That's actually an easier thing to do, since you simply want to level
> shift that current signal from 0V down to -5V ? use a FET cascode
> transistor.  For an nMOS (enhancement, not JFET), the gate would be kept
> one Vth above -5V and everything else takes care of itself.  Now, Vth
> changes with temperature and is different for each transistor, so you'll
> have to put on a regulator that keeps the drain side at 0V to keep the
> 2164 happy.

There will probably be another (pMOS) cascode needed at the 0V side if the 
range of currents gets large and the channel resistance of the nMOS can't 
track so that the voltage drop is always 5V at the lower end of currents.  
Also, I won't figure out today (if ever) what happens when the 2164 wants to 
pull in current...


Regards,
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 nicolas3141 at yahoo.com.au  Tue Feb  7 00:39:17 2012
From: nicolas3141 at yahoo.com.au (nicolas)
Date: Mon, 6 Feb 2012 15:39:17 -0800 (PST)
Subject: [sdiy] LM358 datasheet VCO on spilt rails
In-Reply-To: <4F303904.1090005@cox.net>
Message-ID: <1328571557.88265.YahooMailClassic@web161606.mail.bf1.yahoo.com>

That datasheet circuit has been designed around an assymetrical supply with the CV referenced to the negative supply.  If you have a symmetrical supply available you would be better to go with a more conventional approach which really just means rearranging those four resistors and the transistor on the CV input side.  For symmetrical supply and CV referenced to 0V that resistor network would be:
 - 50k between the CV-in and the transistor collector.
 - 50k between the transistor collector and the -ve in of the integrator op-amp.
 - 100k between the CV-in and the +ve in of the integrator op-amp.
 - 50k between the +ve in of the integrator op-amp and 0V.
 - transitor emitter connected to 0V.

Nicolas


--- On Tue, 7/2/12, James Patchell <patchell at cox.net> wrote:

> From: James Patchell <patchell at cox.net>
> Subject: Re: [sdiy] LM358 datasheet VCO on spilt rails
> To: synth-diy at dropmix.xs4all.nl
> Received: Tuesday, 7 February, 2012, 9:33 AM
> Yes, you can run it on split rails,
> BUT, and it is a big BUT...
> 
> Because of the nature of the LM358/LM324, you may find that
> this causes more problems that it may solve.? The
> common mode input range of the LM358 includes ground, and
> the designer of this VCO took advantage of this fact.?
> Also, you will note, that the control voltage range is from
> 0 to 2 * VCC - <some amount>.? If you were to run
> it from +/- 15 V, well, you can see the problem.
> 
> I used this VCO in the first synth I built, which was the
> circuits for the Paia 2700.? I did not like the VCO
> circuit that was in the magazine (Paia later made some major
> improvements on it), and when I built it discovered it
> worked a lot better.? The supply rails in t6he 2700
> were +18, +9 and -9 volts.? I ran the VCO on 0 to +9,
> and with the 18 volt rail, I was able to provide the VCO
> with all the voltage it needed to go through its tuning
> range.
> 
> ? ? My recommendation is to use it in the single
> supply mode.? If need be, use level shifters to get the
> signal swings (using op-amps running on split supply rails)
> to get what you need.
> 
> ? ? Oh, yes, and this VCO is a true VCO.?
> That, of course, has it's own problems.? This VCO will
> never be anything more than a linear control VCO.
> 
> ? ? -Jim
> 
> On 2/6/2012 7:31 AM, Dave Kendall wrote:
> > Hi All.
> > 
> > Wondering if any of you have tried the VCO on page 1 of
> the National semiconductor LM358 datasheet, and if it could
> run on a spilt rail instead of a single rail.
> > http://www.hebertech.com/view/1448-national-semiconductor-lm358.pdf
> > As it has V+ /2 going to the + input of the right hand
> opamp, could that be replaced by GND, and all GND signals
> connected to -V?
> > 
> > Am most interested in using it as a simple voltage
> controlled TRI wave LFO.
> > 
> > Any thoughts anyone?
> > 
> > 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 matt at smiffytech.com  Tue Feb  7 03:07:47 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Tue, 07 Feb 2012 12:37:47 +1030
Subject: [sdiy] Matched transistors - critical parameters?
Message-ID: <4F308773.9060003@smiffytech.com>


What are the critical parameters of old matched transistor arrays, such 
as CA3096?

I've been looking at various modern ones, and the only thing that seems 
to stand out is that the hFE of the CA3096 is somewhat higher. (I'm 
comparing with the DMMT5551.)

Is this a critical factor in, say, a VCF, or is it the actual matching 
that is of greatest importance?

Just trying to figure out what the "magic" is that makes the old parts 
desirable over a nice little SOT-26 part costing somewhat less than half 
a dollar.


-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From ijfritz at comcast.net  Tue Feb  7 04:06:03 2012
From: ijfritz at comcast.net (Ian Fritz)
Date: Mon, 06 Feb 2012 20:06:03 -0700
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F308773.9060003@smiffytech.com>
References: <4F308773.9060003@smiffytech.com>
Message-ID: <6.2.1.2.2.20120206200348.025e8c28@mail.comcast.net>

One reason sometimes given is that the newer (SMT) parts are not 
monolithic, ie the devices are not on a common substrate.  This makes the 
thermal coupling worse, although it may not matter that much.

Ian


At 07:07 PM 2/6/2012, Matthew Smith wrote:

>What are the critical parameters of old matched transistor arrays, such as 
>CA3096?
>
>I've been looking at various modern ones, and the only thing that seems to 
>stand out is that the hFE of the CA3096 is somewhat higher. (I'm comparing 
>with the DMMT5551.)
>
>Is this a critical factor in, say, a VCF, or is it the actual matching 
>that is of greatest importance?
>
>Just trying to figure out what the "magic" is that makes the old parts 
>desirable over a nice little SOT-26 part costing somewhat less than half a 
>dollar.
>
>
>--
>Matthew Smith
>
>Business: http://www.smiffytech.com
>Blog:     http://www.smiffysplace.com
>Linkedin: http://www.linkedin.com/in/smiffy
>Flickr:   http://www.flickr.com/photos/msmiffy
>Twitter:  http://twitter.com/smiffy
>
>ABN 16 391 203 815
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From obl64 at ix.netcom.com  Tue Feb  7 04:09:31 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Mon, 06 Feb 2012 21:09:31 -0600
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F308773.9060003@smiffytech.com>
References: <4F308773.9060003@smiffytech.com>
Message-ID: <4F3095EB.6050902@ix.netcom.com>



On 2/6/2012 8:07 PM, Matthew Smith wrote:
>
> What are the critical parameters of old matched transistor arrays, such
> as CA3096?
>
> I've been looking at various modern ones, and the only thing that seems
> to stand out is that the hFE of the CA3096 is somewhat higher. (I'm
> comparing with the DMMT5551.)
>
> Is this a critical factor in, say, a VCF, or is it the actual matching
> that is of greatest importance?
>
> Just trying to figure out what the "magic" is that makes the old parts
> desirable over a nice little SOT-26 part costing somewhat less than half
> a dollar.
>
>

In the CA3xxx arrays, the transistors are on the same chip which is 
important for best thermal tracking. Vbe match is typically spec'd to 
5mV for the first two transistors in some of these. In reality the match 
is often much better than that, and often all 5 transistors match 
closely, making them great for mirroring control current to sections of 
a four pole filter. The CA3083 arrays worked really well and are cheap.

Some of these small devices are multiple single 2N3904, 2N5551, etc, 
transistor die encapsulated in one package.
It can still work well your design. The Vbe's are likely to be pretty 
close. Put something together and try it - your ears are the ultimate 
judge (assuming it's synth related).

- Oren


From patchell at cox.net  Tue Feb  7 04:25:52 2012
From: patchell at cox.net (James Patchell)
Date: Mon, 06 Feb 2012 19:25:52 -0800
Subject: [sdiy] LM358 datasheet VCO on spilt rails
In-Reply-To: <4F3051EB.9040806@smiffytech.com>
References: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>	<4F303904.1090005@cox.net>
	<4F3051EB.9040806@smiffytech.com>
Message-ID: <4F3099C0.1010804@cox.net>

As I recall (this was 40 years ago...well, 39), I just used a voltage 
divider and a bypass cap.

The control range was 0 volts to about +18 (just a hair less as I 
recall).  If you look at the frequency control part of the circuit, one 
leg is basically a voltage divider that goes to the + input of the 
op-amp.  The common mode input range of the LM358 is 0 to VCC-1.5 
volts.  So, you can run the control voltage up to the point where the + 
input is at that voltage.

And yes, it is a very cheap VCO.  At the time I used this circuit 
myself, I had no way to check to see how accurate it was.

http://www.noniandjim.com/Jim/FirstSynth/FirstSynth.html

On this web page, I have a picture of this thing as I built it.

-Jim

On 2/6/2012 2:19 PM, Matthew Smith wrote:
> Just out of curiosity, is the V+/2 shown on the schematic simply the 
> supply voltage split with a potential divider, or does it require 
> buffering?
>
> Jim - what was your actual control range - 0V to +18V, or -9V to +18V? 
> (Assuming the first, wanted to be clear.)
>
> Given me an idea. Excluding PCB cost, a VCO for about $0.25. 4 for a 
> dollar. Hmm.
>



From jays at aracnet.com  Tue Feb  7 04:39:45 2012
From: jays at aracnet.com (Jay Schwichtenberg)
Date: Mon, 6 Feb 2012 19:39:45 -0800
Subject: [sdiy] SMD capacitors : choosing dielectric type
In-Reply-To: <op.v891wysg1ee36r@fred-pad.res.insa>
References: <op.v89zg7yt1ee36r@fred-pad.res.insa>	<6821021244fda38c039ee067d81c5294@mail.spiritone.com>
	<op.v891wysg1ee36r@fred-pad.res.insa>
Message-ID: <000501cce54a$227b7a80$67726f80$@com>

Fr?d?ric,

I've used PPS caps in audio DAC/ADC filters on sound cards and thought they
sounded pretty good. When we were doing tests on our circuits we found the
converters and op-amps were more critical than the caps in the circuit. I
still use one of the cards in my DAW and it still holds up to a lot of newer
cards. Biggest problem is that the cards are PCI and that's going away
pretty fast now.

We used the ECHU caps from Panasonic.

But here's the problem. If you look at the data sheet the flow/reflow
soldering temperature it is 260C for these parts. If I've done my math right
that is 500F. Now the Kester 331 organic/water soluble and 245 no clean
solders have a soldering temp of 600F-700F. So you have to be really fast
soldering these things down. There is also no reuse if you pull one off a
board. There is a real high probablity it will be melted.

Jay S.


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Fr?d?ric Meslin
(Gmail)
Sent: Monday, February 06, 2012 1:57 PM
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] SMD capacitors : choosing dielectric type

Hi Jay S.

Thank you for your answer but soldering issues with 1206 or 805 SMD
caps are not big problems for me. I have the tools for soldering
this kind of components.

I think PPS caps are rather good according to this article :
http://www2.electronicproducts.com/PPS_stands_in_for_polycarbonate_in_film_c
apacitors-article-NOVDEA1-nov2000-html.aspx

Do you think so ?

Thank you by advance,
Fr?d?ric.


> I don't know which caps you are looking at or how you plan on soldering
> them.
>
> But one issue with plastic SMD caps is they can be very temperature
> sensitive. There are some that you can melt quite easily soldering with
> a soldering iron. So check your specs about soldering them before you
> buy.
>
> Good luck!
> Jay S.

-- 
Utilisant le logiciel de courrier r?volutionnaire d'Opera :  
http://www.opera.com/mail/
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy




From dixon at mail.ubc.ca  Tue Feb  7 04:48:04 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 6 Feb 2012 19:48:04 -0800
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F308773.9060003@smiffytech.com>
References: <4F308773.9060003@smiffytech.com>
Message-ID: <8B91DBDB6FF84C10B708B60BADD0CB4D@galvanox01>

> Is this a critical factor in, say, a VCF, or is it the actual 
> matching that is of greatest importance?

In my experience, with multistage filters, if you are sending the same
current to the Iabc inputs of OTAs, you don't even need to mirror the
current -- just connect all of Iabc's directly to the current source.  Each
one should suck the same amount of current.



From dixon at mail.ubc.ca  Tue Feb  7 04:49:52 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 6 Feb 2012 19:49:52 -0800
Subject: [sdiy] SMD capacitors : choosing dielectric type
In-Reply-To: <000501cce54a$227b7a80$67726f80$@com>
References: <op.v89zg7yt1ee36r@fred-pad.res.insa>	<6821021244fda38c039ee067d81c5294@mail.spiritone.com><op.v891wysg1ee36r@fred-pad.res.insa>
	<000501cce54a$227b7a80$67726f80$@com>
Message-ID: <48EC40D7E96E42FFBFD2193DA3FC7871@galvanox01>

> I've used PPS caps in audio DAC/ADC filters on sound cards 
> and thought they sounded pretty good. When we were doing 
> tests on our circuits we found the converters and op-amps 
> were more critical than the caps in the circuit. I still use 
> one of the cards in my DAW and it still holds up to a lot of 
> newer cards. Biggest problem is that the cards are PCI and 
> that's going away pretty fast now.

I've had good luck with the WIMA metallized PPE caps for filters.



From pfperry at melbpc.org.au  Tue Feb  7 05:22:46 2012
From: pfperry at melbpc.org.au (Paul Perry)
Date: Tue, 7 Feb 2012 15:22:46 +1100
Subject: [sdiy] Matched transistors - critical parameters?
References: <4F308773.9060003@smiffytech.com>
	<8B91DBDB6FF84C10B708B60BADD0CB4D@galvanox01>
Message-ID: <61CCDD42CAF947C2884D26A3B6F84D33@ownerf0d9273f5>

And maybe this is why multiple OTA filters sound so different from each 
other.. my workshop is in storage, but maybe someone can take a few 
measurements. I think that transconductance is not guaranteed to be better 
than 50% in agreement.

----- Original Message ----- 
From: "David G Dixon"
> In my experience, with multistage filters, if you are sending the same
> current to the Iabc inputs of OTAs, you don't even need to mirror the
> current -- just connect all of Iabc's directly to the current source. 
> Each
> one should suck the same amount of current.

paul perry Melbourne Australia



From music.maker at gte.net  Tue Feb  7 05:30:14 2012
From: music.maker at gte.net (Scott Gravenhorst)
Date: Mon, 06 Feb 2012 21:30:14 -0700
Subject: [sdiy] Some Musical Diversion
Message-ID: <201202070530.q175UEkI017810@linux7.lan>


If you like this kind of thing...

Beethoven's Moonlight Sonata

http://electro-music.com/forum/viewtopic.php?p=353470#353470

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
-- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
-- Some Random Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/
-- When the going gets tough, the tough use the command line.



From dixon at mail.ubc.ca  Tue Feb  7 06:21:48 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 6 Feb 2012 21:21:48 -0800
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <61CCDD42CAF947C2884D26A3B6F84D33@ownerf0d9273f5>
References: <4F308773.9060003@smiffytech.com><8B91DBDB6FF84C10B708B60BADD0CB4D@galvanox01>
	<61CCDD42CAF947C2884D26A3B6F84D33@ownerf0d9273f5>
Message-ID: <A17F7F2036E2440099780FF44706EC4B@galvanox01>

Well, in the interests of full disclosure, I typically put current mirrors
on my filter OTAs.  Of course, I haven't used an OTA in years, ever since I
discovered the 2164 quad VCA, and I've never looked back.  No expo
converter, no currents or current mirrors -- just a single buffered control
voltage sent to all VC pins, and four VCAs gain-matched to within a few
hundredths of a dB.

But, looking at the schematic of the LM13700, I see no reason why the Iabc
pin current draw of different OTAs shouldn't be very similar.

> And maybe this is why multiple OTA filters sound so different 
> from each other.. my workshop is in storage, but maybe 
> someone can take a few measurements. I think that 
> transconductance is not guaranteed to be better than 50% in agreement.
> 
> ----- Original Message -----
> From: "David G Dixon"
> > In my experience, with multistage filters, if you are 
> sending the same 
> > current to the Iabc inputs of OTAs, you don't even need to 
> mirror the 
> > current -- just connect all of Iabc's directly to the 
> current source.
> > Each
> > one should suck the same amount of current.



From pfperry at melbpc.org.au  Tue Feb  7 07:17:05 2012
From: pfperry at melbpc.org.au (Paul Perry)
Date: Tue, 7 Feb 2012 17:17:05 +1100
Subject: [sdiy] Matched transistors - critical parameters?
References: <4F308773.9060003@smiffytech.com><8B91DBDB6FF84C10B708B60BADD0CB4D@galvanox01>
	<61CCDD42CAF947C2884D26A3B6F84D33@ownerf0d9273f5>
	<A17F7F2036E2440099780FF44706EC4B@galvanox01>
Message-ID: <1D2096E2D43A4A88BFD0DF1B1F1CC1E5@ownerf0d9273f5>

No reason why they shouldn't match, I agree.. and I would hope that the two 
halves of a LM13700 were reasonably alike - but going by the data sheet, the 
transconductance specs do indeed vary by 2 to 1 (well, min 6700umho, max 
13000umho.)
Matching of the transconductance tracking is 0.3dB - certainly good enough 
for my ears if you are making a stereo VCA, but you can imagine some SDIY 
applications where there could be problems.
----- Original Message ----- 
From: "David G Dixon"
> Well, in the interests of full disclosure, I typically put current mirrors
> on my filter OTAs.  Of course, I haven't used an OTA in years, ever since 
> I
> discovered the 2164 quad VCA, and I've never looked back.  No expo
> converter, no currents or current mirrors -- just a single buffered 
> control
> voltage sent to all VC pins, and four VCAs gain-matched to within a few
> hundredths of a dB.
>
> But, looking at the schematic of the LM13700, I see no reason why the Iabc
> pin current draw of different OTAs shouldn't be very similar.
>
>> And maybe this is why multiple OTA filters sound so different
>> from each other.. my workshop is in storage, but maybe
>> someone can take a few measurements. I think that
>> transconductance is not guaranteed to be better than 50% in agreement.
>>
>> ----- Original Message -----
>> From: "David G Dixon"
>> > In my experience, with multistage filters, if you are
>> sending the same
>> > current to the Iabc inputs of OTAs, you don't even need to
>> mirror the
>> > current -- just connect all of Iabc's directly to the
>> current source.
>> > Each
>> > one should suck the same amount of current.
>
paul perry melbourne australia



From Stromeko at nexgo.de  Tue Feb  7 07:22:40 2012
From: Stromeko at nexgo.de (ASSI)
Date: Tue, 07 Feb 2012 07:22:40 +0100
Subject: [sdiy] current conveyor?
In-Reply-To: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
Message-ID: <1509359.tQgT3GD2lc@rainer>

On Monday 06 February 2012, 12:47:39, David G Dixon wrote:
> The current needs to be able to flow in both directions.

Some sleep and a coffee later... you do need an active current source rather 
than a passive level shift to have the current flowing back, of course.

An OTA with linearizing diodes will do, although the biasing is a bit tricky 
and I don't know how good the precision is at low currents and you will 
probably need an offset trim.  In essence, the output of the OTA goes to the 
-5V integrator input; both Iabc and Idiode need to be the same current (you 
need a mirror there since one will be sitting at +0.7V and the other 1.4V 
above the negative supply), slightly larger than the maximum current you're 
going to use; the negative input goes to ground (here's where you add the 
buffered offset trim, since it needs to be low-impedance); and the positive 
connects to the output of the 2164.  It may be advantageous to rig the 
supply of the OTA so that the mid-supply becomes close to -5V (requires a 
+-15V system w/ additional 5V rail due to head room requirements, probably 
not worth the trouble if you only have +-12V).

It may be easier to level shift all the inputs to the 2164 down by 5V with 
some zero-offset, zero drift opamp.  I assume you do not want to change the 
integrator to have its output symmetric about zero?


Regards,
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 dixon at mail.ubc.ca  Tue Feb  7 07:48:11 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 6 Feb 2012 22:48:11 -0800
Subject: [sdiy] current conveyor?
In-Reply-To: <1509359.tQgT3GD2lc@rainer>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
	<1509359.tQgT3GD2lc@rainer>
Message-ID: <55EFF4CF68D14A5C97B63B7F5FA6F43C@galvanox01>

Thanks to all for your suggestions.  Actually, in this particular case, I
figured out a very simple and elegant solution to my problem.  Through the
glories of feedback (around quite a large circuit, not just a single opamp),
I realized that I could just level-shift the output of my integrator, and
the integrator output itself would shift upward to compensate, while the
ultimate output of my VCO would stay perfectly centred.  In this way I could
reset my triangle integrator to ground (i.e., normally) and it looks like
resetting to -5V at the triangle output.  So now I've got hard sync in my
triangle core VCO, the 2164 expo is still terminating to virtual ground, and
all it took was one more opamp.

> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl 
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of ASSI
> Sent: Monday, February 06, 2012 10:23 PM
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] current conveyor?
> 
> On Monday 06 February 2012, 12:47:39, David G Dixon wrote:
> > The current needs to be able to flow in both directions.
> 
> Some sleep and a coffee later... you do need an active 
> current source rather than a passive level shift to have the 
> current flowing back, of course.
> 
> An OTA with linearizing diodes will do, although the biasing 
> is a bit tricky and I don't know how good the precision is at 
> low currents and you will probably need an offset trim.  In 
> essence, the output of the OTA goes to the -5V integrator 
> input; both Iabc and Idiode need to be the same current (you 
> need a mirror there since one will be sitting at +0.7V and 
> the other 1.4V above the negative supply), slightly larger 
> than the maximum current you're going to use; the negative 
> input goes to ground (here's where you add the buffered 
> offset trim, since it needs to be low-impedance); and the 
> positive connects to the output of the 2164.  It may be 
> advantageous to rig the supply of the OTA so that the 
> mid-supply becomes close to -5V (requires a 
> +-15V system w/ additional 5V rail due to head room requirements, 
> +probably
> not worth the trouble if you only have +-12V).
> 
> It may be easier to level shift all the inputs to the 2164 
> down by 5V with some zero-offset, zero drift opamp.  I assume 
> you do not want to change the integrator to have its output 
> symmetric about zero?
> 
> 
> Regards,
> 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
> 
> _______________________________________________
> 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 Feb  7 10:56:29 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 7 Feb 2012 09:56:29 +0000
Subject: [sdiy] SMD capacitors : choosing dielectric type
In-Reply-To: <48EC40D7E96E42FFBFD2193DA3FC7871@galvanox01>
References: <op.v89zg7yt1ee36r@fred-pad.res.insa>
	<6821021244fda38c039ee067d81c5294@mail.spiritone.com>
	<op.v891wysg1ee36r@fred-pad.res.insa>
	<000501cce54a$227b7a80$67726f80$@com>
	<48EC40D7E96E42FFBFD2193DA3FC7871@galvanox01>
Message-ID: <CAEaByMTwzM1gU6EbystgwsRC+YEPY=Fr2ASixGT32VSmETu8EA@mail.gmail.com>

David wrote:
> I've had good luck with the WIMA metallized PPE caps for filters.

Do you have a link to those SMD caps?  I can only see PET and PPS
capacitors on the Wima website.

Cheers,
Neil
-- 
Modules and more: http://www.cesyg.com
Homepage: http://www.njohnson.co.uk


From antoniotuzzi at gmail.com  Tue Feb  7 12:37:38 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Tue, 7 Feb 2012 12:37:38 +0100
Subject: [sdiy] yamaha dx7 sliders
Message-ID: <6909C8CF-E7AD-494D-A813-DCF46875B756@gmail.com>

Hello friends...

a more digital question:

do you have info were I can buy the volume and data sliders ?

one is 10k LOG and the other 10k linear

do you have a pointer to the model ?

thank you
Antonio


From subjectivity at hotmail.com  Tue Feb  7 16:58:50 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Tue, 7 Feb 2012 10:58:50 -0500
Subject: [sdiy] (OT) theory of programming/philosophy of programming books?
Message-ID: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>

I have been spending a lot of time lately with C, mainly for the AVR, and I am learning a lot of the commands, and am getting pretty good at modifying other peoples code.
But I am looking for some books which might go beyond just learning one particular language, books which might give some insight into how to attack specific types of problems, etc.

Philosophy of programming? or theory books.

I looked on Amazon but there were so many books I didnt know where to start.


any advice appreciated.






From grant at musictechnologiesgroup.com  Tue Feb  7 17:09:50 2012
From: grant at musictechnologiesgroup.com (MTG)
Date: Tue, 7 Feb 2012 08:09:50 -0800
Subject: [sdiy] Cheap microscope for SMD
References: <AEBE3DBCBF654095B61121DA5FC8B8D5@LIFEBOOK><B156A86831A33949A097784064880247385C85C274@S060VS20.kapsch.co.at><6B16794FD98610449F66759BBF503D400278EF19@wdscexbe03.sc.wdc.com><BC722828-0861-46E5-8654-4C7FA949842E@ntlworld.com>
	<A8C6B03B59774F0DB2B00AF9874B2214@ownerf0d9273f5>
Message-ID: <A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>

Just found this place down the street from where I work. www.amscope.com . 
Picked up a stereo, dual-lamp version that does 10x & 30x.  find 10x in 
stereo just about perfect.  I'm done with loupes!

GB
www.musictechnologiesgroup.com


----- Original Message ----- 
From: "Paul Perry" <pfperry at melbpc.org.au>
To: <Synth-diy at dropmix.xs4all.nl>
Sent: Wednesday, February 17, 2010 5:58 PM
Subject: Re: [sdiy] Cheap microscope for SMD


> I've always found those headband type magnifiers
> easier than the big desk mounted magnifying lenses
> (which tend to give me nausea as I peer into them).
>
> http://ucanhealth.com/compare.php?item1=580-3&item2=1200
> not the exact ones - mine are cheaper hobbyist types.
>
> Cheapest of all is a stacked pair of +3 generic reading spectacles
> from the dollar shop..
>
> paul perry Melbourne Australia
> _______________________________________________
> 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 Feb  7 17:16:11 2012
From: nvawter at media.mit.edu (Noah Vawter)
Date: Tue, 7 Feb 2012 11:16:11 -0500
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
Message-ID: <B404DD88-6305-47B4-806D-8CFD979278A5@media.mit.edu>


If you're going to go for the long-haul, I recommend checking out "antlr." 
http://www.antlr.org/download.html 

It's a free academic project and is essentially a way to parse anything and then translate it into anything else.
It's kind of a hardcore CS project to an EE like me, but I am getting up to speed on it after learning its key vocab.  
It's really just a big state machine with a very helpful user interface.  It has shown me similarities between so many kinds of data structures, and I'm just getting started.  It also encourages writing parseable computer languages and possibly even more spontaneous computer languages?  But I think it in practical reality, it's more often used for refactoring large projects?   Personally, I'm trying to design a high-level music DSP language.  e.g.

my high-level generic DSP code:

cb  = circBuff(256)
rc0 = RCStage(0.5);
rc1 = RCStage(0.5);

mainLoop
{
    cb.add(in1);      // write input1 to circularBuffer cb

    rc0(in1);        // apply rc stage to in1

    rc1(rc0.l);        // apply rc stage to rc0

    out1 = rc1.out;    // hear 
}


which can be antlr-converted into many different languages, from perl to C to 56k assembly.



e.g.  off-line simulation in perl:

#!/usr/bin/perl

# initialize circularBuffer cb(256)
$cbIdx = 0;
$cbMask = 0xff;   

# initialize RCState rc0
$rc0Out=0;
$rc0Coeff=20000/44100;   # greater than .5 at first

# initialize RCState rc1
$rc1Out=0;
$rc1Coeff= 20000/44100;

# main loop: highpass, lowpass
while(<>)
{
    $t++;
    chomp;
    $in1=$_;

    # write input1 to circularBuffer cb
    $cbIdx = ($cbIdx + 1)&$cbMask;
    $cb[$cbIdx]=$in1;

    # RC stage rc0  - operates on input -
    $rc0l = (1-$rc0Coeff) * $rc0l + $rc0Coeff * $in1;
    $rc0h = $in1 - $rc0l;

    # RC stage rc1 - operates on rc0h
    $rc1l = (1-$rc1Coeff) * $rc1l + $rc1Coeff * $rc0h;
    $rc1h = $rc0h - $rc1l;

    # listen to ...
    $out1 = $rc1h;

    # print it
    if($t>10000){print "$out1\n";}
}




or C for MaxMSP:

////////////////////////// object struct
typedef struct _simplemsp 
{
        t_pxobject                                      ob;                     // the object itself (t_pxobject in MSP)
        float                                           offset; 

    float rc0Coeff;   
    float rc0l,rc0h;
    float rc1Coeff;
    float rc1l,rc1h;
} t_simplemsp;

t_float filterQueue(t_simplemsp *x,float in)
{
    // RC stage rc0  - lowpass
    x->rc0l = (1.0 - x->rc0Coeff) * x->rc0l + x->rc0Coeff * in;
    x->rc0l = enforce_safety(x->rc0l);
    x->rc0h = in - x->rc0l;
    
    // RC stage rc1 - highpass
    x->rc1l = (1.0 - x->rc1Coeff) * x->rc1l + x->rc1Coeff * x->rc0l;
    x->rc1l = enforce_safety(x->rc1l);
    x->rc1h = x->rc0l - x->rc1l;
    
    // listen to ...
    return(x->ap0Out);
}



?. or possibly even an analog schematic?!?!?!     



On Feb 7, 2012, at 10:58 AM, dan snazelle wrote:

> I have been spending a lot of time lately with C, mainly for the AVR, and I am learning a lot of the commands, and am getting pretty good at modifying other peoples code.
> But I am looking for some books which might go beyond just learning one particular language, books which might give some insight into how to attack specific types of problems, etc.
> 
> Philosophy of programming? or theory books.
> 
> I looked on Amazon but there were so many books I didnt know where to start.
> 
> 
> any advice appreciated.
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

Noah Vawter

http://www.antlr.org/download.html  <-    use to translate a language into others 
http://forums.openmusiclabs.com/viewtopic.php?f=21&t=272     <- Guitar stompbox chaos hacking
http://forums.openmusiclabs.com/viewtopic.php?f=11&t=256   <-  Commodore 1541 floppy audio
http://web.media.mit.edu/~nvawter  <-   Media Lab documentation
http://exertion.pbworks.com   <-    Ph.D. research
http://Synthshopping.com   <-    My commercial site
http://diydsp.com   <-   commercial educational 
http://kaptheshampoo.com   <-   webcomic
http://youtube.com/diydsp        <-  My youtube channel



















From grant at musictechnologiesgroup.com  Tue Feb  7 17:25:23 2012
From: grant at musictechnologiesgroup.com (MTG)
Date: Tue, 7 Feb 2012 08:25:23 -0800
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
Message-ID: <3BB443A7109440E8AF84B5C10F08058E@LIFEBOOK>

Most of the books I like are probably too old to be directly useful for 
modern microcontrollers, but I would look for books that cover queues, 
interrupts, maybe simple RTOS basics (only because interrupts and breaking 
programs up into "tasks" is well covered then).

GB
www.musictechnologiesgroup.com


----- Original Message ----- 
From: "dan snazelle" <subjectivity at hotmail.com>
To: "synthdiy diy" <synth-diy at dropmix.xs4all.nl>
Sent: Tuesday, February 07, 2012 7:58 AM
Subject: [sdiy] (OT) theory of programming/philosophy of programming books?


>I have been spending a lot of time lately with C, mainly for the AVR, and I 
>am learning a lot of the commands, and am getting pretty good at modifying 
>other peoples code.
> But I am looking for some books which might go beyond just learning one 
> particular language, books which might give some insight into how to 
> attack specific types of problems, etc.
>
> Philosophy of programming? or theory books.
>
> I looked on Amazon but there were so many books I didnt know where to 
> start.
>
>
> any advice appreciated.
>
>
>
>
> _______________________________________________
> 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 Feb  7 17:29:19 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Tue, 7 Feb 2012 17:29:19 +0100
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
Message-ID: <CAJoLJ5V2TYsMQ7G9obQB+t6VnQR+1gW_bhGqWhxsSdXuoS3exA@mail.gmail.com>

Philosophy of programming? Maybe "Structure and Interpretation of
Computer Programs".  The risk here is that it will make you fly so
high that it will take time to "close loop" back to embedded systems.
It will eventually happen.  Every time I looked at code written by
people with no CS training but a strong EE background what I noticed
the most was how little effort was spent defining and building
abstractions - maybe because in EE you won't deal with as many
abstraction layers than in software development (a programmer can
encapsulate some functionality in a class or procedure and never, ever
look at it.  An EE can't unfortunately bundle bits of circuits into
his own library of chips and reuse it at will ; or bundle chips and
call it a new chip...).  So I think there's something that can be
learnt from a book that presents CS as the art of building
abstractions and giving name to things.

Just learning a high level language which reads like pseudo-code
(scala, python...) + an algorithms book?  General knowledge of
algorithms and data structures is always useful.  Pops up all the time
when doing sequencing or MIDI processing!

I find books like "Programmers at Work" and "Coders at work" (the 80s
and 00s ones) very interesting read... but again, very far from the
realms of embedded stuff

Hard to think of something that will matter for embedded systems...
Maybe you should try to read a compiler book (classic textbook:
Compilers: Principles, Techniques, and Tools) to get a good feel as to
what your compiler will do with the code you throw at it?

Olivier


From neil.johnson97 at ntlworld.com  Tue Feb  7 17:29:57 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Tue, 7 Feb 2012 16:29:57 +0000
Subject: [sdiy] Cheap microscope for SMD
In-Reply-To: <A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>
References: <AEBE3DBCBF654095B61121DA5FC8B8D5@LIFEBOOK>
	<B156A86831A33949A097784064880247385C85C274@S060VS20.kapsch.co.at>
	<6B16794FD98610449F66759BBF503D400278EF19@wdscexbe03.sc.wdc.com>
	<BC722828-0861-46E5-8654-4C7FA949842E@ntlworld.com>
	<A8C6B03B59774F0DB2B00AF9874B2214@ownerf0d9273f5>
	<A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>
Message-ID: <CAEaByMS85fMTJZaTb=DZ=Oe5Ur4cKF-bzf+dCGuH2M7SKiJBOA@mail.gmail.com>

Grant wrote:
> Picked up a stereo, dual-lamp version that does 10x & 30x. ?find 10x in
> stereo just about perfect. ?I'm done with loupes!

Yeah, agreed!  I picked this stereo microscope off eBay a few years
ago, and it sure makes inspecting SMD work much easier, and soldering
small parts a doddle:

http://www.njohnson.co.uk/img/microscope.jpg

The heavy base allows the arm to swing out over the bench.

For those in the UK on the hunt for something similar I see a few of
them on eBay right now (290666512618, 280819266918, 190629249787).

Cheers,
Neil
-- 
Modules and more: http://www.cesyg.com
Homepage: http://www.njohnson.co.uk


From eric at ericframpton.com  Tue Feb  7 17:59:55 2012
From: eric at ericframpton.com (Eric Frampton)
Date: Tue, 7 Feb 2012 11:59:55 -0500
Subject: [sdiy] Oberheim DMX wackiness
Message-ID: <8F553EFA-F5F3-4F76-B1CB-C935543505BB@ericframpton.com>

To follow up on my earlier post -

> 1. the first few characters of the display are prone to show incorrect - but not random - characters. It looks like the display is hanging off the same data bus as everybody else, and since the rest of the machine seems to be OK, I'm not sure where the trouble is. I've tried swapping out the 74LS42 driving it to no avail.

A replacement LT1414 display module did the trick.

> 2. The hi-hat card is working, and the Tom 1 card is working, but only in any slot except the one they're supposed to go it. As in, the hi-hat doesn't work in hi-hat but does work in tom/snare/bass/etc, and the same for the Tom 1 card. Ideas?

Turns out they both had dodgy TL082s on the outputs. At least, replacing them solved the problems with both cards, though I must admit I don't know specifically why.

I do know I have a working drum machine. Yay!

e



From czvekan at gmail.com  Tue Feb  7 18:07:35 2012
From: czvekan at gmail.com (Csaba Zvekan)
Date: Tue, 7 Feb 2012 18:07:35 +0100
Subject: [sdiy] Cheap microscope for SMD
In-Reply-To: <A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>
References: <AEBE3DBCBF654095B61121DA5FC8B8D5@LIFEBOOK><B156A86831A33949A097784064880247385C85C274@S060VS20.kapsch.co.at><6B16794FD98610449F66759BBF503D400278EF19@wdscexbe03.sc.wdc.com><BC722828-0861-46E5-8654-4C7FA949842E@ntlworld.com>
	<A8C6B03B59774F0DB2B00AF9874B2214@ownerf0d9273f5>
	<A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>
Message-ID: <C17054EE-6B28-46CD-ACA3-E70A5C1B25B2@gmail.com>

I have a USB microscope(20$) and mounted it on my DIY CNC. With the joystick I can move XY and Z axis and inspect the thing on my 24" monitor :). It works !

Csaba
On 7 Feb 2012, at 17:09, MTG wrote:

> Just found this place down the street from where I work. www.amscope.com . Picked up a stereo, dual-lamp version that does 10x & 30x.  find 10x in stereo just about perfect.  I'm done with loupes!
> 
> GB
> www.musictechnologiesgroup.com
> 
> 
> ----- Original Message ----- From: "Paul Perry" <pfperry at melbpc.org.au>
> To: <Synth-diy at dropmix.xs4all.nl>
> Sent: Wednesday, February 17, 2010 5:58 PM
> Subject: Re: [sdiy] Cheap microscope for SMD
> 
> 
>> I've always found those headband type magnifiers
>> easier than the big desk mounted magnifying lenses
>> (which tend to give me nausea as I peer into them).
>> 
>> http://ucanhealth.com/compare.php?item1=580-3&item2=1200
>> not the exact ones - mine are cheaper hobbyist types.
>> 
>> Cheapest of all is a stacked pair of +3 generic reading spectacles
>> from the dollar shop..
>> 
>> paul perry Melbourne Australia
>> _______________________________________________
>> 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 Feb  7 18:30:52 2012
From: thx1138 at earthlink.net (thx1138)
Date: Tue, 07 Feb 2012 09:30:52 -0800
Subject: [sdiy] yamaha dx7 sliders
In-Reply-To: <6909C8CF-E7AD-494D-A813-DCF46875B756@gmail.com>
Message-ID: <CB569FCC.29C62%thx1138@earthlink.net>

On 2/7/12 3:37 AM, "Antonio Tuzzi" <antoniotuzzi at gmail.com> wrote:

> Hello friends...
> 
> a more digital question:
> 
> do you have info were I can buy the volume and data sliders ?
> 
> one is 10k LOG and the other 10k linear
> 
> do you have a pointer to the model ?
> 
> thank you
> Antonio
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
Hi Antonio,

Paul Morte Technical Serices

Orange Calif.

(714)532-9540

Paul Morte's business is the Yamaha Corp. Repair center for N. America and
is a great guy to work with. Tell Paul I said hello.

Terry Shultz
Freescale Inc.



From giles at rolamtech.com  Tue Feb  7 18:56:58 2012
From: giles at rolamtech.com (Giles Ward)
Date: Tue, 07 Feb 2012 17:56:58 +0000
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
Message-ID: <4F3165EA.5070709@rolamtech.com>

> I have been spending a lot of time lately with C, mainly for the AVR, and I am learning a lot of the commands, and am getting pretty good at modifying other peoples code.
> But I am looking for some books which might go beyond just learning one particular language, books which might give some insight into how to attack specific types of problems, etc.
> 
> Philosophy of programming? or theory books.
> 
> I looked on Amazon but there were so many books I didnt know where to start.
> 
> 
> any advice appreciated.

Code Complete by Steve McConnell is a good read.


From blacet at blacet.com  Tue Feb  7 19:40:26 2012
From: blacet at blacet.com (blacet at blacet.com)
Date: Tue, 7 Feb 2012 10:40:26 -0800
Subject: [sdiy] Cheap microscope for SMD
In-Reply-To: <C17054EE-6B28-46CD-ACA3-E70A5C1B25B2@gmail.com>
References: <AEBE3DBCBF654095B61121DA5FC8B8D5@LIFEBOOK><B156A86831A33949A097784064880247385C85C274@S060VS20.kapsch.co.at><6B16794FD98610449F66759BBF503D400278EF19@wdscexbe03.sc.wdc.com><BC722828-0861-46E5-8654-4C7FA949842E@ntlworld.com>
	<A8C6B03B59774F0DB2B00AF9874B2214@ownerf0d9273f5>
	<A8E4E65BB7204530BCCC2913DEB33374@LIFEBOOK>
	<C17054EE-6B28-46CD-ACA3-E70A5C1B25B2@gmail.com>
Message-ID: <d610e1d26a5a424b54229ce8337e5946.squirrel@webmail.blacet.com>

I have one of those Amscope stereo microscopes. Works quite well.


> I have a USB microscope(20$) and mounted it on my DIY CNC. With the
> joystick I can move XY and Z axis and inspect the thing on my 24" monitor
> :). It works !
>
> Csaba
> On 7 Feb 2012, at 17:09, MTG wrote:
>
>> Just found this place down the street from where I work. www.amscope.com
>> . Picked up a stereo, dual-lamp version that does 10x & 30x.  find 10x
>> in stereo just about perfect.  I'm done with loupes!
>>
>> GB
>> www.musictechnologiesgroup.com
>>
>>
>> ----- Original Message ----- From: "Paul Perry" <pfperry at melbpc.org.au>
>> To: <Synth-diy at dropmix.xs4all.nl>
>> Sent: Wednesday, February 17, 2010 5:58 PM
>> Subject: Re: [sdiy] Cheap microscope for SMD
>>
>>
>>> I've always found those headband type magnifiers
>>> easier than the big desk mounted magnifying lenses
>>> (which tend to give me nausea as I peer into them).
>>>
>>> http://ucanhealth.com/compare.php?item1=580-3&item2=1200
>>> not the exact ones - mine are cheaper hobbyist types.
>>>
>>> Cheapest of all is a stacked pair of +3 generic reading spectacles
>>> from the dollar shop..
>>>
>>> paul perry Melbourne Australia
>>> _______________________________________________
>>> 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 Peter.Ullrich at kapsch.net  Tue Feb  7 20:30:38 2012
From: Peter.Ullrich at kapsch.net (Ullrich Peter)
Date: Tue, 7 Feb 2012 20:30:38 +0100
Subject: [sdiy] :  Cheap microscope for SMD
Message-ID: <B156A86831A33949A0977840648802476FB81B617D@S060VS20.kapsch.co.at>

Hi!

I also used an USB microscope mounted on a gooseneck and another gooseneck with mounted fan beside it to blow away the solder smoke. I wanted to use this constelation for SMD soldering but the latency was too high. It was fast enough with lower resolution and but the resolution wasn't enough for soldering (320x240).
 So I kept on soldering und a magnifying glass with LED light and use the USB microscope for solder joint inspection after soldering.
For this it doesn't matter if there is some latency.

Ciao
Peter

http://www.ullrich.at.tt

________________________________________
Von: synth-diy-bounces at dropmix.xs4all.nl [synth-diy-bounces at dropmix.xs4all.nl] im Auftrag von Csaba Zvekan [czvekan at gmail.com]
Gesendet: Dienstag, 07. Februar 2012 18:07
An: Synth-diy at dropmix.xs4all.nl
Betreff: Re: [sdiy] Cheap microscope for SMD

I have a USB microscope(20$) and mounted it on my DIY CNC. With the joystick I can move XY and Z axis and inspect the thing on my 24" monitor :). It works !

Csaba
On 7 Feb 2012, at 17:09, MTG wrote:

> Just found this place down the street from where I work. www.amscope.com . Picked up a stereo, dual-lamp version that does 10x & 30x.  find 10x in stereo just about perfect.  I'm done with loupes!
>
> GB
> www.musictechnologiesgroup.com
>
>
> ----- Original Message ----- From: "Paul Perry" <pfperry at melbpc.org.au>
> To: <Synth-diy at dropmix.xs4all.nl>
> Sent: Wednesday, February 17, 2010 5:58 PM
> Subject: Re: [sdiy] Cheap microscope for SMD
>
>
>> I've always found those headband type magnifiers
>> easier than the big desk mounted magnifying lenses
>> (which tend to give me nausea as I peer into them).
>>
>> http://ucanhealth.com/compare.php?item1=580-3&item2=1200
>> not the exact ones - mine are cheaper hobbyist types.
>>
>> Cheapest of all is a stacked pair of +3 generic reading spectacles
>> from the dollar shop..
>>
>> paul perry Melbourne Australia
>> _______________________________________________
>> 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

_______________________________________________
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http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

The information contained in this e-mail message is privileged and
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thereof, and is kindly asked to notify the sender and delete the e-mail
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From magnus at rubidium.dyndns.org  Tue Feb  7 21:47:10 2012
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Tue, 07 Feb 2012 21:47:10 +0100
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
Message-ID: <4F318DCE.4090001@rubidium.dyndns.org>

On 02/07/2012 04:58 PM, dan snazelle wrote:
> I have been spending a lot of time lately with C, mainly for the AVR, and I am learning a lot of the commands, and am getting pretty good at modifying other peoples code.
> But I am looking for some books which might go beyond just learning one particular language, books which might give some insight into how to attack specific types of problems, etc.
>
> Philosophy of programming? or theory books.
>
> I looked on Amazon but there were so many books I didnt know where to start.
>
>
> any advice appreciated.

There are several angles to this. A few different books relating to 
algorithms is recommended. They help you think about how you design your 
programs and the consequences of design-approaches. Learning about 
different complexities and the ordo-analysis is one such tool and 
eye-opener. It's not all, but it is a good education.

Thomas H. Cormen, Ronald L. Rivest, Charles E. Leiserson and Clifford 
Stein, "Introduction to Algorithms"

Robert Sedgewick "Algorithms"

Are two good books to start with, either one. They have common coverage, 
but also different strengths.

Then of coarse the grand-master of Donald Knuth "The Art of Computer 
Programming" is takes it a good step forward both good education, good 
coverage and good science.

Then, when you design large systems, there is the issue of learning the 
information hiding principles, which forms the basis of the object 
oriented programming, which then can be morphed into many other aspects.

There are several principles of organising processing, and it is very 
good to learn a number of them, since the ability to find the right one 
can dominate the performance and for that matter complexity of the 
solution. You can do bulk processing, event-oriented processing, state 
machines which get events with data, main loop with interrupts etc. etc. 
etc.

There are so many aspects, so many approaches. The only one thing one 
has to recall is that there is no silver bullet, but only more things to 
learn.

Cheers,
Magnus


From subjectivity at hotmail.com  Tue Feb  7 22:36:24 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Tue, 7 Feb 2012 16:36:24 -0500
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <4F318DCE.4090001@rubidium.dyndns.org>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
	<4F318DCE.4090001@rubidium.dyndns.org>
Message-ID: <BLU0-SMTP46665910D8860E28A42F5DC8750@phx.gbl>

Thanks all!


I didnt really think any of these would be micro specific and thats fine...my interest in programming is growing and id like to feed that!




On Feb 7, 2012, at 3:47 PM, Magnus Danielson <magnus at rubidium.dyndns.org> wrote:

> On 02/07/2012 04:58 PM, dan snazelle wrote:
>> I have been spending a lot of time lately with C, mainly for the AVR, and I am learning a lot of the commands, and am getting pretty good at modifying other peoples code.
>> But I am looking for some books which might go beyond just learning one particular language, books which might give some insight into how to attack specific types of problems, etc.
>> 
>> Philosophy of programming? or theory books.
>> 
>> I looked on Amazon but there were so many books I didnt know where to start.
>> 
>> 
>> any advice appreciated.
> 
> There are several angles to this. A few different books relating to algorithms is recommended. They help you think about how you design your programs and the consequences of design-approaches. Learning about different complexities and the ordo-analysis is one such tool and eye-opener. It's not all, but it is a good education.
> 
> Thomas H. Cormen, Ronald L. Rivest, Charles E. Leiserson and Clifford Stein, "Introduction to Algorithms"
> 
> Robert Sedgewick "Algorithms"
> 
> Are two good books to start with, either one. They have common coverage, but also different strengths.
> 
> Then of coarse the grand-master of Donald Knuth "The Art of Computer Programming" is takes it a good step forward both good education, good coverage and good science.
> 
> Then, when you design large systems, there is the issue of learning the information hiding principles, which forms the basis of the object oriented programming, which then can be morphed into many other aspects.
> 
> There are several principles of organising processing, and it is very good to learn a number of them, since the ability to find the right one can dominate the performance and for that matter complexity of the solution. You can do bulk processing, event-oriented processing, state machines which get events with data, main loop with interrupts etc. etc. etc.
> 
> There are so many aspects, so many approaches. The only one thing one has to recall is that there is no silver bullet, but only more things to learn.
> 
> Cheers,
> Magnus
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From matt at smiffytech.com  Tue Feb  7 22:49:17 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 08:19:17 +1030
Subject: [sdiy] (OT) theory of programming/philosophy of
	programming	books?
In-Reply-To: <BLU0-SMTP46665910D8860E28A42F5DC8750@phx.gbl>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>	<4F318DCE.4090001@rubidium.dyndns.org>
	<BLU0-SMTP46665910D8860E28A42F5DC8750@phx.gbl>
Message-ID: <4F319C5D.4050200@smiffytech.com>

Dan, if it's of any interest, this is (some of) my current relevant 
reading list:

http://twitpic.com/8eo2dw

Microcontroller-wise, I'm moving into the Freescale camp, will be 
working with HCS08 (using MC9S08AC128 to replace ATMega128 - at 
something like quarter of the price) and Kinetis ARM Cortex M4 parts for 
"bigger" stuff.  Anticipating that most of my audio stuff will be using 
FreeRTOS.

The MSP430 and embedded Linux books are the ones in this collection not 
SDIY-related.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From matt at smiffytech.com  Tue Feb  7 23:35:50 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 09:05:50 +1030
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F3095EB.6050902@ix.netcom.com>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
Message-ID: <4F31A746.3040105@smiffytech.com>

Oren, Ian, All, thanks for the feedback on this.

As I haven't looked into the theory of the circuits in question and am 
just taking a "cookbook" approach at present, I wasn't sure if the lack 
of gain in the new devices might be an issue.

If this is all about heat, I don't see a problem.

The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically 
matched," which is explained as being built on adjacent dies from a 
single wafer. So, with the constant improvement in fabrication 
technologies, I wouldn't be at all surprised if electrical matching were 
not as good as, if not better, than what might be considered dinosaurs, 
in silicon terms.

As far as heat matching is concerned, and I realise I could well be 
wrong on this, I can't see how the two dies, encapsulated in an area of 
about 1.5 square millimetres or less, wouldn't be isothermal as near as 
dammit. Not sure about the thermal conductivity of the lead bonding but, 
even with emitters connected externally, there is still a thermal path 
going that way.

I'm trying to cram an entire synth, with modern components, into as 
small a space as possible (all on one board, hard-wired.) No accuracy is 
required, as this will not be played in the conventional sense, but will 
receive control voltages from optical feedback in a multi-sensory 
sculpture. This is why I was asking about getting control voltages out 
of LDRs the other day, and why the LM358 VCOs caught my interest.

Hey, if I like the sound of it, I can always break it out into modular.


-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From matt at smiffytech.com  Tue Feb  7 23:59:55 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 09:29:55 +1030
Subject: [sdiy] LM358 datasheet VCO on spilt rails
In-Reply-To: <4F3099C0.1010804@cox.net>
References: <A075A39E-50D7-11E1-9859-000393A85F9E@ntlworld.com>	<4F303904.1090005@cox.net>	<4F3051EB.9040806@smiffytech.com>
	<4F3099C0.1010804@cox.net>
Message-ID: <4F31ACEB.4010109@smiffytech.com>

Quoth James Patchell at 07/02/12 13:55...
> As I recall (this was 40 years ago...well, 39), I just used a voltage
> divider and a bypass cap.

Good enough for breadboarding :-)

> The control range was 0 volts to about +18 (just a hair less as I
> recall).  If you look at the frequency control part of the circuit, one
> leg is basically a voltage divider that goes to the + input of the
> op-amp.  The common mode input range of the LM358 is 0 to VCC-1.5
> volts.  So, you can run the control voltage up to the point where the +
> input is at that voltage.

Got it. I have a 24V supply here, so will have a go with 12V/24V.

> And yes, it is a very cheap VCO.  At the time I used this circuit
> myself, I had no way to check to see how accurate it was.
>
> http://www.noniandjim.com/Jim/FirstSynth/FirstSynth.html
>
> On this web page, I have a picture of this thing as I built it.

Love the sequencer!

Lots of potential for this VCO, especially when pitch accuracy isn't 
important. Although, with digital (via MIDI) control, counting the 
timing of the square output could make for very simple automatic tuning.

Thanks for your input, Jim.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From matt at smiffytech.com  Wed Feb  8 00:30:32 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 10:00:32 +1030
Subject: [sdiy] Buffer amp
Message-ID: <4F31B418.9090209@smiffytech.com>

Anyone know of something like the BUF634, but with higher output 
current? (For use in conjunction with a TLE2426 rail splitter to get a 
dual supply out of a single one.)

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From subjectivity at hotmail.com  Wed Feb  8 01:57:15 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Tue, 7 Feb 2012 19:57:15 -0500
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
Message-ID: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>

does anyone know where I can find the .hex file I would need to have the
arduino Dueminalove  bootloader burned onto 100 atmega 328pu chips?

I am going to be purchasing quite a few 328 chips and I am going to have the bootloader burned onto them

thanks








From junkrhythm at gmail.com  Wed Feb  8 02:13:06 2012
From: junkrhythm at gmail.com (George P. Macklin)
Date: Tue, 7 Feb 2012 17:13:06 -0800
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
Message-ID: <676CA400-8775-4ACF-922E-A4FA3F24DC8B@gmail.com>

http://arduino.cc/en/Main/Bootloader



Cheers,
George P. Macklin
www.granularmatter.com

Eurorack Modules
www.toppobrillo.com

On Feb 7, 2012, at 4:57 PM, dan snazelle <subjectivity at hotmail.com> wrote:

> does anyone know where I can find the .hex file I would need to have the
> arduino Dueminalove  bootloader burned onto 100 atmega 328pu chips?
> 
> I am going to be purchasing quite a few 328 chips and I am going to have the bootloader burned onto them
> 
> thanks
> 
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From nitro2k01 at gmail.com  Wed Feb  8 02:19:36 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Wed, 8 Feb 2012 02:19:36 +0100
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
Message-ID: <CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>

On 8 February 2012 01:57, dan snazelle <subjectivity at hotmail.com> wrote:
> does anyone know where I can find the .hex file I would need to have the
> arduino Dueminalove ?bootloader burned onto 100 atmega 328pu chips?
>
> I am going to be purchasing quite a few 328 chips and I am going to have the bootloader burned onto them

It's included with the Arduino development environment. Follow the
download link on <http://www.arduino.cc/>, and fetch the 80 MB file
then look in arduino-1.0/hardware/arduino/bootloaders/atmega.
If you're going to use the exact same program on all chips, you could
burn it with the bootloader to one chip, then read out the full flash
contents from that chip and use that to program the other chips, so
you only need on programming step for each chip. (At least until you
need to upgrade, in which case you can conveniently use the bootloader
which is now also on each chip.) Just make sure the option flags are
preserved.

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From subjectivity at hotmail.com  Wed Feb  8 02:44:38 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Tue, 7 Feb 2012 20:44:38 -0500
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
	<CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>
Message-ID: <BLU0-SMTP129F8F13F4C495677E4B52AC87A0@phx.gbl>




On Feb 7, 2012, at 8:19 PM, Ove Rid? wrote:

> On 8 February 2012 01:57, dan snazelle <subjectivity at hotmail.com> wrote:
>> does anyone know where I can find the .hex file I would need to have the
>> arduino Dueminalove  bootloader burned onto 100 atmega 328pu chips?
>> 
>> I am going to be purchasing quite a few 328 chips and I am going to have the bootloader burned onto them
> 
> It's included with the Arduino development environment. Follow the
> download link on <http://www.arduino.cc/>, and fetch the 80 MB file
> then look in arduino-1.0/hardware/arduino/bootloaders/atmega.
> If you're going to use the exact same program on all chips, you could
> burn it with the bootloader to one chip, then read out the full flash
> contents from that chip and use that to program the other chips, so
> you only need on programming step for each chip. (At least until you
> need to upgrade, in which case you can conveniently use the bootloader
> which is now also on each chip.) Just make sure the option flags are
> preserved.
> 
> -- 
> /Ove
> 
> Blog: <http://blog.gg8.se/>
> 
> "Here is Evergreen City. Evergreen? is the color of green forever."
> 


interesting

how would I "Read out" the contents of the flash area?

as I am only used to the arduino IDE, and that IDE keeps so much of the details hidden, the only experience I have is either hitting UPLOAD or selecting "burn bootloader" from 
the dropdown menu


thanks






From nitro2k01 at gmail.com  Wed Feb  8 03:00:17 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Wed, 8 Feb 2012 03:00:17 +0100
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <BLU0-SMTP129F8F13F4C495677E4B52AC87A0@phx.gbl>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
	<CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>
	<BLU0-SMTP129F8F13F4C495677E4B52AC87A0@phx.gbl>
Message-ID: <CABacs=AmbBgzoGzt-xzyxNHKYMx7rYeOA-KZwrRZwVZKAL9MxA@mail.gmail.com>

On 8 February 2012 02:44, dan snazelle <subjectivity at hotmail.com> wrote:
> interesting
>
> how would I "Read out" the contents of the flash area?
>
> as I am only used to the arduino IDE, and that IDE keeps so much of the details hidden, the only experience I have is either hitting UPLOAD or selecting "burn bootloader" from
> the dropdown menu

What kind of adapter are you using for the bootloader flashing? If for
example you're using a simple parallel port adapter, you could use
PonyProg, for example. (Windows)  Or avrdude that comes with the
Arduino environment, which is what I believe is what's used for the
bootloader flashing when used from the GUI. I'm not familiar with the
specifics of how to use it, but it should be able to do everything you
would ever want to do, read, write, verify and more.

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From subjectivity at hotmail.com  Wed Feb  8 03:08:38 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Tue, 7 Feb 2012 21:08:38 -0500
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <CABacs=AmbBgzoGzt-xzyxNHKYMx7rYeOA-KZwrRZwVZKAL9MxA@mail.gmail.com>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
	<CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>
	<BLU0-SMTP129F8F13F4C495677E4B52AC87A0@phx.gbl>
	<CABacs=AmbBgzoGzt-xzyxNHKYMx7rYeOA-KZwrRZwVZKAL9MxA@mail.gmail.com>
Message-ID: <BLU0-SMTP26909E38BF090492C915FF2C87A0@phx.gbl>

thanks

I am using the arduino board itself with a few wires going to a breadboard....i think i will look up how to do this with AVRdude...i know it CAN be done


check out dans music at
myspace.com/lossnyc

myspace.com/snazelle

http://www.soundclick.com/bands/default.cfm?bandID=212570

youtube channel:

http://www.youtube.com/user/snazelle



On Feb 7, 2012, at 9:00 PM, Ove Rid? wrote:

> On 8 February 2012 02:44, dan snazelle <subjectivity at hotmail.com> wrote:
>> interesting
>> 
>> how would I "Read out" the contents of the flash area?
>> 
>> as I am only used to the arduino IDE, and that IDE keeps so much of the details hidden, the only experience I have is either hitting UPLOAD or selecting "burn bootloader" from
>> the dropdown menu
> 
> What kind of adapter are you using for the bootloader flashing? If for
> example you're using a simple parallel port adapter, you could use
> PonyProg, for example. (Windows)  Or avrdude that comes with the
> Arduino environment, which is what I believe is what's used for the
> bootloader flashing when used from the GUI. I'm not familiar with the
> specifics of how to use it, but it should be able to do everything you
> would ever want to do, read, write, verify and more.
> 
> -- 
> /Ove
> 
> Blog: <http://blog.gg8.se/>
> 
> "Here is Evergreen City. Evergreen? is the color of green forever."
> 



From jluciani at gmail.com  Wed Feb  8 03:14:59 2012
From: jluciani at gmail.com (John Luciani)
Date: Tue, 7 Feb 2012 21:14:59 -0500
Subject: [sdiy] (OT) theory of programming/philosophy of programming
	books?
In-Reply-To: <4F319C5D.4050200@smiffytech.com>
References: <BLU0-SMTP182248D49C772DB21169D48C8750@phx.gbl>
	<4F318DCE.4090001@rubidium.dyndns.org>
	<BLU0-SMTP46665910D8860E28A42F5DC8750@phx.gbl>
	<4F319C5D.4050200@smiffytech.com>
Message-ID: <CA+qhd=-AOxQEhMtoSU7s3U+TPE67PO8zU4f+TaE6=ivYgziJmg@mail.gmail.com>

As was mentioned

SICP
TAOCP
Introduction to Algorithms

All excellent.
All in my library ;)

(* jcl *)

On Tue, Feb 7, 2012 at 4:49 PM, Matthew Smith <matt at smiffytech.com> wrote:
> Dan, if it's of any interest, this is (some of) my current relevant reading
> list:
>
> http://twitpic.com/8eo2dw
>
> Microcontroller-wise, I'm moving into the Freescale camp, will be working
> with HCS08 (using MC9S08AC128 to replace ATMega128 - at something like
> quarter of the price) and Kinetis ARM Cortex M4 parts for "bigger" stuff.
> ?Anticipating that most of my audio stuff will be using FreeRTOS.
>
> The MSP430 and embedded Linux books are the ones in this collection not
> SDIY-related.
>
> --
> Matthew Smith
>
> Business: http://www.smiffytech.com
> Blog: ? ? http://www.smiffysplace.com
> Linkedin: http://www.linkedin.com/in/smiffy
> Flickr: ? http://www.flickr.com/photos/msmiffy
> Twitter: ?http://twitter.com/smiffy
>
> ABN 16 391 203 815
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



-- 
http://www.wiblocks.com


From jluciani at gmail.com  Wed Feb  8 03:17:30 2012
From: jluciani at gmail.com (John Luciani)
Date: Tue, 7 Feb 2012 21:17:30 -0500
Subject: [sdiy] (ot) arduino DUEMINALOVE 328 bootloader hex file?
In-Reply-To: <BLU0-SMTP26909E38BF090492C915FF2C87A0@phx.gbl>
References: <BLU0-SMTP46485DC4BC7138902478AE0C87A0@phx.gbl>
	<CABacs=DB1QWZU4WoWnGk-DyMyga1HbE213YOS1hj8tEx8rcC3g@mail.gmail.com>
	<BLU0-SMTP129F8F13F4C495677E4B52AC87A0@phx.gbl>
	<CABacs=AmbBgzoGzt-xzyxNHKYMx7rYeOA-KZwrRZwVZKAL9MxA@mail.gmail.com>
	<BLU0-SMTP26909E38BF090492C915FF2C87A0@phx.gbl>
Message-ID: <CA+qhd=9tfQ9vJnY25kuaUk0mfBK-91E1NpZXfjNtQzxoYLy9-g@mail.gmail.com>

IIRC there is a Makefile that can compile an Arduino program from the
command line. After you type make the hex file should be in the same
directory.

(* jcl *)

On Tue, Feb 7, 2012 at 9:08 PM, dan snazelle <subjectivity at hotmail.com> wrote:
> thanks
>
> I am using the arduino board itself with a few wires going to a breadboard....i think i will look up how to do this with AVRdude...i know it CAN be done
>
>
> check out dans music at
> myspace.com/lossnyc
>
> myspace.com/snazelle
>
> http://www.soundclick.com/bands/default.cfm?bandID=212570
>
> youtube channel:
>
> http://www.youtube.com/user/snazelle
>
>
>
> On Feb 7, 2012, at 9:00 PM, Ove Rid? wrote:
>
>> On 8 February 2012 02:44, dan snazelle <subjectivity at hotmail.com> wrote:
>>> interesting
>>>
>>> how would I "Read out" the contents of the flash area?
>>>
>>> as I am only used to the arduino IDE, and that IDE keeps so much of the details hidden, the only experience I have is either hitting UPLOAD or selecting "burn bootloader" from
>>> the dropdown menu
>>
>> What kind of adapter are you using for the bootloader flashing? If for
>> example you're using a simple parallel port adapter, you could use
>> PonyProg, for example. (Windows) ?Or avrdude that comes with the
>> Arduino environment, which is what I believe is what's used for the
>> bootloader flashing when used from the GUI. I'm not familiar with the
>> specifics of how to use it, but it should be able to do everything you
>> would ever want to do, read, write, verify and more.
>>
>> --
>> /Ove
>>
>> Blog: <http://blog.gg8.se/>
>>
>> "Here is Evergreen City. Evergreen? is the color of green forever."
>>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



-- 
http://www.wiblocks.com


From stewpye at optusnet.com.au  Wed Feb  8 04:57:35 2012
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Wed, 08 Feb 2012 13:57:35 +1000
Subject: [sdiy] Buffer amp
In-Reply-To: <4F31B418.9090209@smiffytech.com>
References: <4F31B418.9090209@smiffytech.com>
Message-ID: <4F31F2AF.8040302@optusnet.com.au>

Hi Matthew,

I'm not sure if will provide the current you require, but the lm386 has 
a self centering output so you could do away with the TLE2426 as well.

Regards,
Stewart.

On 2/8/2012 9:30 AM, Matthew Smith wrote:
> Anyone know of something like the BUF634, but with higher output 
> current? (For use in conjunction with a TLE2426 rail splitter to get a 
> dual supply out of a single one.)
>



From brockr0 at shaw.ca  Wed Feb  8 06:00:27 2012
From: brockr0 at shaw.ca (Brock Russell)
Date: Tue, 07 Feb 2012 21:00:27 -0800
Subject: [sdiy] Buffer amp
In-Reply-To: <4F31B418.9090209@smiffytech.com>
References: <4F31B418.9090209@smiffytech.com>
Message-ID: <0707d2$2emg6i@pd2mo1so-svcs.prod.shaw.ca>

LT1010 and a couple of resistors will do for both. 
http://cds.linear.com/docs/Datasheet/1010fe.pdf see page 12.

Brock

At 03:30 PM 07/02/2012, Matthew Smith wrote:
>Anyone know of something like the BUF634, but with higher output 
>current? (For use in conjunction with a TLE2426 rail splitter to get 
>a dual supply out of a single one.)
>
>--
>Matthew Smith
>
>Business: http://www.smiffytech.com
>Blog:     http://www.smiffysplace.com
>Linkedin: http://www.linkedin.com/in/smiffy
>Flickr:   http://www.flickr.com/photos/msmiffy
>Twitter:  http://twitter.com/smiffy
>
>ABN 16 391 203 815
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From matt at smiffytech.com  Wed Feb  8 06:12:26 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 15:42:26 +1030
Subject: [sdiy] Buffer amp
In-Reply-To: <0707d2$2emg6i@pd2mo1so-svcs.prod.shaw.ca>
References: <4F31B418.9090209@smiffytech.com>
	<0707d2$2emg6i@pd2mo1so-svcs.prod.shaw.ca>
Message-ID: <4F32043A.5000506@smiffytech.com>

Quoth Brock Russell at 08/02/12 15:30...
> LT1010 and a couple of resistors will do for both.
> http://cds.linear.com/docs/Datasheet/1010fe.pdf see page 12.

Hmm. Lower current (150mA against 250mA,) but cheaper. Could use one per 
board, rather than my original idea of having a single power board 
driving 2-3 devices. Thanks for that, I'll ping Element14 and see what 
wonderful price they can do me, bet they can do it better than my 
regular discount.

Stewart - were you talking about the LM386 as in the audio amp?

Cheers for that, guys.

M

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From brockr0 at shaw.ca  Wed Feb  8 06:37:01 2012
From: brockr0 at shaw.ca (Brock Russell)
Date: Tue, 07 Feb 2012 21:37:01 -0800
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F31A746.3040105@smiffytech.com>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com>
Message-ID: <0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>

Hi Matthew,

I've been working on some very small modules and synth voices too. 
I'm using some unmatched high gain dual transistors from On Semi, PNP

BC857CDW1T1G and NPN BC847CDW1T1G. These are smaller parts, SC-70-6 
(SOT-363). They are cheap, seem very well matched and fine for 
filters. Mouser has them in stock.

Brock


At 02:35 PM 07/02/2012, you wrote:
>Oren, Ian, All, thanks for the feedback on this.
>
>As I haven't looked into the theory of the circuits in question and 
>am just taking a "cookbook" approach at present, I wasn't sure if 
>the lack of gain in the new devices might be an issue.
>
>If this is all about heat, I don't see a problem.
>
>The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are 
>"intrinsically matched," which is explained as being built on 
>adjacent dies from a single wafer. So, with the constant improvement 
>in fabrication technologies, I wouldn't be at all surprised if 
>electrical matching were not as good as, if not better, than what 
>might be considered dinosaurs, in silicon terms.
>
>As far as heat matching is concerned, and I realise I could well be 
>wrong on this, I can't see how the two dies, encapsulated in an area 
>of about 1.5 square millimetres or less, wouldn't be isothermal as 
>near as dammit. Not sure about the thermal conductivity of the lead 
>bonding but, even with emitters connected externally, there is still 
>a thermal path going that way.
>
>I'm trying to cram an entire synth, with modern components, into as 
>small a space as possible (all on one board, hard-wired.) No 
>accuracy is required, as this will not be played in the conventional 
>sense, but will receive control voltages from optical feedback in a 
>multi-sensory sculpture. This is why I was asking about getting 
>control voltages out of LDRs the other day, and why the LM358 VCOs 
>caught my interest.
>
>Hey, if I like the sound of it, I can always break it out into modular.
>
>
>--
>Matthew Smith
>
>Business: http://www.smiffytech.com
>Blog:     http://www.smiffysplace.com
>Linkedin: http://www.linkedin.com/in/smiffy
>Flickr:   http://www.flickr.com/photos/msmiffy
>Twitter:  http://twitter.com/smiffy
>
>ABN 16 391 203 815
>_______________________________________________
>Synth-diy mailing list
>Synth-diy at dropmix.xs4all.nl
>http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From matt at smiffytech.com  Wed Feb  8 10:32:52 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 20:02:52 +1030
Subject: [sdiy] Buffer amp
In-Reply-To: <4F320870.6020505@optusnet.com.au>
References: <4F31B418.9090209@smiffytech.com>
	<0707d2$2emg6i@pd2mo1so-svcs.prod.shaw.ca>
	<4F32043A.5000506@smiffytech.com>
	<4F320870.6020505@optusnet.com.au>
Message-ID: <4F324144.7040301@smiffytech.com>

Quoth Stewart Pye at 08/02/12 16:00...
...
> Why not just use a voltage regulator?

Because I have little experience of analogue/power electronics and am 
thus shy of going for "off-label" use.

The BUF634 and the LT1010 both show driving a virtual ground as 
application examples in the datasheet. Whilst I'm not saying that other 
things won't work, in both these cases I have the device manufacturer 
saying explicitly that this is a suitable application for the part.

I guess with all my corporate years, I tend to be quite guarded in my 
approach to anything where I don't already have considerable experience.



-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From matt at smiffytech.com  Wed Feb  8 10:35:50 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 20:05:50 +1030
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com>
	<0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>
Message-ID: <4F3241F6.6040900@smiffytech.com>

Quoth Brock Russell at 08/02/12 16:07...

> BC857CDW1T1G and NPN BC847CDW1T1G. These are smaller parts, SC-70-6
> (SOT-363). They are cheap, seem very well matched and fine for
> filters. Mouser has them in stock.

Thanks. Whilst I can't get these exact parts through Element14 (Mouser 
has a $60 freight charge to Australia for orders under $200, last time I 
checked,) I can get equivalents from NXP/Philips - and they are cheap, 
at $0.08 a pop.

I've already got the Diodes Inc parts on order, but think I'll start 
drawing up a list of proved/possible parts for this. Nostalgia is all 
very well, but eight cents is eight cents ;-)

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From matt at smiffytech.com  Wed Feb  8 10:37:51 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 08 Feb 2012 20:07:51 +1030
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <CAP92RBUrTEYv45XpThBYZXaZt_sU0bEzZcSQcR5rCHpRjTEzKg@mail.gmail.com>
References: <4F308773.9060003@smiffytech.com>	<4F3095EB.6050902@ix.netcom.com>	<4F31A746.3040105@smiffytech.com>	<CAP92RBV=9QzSJAZX=LGo+H7Pg9vA71Jq4kAPtxKsxmV0PnA2ZQ@mail.gmail.com>
	<CAP92RBUrTEYv45XpThBYZXaZt_sU0bEzZcSQcR5rCHpRjTEzKg@mail.gmail.com>
Message-ID: <4F32426F.8030500@smiffytech.com>

Quoth Mattias Rickardsson at 08/02/12 19:56...
...
> Heat from one transistor's own power dissipation, on the other hand,
> gives a *much* greater temperature gradient in the chip, causing a small
> temperature difference between the two. Even if it's much much smaller
> than when gluing single transistors together, and unproblematic for
> synth applications, I guess different constructions & fabrication
> processes could differ by some order of magnitude in this respect.

Thank you. I don't see this as a problem, but it does pick up the gap in 
my reckoning, of where ?t could get into the works!

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From mr at analogue.org  Wed Feb  8 12:03:46 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 8 Feb 2012 12:03:46 +0100
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F32426F.8030500@smiffytech.com>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com>
	<CAP92RBV=9QzSJAZX=LGo+H7Pg9vA71Jq4kAPtxKsxmV0PnA2ZQ@mail.gmail.com>
	<CAP92RBUrTEYv45XpThBYZXaZt_sU0bEzZcSQcR5rCHpRjTEzKg@mail.gmail.com>
	<4F32426F.8030500@smiffytech.com>
Message-ID: <CAP92RBVHxdxox2Z4O2Jd8_9vRD_QrARjZNVxBOOyeubjf0onCQ@mail.gmail.com>

On 8 February 2012 10:37, Matthew Smith <matt at smiffytech.com> wrote:
>
>> Heat from one transistor's own power dissipation, on the other hand,
>> gives a *much* greater temperature gradient in the chip, causing a small
>> temperature difference between the two. Even if it's much much smaller
>> than when gluing single transistors together, and unproblematic for
>> synth applications, I guess different constructions & fabrication
>> processes could differ by some order of magnitude in this respect.
>
> Thank you. I don't see this as a problem, but it does pick up the gap in my
> reckoning, of where ?t could get into the works!

In other words, if temperature matching is extremely important, it's
worth ensuring that the surrounding circuit design allows the
transistors to dissipate as little power as possible in the
application - or at least to not vary its power dissipation much over
time. :-)

/mr


From mr at analogue.org  Wed Feb  8 12:55:54 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 8 Feb 2012 12:55:54 +0100
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com>
	<0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>
Message-ID: <CAP92RBU2eGwQ6_og=7BRrXF8m6si0ePme0nZK=y8td1iMju+ZQ@mail.gmail.com>

Speaking of parameter matching:

On 7 February 2012 23:35, Matthew Smith <matt at smiffytech.com> wrote:
> The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically
> matched," which is explained as being built on adjacent dies from a single
> wafer.

Is "intrinsically matched" mostly a buzzword from the sales department
:-) or do the transistor parameters really end up so similar that it
can be considered as transistor matching? If so, what parameters are
matched by design? hFE? UBE? Something else?

(Diodes Inc. writes in the datasheet:
"Key Features
1. Intrinsically matched PNP ? DMMT3906W or NPN ? DMMT3904W die
selected from adjacent locations on the wafer to ensure the closest
match possible.
2. Matched tolerance for hFE (DC current gain), Vbe(SAT), and
Vce(SAT), guaranteed within 2% maximum, and less than 1% typical. 1%
matching available upon request")

On 8 February 2012 06:37, Brock Russell <brockr0 at shaw.ca> wrote:
> I'm using some unmatched high gain dual transistors from On Semi,
> PNP BC857CDW1T1G and NPN BC847CDW1T1G. These are smaller parts,
> SOT-363. They are cheap, seem very well matched and fine for filters.

Nothing seems to be mentioned about matching or selection in these
datasheets, what kind of matching could be expected here? Silicon
fabrication gurus out there, welcome to give some selected wisdoms.
:-)

/mr


From Stromeko at nexgo.de  Wed Feb  8 20:17:29 2012
From: Stromeko at nexgo.de (ASSI)
Date: Wed, 08 Feb 2012 20:17:29 +0100
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F31A746.3040105@smiffytech.com>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com>
Message-ID: <1813286.vmv677DeOd@rainer>

On Wednesday 08 February 2012, 09:05:50, Matthew Smith wrote:
> The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically
> matched," which is explained as being built on adjacent dies from a
> single wafer.

This might be a marketing term for "we have no reason to believe otherwise, 
but we don't bother to actually measure it".  Check the datasheet for what 
they _guarantee_ for the matching (I'd be very surprised if Vbe matching was 
guaranteed to be better than about 10mV, for instance).  Actual measurements 
of matching properties are rather expensive since they take time.

> So, with the constant improvement in fabrication
> technologies, I wouldn't be at all surprised if electrical matching were
> not as good as, if not better, than what might be considered dinosaurs,
> in silicon terms.

That's OK, just as long as you are also not surprised if that assumption 
turns out to be wrong.

Matching is a function of the technology type and maturity, but even then 
there are limits: all other things equal, matching improves with sqrt(area) 
and with less distance between matched features on the wafer (obviously 
since that feature takes up space, there's a conflict between those two 
rules).  If any variable that bears on the matching has a gradient over the 
wafer or package, then the matched features need to be on an isoline of that 
variable.  That's the reason those expensive matched transistors are not 
only made on the same die, but are much larger than their single-transistor 
brethren and have interdigitated and common centroid layout - that cancels 
all linear gradients.  With higher orders of symmetry you can cancel 
nonlinear gradients of increasing order if you really care about that.

> As far as heat matching is concerned, and I realise I could well be
> wrong on this, I can't see how the two dies, encapsulated in an area of
> about 1.5 square millimetres or less, wouldn't be isothermal as near as
> dammit. Not sure about the thermal conductivity of the lead bonding but,
> even with emitters connected externally, there is still a thermal path
> going that way.

Two transistors on the same die are in better thermal contact than two 
transistors on separate dies in the same package by at least an order of 
magnitude.  This can become readily apparent if the power dissipation of the 
two transistors is not similar or if there are thermal gradients on the 
board.  If you want to to do a nice stunt circuit, put a heater left and 
right from the transistor pair  and trim the offset by adjusting the power 
of the heaters...

If you are replacing a circuit that usually can be built by gluing two hand-
matched transistor packages together, then those non-monolithically dual 
transistors are a much nicer option: easier to work with and probably even 
cheaper.  Don't forget you can still select the best matching ones according 
to your needs if you want to wring out some better performance.  Just don't 
think that you've found a replacement for a MAT03.


Regards,
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 pfperry at melbpc.org.au  Thu Feb  9 01:49:15 2012
From: pfperry at melbpc.org.au (Paul Perry)
Date: Thu, 9 Feb 2012 11:49:15 +1100
Subject: [sdiy] Ovenize your synth?
References: <4F308773.9060003@smiffytech.com>
	<4F3095EB.6050902@ix.netcom.com><4F31A746.3040105@smiffytech.com><0707d2$2emp4l@pd2mo1so-svcs.prod.shaw.ca>
	<CAP92RBU2eGwQ6_og=7BRrXF8m6si0ePme0nZK=y8td1iMju+ZQ@mail.gmail.com>
Message-ID: <F56FB665A9514C189484F7E94E620E53@ownerf0d9273f5>

Or at least your module..
All the DIY concern about temperature compensation & matching makes me 
wonder whether it would be easier to just run the synth at a constant 
temperature. That is what people used to do with some of the old electronic 
gear, for example quartz crystals in frequency standards.
Now that we have peltier effect cooler/heaters, it can't be all that hard 
;-D

paul perry Melbourne Australia 



From obl64 at ix.netcom.com  Thu Feb  9 02:54:17 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Wed, 08 Feb 2012 19:54:17 -0600
Subject: [sdiy] Some Musical Diversion
In-Reply-To: <201202070530.q175UEkI017810@linux7.lan>
References: <201202070530.q175UEkI017810@linux7.lan>
Message-ID: <4F332749.8030704@ix.netcom.com>



On 2/6/2012 10:30 PM, Scott Gravenhorst wrote:
>
> If you like this kind of thing...
>
> Beethoven's Moonlight Sonata
>
> http://electro-music.com/forum/viewtopic.php?p=353470#353470
>
> -- ScottG
> ________________________________________________________________________
> -- Scott Gravenhorst
> -- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
> -- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
> -- Some Random Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/
> -- When the going gets tough, the tough use the command line.
>

Nice work Scott!
Beef up the bass lines with that FatMan.

- Oren


From dlmanley at sonic.net  Thu Feb  9 08:46:24 2012
From: dlmanley at sonic.net (Dave Manley)
Date: Wed, 08 Feb 2012 23:46:24 -0800
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <1813286.vmv677DeOd@rainer>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com> <1813286.vmv677DeOd@rainer>
Message-ID: <4F3379D0.8030609@sonic.net>

On 2/8/2012 11:17 AM, ASSI wrote:
> On Wednesday 08 February 2012, 09:05:50, Matthew Smith wrote:
>> The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically
>> matched," which is explained as being built on adjacent dies from a
>> single wafer.
>
> This might be a marketing term for "we have no reason to believe otherwise,
> but we don't bother to actually measure it".  Check the datasheet for what
> they _guarantee_ for the matching (I'd be very surprised if Vbe matching was
> guaranteed to be better than about 10mV, for instance).  Actual measurements
> of matching properties are rather expensive since they take time.

http://www.diodes.com/datasheets/ds30436.pdf:

"8.   The DC Current Gain, hFE, (matched at IC = 10mA and VCE = 5V) Collector
Emitter Saturation Voltage, VCE(SAT), and Base Emitter Saturation Voltage,
VBE(SAT) are matched with typical matched tolerances of 1% and maximum of 2%."



From dixon at mail.ubc.ca  Thu Feb  9 10:19:38 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Thu, 9 Feb 2012 01:19:38 -0800
Subject: [sdiy] Benjolin filter issues
Message-ID: <EFD03E4A667348CF8A1AA859019F46D4@galvanox01>

I'm building a few Benjolin boards (based on the PCB layout and schematics
posted by Rob Hordyk on electro-music.com), and while testing them I noticed
that the filter was putting out a very weak signal (just a few hundred mV
peak-to-peak).  The oscillators are robust, and everything else is working
perfectly.  This problem is on both boards I've built so far.  I've even
simulated the filter part of the circuit, and the simulations give the same
thing.

I'm wondering, has anybody here built these things, and if so, did you
encounter similar problems?  Any help most appreciated!



From tom at electricdruid.net  Thu Feb  9 16:56:56 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Thu, 9 Feb 2012 15:56:56 +0000
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F3379D0.8030609@sonic.net>
References: <4F308773.9060003@smiffytech.com> <4F3095EB.6050902@ix.netcom.com>
	<4F31A746.3040105@smiffytech.com> <1813286.vmv677DeOd@rainer>
	<4F3379D0.8030609@sonic.net>
Message-ID: <FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net>


On 9 Feb 2012, at 07:46, Dave Manley wrote:

> On 2/8/2012 11:17 AM, ASSI wrote:
>> On Wednesday 08 February 2012, 09:05:50, Matthew Smith wrote:
>>> The DMMT5551 (and DMMT5401 for PNP) from Diodes Inc., are "intrinsically
>>> matched," which is explained as being built on adjacent dies from a
>>> single wafer.
>> 
>> This might be a marketing term for "we have no reason to believe otherwise,
>> but we don't bother to actually measure it".  Check the datasheet for what
>> they _guarantee_ for the matching (I'd be very surprised if Vbe matching was
>> guaranteed to be better than about 10mV, for instance).  Actual measurements
>> of matching properties are rather expensive since they take time.
> 
> http://www.diodes.com/datasheets/ds30436.pdf:
> 
> "8.   The DC Current Gain, hFE, (matched at IC = 10mA and VCE = 5V) Collector
> Emitter Saturation Voltage, VCE(SAT), and Base Emitter Saturation Voltage,
> VBE(SAT) are matched with typical matched tolerances of 1% and maximum of 2%."


Is that good or not? I'm not familiar with the standards that are expected of matched transistors, so I'd like to know if that represents a decent level of matching, a good level, or a poor level.

I'm guessing that you wouldn't do much better by hand, unless you got really autistic about it.

Thanks,
Tom



From synth1 at airmail.net  Thu Feb  9 18:06:01 2012
From: synth1 at airmail.net (Paul Schreiber)
Date: Thu, 9 Feb 2012 11:06:01 -0600
Subject: [sdiy] MOTM kits + a few CEM3340s
Message-ID: <BF0D0CE39E3341408B0C9744C40A6775@optiplex>

I have added some leftover full MOTM kits and a few CEM3340s (with free 
shpping!) to the order page at:

www.synthtech.com

Orders placed shipped < 48 hours.

Paul Schreiber
Synthesis Technology 



From Stromeko at nexgo.de  Thu Feb  9 21:25:32 2012
From: Stromeko at nexgo.de (ASSI)
Date: Thu, 09 Feb 2012 21:25:32 +0100
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net>
References: <4F308773.9060003@smiffytech.com> <4F3379D0.8030609@sonic.net>
	<FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net>
Message-ID: <1410682.eba6TgDPYE@rainer>

On Thursday 09 February 2012, 15:56:56, Tom Wiltshire wrote:
> > "8.   The DC Current Gain, hFE, (matched at IC = 10mA and VCE = 5V)
> > Collector Emitter Saturation Voltage, VCE(SAT), and Base Emitter
> > Saturation Voltage, VBE(SAT) are matched with typical matched
> > tolerances of 1% and maximum of 2%."

> Is that good or not?

Vbe(sat) should be around 700mV, so 2% of that is 14mV.

> I'm not familiar with the standards that are expected
> of matched transistors, so I'd like to know if that represents a decent
> level of matching, a good level, or a poor level.

For discretes this can be considered fair but not exciting.  The typical 
values you can expect are probably a lot better than 14mV, though ? 
otherwise they couldn't guarantee the 2% value without actually measuring 
and selecting.  Assuming a zero median on the Vbe matching and normal 
distribution a sigma of 2.8mV would make about 6 parts in a million match 
worse than 14mV.

> I'm guessing that you wouldn't do much better by hand, unless you got
> really autistic about it.

You can do quite a bit better than 1mV by hand using the balanced bridge 
measurement method; Ian Fritz routinely matches to tens-of-micro-Volt 
levels(*).

Starting with a bag of duals with the distribution outlined above it would 
even be easy, since about every fifth should match better than 1mV and only 
every tenth would be outside 5mV ? you wouldn't get too bored stuffing a 
Moog ladder, say.  About one in hundred would even match to Ians exactness 
of 50?V... but that is better left to monolithic integrated transistors.

(*) http://home.comcast.net/~ijfritz/projects/transmat001.pdf


[you can safely skip this]
When I was on the test floor (IIRC, it's been a while) we wouldn't bother to 
make the selection bin nominally wider than maybe 5mV depending on where in 
the distribution we were selecting and how fast the bin needed to fill.  
Most often that was all the matching required, but sometimes we'd sort those 
pre-selected transistors again to some tighter tolerance on the "slow but 
precise" tester and maybe on some different parameters as well to make 
precision pairs (we mostly had requests for pairs).  Noise and limited 
resolution on the tester would preclude going better than about 0.25mV, so 
anything beyond that you'd do by hand.  Using a tight pre-selection 
criterion had the advantage that you could get matched quad or even octal 
sets of transistors in a reasonable time.  We would also have some fun 
selecting for hfe of exactly 100.0 or similarly silly numbers if there was 
nothing better to do (and then check it by hand if we got really bored ? 
uncovered some drifting calibration this way :-).


Regards,
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 matt at smiffytech.com  Thu Feb  9 22:48:33 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Fri, 10 Feb 2012 08:18:33 +1030
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <1410682.eba6TgDPYE@rainer>
References: <4F308773.9060003@smiffytech.com>
	<4F3379D0.8030609@sonic.net>	<FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net>
	<1410682.eba6TgDPYE@rainer>
Message-ID: <4F343F31.6050902@smiffytech.com>

Quoth ASSI at 10/02/12 06:55...
...
> You can do quite a bit better than 1mV by hand using the balanced bridge
> measurement method; Ian Fritz routinely matches to tens-of-micro-Volt
> levels(*).

Thanks, Achim, more interesting stuff! Finding this topic fascinating.

As we're talking SMDs, footprint on a PCB (mine are gold-plated anyway) 
and some sort of spring clip to hold the part down?


-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From synth1 at airmail.net  Thu Feb  9 22:51:11 2012
From: synth1 at airmail.net (Paul Schreiber)
Date: Thu, 9 Feb 2012 15:51:11 -0600
Subject: [sdiy] Matched transistors - critical parameters?
References: <4F308773.9060003@smiffytech.com><4F3379D0.8030609@sonic.net>	<FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net><1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com>
Message-ID: <27D6D68111D442B8A8C27167B6A489EC@optiplex>

Use a wooden spring-loaded clothes pin :)

Paul S.


----- Original Message ----- 
From: "Matthew Smith" <matt at smiffytech.com>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, February 09, 2012 3:48 PM
Subject: Re: [sdiy] Matched transistors - critical parameters?


> Quoth ASSI at 10/02/12 06:55...
> ...
>> You can do quite a bit better than 1mV by hand using the balanced bridge
>> measurement method; Ian Fritz routinely matches to tens-of-micro-Volt
>> levels(*).
> 
> Thanks, Achim, more interesting stuff! Finding this topic fascinating.
> 
> As we're talking SMDs, footprint on a PCB (mine are gold-plated anyway) 
> and some sort of spring clip to hold the part down?
> 
> 
> -- 
> Matthew Smith
> 
> Business: http://www.smiffytech.com
> Blog:     http://www.smiffysplace.com
> Linkedin: http://www.linkedin.com/in/smiffy
> Flickr:   http://www.flickr.com/photos/msmiffy
> Twitter:  http://twitter.com/smiffy
> 
> ABN 16 391 203 815
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From subjectivity at hotmail.com  Fri Feb 10 02:10:45 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Thu, 9 Feb 2012 20:10:45 -0500
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <27D6D68111D442B8A8C27167B6A489EC@optiplex>
References: <4F308773.9060003@smiffytech.com><4F3379D0.8030609@sonic.net>	<FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net><1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com>
	<27D6D68111D442B8A8C27167B6A489EC@optiplex>
Message-ID: <BLU0-SMTP39288AFB43320CB638B0B29C8780@phx.gbl>


On Feb 9, 2012, at 4:51 PM, Paul Schreiber wrote:

> Use a wooden spring-loaded clothes pin :)
> 
> Paul S.




hmmm...jumping into this thread at the very end and seeing this really made me stop and wonder!




> 
> 
> ----- Original Message ----- From: "Matthew Smith" <matt at smiffytech.com>
> To: <synth-diy at dropmix.xs4all.nl>
> Sent: Thursday, February 09, 2012 3:48 PM
> Subject: Re: [sdiy] Matched transistors - critical parameters?
> 
> 
>> Quoth ASSI at 10/02/12 06:55...
>> ...
>>> You can do quite a bit better than 1mV by hand using the balanced bridge
>>> measurement method; Ian Fritz routinely matches to tens-of-micro-Volt
>>> levels(*).
>> Thanks, Achim, more interesting stuff! Finding this topic fascinating.
>> As we're talking SMDs, footprint on a PCB (mine are gold-plated anyway) and some sort of spring clip to hold the part down?
>> -- 
>> Matthew Smith
>> Business: http://www.smiffytech.com
>> Blog:     http://www.smiffysplace.com
>> Linkedin: http://www.linkedin.com/in/smiffy
>> Flickr:   http://www.flickr.com/photos/msmiffy
>> Twitter:  http://twitter.com/smiffy
>> ABN 16 391 203 815
>> _______________________________________________
>> 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 gazzaca77 at gmail.com  Fri Feb 10 03:15:03 2012
From: gazzaca77 at gmail.com (d b)
Date: Thu, 9 Feb 2012 18:15:03 -0800
Subject: [sdiy] TB303 debounce?
Message-ID: <CA+owYpOkf-Aud_31RPrVDscGQDahrq2kmiZ8xJ27dhYP_59dwQ@mail.gmail.com>

Hi all,

Has anyone ever looked at the TB303 circuit to see if some quick
switch debounce could be added so we don't have to replace all these
marginal switches?


From dlmanley at sonic.net  Fri Feb 10 03:19:05 2012
From: dlmanley at sonic.net (dlmanley at sonic.net)
Date: Thu, 09 Feb 2012 18:19:05 -0800
Subject: [sdiy] Matched transistors - critical parameters?
Message-ID: <kqj0kjhxw9aanupm1roi1517.1328840345045@email.android.com>

It does sound like one of Eno's "Oblique Strategies"

-Dave

-------- Original Message --------
 From: dan snazelle <subjectivity at hotmail.com>
 Sent: Thu, Feb 9, 2012 5:10 PM
 To: Paul Schreiber <synth1 at airmail.net>; synthdiy diy <synth-diy at dropmix.xs4all.nl>
 CC: 
 Subject: Re: [sdiy] Matched transistors - critical parameters?

>
>On Feb 9, 2012, at 4:51 PM, Paul Schreiber wrote:
>
>> Use a wooden spring-loaded clothes pin :)
>> 
>> Paul S.
>
>
>
>
>hmmm...jumping into this thread at the very end and seeing this really made me stop and wonder!
>
>
>
>
>> 
>> 
>> ----- Original Message ----- From: "Matthew Smith" <matt at smiffytech.com>
>> To: <synth-diy at dropmix.xs4all.nl>
>> Sent: Thursday, February 09, 2012 3:48 PM
>> Subject: Re: [sdiy] Matched transistors - critical parameters?
>> 
>> 
>>> Quoth ASSI at 10/02/12 06:55...
>>> ...
>>>> You can do quite a bit better than 1mV by hand using the balanced bridge
>>>> measurement method; Ian Fritz routinely matches to tens-of-micro-Volt
>>>> levels(*).
>>> Thanks, Achim, more interesting stuff! Finding this topic fascinating.
>>> As we're talking SMDs, footprint on a PCB (mine are gold-plated anyway) and some sort of spring clip to hold the part down?
>>> -- 
>>> Matthew Smith
>>> Business: http://www.smiffytech.com
>>> Blog:     http://www.smiffysplace.com
>>> Linkedin: http://www.linkedin.com/in/smiffy
>>> Flickr:   http://www.flickr.com/photos/msmiffy
>>> Twitter:  http://twitter.com/smiffy
>>> ABN 16 391 203 815
>>> _______________________________________________
>>> 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 patchell at cox.net  Fri Feb 10 06:09:27 2012
From: patchell at cox.net (James Patchell)
Date: Thu, 09 Feb 2012 21:09:27 -0800
Subject: [sdiy] Sparkfun Keypad Controllers
Message-ID: <4F34A687.1050207@cox.net>

     I am thinking about using these things in my current project:

http://www.sparkfun.com/products/9840

     I was wondering if anybody here has tried them?  They are pretty 
pricey at $40 each.  But, the multicolor buttons I think would be pretty 
fun.

Any Thoughts?

-Jim



From tom at electricdruid.net  Fri Feb 10 12:03:10 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 10 Feb 2012 11:03:10 +0000
Subject: [sdiy] Sparkfun Keypad Controllers
In-Reply-To: <4F34A687.1050207@cox.net>
References: <4F34A687.1050207@cox.net>
Message-ID: <868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>

Groovy, certainly, but you need the buttons too, so make that $50.

Couldn't you do your own for cheaper? But I suppose the hassle is probably worth the difference in price.

If only the MEC switches we talked about the other day were available with an RGB LED. That'd be very handy. So far, they only have bicolour options.

T.


On 10 Feb 2012, at 05:09, James Patchell wrote:

>    I am thinking about using these things in my current project:
> 
> http://www.sparkfun.com/products/9840
> 
>    I was wondering if anybody here has tried them?  They are pretty pricey at $40 each.  But, the multicolor buttons I think would be pretty fun.
> 
> Any Thoughts?
> 
> -Jim
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From mr at analogue.org  Fri Feb 10 12:29:05 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 10 Feb 2012 12:29:05 +0100
Subject: [sdiy] Sparkfun Keypad Controllers
In-Reply-To: <868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>
References: <4F34A687.1050207@cox.net>
	<868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>
Message-ID: <CAP92RBVGD2rKbavTnuNJxg1VzRfGgWYWeUDVeHo41325fAZzdw@mail.gmail.com>

On 10 February 2012 12:03, Tom Wiltshire <tom at electricdruid.net> wrote:
> If only the MEC switches we talked about the other day were available with an RGB LED. That'd be very handy. So far, they only have bicolour options.

Alas! So true! And what is worse, the red LEDs in the red/green MEC
switches is more likely to be quite orangeish-reddish, if the I read
their specified nanometers right... I was only looking for red/green,
not RGB, but I want red to be red! :'-/ So much that I'm thinking of
the possibility of mounting a decent red/green LED in their non-LED
version...? :-)

/mr


From rburnett at richieburnett.co.uk  Fri Feb 10 12:56:34 2012
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Fri, 10 Feb 2012 11:56:34 -0000 (GMT)
Subject: [sdiy] TB303 debounce?
In-Reply-To: <CA+owYpOkf-Aud_31RPrVDscGQDahrq2kmiZ8xJ27dhYP_59dwQ@mail.gmail.com>
References: <CA+owYpOkf-Aud_31RPrVDscGQDahrq2kmiZ8xJ27dhYP_59dwQ@mail.gmail.com>
Message-ID: <56526.128.240.229.3.1328874994.squirrel@www.richieburnett.co.uk>

The tact switches in the 303 are read periodically by the microcontroller. 
(1.8ms interrupt)  So there is probably already some switch debouncing going on
in the software.  However, this can only do so much.  (The exception to this is
the Run/Stop switch which is debounced using conventional hardware, which you
could tinker about with!)

I've replaced tact switches on several TB-303 machines and investigated a few of
the worst components after removal.  They really were in a terrible state
electrically.  You had to push down quite hard to get a good low resistance
electrical contact, and even then any side-to-side movement of the finger would
cause rapid-fire breaking and making of the contact.  No software is going to be
able to filter out bounces that happen hundreds or even thousands of
milliseconds after the initial key down.

If in doubt whip the switches out.  Replacement is an easy enough job to do,
just handle those old phenolic PCBs carefully as they are prone to hairline
cracks!

-Richie,


> Hi all,
>
> Has anyone ever looked at the TB303 circuit to see if some quick
> switch debounce could be added so we don't have to replace all these
> marginal switches?
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From mr at analogue.org  Fri Feb 10 13:16:51 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 10 Feb 2012 13:16:51 +0100
Subject: [sdiy] Sparkfun Keypad Controllers
In-Reply-To: <CAL3=FbZ8QRw6HA3KoaLfuxVvf7cyzswn7+63yJfdHi7ekcZz7A@mail.gmail.com>
References: <4F34A687.1050207@cox.net>
	<868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>
	<CAP92RBVGD2rKbavTnuNJxg1VzRfGgWYWeUDVeHo41325fAZzdw@mail.gmail.com>
	<CAL3=FbZ8QRw6HA3KoaLfuxVvf7cyzswn7+63yJfdHi7ekcZz7A@mail.gmail.com>
Message-ID: <CAP92RBUQy8LzQvT+1Dh09owyVn1fiPoGKBRUC4Ay=qUNJeYOvg@mail.gmail.com>

On 10 February 2012 12:57, Jason Tribbeck <jason at tribbeck.com> wrote:
> The non-LED versions are just the same as the LED ones (i.e they have the
> casting for LEDs), so you should be able to buy non-LED versions, and insert
> your own LEDs into them.

Thanks, yes, that's the impression I got from the pictures and datasheets. :-)

/mr


From tom at electricdruid.net  Fri Feb 10 13:25:37 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 10 Feb 2012 12:25:37 +0000
Subject: [sdiy] Custom LED MEC switches ( was Re: Sparkfun Keypad
	Controllers)
In-Reply-To: <CAL3=FbZ8QRw6HA3KoaLfuxVvf7cyzswn7+63yJfdHi7ekcZz7A@mail.gmail.com>
References: <4F34A687.1050207@cox.net>
	<868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>
	<CAP92RBVGD2rKbavTnuNJxg1VzRfGgWYWeUDVeHo41325fAZzdw@mail.gmail.com>
	<CAL3=FbZ8QRw6HA3KoaLfuxVvf7cyzswn7+63yJfdHi7ekcZz7A@mail.gmail.com>
Message-ID: <F32E5759-17A7-45E1-95E8-1EB0EFC8C807@electricdruid.net>


On 10 Feb 2012, at 11:57, Jason Tribbeck wrote:

> On 10 February 2012 11:29, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> not RGB, but I want red to be red! :'-/ So much that I'm thinking of
> the possibility of mounting a decent red/green LED in their non-LED
> version...? :-)
>  
> You can easily switch them over - they're just standard 3mm LEDs from what I've seen. The non-LED versions are just the same as the LED ones (i.e they have the casting for LEDs), so you should be able to buy non-LED versions, and insert your own LEDs into them.

Seconded. It can be done - I just tried it. The LED leg-bending is a bit fiddly and I wouldn't like to have to do 100 (this is not a production technique!) but for a one-off it's doable.
So custom blue or violet MEC switches are possible. The switch body only has holes for 2 LED legs though, so we still can't do RGB, only bicolour.

T.




From mr at analogue.org  Fri Feb 10 13:38:48 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 10 Feb 2012 13:38:48 +0100
Subject: [sdiy] Custom LED MEC switches ( was Re: Sparkfun Keypad
	Controllers)
In-Reply-To: <F32E5759-17A7-45E1-95E8-1EB0EFC8C807@electricdruid.net>
References: <4F34A687.1050207@cox.net>
	<868B86A5-3233-4FC6-9824-D314F7AA8808@electricdruid.net>
	<CAP92RBVGD2rKbavTnuNJxg1VzRfGgWYWeUDVeHo41325fAZzdw@mail.gmail.com>
	<CAL3=FbZ8QRw6HA3KoaLfuxVvf7cyzswn7+63yJfdHi7ekcZz7A@mail.gmail.com>
	<F32E5759-17A7-45E1-95E8-1EB0EFC8C807@electricdruid.net>
Message-ID: <CAP92RBXkU7SE6aFi8Kyr5J635XZ9G1U4xH4TFshqGgW-i7f+6w@mail.gmail.com>

On 10 February 2012 13:25, Tom Wiltshire <tom at electricdruid.net> wrote:
> The switch body only has holes for 2 LED legs though, so we still can't do RGB, only bicolour.

Splendid! The less the blue LEDs in the studios around the world, the
better. ;-)

/mr  -  old boffin


From mr at analogue.org  Fri Feb 10 19:36:39 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Fri, 10 Feb 2012 19:36:39 +0100
Subject: [sdiy] TB303 debounce?
In-Reply-To: <56526.128.240.229.3.1328874994.squirrel@www.richieburnett.co.uk>
References: <CA+owYpOkf-Aud_31RPrVDscGQDahrq2kmiZ8xJ27dhYP_59dwQ@mail.gmail.com>
	<56526.128.240.229.3.1328874994.squirrel@www.richieburnett.co.uk>
Message-ID: <CAP92RBUevgzm-rq6a=rc=9wQYip6Ajqt=EB8TxSZtKa81Kdcwg@mail.gmail.com>

On 10 February 2012 12:56, Richie Burnett <rburnett at richieburnett.co.uk> wrote:
> You had to push down quite hard to get a good low resistance
> electrical contact, and even then any side-to-side movement of the finger would
> cause rapid-fire breaking and making of the contact. ?No software is going to be
> able to filter out bounces that happen hundreds or even thousands of
> milliseconds after the initial key down.

Yes, if they are short enough, and if the software doesn't just switch
state on the first sample.

But of course, a sudden glitching break will be interpreted as a real
break if it's longer than normal tolerated contact bounces... :-)

/mr


From Stromeko at nexgo.de  Fri Feb 10 20:23:23 2012
From: Stromeko at nexgo.de (ASSI)
Date: Fri, 10 Feb 2012 20:23:23 +0100
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F343F31.6050902@smiffytech.com>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com>
Message-ID: <1801296.SndT5bfmd8@rainer>

On Friday 10 February 2012, 08:18:33, Matthew Smith wrote:
> As we're talking SMDs, footprint on a PCB (mine are gold-plated anyway)
> and some sort of spring clip to hold the part down?

If you are serious about it you'll need something like this (not cheap):

http://www.emulation.com/catalog/off-the-shelf_solutions/sockets/sot/

If you just want to do a quick check, get a manipulator with vacuum tip and 
just pat them down on the test board.

However, as already said before we got carried into how closely one can 
match discrete transistors by hand: most circuits that were designed for 
discrete transistors and employ pairwise matching are fine with less 
precision (even if not trimmed) and non-monolithic duals would often be good 
enough without even checking.  Consider using a different circuit if that 
isn't the case.  If it turns out once in a while a dual is at the edge of 
the distribution, just take it off and solder the next one in.  If that 
isn't an option, use a proper matched pair transistor.  Still less work and 
expense than sitting through a matching session.

If you'd rather be in the matching business, get a used tape&reel feeder 
with at least 6 rails and build a matching robot to sort from tape to tape.  


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

Wavetables for the Waldorf Blofeld:
http://Synth.Stromeko.net/Downloads.html#BlofeldUserWavetables



From matt at smiffytech.com  Fri Feb 10 21:54:54 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Sat, 11 Feb 2012 07:24:54 +1030
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <1801296.SndT5bfmd8@rainer>
References: <4F308773.9060003@smiffytech.com>
	<1410682.eba6TgDPYE@rainer>	<4F343F31.6050902@smiffytech.com>
	<1801296.SndT5bfmd8@rainer>
Message-ID: <4F35841E.7020500@smiffytech.com>

Quoth ASSI at 11/02/12 05:53...
...
> However, as already said before we got carried into how closely one can
> match discrete transistors by hand: most circuits that were designed for
> discrete transistors and employ pairwise matching are fine with less
> precision (even if not trimmed) and non-monolithic duals would often be good
> enough without even checking...

Yes, was going off on a bit of a tangent there.

Rest assured, those parts will be going straight on without testing - 
and will only be investigated if the thing doesn't work!

So, with nice little parts like this, I end up with a VSSVF ;-) (Very 
Small State Variable Filter.)


-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From stewpye at optusnet.com.au  Fri Feb 10 23:47:55 2012
From: stewpye at optusnet.com.au (Stewart Pye)
Date: Sat, 11 Feb 2012 08:47:55 +1000
Subject: [sdiy] Matched transistors - critical parameters?
In-Reply-To: <4F343F31.6050902@smiffytech.com>
References: <4F308773.9060003@smiffytech.com>
	<4F3379D0.8030609@sonic.net>	<FC11DA18-5314-4252-A838-BEA1A6420E53@electricdruid.net>
	<1410682.eba6TgDPYE@rainer> <4F343F31.6050902@smiffytech.com>
Message-ID: <4F359E9B.4090409@optusnet.com.au>

HI Matthew,

If you use the BCM series they are matched to a maximum of 2mV (Vbe1 - Vbe2)

http://au.element14.com/nxp/bcm856bs/transistor-pnp-pnp-matched-sot363/dp/1829187

Regards,
Stewart.


On 2/10/2012 7:48 AM, Matthew Smith wrote:
> Quoth ASSI at 10/02/12 06:55...
> ...
>> You can do quite a bit better than 1mV by hand using the balanced bridge
>> measurement method; Ian Fritz routinely matches to tens-of-micro-Volt
>> levels(*).
>
> Thanks, Achim, more interesting stuff! Finding this topic fascinating.
>
> As we're talking SMDs, footprint on a PCB (mine are gold-plated 
> anyway) and some sort of spring clip to hold the part down?
>
>



From patchell at cox.net  Sat Feb 11 08:29:16 2012
From: patchell at cox.net (James Patchell)
Date: Fri, 10 Feb 2012 23:29:16 -0800
Subject: [sdiy] Discrete blackmer vca
Message-ID: <4F3618CC.7020508@cox.net>

Anybody here experiment making Blackmer VCA's from discrete 
transistors?  I know it has been done.   I am pretty sure Hearn Morley 
does or will sell a discrete one in a module.  I thought it might be fun 
to experiment a bit with them.  Kind of the cool thing about them is 
that they take an input current and produce an output current with a 
gain that is controled by a voltage.

For those who may not know what a blackmer vca is, here is a link to a 
prelim schematic of a very basic (and descrete) BMvca

http://www.noniandjim.com/Jim/SMB2/SMB2.html

-Jim



From jdm at synthcom.com  Sat Feb 11 11:46:45 2012
From: jdm at synthcom.com (J.D. McEachin)
Date: Sat, 11 Feb 2012 02:46:45 -0800
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <4F35841E.7020500@smiffytech.com>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
Message-ID: <20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>

Does anyone remember who designed it?  Gene Stopp, one of the 
Electronotes guys, or someone else?

I'm wondering because, after all these years of taking a lot of crap 
about it from a good friend of mine, I've decided that I'm FINALLY 
going to finish my ASM-1.  LOLZ.  Or more accurately, I'm going to 
saw the PCB into 3 pieces, and build MOTM-format VCF, dual VCO, and 
dual ADSR/VCA modules.  And I'd like to give credit where credit is 
due on the front panels.

Thanks!
Jeffrey



From tom at electricdruid.net  Sat Feb 11 14:03:26 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sat, 11 Feb 2012 13:03:26 +0000
Subject: [sdiy] Discrete blackmer vca
In-Reply-To: <4F3618CC.7020508@cox.net>
References: <4F3618CC.7020508@cox.net>
Message-ID: <18C97DE3-3480-45AA-AEC1-C95983841034@electricdruid.net>

Is that an exponential or linear VCA Jim?

The THAT VCAs are all based on the blackmer gain cell, and they're exponential, but the Hearn Morley VCA is linear, so maybe George did something else? I'm not sure.

Thanks,
Tom


On 11 Feb 2012, at 07:29, James Patchell wrote:

> Anybody here experiment making Blackmer VCA's from discrete transistors?  I know it has been done.   I am pretty sure Hearn Morley does or will sell a discrete one in a module.  I thought it might be fun to experiment a bit with them.  Kind of the cool thing about them is that they take an input current and produce an output current with a gain that is controled by a voltage.
> 
> For those who may not know what a blackmer vca is, here is a link to a prelim schematic of a very basic (and descrete) BMvca
> 
> http://www.noniandjim.com/Jim/SMB2/SMB2.html
> 
> -Jim
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From thebot at btinternet.com  Sat Feb 11 14:34:27 2012
From: thebot at btinternet.com (Scott Young)
Date: Sat, 11 Feb 2012 13:34:27 +0000
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
	<20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
Message-ID: <C645D902-8BE4-47AA-A942-E9B86C60187D@btinternet.com>

Jeffrey, see here - assume this is the same project?

http://www.elby-designs.com/asm-1/asm1.htm

Cheers,
Scott.

On 11 Feb 2012, at 10:46, J.D. McEachin wrote:

> Does anyone remember who designed it?  Gene Stopp, one of the Electronotes guys, or someone else?
> 
> I'm wondering because, after all these years of taking a lot of crap about it from a good friend of mine, I've decided that I'm FINALLY going to finish my ASM-1.  LOLZ.  Or more accurately, I'm going to saw the PCB into 3 pieces, and build MOTM-format VCF, dual VCO, and dual ADSR/VCA modules.  And I'd like to give credit where credit is due on the front panels.
> 
> Thanks!
> Jeffrey
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From Stromeko at nexgo.de  Sat Feb 11 19:30:07 2012
From: Stromeko at nexgo.de (ASSI)
Date: Sat, 11 Feb 2012 19:30:07 +0100
Subject: [sdiy] current conveyor?
In-Reply-To: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
Message-ID: <4999256.TtfJGVCklB@rainer>

On Monday 06 February 2012, 12:47:39, David G Dixon wrote:
> Do any gurus here know of a circuit to convey a current from a virtual
> ground point to another point at any voltage?

I know you've already solved your problem, but there's is another possible 
solution: use a bidirectional current monitor IC with current output.


Regards,
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 dixon at mail.ubc.ca  Sat Feb 11 19:44:07 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Sat, 11 Feb 2012 10:44:07 -0800
Subject: [sdiy] current conveyor?
In-Reply-To: <4999256.TtfJGVCklB@rainer>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
	<4999256.TtfJGVCklB@rainer>
Message-ID: <7717482D8E5B45C4A7C370287AA5AB01@galvanox01>

> > Do any gurus here know of a circuit to convey a current 
> from a virtual 
> > ground point to another point at any voltage?
> 
> I know you've already solved your problem, but there's is 
> another possible
> solution: use a bidirectional current monitor IC with current output.

Yes, this problem was actually very easy to solve, but only because of the
specifics of the oscillator core in my case.  I'm still very much interested
in this problem generally, since the requirement to terminate 2164 to
virtual ground can be a nuisance in many applications.

Can you suggest a specific IC so I can have a look at the datasheet?



From mverbos at earthlink.net  Sat Feb 11 20:34:09 2012
From: mverbos at earthlink.net (mark verbos)
Date: Sat, 11 Feb 2012 14:34:09 -0500
Subject: [sdiy] Discrete blackmer vca
In-Reply-To: <4F3618CC.7020508@cox.net>
References: <4F3618CC.7020508@cox.net>
Message-ID: <6BFF189A-C008-4211-821C-B0FA2C88D187@earthlink.net>

Another cool thing about them is that they are exponential without any converter. Early Serge VCAs were a version using 4 transistors and a dual opamp. I have the DBX 202 and 200 schematics if you want them. Both of these seem to be simpler than what you have going there. I'm not sure about sound quality on these. I know both Serge and DBX switched to THAT corp ICs later on.

Mark




On Feb 11, 2012, at 2:29 AM, James Patchell wrote:

> Anybody here experiment making Blackmer VCA's from discrete transistors?  I know it has been done.   I am pretty sure Hearn Morley does or will sell a discrete one in a module.  I thought it might be fun to experiment a bit with them.  Kind of the cool thing about them is that they take an input current and produce an output current with a gain that is controled by a voltage.
> 
> For those who may not know what a blackmer vca is, here is a link to a prelim schematic of a very basic (and descrete) BMvca
> 
> http://www.noniandjim.com/Jim/SMB2/SMB2.html
> 
> -Jim
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From mverbos at earthlink.net  Sat Feb 11 20:35:26 2012
From: mverbos at earthlink.net (mark verbos)
Date: Sat, 11 Feb 2012 14:35:26 -0500
Subject: [sdiy] Discrete blackmer vca
In-Reply-To: <6BFF189A-C008-4211-821C-B0FA2C88D187@earthlink.net>
References: <4F3618CC.7020508@cox.net>
	<6BFF189A-C008-4211-821C-B0FA2C88D187@earthlink.net>
Message-ID: <22FB6B17-4E8E-4596-A349-D1CE57D55D4E@earthlink.net>

actually, here's the DBX doc...

www.gyraf.dk/schematics/Dbx202.pdf



On Feb 11, 2012, at 2:34 PM, mark verbos wrote:

> Another cool thing about them is that they are exponential without any converter. Early Serge VCAs were a version using 4 transistors and a dual opamp. I have the DBX 202 and 200 schematics if you want them. Both of these seem to be simpler than what you have going there. I'm not sure about sound quality on these. I know both Serge and DBX switched to THAT corp ICs later on.
> 
> Mark
> 
> 
> 
> 
> On Feb 11, 2012, at 2:29 AM, James Patchell wrote:
> 
>> Anybody here experiment making Blackmer VCA's from discrete transistors?  I know it has been done.   I am pretty sure Hearn Morley does or will sell a discrete one in a module.  I thought it might be fun to experiment a bit with them.  Kind of the cool thing about them is that they take an input current and produce an output current with a gain that is controled by a voltage.
>> 
>> For those who may not know what a blackmer vca is, here is a link to a prelim schematic of a very basic (and descrete) BMvca
>> 
>> http://www.noniandjim.com/Jim/SMB2/SMB2.html
>> 
>> -Jim
>> 
>> _______________________________________________
>> 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 Stromeko at nexgo.de  Sat Feb 11 20:55:48 2012
From: Stromeko at nexgo.de (ASSI)
Date: Sat, 11 Feb 2012 20:55:48 +0100
Subject: [sdiy] current conveyor?
In-Reply-To: <7717482D8E5B45C4A7C370287AA5AB01@galvanox01>
References: <D367111DF35543A9B291A8F9CB84B333@galvanox01>
	<4999256.TtfJGVCklB@rainer>
	<7717482D8E5B45C4A7C370287AA5AB01@galvanox01>
Message-ID: <2342843.1tcTGNIj1H@rainer>

On Saturday 11 February 2012, 10:44:07, David G Dixon wrote:
> I'm still very much
> interested in this problem generally, since the requirement to terminate
> 2164 to virtual ground can be a nuisance in many applications.

You will still need to run it into a virtual ground, but the signal for the 
current sense amplifier can directly be taken from the feedback resistor of 
that opamp.  The sad reality is that CoolAudio simply copied the 2164 and 
its datasheet instead of thinking and adding two current mirrors to the 
output (and allowing to take that base resistor out of the loop).

> Can you suggest a specific IC so I can have a look at the datasheet?

MAX9934 for instance, but you'll find many more (LT1787, ZXCT1010, INA193).  
Since they aren't directly made for this application, these will require 
varying support from additional circuitry depending on what exactly you want 
to do.

http://www.maxim-ic.com/app-notes/index.mvp/id/746
http://cds.linear.com/docs/Application%20Note/an105.pdf
http://www.diodes.com/zetex/_pdfs/3.0/appnotes/apps/an39.pdf
http://www.ti.com/lit/an/slyt311/slyt311.pdf


Regards,
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 jdm at synthcom.com  Sun Feb 12 00:21:33 2012
From: jdm at synthcom.com (J.D. McEachin)
Date: Sat, 11 Feb 2012 15:21:33 -0800
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <C645D902-8BE4-47AA-A942-E9B86C60187D@btinternet.com>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
	<20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
	<C645D902-8BE4-47AA-A942-E9B86C60187D@btinternet.com>
Message-ID: <20120211235918.777FD1679023@dropmix.xs4all.nl>

At 05:34 AM 2/11/2012, Scott Young wrote:
>Jeffrey, see here - assume this is the same project?
>
>http://www.elby-designs.com/asm-1/asm1.htm

Yup, that's it.  I couldn't find anything there on the provenance of 
the ADSR circuit, though.  I checked in Electronotes, and the ASM-1 
ADSR doesn't look like the ENS-76 ADSRs.

For those wondering why I don't just buy an ASM-2 board, it's because 
I have a stuffed ASM-1 pcb, and it seems to me that it'll be easier 
to make a few mods to it to improve it than to desolder the expensive 
parts and stuff them in a new pcb.  My friend built 3 of them, and I 
think they sound pretty good.

Here's what I have in mind:

<http://www.synthcom.com/~jdm/diy/ASM_VCO2.GIF>http://www.synthcom.com/~jdm/diy/ASM_VCO2.GIF 


http://www.synthcom.com/~jdm/diy/ASM_VCF.GIF

<http://www.synthcom.com/~jdm/diy/ASM_ADSR.GIF>http://www.synthcom.com/~jdm/diy/ASM_ADSR.GIF 


I believe the glide, noise, and lfo would be more trouble than 
they're worth, so I've left them out.  I guess I'll find out if the 
rest of it is worth the trouble soon enough.  ;)

Jeffrey



From jdelgoulet at free.fr  Sun Feb 12 00:22:43 2012
From: jdelgoulet at free.fr (Julien Delgoulet)
Date: Sun, 12 Feb 2012 00:22:43 +0100
Subject: [sdiy] Moog Rogue Tempco
Message-ID: <D03EC1CF-03CB-418C-BAE7-E57DBBB4B000@free.fr>

Hi all,

I'm trying to replicate the moog rogue VCO and was wondering what could be the ppm for the 100Ohm tempo ?
The service manual only says : "100Ohm TC" ? :-(

Any idea ?

From fluxmonk at gmail.com  Sun Feb 12 16:15:32 2012
From: fluxmonk at gmail.com (bbob)
Date: Sun, 12 Feb 2012 10:15:32 -0500
Subject: [sdiy] Benjolin filter issues
In-Reply-To: <EFD03E4A667348CF8A1AA859019F46D4@galvanox01>
References: <EFD03E4A667348CF8A1AA859019F46D4@galvanox01>
Message-ID: <CABbX2d-awcmX1=HRvWV3L5JW6z3Xr+AEZ29ew_cfRjtJqcGpxQ@mail.gmail.com>

i believe that is by design: filter out is intended to be line level,
all the individual and cv outs are closer to 5v.  my builds are like
that too, i combed thru the postings at electromusic.com and found
confirmation from rob to that effect.

lovely box, played it again last nite in a trio, including a nice
benjolin/sax break.

b

On Thu, Feb 9, 2012 at 4:19 AM, David G Dixon <dixon at mail.ubc.ca> wrote:
> I'm building a few Benjolin boards (based on the PCB layout and schematics
> posted by Rob Hordyk on electro-music.com), and while testing them I noticed
> that the filter was putting out a very weak signal (just a few hundred mV
> peak-to-peak). ?The oscillators are robust, and everything else is working
> perfectly. ?This problem is on both boards I've built so far. ?I've even
> simulated the filter part of the circuit, and the simulations give the same
> thing.
>
> I'm wondering, has anybody here built these things, and if so, did you
> encounter similar problems? ?Any help most appreciated!
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From patchell at cox.net  Mon Feb 13 05:38:09 2012
From: patchell at cox.net (James Patchell)
Date: Sun, 12 Feb 2012 20:38:09 -0800
Subject: [sdiy] What happened to Mylar (Polyester)  Capacitors
Message-ID: <4F3893B1.3080508@cox.net>

Still working on the BOM for my new synth project.  I used to use these 
Polyester (Mylar) Caps that you could get through Mouser that were made 
by Xicon.  They just don't seem to be there any more.  What happened?  I 
also used to use the Xicon Polystyrene capacitors.  I was relieved to 
see that those are still available,  but they are not ROHS (which just 
doesn't matter to me).  The main attraction was they were dirt cheap.

This really sucks.  Don't do SDIY for a few years and BAM, all the parts 
just disappear.

I did find some Polypropylene parts at mouser, but they were a lot 
pricer than I remember the Xicon parts (Although, I bet these are much 
higher quality).

Oh, well, I will keep looking.

-Jim



From jim at antsclimbtree.com  Mon Feb 13 07:16:41 2012
From: jim at antsclimbtree.com (Jim Coursey)
Date: Sun, 12 Feb 2012 22:16:41 -0800
Subject: [sdiy] JH Triple Chorus build question
In-Reply-To: <4F3893B1.3080508@cox.net>
References: <4F3893B1.3080508@cox.net>
Message-ID: <33D209F8-F34B-43A4-8AFD-58664D918BFC@antsclimbtree.com>

Hi SDIY folks,

I've posted about this issue to both electro-music and muffwiggler forums, and I'm not getting any replies.  I'm sorry for cross-posting, but I'm just looking for any ideas.  So far I haven't even been able to get someone to tell me they think I'm imagining things.

In a nutshell, I have a JH Solina / Triple Chorus that I've long considered working. Here's the thing: it makes chorus and it sounds nice enough. So what's the problem? Well, I have little experience with the Solina but based on JH's samples I think my chorus stops short of the saturated, gooey sound J?rgen achieved.  It *seems* like my modulation is less extreme than his, and it also *seems* that I'm lacking in what he describes as "soft-clipping."

In my posting, there's an audio file in which I go so far as to process dry sounds from J?rgen's own samples and compare it to his chorused results.  Anyone able to help can decide for yourself whether my results are different.  Or perhaps whether my results sound different than your own builds.

More info and sound files here:

http://www.muffwiggler.com/forum/viewtopic.php?t=52638

Thanks in advance,
Jim

From osalas at electronic-sea.net  Mon Feb 13 09:27:24 2012
From: osalas at electronic-sea.net (Oscar Salas)
Date: Mon, 13 Feb 2012 10:27:24 +0200
Subject: [sdiy] What happened to Mylar (Polyester)  Capacitors
In-Reply-To: <4F3893B1.3080508@cox.net>
References: <4F3893B1.3080508@cox.net>
Message-ID: <d3ec58d416d836b436c9a9efbaf8e32c.squirrel@webmail.electronic-sea.net>

You could try Ceramic NPO instead of Polypropylenes.
> Still working on the BOM for my new synth project.  I used to use these
> Polyester (Mylar) Caps that you could get through Mouser that were made
> by Xicon.  They just don't seem to be there any more.  What happened?  I
> also used to use the Xicon Polystyrene capacitors.  I was relieved to
> see that those are still available,  but they are not ROHS (which just
> doesn't matter to me).  The main attraction was they were dirt cheap.
>
> This really sucks.  Don't do SDIY for a few years and BAM, all the parts
> just disappear.
>
> I did find some Polypropylene parts at mouser, but they were a lot
> pricer than I remember the Xicon parts (Although, I bet these are much
> higher quality).
>
> Oh, well, I will keep looking.
>
> -Jim
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>


electronic-sea.net



From carsten at analog-monster.de  Mon Feb 13 09:57:25 2012
From: carsten at analog-monster.de (Carsten Toensmann)
Date: Mon, 13 Feb 2012 09:57:25 +0100
Subject: [sdiy] JH Triple Chorus build question
In-Reply-To: <33D209F8-F34B-43A4-8AFD-58664D918BFC@antsclimbtree.com>
References: <4F3893B1.3080508@cox.net>
	<33D209F8-F34B-43A4-8AFD-58664D918BFC@antsclimbtree.com>
Message-ID: <A1AC3BBF6F6849CC8FAD51FF6FF702E1@ww930.myitsolutions.net>


Hi Jim,

also for my ears J?rgen's part sounds a bit more fat, but just a little bit. 
and *both* sound slightly less wet than my original Solina. On the other 
hand one can hear the modulation oscillator in my Solina, what is not so 
nice and what I've not heard in your example.

So your chorus sounds absolutely fine for me.

Cheers

Carsten

-----Urspr?ngliche Nachricht----- 
From: Jim Coursey
Sent: Monday, February 13, 2012 7:16 AM
To: synthdiy diy
Subject: [sdiy] JH Triple Chorus build question

Hi SDIY folks,

I've posted about this issue to both electro-music and muffwiggler forums, 
and I'm not getting any replies.  I'm sorry for cross-posting, but I'm just 
looking for any ideas.  So far I haven't even been able to get someone to 
tell me they think I'm imagining things.

In a nutshell, I have a JH Solina / Triple Chorus that I've long considered 
working. Here's the thing: it makes chorus and it sounds nice enough. So 
what's the problem? Well, I have little experience with the Solina but based 
on JH's samples I think my chorus stops short of the saturated, gooey sound 
J?rgen achieved.  It *seems* like my modulation is less extreme than his, 
and it also *seems* that I'm lacking in what he describes as 
"soft-clipping."

In my posting, there's an audio file in which I go so far as to process dry 
sounds from J?rgen's own samples and compare it to his chorused results. 
Anyone able to help can decide for yourself whether my results are 
different.  Or perhaps whether my results sound different than your own 
builds.

More info and sound files here:

http://www.muffwiggler.com/forum/viewtopic.php?t=52638

Thanks in advance,
Jim
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy 



From osalas at electronic-sea.net  Mon Feb 13 10:04:36 2012
From: osalas at electronic-sea.net (Oscar Salas)
Date: Mon, 13 Feb 2012 11:04:36 +0200
Subject: [sdiy] What happened to Mylar (Polyester)  Capacitors
In-Reply-To: <d3ec58d416d836b436c9a9efbaf8e32c.squirrel@webmail.electronic-sea.net>
References: <4F3893B1.3080508@cox.net>
	<d3ec58d416d836b436c9a9efbaf8e32c.squirrel@webmail.electronic-sea.net>
Message-ID: <0ffb82032d1a6bca9fb978d970a2577a.squirrel@webmail.electronic-sea.net>

Like for example
http://gr.mouser.com/ProductDetail/Kemet/C410C102J1G5CA/?qs=sGAEpiMZZMuAYrNc52CMZPJhxtnDkxmzt3vvtOjulc8%3d


> You could try Ceramic NPO instead of Polypropylenes.
>> Still working on the BOM for my new synth project.  I used to use these
>> Polyester (Mylar) Caps that you could get through Mouser that were made
>> by Xicon.  They just don't seem to be there any more.  What happened?  I
>> also used to use the Xicon Polystyrene capacitors.  I was relieved to
>> see that those are still available,  but they are not ROHS (which just
>> doesn't matter to me).  The main attraction was they were dirt cheap.
>>
>> This really sucks.  Don't do SDIY for a few years and BAM, all the parts
>> just disappear.
>>
>> I did find some Polypropylene parts at mouser, but they were a lot
>> pricer than I remember the Xicon parts (Although, I bet these are much
>> higher quality).
>>
>> Oh, well, I will keep looking.
>>
>> -Jim
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>>
>>
>
>
> electronic-sea.net
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>


electronic-sea.net



From lanterma at ece.gatech.edu  Mon Feb 13 11:44:45 2012
From: lanterma at ece.gatech.edu (Lanterman, Aaron)
Date: Mon, 13 Feb 2012 10:44:45 +0000
Subject: [sdiy] Bob Moog and Don Buchla both get a mention
Message-ID: <7781A3C5-B8CD-4EAB-888E-5386ADE9B190@ece.gatech.edu>

Cool article:

http://www.theatlantic.com/entertainment/archive/2012/02/why-is-it-so-hard-for-new-musical-instruments-to-catch-on/252668/

I confess I didn't know anything about the fascinating history of the saxophone...

- Aaron

From harrybissell at wowway.com  Mon Feb 13 17:33:32 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 13 Feb 2012 11:33:32 -0500 (EST)
Subject: [sdiy] Moog Rogue Tempco
In-Reply-To: <D03EC1CF-03CB-418C-BAE7-E57DBBB4B000@free.fr>
Message-ID: <1567897246.308735.1329150812004.JavaMail.root@md01.wow.synacor.com>

usually +3500ppm. people have used more common +3300 and +3900 as well, check the archives
for more info. In particular, some have used an additional low drift NON compensated resistor (maybe 50ppm) in series
to trim the total tempco.

H^) harry


----- Original Message -----
From: Julien Delgoulet <jdelgoulet at free.fr>
To: synthdiy diy <synth-diy at dropmix.xs4all.nl>
Sent: Sat, 11 Feb 2012 18:22:43 -0500 (EST)
Subject: [sdiy] Moog Rogue Tempco

Hi all,

I'm trying to replicate the moog rogue VCO and was wondering what could be the ppm for the 100Ohm tempo ?
The service manual only says : "100Ohm TC" ? :-(

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

-- 
Harry Bissell & Nora Abdullah 4eva


From magnus at rubidium.dyndns.org  Tue Feb 14 09:25:59 2012
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Tue, 14 Feb 2012 09:25:59 +0100
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
	<20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
Message-ID: <4F3A1A97.40208@rubidium.dyndns.org>

Hi Jeffrey,
'
On 02/11/2012 11:46 AM, J.D. McEachin wrote:
> Does anyone remember who designed it? Gene Stopp, one of the
> Electronotes guys, or someone else?
>
> I'm wondering because, after all these years of taking a lot of crap
> about it from a good friend of mine, I've decided that I'm FINALLY going
> to finish my ASM-1. LOLZ. Or more accurately, I'm going to saw the PCB
> into 3 pieces, and build MOTM-format VCF, dual VCO, and dual ADSR/VCA
> modules. And I'd like to give credit where credit is due on the front
> panels.

Well, I simply asked Gene and got this reply:

Yes, that's my design, I based it on whatever chips I happened to have 
in my parts drawer at the time. I doubled up the attack analog switches 
since I had a spare and I wanted to reduce the ON resistance as much as 
possible for the fastest attack. In retrospect I should have used a 555 
timer as the A/D flip flop but oh well.

- Gene

So I hope we have settled your curiosity.

Cheers,
Magnus


From magnus at rubidium.dyndns.org  Tue Feb 14 09:30:48 2012
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Tue, 14 Feb 2012 09:30:48 +0100
Subject: [sdiy] Moog Rogue Tempco
In-Reply-To: <1567897246.308735.1329150812004.JavaMail.root@md01.wow.synacor.com>
References: <1567897246.308735.1329150812004.JavaMail.root@md01.wow.synacor.com>
Message-ID: <4F3A1BB8.9050809@rubidium.dyndns.org>

On 02/13/2012 05:33 PM, Harry Bissell wrote:
> usually +3500ppm. people have used more common +3300 and +3900 as well, check the archives
> for more info. In particular, some have used an additional low drift NON compensated resistor (maybe 50ppm) in series
> to trim the total tempco.

The archives should be stuffed with this stuff, it's been a re-occuring 
discussion over the years I've been here. People have tried many 
different solutions and reported back.

Cheers,
Magnus


From xyzzy at sysabend.org  Tue Feb 14 21:50:59 2012
From: xyzzy at sysabend.org (Tom Arnold)
Date: Tue, 14 Feb 2012 12:50:59 -0800
Subject: [sdiy] Nifty Arduinofamily device - Ardweeny
Message-ID: <20120214205059.GE21829@moo.sysabend.org>

Wanted to mention this little guy since I've been eating'em like popcorn
lately.

The Solarbiotics Ardweeny.

Its a Mega328 with a little circuit board you solder on top that holds all
the arduino bits ( serial port, reset button ) and has the 16mhz resonator.
The chip still fits in a standard socket with no problem.  

I originally bought one to use while breadboarding, but at $10ea they are
cheap enough that I've just started using them in projects and leaving them
there.  If you are tight on space you can mount the parts under the board,
use a right angle connector and an SMD LED and shave 3mm or so.

Its cheap enough and easy enough to deal with that I've started using'em to
replace logic.  Yeah, cleaner ways to do it but this is just so easy...

http://www.solarbotics.com/products/kardw/

-- 
 -----------------------------------------------------------------
 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -  "...is it a virus, a drug, or a religion?"
 - K6AET            -  Juanita Shrugs. "What's the difference? 
 --------------------         -- Neal Stephenson,  Snow Crash


From jdm at synthcom.com  Wed Feb 15 07:50:52 2012
From: jdm at synthcom.com (J.D. McEachin)
Date: Tue, 14 Feb 2012 22:50:52 -0800
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <4F3A1A97.40208@rubidium.dyndns.org>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
	<20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
	<4F3A1A97.40208@rubidium.dyndns.org>
Message-ID: <20120215075611.BB3AA167EFDD@dropmix.xs4all.nl>

At 12:25 AM 2/14/2012, Magnus Danielson wrote:

>Well, I simply asked Gene and got this reply:
>
>Yes, that's my design, I based it on whatever chips I happened to 
>have in my parts drawer at the time. I doubled up the attack analog 
>switches since I had a spare and I wanted to reduce the ON 
>resistance as much as possible for the fastest attack. In retrospect 
>I should have used a 555 timer as the A/D flip flop but oh well.
>
>- Gene
>
>So I hope we have settled your curiosity.

Yes, you have.  Thank you VERY MUCH!

I'll put Gene's name on the panel, and I'll post a pic when I get 
around to making the panels.

Jeffrey 



From juzowen at gmail.com  Wed Feb 15 14:40:20 2012
From: juzowen at gmail.com (Justin Owen)
Date: Wed, 15 Feb 2012 13:40:20 +0000
Subject: [sdiy] OT: Jobs at SSL
Message-ID: <4f3bb5c5.e856b40a.77dd.0805@mx.google.com>

Thought some of you might be interested in this:

http://dmtrk.net/7YS-PAF8-CA16POGW22/cr.aspx

J



From magnus at rubidium.dyndns.org  Wed Feb 15 22:21:15 2012
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 15 Feb 2012 22:21:15 +0100
Subject: [sdiy] ASM-1 ADSR
In-Reply-To: <20120215075611.BB3AA167EFDD@dropmix.xs4all.nl>
References: <4F308773.9060003@smiffytech.com> <1410682.eba6TgDPYE@rainer>
	<4F343F31.6050902@smiffytech.com> <1801296.SndT5bfmd8@rainer>
	<4F35841E.7020500@smiffytech.com>
	<20120211104327.2BD5C1675F9B@dropmix.xs4all.nl>
	<4F3A1A97.40208@rubidium.dyndns.org>
	<20120215075611.BB3AA167EFDD@dropmix.xs4all.nl>
Message-ID: <4F3C21CB.1050608@rubidium.dyndns.org>

Hi Jeff,

On 02/15/2012 07:50 AM, J.D. McEachin wrote:
> At 12:25 AM 2/14/2012, Magnus Danielson wrote:
>
>> Well, I simply asked Gene and got this reply:
>>
>> Yes, that's my design, I based it on whatever chips I happened to have
>> in my parts drawer at the time. I doubled up the attack analog
>> switches since I had a spare and I wanted to reduce the ON resistance
>> as much as possible for the fastest attack. In retrospect I should
>> have used a 555 timer as the A/D flip flop but oh well.
>>
>> - Gene
>>
>> So I hope we have settled your curiosity.
>
> Yes, you have. Thank you VERY MUCH!

Oh, I'm so happy to give credit where credit is due, especially in the 
case of Gene. It's fabulous to see how about 15 years of ASM-1 on the 
web and as a building project still get responses. I've tried to 
contribute further for those continuing the work.

> I'll put Gene's name on the panel, and I'll post a pic when I get around
> to making the panels.

Love to see it!

Cheers,
Magnus


From dixon at mail.ubc.ca  Thu Feb 16 09:07:01 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Thu, 16 Feb 2012 00:07:01 -0800
Subject: [sdiy] Looking for 79L09
Message-ID: <9ADFC7C19C8A4DDB848A766A93759031@galvanox01>

If anyone in N. America would be willing to part with a couple of 79L09 -9V
regulators in the TO-92 package, please email me privately.  I need a couple
to finish my Benjolin boards.  Thanks in advance!



From gazzaca77 at gmail.com  Fri Feb 17 08:58:18 2012
From: gazzaca77 at gmail.com (d b)
Date: Thu, 16 Feb 2012 23:58:18 -0800
Subject: [sdiy] Nifty Arduinofamily device - Ardweeny
In-Reply-To: <20120214205059.GE21829@moo.sysabend.org>
References: <20120214205059.GE21829@moo.sysabend.org>
Message-ID: <CA+owYpNKcnjtekJO_P+0+NmvWJ+KzFymEZSr20DUtyPSUV66WA@mail.gmail.com>

Any idea why they don't use the Optibootloader?

On Tue, Feb 14, 2012 at 12:50 PM, Tom Arnold <xyzzy at sysabend.org> wrote:
> Wanted to mention this little guy since I've been eating'em like popcorn
> lately.
>
> The Solarbiotics Ardweeny.
>
> Its a Mega328 with a little circuit board you solder on top that holds all
> the arduino bits ( serial port, reset button ) and has the 16mhz resonator.
> The chip still fits in a standard socket with no problem.
>
> I originally bought one to use while breadboarding, but at $10ea they are
> cheap enough that I've just started using them in projects and leaving them
> there. ?If you are tight on space you can mount the parts under the board,
> use a right angle connector and an SMD LED and shave 3mm or so.
>
> Its cheap enough and easy enough to deal with that I've started using'em to
> replace logic. ?Yeah, cleaner ways to do it but this is just so easy...
>
> http://www.solarbotics.com/products/kardw/
>
> --
> ?-----------------------------------------------------------------
> ?- Tom Arnold ? ? ? - ?Free Synth DIY webspace http://www.sdiy.org
> ?- SynthGeek ? ? ? ?- ?"...is it a virus, a drug, or a religion?"
> ?- K6AET ? ? ? ? ? ?- ?Juanita Shrugs. "What's the difference?
> ?-------------------- ? ? ? ? -- Neal Stephenson, ?Snow Crash
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From dougt55 at yahoo.com  Fri Feb 17 09:44:41 2012
From: dougt55 at yahoo.com (Doug Terrebonne)
Date: Fri, 17 Feb 2012 00:44:41 -0800 (PST)
Subject: [sdiy] IR3R03 chip wanted
Message-ID: <1329468281.13830.YahooMailRC@web181707.mail.ne1.yahoo.com>

Hi, does anyone have a Roland IR3R03 VCO chip?

Thanks,
Doug



From xyzzy at sysabend.org  Fri Feb 17 20:09:27 2012
From: xyzzy at sysabend.org (Tom Arnold)
Date: Fri, 17 Feb 2012 11:09:27 -0800
Subject: [sdiy] Nifty Arduinofamily device - Ardweeny
In-Reply-To: <CA+owYpNKcnjtekJO_P+0+NmvWJ+KzFymEZSr20DUtyPSUV66WA@mail.gmail.com>
References: <20120214205059.GE21829@moo.sysabend.org>
	<CA+owYpNKcnjtekJO_P+0+NmvWJ+KzFymEZSr20DUtyPSUV66WA@mail.gmail.com>
Message-ID: <20120217190927.GN21829@moo.sysabend.org>

On Thu, Feb 16, 2012 at 11:58:18PM -0800, d b wrote:
> Any idea why they don't use the Optibootloader?

No idea.  I usually use a hacked version of AdaBoot just from laziness and
that its timing is a bit more relaxed.  Optiboot is a little picky on timing
to get into the bootloader.  Usually not a problem unless I'm doing
something by hand and have to hit the reset button and start a process.  Not
such an issue these days now that everything supports DTR toggling. ( or is
it RTS... whichever ).

That and I patched the loader for one of my projects so it would disconnect
internal connections from the serial port during the boot process so wiring
you might have on the serial port ( MIDI, etc ) wouldn't interfear with the
upgrade.

You could always drop them an email and ask.

 -Tom

> 
> On Tue, Feb 14, 2012 at 12:50 PM, Tom Arnold <xyzzy at sysabend.org> wrote:
> > Wanted to mention this little guy since I've been eating'em like popcorn
> > lately.
> >
> > The Solarbiotics Ardweeny.
> >
> > Its a Mega328 with a little circuit board you solder on top that holds all
> > the arduino bits ( serial port, reset button ) and has the 16mhz resonator.
> > The chip still fits in a standard socket with no problem.
> >
> > I originally bought one to use while breadboarding, but at $10ea they are
> > cheap enough that I've just started using them in projects and leaving them
> > there. ?If you are tight on space you can mount the parts under the board,
> > use a right angle connector and an SMD LED and shave 3mm or so.
> >
> > Its cheap enough and easy enough to deal with that I've started using'em to
> > replace logic. ?Yeah, cleaner ways to do it but this is just so easy...
> >
> > http://www.solarbotics.com/products/kardw/
> >
> > --
> > ?-----------------------------------------------------------------
> > ?- Tom Arnold ? ? ? - ?Free Synth DIY webspace http://www.sdiy.org
> > ?- SynthGeek ? ? ? ?- ?"...is it a virus, a drug, or a religion?"
> > ?- K6AET ? ? ? ? ? ?- ?Juanita Shrugs. "What's the difference?
> > ?-------------------- ? ? ? ? -- Neal Stephenson, ?Snow Crash
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
 -----------------------------------------------------------------
 - Tom Arnold       -  Free Synth DIY webspace http://www.sdiy.org 
 - SynthGeek        -  "...is it a virus, a drug, or a religion?"
 - K6AET            -  Juanita Shrugs. "What's the difference? 
 --------------------         -- Neal Stephenson,  Snow Crash


From Stromeko at nexgo.de  Fri Feb 17 20:25:53 2012
From: Stromeko at nexgo.de (ASSI)
Date: Fri, 17 Feb 2012 20:25:53 +0100
Subject: [sdiy] Nice info on decoupling caps
In-Reply-To: <3541920.LSMlsODR9o@rainer>
References: <CACDGQT8J+XJTQcGF7KQCPotExoSs_2Q4o7e7YZupp8SGEr=Qpw@mail.gmail.com>
	<3541920.LSMlsODR9o@rainer>
Message-ID: <3596309.sWZm5AeFou@rainer>

A little addition to the link collection:

http://www.williamson-labs.com/glencoe-bypass-11.html


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

Factory and User Sound Singles for Waldorf Q+, Q and microQ:
http://Synth.Stromeko.net/Downloads.html#WaldorfSounds



From jpdesroc at oricom.ca  Fri Feb 17 21:36:01 2012
From: jpdesroc at oricom.ca (Jean-Pierre Desrochers)
Date: Fri, 17 Feb 2012 15:36:01 -0500
Subject: [sdiy] Any simple circuit to test MAT02-EH or MAT12 ?
Message-ID: <43501.1329510961@oricom.ca>


I have good and untested MAT02-EH (from China)  transistors
on hand and was wondering if there would be an easy to build
proto circuit to test them...

Any idea ?
Thanks

 


From patchell at cox.net  Fri Feb 17 21:57:36 2012
From: patchell at cox.net (James Patchell)
Date: Fri, 17 Feb 2012 12:57:36 -0800
Subject: [sdiy] Any simple circuit to test MAT02-EH or MAT12 ?
In-Reply-To: <43501.1329510961@oricom.ca>
References: <43501.1329510961@oricom.ca>
Message-ID: <4F3EBF40.4010304@cox.net>

Check out the circuit on Ian Fritz's web page.  I would have to say that 
it is probably the best one out there.

home.comcast.net/~ij*fritz*/projects/transmat001.pdf

-Jim

On 2/17/2012 12:36 PM, Jean-Pierre Desrochers wrote:
> I have good and untested MAT02-EH (from China)  transistors
> on hand and was wondering if there would be an easy to build
> proto circuit to test them...
>
> Any idea ?
> Thanks
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From subjectivity at hotmail.com  Fri Feb 17 21:59:14 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Fri, 17 Feb 2012 15:59:14 -0500
Subject: [sdiy] audio effects in C??
Message-ID: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>

Ok lets say I have a  program (on an Avr or pic) that has a few different variables.

maybe one of them is a triangle. one of them is a pot value. one of them is just a random number.


the normal thing to do would be to do something like:

analogWrite (3, outputValue)

or 

dacOutput(outputValue)


I am wondering what i can DO to the signal in C before it gets sent out.

I believe I can XOR it by doing this

XORvalue=outputValue^SineValue;
dacOutput(XORvalue);


I know I can also multiply 2 values together.


but there must be some more interesting "FX" based on algorithms or tricks.

anyone have any ideas? they dont't have to be pretty or entirely practical ;)



thanks so much









From patchell at cox.net  Fri Feb 17 22:04:42 2012
From: patchell at cox.net (James Patchell)
Date: Fri, 17 Feb 2012 13:04:42 -0800
Subject: [sdiy] Any simple circuit to test MAT02-EH or MAT12 ?
In-Reply-To: <4F3EBF40.4010304@cox.net>
References: <43501.1329510961@oricom.ca> <4F3EBF40.4010304@cox.net>
Message-ID: <4F3EC0EA.3050802@cox.net>

Lets try that link again....

http://home.comcast.net/~ijfritz/projects/transmat001.pdf

-Jim

On 2/17/2012 12:57 PM, James Patchell wrote:
> Check out the circuit on Ian Fritz's web page.  I would have to say 
> that it is probably the best one out there.
>
> home.comcast.net/~ij*fritz*/projects/transmat001.pdf
>
> -Jim
>
> On 2/17/2012 12:36 PM, Jean-Pierre Desrochers wrote:
>> I have good and untested MAT02-EH (from China)  transistors
>> on hand and was wondering if there would be an easy to build
>> proto circuit to test them...
>>
>> Any idea ?
>> 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 tom at electricdruid.net  Fri Feb 17 22:18:48 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 17 Feb 2012 21:18:48 +0000
Subject: [sdiy] Any simple circuit to test MAT02-EH or MAT12 ?
In-Reply-To: <4F3EC0EA.3050802@cox.net>
References: <43501.1329510961@oricom.ca> <4F3EBF40.4010304@cox.net>
	<4F3EC0EA.3050802@cox.net>
Message-ID: <024BEE96-08CF-4170-AB04-27BF041AD6FA@electricdruid.net>

Link on the fritz, Jim?

T.

On 17 Feb 2012, at 21:04, James Patchell wrote:

> Lets try that link again....
> 
> http://home.comcast.net/~ijfritz/projects/transmat001.pdf
> 
> -Jim
> 
> On 2/17/2012 12:57 PM, James Patchell wrote:
>> Check out the circuit on Ian Fritz's web page.  I would have to say that it is probably the best one out there.
>> 
>> home.comcast.net/~ij*fritz*/projects/transmat001.pdf
>> 
>> -Jim
>> 
>> On 2/17/2012 12:36 PM, Jean-Pierre Desrochers wrote:
>>> I have good and untested MAT02-EH (from China)  transistors
>>> on hand and was wondering if there would be an easy to build
>>> proto circuit to test them...
>>> 
>>> Any idea ?
>>> 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 nitro2k01 at gmail.com  Fri Feb 17 22:54:46 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Fri, 17 Feb 2012 22:54:46 +0100
Subject: [sdiy] audio effects in C??
In-Reply-To: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
Message-ID: <CABacs=AKCvmGboCS4S0YjK3W3kETi1GAMJxiepgrD4cJG0N6og@mail.gmail.com>

On 17 February 2012 21:59, dan snazelle <subjectivity at hotmail.com> wrote:
> but there must be some more interesting "FX" based on algorithms or tricks.
>
> anyone have any ideas? they dont't have to be pretty or entirely practical ;)

More than you asked for:

http://pouet.net/topic.php?which=8357
http://canonical.org/~kragen/bytebeat/

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From gordonjcp at gjcp.net  Fri Feb 17 23:31:08 2012
From: gordonjcp at gjcp.net (Gordon JC Pearc e)
Date: Fri, 17 Feb 2012 22:31:08 +0000
Subject: [sdiy] audio effects in C??
In-Reply-To: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
Message-ID: <4F3ED52C.7060709@gjcp.net>

On 17/02/12 20:59, dan snazelle wrote:
> Ok lets say I have a  program (on an Avr or pic) that has a few different variables.

<snip>

Dan, I hope you don't mind me answering your off-list questions on-list. 
  If you do, tough, it's a bit late now ;-)

The reason I want to tackle it on-list is because I want some 
constructive (hopefully) criticism of my project.

Firstly take a look at this article:

http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-generator/

This is what a lot of my AVR synthesis stuff is based on.  Where 
possible I tried to keep it in line with the Arduino environment but for 
the more outr? experiments I needed to go to bare metal because things 
had already hooked ISRs that I needed.

Okay, now you asked me about fmtoy.  Let's look at that:
https://github.com/gordonjcp/gyoza/blob/master/fmtoy/fmtoy.pde

The first few lines define various preprocessor things, and some lookup 
tables to go into flash including an 8-bit sine and floating point 
pitch-in-Hz table.

Next there's a struct that contains patch data, and an array of values 
that comprise the eight "stock" patches - note that N_PATCH is one less 
than the number of patches!

We can skip over lots of horrible global variables.

set_env() calculates the envelope parameters from the current patch
set_patch() copies a patch from flash to RAM

In setup() there is some cruft used when I was driving an analogue 
resonant filter from fmtoy - yes, it was pretty awesome.  No, it didn't 
work very well.

Okay, in the main loop there is a *horrible* buggy MIDI parser that 
accepts note on, note off, and some continuous controllers.  They are 
inadequately documented.

Line 366 to 385 calculate the oscillator pitch, envelope levels and 
phase and ultimately the timing word for the oscillators

Line 418 and down is the PWM ISR that actually does the sound 
generation.  Now from reading the sine DDS article you should know that 
Arduino pin 11 (PWM2A) is the PWM output and needs to be lowpass 
filtered and fed to an amp.

Every 32 times round the loop, we fire the update flag to tell it to 
update the voice every (roughly) 1ms

Each operator adds the timing word value to the phase accumulator, and 
takes the top bits as the pointer to the sine table.  So we calculate 
the offset into the table from the phase accumulator plus the feedback 
(or Op1) amount, and wrap by taking it modulo 256 (doing  & 0xff would 
maybe be faster, if the compiler doesn't optimise this).

Line 430 calculates the amount of feedback to apply, by multiplying the 
output, adding the feedback, and shifting right by 8 bits to scale it 
back down to an unsigned byte.

Line 441 does a trick to keep the DC offset steady even though we're 
using unsigned numbers because the AVR8 family only support unsigned int 
multiply

Lines 444-447 put it back into a sensible range and ensure that the 
output value is clipped rather than going off-scale which would cause it 
to "wrap around" with very objectionable noises.

Finally, the value is written to OCR2A where it sets the output PWM 
width, and hence the "DAC" voltage.

So you asked me:
1) Where the output is defined - it's defined in setup() and actually 
created in the ISR at the end.  For practical purposes, noises come out 
on pin 11.

2) It looks for MIDI on the serial port.  In this case, it actually 
receives at 57600bps so you will need something to take MIDI and connect 
to a serial port.
Grab this: http://www.gjcp.net/~gordonjcp/alsabridge.c and compile it 
with the instructions at the top of the file.  It's crap but it works.
You could also hook up an optoisolator and use it with MIDI directly if 
you set the baud rate.

3) You could convert it to look for CV and gate.  Use the analogue 
inputs for CV (I guess you need to clip to 5V, or scale by 2) and work 
out the relationship between the input voltage and pitch.  Probably 1024 
steps will give you accurate enough pitch tracking.  Use a GPIO pin for 
gate, and remove all the note queuing stuff from lines 211 to 260.  Then 
figure out where to handle your CV on in there somewhere.

Hope this helps.  I welcome any comments or suggestions, but not half as 
much as I welcome patches ;-)

-- 
Gordon JC Pearce MM0YEQ









From tom at electricdruid.net  Fri Feb 17 23:51:46 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 17 Feb 2012 22:51:46 +0000
Subject: [sdiy] audio effects in C??
In-Reply-To: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
Message-ID: <5FB1D438-AFF6-42C3-862D-9279C80BC86D@electricdruid.net>

Dan,

Let me check I understand what you're asking...you've got something like this:

inputValue = getInput();
outputValue = someFunction(inputValue);
dacOutput(outputValue);

And you're wondering what might be fun to put in someFunction(), right?

You could try experimenting with different waveshaping curves. Set up a table which gives you an arbitrary output value for each input value. Fill it with values. Off you go!
Try some distortion curves (tube-like soft distortion stuff like tanh, hard edged distortion, etc etc - and don't forget to add a DC offset to the curve!), try some quadratic/cube functions (ax^2+bx+c and such like), try some functions made of sums of sines or cosines (sin(ax)+0.5sin(bx)+0.5cos(cx) etc etc) and see what you get coming out. It won't be what you put in, that's for sure.

Alternatively, there's a whole host of standard effects algorithms based around delays (every type of chorus, flangers, echos, ping pong, vibratos) so maybe you could try implementing a short delay line and using that. Many effects vary the length of the delay by varying the point where the sample is read out (using an LFO, say). Feedback (either positive or negative) is great with delay lines too.

Hope these ideas help,
Tom




On 17 Feb 2012, at 20:59, dan snazelle wrote:

> Ok lets say I have a  program (on an Avr or pic) that has a few different variables.
> 
> maybe one of them is a triangle. one of them is a pot value. one of them is just a random number.
> 
> 
> the normal thing to do would be to do something like:
> 
> analogWrite (3, outputValue)
> 
> or 
> 
> dacOutput(outputValue)
> 
> 
> I am wondering what i can DO to the signal in C before it gets sent out.
> 
> I believe I can XOR it by doing this
> 
> XORvalue=outputValue^SineValue;
> dacOutput(XORvalue);
> 
> 
> I know I can also multiply 2 values together.
> 
> 
> but there must be some more interesting "FX" based on algorithms or tricks.
> 
> anyone have any ideas? they dont't have to be pretty or entirely practical ;)
> 
> 
> 
> thanks so much
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From tim.parkhurst at gmail.com  Sat Feb 18 00:10:01 2012
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Fri, 17 Feb 2012 15:10:01 -0800
Subject: [sdiy] Any simple circuit to test MAT02-EH or MAT12 ?
In-Reply-To: <024BEE96-08CF-4170-AB04-27BF041AD6FA@electricdruid.net>
References: <43501.1329510961@oricom.ca> <4F3EBF40.4010304@cox.net>
	<4F3EC0EA.3050802@cox.net>
	<024BEE96-08CF-4170-AB04-27BF041AD6FA@electricdruid.net>
Message-ID: <CACDGQT8zOyBCUFbSxGZVXPs802cte-Yx-5DcRPEJ5t-hnx4cbw@mail.gmail.com>

On Fri, Feb 17, 2012 at 1:18 PM, Tom Wiltshire <tom at electricdruid.net> wrote:
> Link on the fritz, Jim?
>
> T.
>
> On 17 Feb 2012, at 21:04, James Patchell wrote:
>
>> Lets try that link again....
>>
>> http://home.comcast.net/~ijfritz/projects/transmat001.pdf
>>

Looks like a Fritz link fritz.


Tim (is sausage.com a sausage link?) Servo
---
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From subjectivity at hotmail.com  Sat Feb 18 00:26:33 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Fri, 17 Feb 2012 18:26:33 -0500
Subject: [sdiy] audio effects in C??
In-Reply-To: <5FB1D438-AFF6-42C3-862D-9279C80BC86D@electricdruid.net>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
	<5FB1D438-AFF6-42C3-862D-9279C80BC86D@electricdruid.net>
Message-ID: <BLU0-SMTP479AD629365A630BA0FADE8C8630@phx.gbl>

These ideas all help!! Inspiring ideas on a friday night!!! Woo hoo


Dan

Sent from my iPhone

On Feb 17, 2012, at 5:51 PM, Tom Wiltshire <tom at electricdruid.net> wrote:

> Dan,
> 
> Let me check I understand what you're asking...you've got something like this:
> 
> inputValue = getInput();
> outputValue = someFunction(inputValue);
> dacOutput(outputValue);
> 
> And you're wondering what might be fun to put in someFunction(), right?
> 
> You could try experimenting with different waveshaping curves. Set up a table which gives you an arbitrary output value for each input value. Fill it with values. Off you go!
> Try some distortion curves (tube-like soft distortion stuff like tanh, hard edged distortion, etc etc - and don't forget to add a DC offset to the curve!), try some quadratic/cube functions (ax^2+bx+c and such like), try some functions made of sums of sines or cosines (sin(ax)+0.5sin(bx)+0.5cos(cx) etc etc) and see what you get coming out. It won't be what you put in, that's for sure.
> 
> Alternatively, there's a whole host of standard effects algorithms based around delays (every type of chorus, flangers, echos, ping pong, vibratos) so maybe you could try implementing a short delay line and using that. Many effects vary the length of the delay by varying the point where the sample is read out (using an LFO, say). Feedback (either positive or negative) is great with delay lines too.
> 
> Hope these ideas help,
> Tom
> 
> 
> 
> 
> On 17 Feb 2012, at 20:59, dan snazelle wrote:
> 
>> Ok lets say I have a  program (on an Avr or pic) that has a few different variables.
>> 
>> maybe one of them is a triangle. one of them is a pot value. one of them is just a random number.
>> 
>> 
>> the normal thing to do would be to do something like:
>> 
>> analogWrite (3, outputValue)
>> 
>> or 
>> 
>> dacOutput(outputValue)
>> 
>> 
>> I am wondering what i can DO to the signal in C before it gets sent out.
>> 
>> I believe I can XOR it by doing this
>> 
>> XORvalue=outputValue^SineValue;
>> dacOutput(XORvalue);
>> 
>> 
>> I know I can also multiply 2 values together.
>> 
>> 
>> but there must be some more interesting "FX" based on algorithms or tricks.
>> 
>> anyone have any ideas? they dont't have to be pretty or entirely practical ;)
>> 
>> 
>> 
>> thanks so much
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> 


From juzowen at gmail.com  Sat Feb 18 13:56:32 2012
From: juzowen at gmail.com (Justin Owen)
Date: Sat, 18 Feb 2012 12:56:32 +0000
Subject: [sdiy] Slightly OT: Workspace lighting
Message-ID: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>

Hello,

Hope nobody minds me asking about this... I want to replace the lighting in my workspace and I figured there'd be a few of you with some wisdom on it.

I have three cheap halogen lamps - one over each desk. Over the last year I've noticed how 'coloured' the light is - very yellow. I first noticed this while using the magnifying (fluorescent) lamp I bought for SMT work - which has a nice, clear white light and then recently while shooting some video using a proper photo lamp - which was much brighter and more importantly - much whiter.

So - what recommendations for bulb/light types/brands, etc. for a nice, bright, clean working environment.

Please keep in mind that it's mid February and I live in London - so please keep any comments about daylight and sunshine to yourself. :)

Thanks ya!


 




From colin at colinfraser.com  Sat Feb 18 14:05:28 2012
From: colin at colinfraser.com (Colin f)
Date: Sat, 18 Feb 2012 13:05:28 -0000
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
Message-ID: <91FF6BE5004941498474CA1853F2580D@zen>

 
 
> So - what recommendations for bulb/light types/brands, etc. 
> for a nice, bright, clean working environment.

Sounds like your magnifier may already have a 'daylight' tube.
Get a couple of full size strip lights and more of the same:
http://tinyurl.com/6wnb3xh

Cheers,
Colin f




From altitude at optrand.com  Sat Feb 18 14:09:19 2012
From: altitude at optrand.com (Altitude)
Date: Sat, 18 Feb 2012 08:09:19 -0500
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
Message-ID: <000001ccee3e$86edb490$94c91db0$@com>

I use 3 of the "daylight" CFL blub ones, they stay cool for hours on end and
give me nice, bright, "white" light.

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Justin Owen
Sent: Saturday, February 18, 2012 7:57 AM
To: SDIY List
Subject: [sdiy] Slightly OT: Workspace lighting

Hello,

Hope nobody minds me asking about this... I want to replace the lighting in
my workspace and I figured there'd be a few of you with some wisdom on it.

I have three cheap halogen lamps - one over each desk. Over the last year
I've noticed how 'coloured' the light is - very yellow. I first noticed this
while using the magnifying (fluorescent) lamp I bought for SMT work - which
has a nice, clear white light and then recently while shooting some video
using a proper photo lamp - which was much brighter and more importantly -
much whiter.

So - what recommendations for bulb/light types/brands, etc. for a nice,
bright, clean working environment.

Please keep in mind that it's mid February and I live in London - so please
keep any comments about daylight and sunshine to yourself. :)

Thanks ya!


 


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



From Stromeko at nexgo.de  Sat Feb 18 15:09:02 2012
From: Stromeko at nexgo.de (ASSI)
Date: Sat, 18 Feb 2012 15:09:02 +0100
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
Message-ID: <1794909.GNQGlUDu3E@rainer>

On Saturday 18 February 2012, 12:56:32, Justin Owen wrote:
> So - what recommendations for bulb/light types/brands, etc. for a nice,
> bright, clean working environment.

I've installed a specular luminaire with a single T8/58W fluorescent tube 
with an electronic ballast directly over the work desk.  It took a bit of 
searching catalogs and finding a source, but it was well worth the effort 
and not much pricier than a "normal" light fixture would have been.

Daylight (or "bright white") might be a better choice for the for the work 
area, but warm-white mixes better with the other lights in my room.  A tri-
phosphor tube would give even better color rendering, but I guess by the 
time the tube needs to be replaced I should be able to drop in an LED strip.  
Depending on where the light fixture gets installed and how much area needs 
to be lit, you might need a different configuration.  They are usually 
optimized for specific ceiling heights or distance from the desk surface, so 
you need to check the datasheets (yes, they should have one).

These are all 2x58W for whatever reason I can't find any single tube 
fixtures on UK sites... :-)

http://www.wirefield.co.uk/product.asp?catId=8&ranId=104

http://www.tlc-
direct.co.uk/Main_Index/Lighting_Menu_Index/Lighting_Fluorescent_Index/Modular_Fittings/index.html


Regards,
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 gkisslak at gmail.com  Sat Feb 18 15:23:45 2012
From: gkisslak at gmail.com (George Kisslak)
Date: Sat, 18 Feb 2012 09:23:45 -0500
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
Message-ID: <CB01788A-8A01-4A21-BCFD-DB7646683C9B@gmail.com>

I have two Waldmann units.  One is a task light (SNE-136), the other is a magnifier (Omnivue).  The perfect light temp of 5400K, no problems reading resistor color codes.  The downside?  They're bloody expensive!  But they come up on ebay sometimes which is how I afforded mine.

George

On Feb 18, 2012, at 7:56 AM, Justin Owen wrote:

> Hello,
> 
> Hope nobody minds me asking about this... I want to replace the lighting in my workspace and I figured there'd be a few of you with some wisdom on it.
> 
> I have three cheap halogen lamps - one over each desk. Over the last year I've noticed how 'coloured' the light is - very yellow. I first noticed this while using the magnifying (fluorescent) lamp I bought for SMT work - which has a nice, clear white light and then recently while shooting some video using a proper photo lamp - which was much brighter and more importantly - much whiter.
> 
> So - what recommendations for bulb/light types/brands, etc. for a nice, bright, clean working environment.
> 
> Please keep in mind that it's mid February and I live in London - so please keep any comments about daylight and sunshine to yourself. :)
> 
> Thanks ya!
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From jluciani at gmail.com  Sat Feb 18 17:39:42 2012
From: jluciani at gmail.com (John Luciani)
Date: Sat, 18 Feb 2012 11:39:42 -0500
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <CB01788A-8A01-4A21-BCFD-DB7646683C9B@gmail.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
	<CB01788A-8A01-4A21-BCFD-DB7646683C9B@gmail.com>
Message-ID: <CA+qhd=9b5mYskZT3tpfkRDQToQt7mxtK5sPxQOgXtDRoUM2bRQ@mail.gmail.com>

As my bulbs die I have been switching to LED lighting.
I found that higher CCT's help me see detail with less magnification.
My preference is 5000K - 8000K. However even the 3000 - 4000K looks
better (to me) than an incandescent light.

(* jcl *)


-- 
http://www.wiblocks.com


From ka4hjh at gmail.com  Sat Feb 18 20:04:30 2012
From: ka4hjh at gmail.com (KA4HJH)
Date: Sat, 18 Feb 2012 14:04:30 -0500
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
References: <4f3fa002.e807b40a.2c47.7a02@mx.google.com>
Message-ID: <p06240802cb65a5bae2ea@[192.168.1.66]>

>So - what recommendations for bulb/light types/brands, etc. for a nice,
>bright, clean working environment.

One other point is that you don't want to have too much light. I used to
repair cable TV amplifiers and at some point a consultant told them they
needed more light in the shop so they put 4 x 48" florescent tubes over
every workstation. It was way too bright and everyone hated it.

I think they were told that all this extra light would improve
productivity. It didn't. Of course, if you have a circadian rhythm problem
this might fix it...

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"


From subjectivity at hotmail.com  Sun Feb 19 04:41:50 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Sat, 18 Feb 2012 22:41:50 -0500
Subject: [sdiy] audio effects in C??
In-Reply-To: <4F3ED52C.7060709@gjcp.net>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
	<4F3ED52C.7060709@gjcp.net>
Message-ID: <BLU0-SMTP14284D75F4725BE10AF0E9DC8610@phx.gbl>

thanks a lot for the help

you know, one of the big problems for me is that you mention this as your starting point:

> http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-generator/


that code has a lot of stuff in it that makes very little sense to me


anyone care to help me through it?


it is very dense...many variables have non descriptive names, the comments are pretty sparse, etc.

I would love to get to grips with it though.


here is the code:


-------------

/*
 *
 * DDS Sine Generator mit ATMEGS 168
 * Timer2 generates the  31250 KHz Clock Interrupt
 *
 * KHM 2009 /  Martin Nawrath
 * Kunsthochschule fuer Medien Koeln
 * Academy of Media Arts Cologne

 */

#include "avr/pgmspace.h"

// table of 256 sine values / one sine period / stored in flash memory
PROGMEM  prog_uchar sine256[]  = {
  127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,184,187,190,192,195,198,200,203,205,208,210,212,215,217,219,221,223,225,227,229,231,233,234,236,238,239,240,
  242,243,244,245,247,248,249,249,250,251,252,252,253,253,253,254,254,254,254,254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,239,238,236,234,233,231,229,227,225,223,
  221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,173,170,167,164,161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,115,111,108,105,102,99,96,93,90,87,84,81,78,
  76,73,70,67,64,62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,18,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0,0,0,0,0,1,1,1,2,2,3,4,5,5,6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,
  33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,90,93,96,99,102,105,108,111,115,118,121,124

};
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

int ledPin = 13;                 // LED pin 7
int testPin = 7;
int t2Pin = 6;
byte bb;




double dfreq;
// const double refclk=31372.549;  // =16MHz / 510
const double refclk=31376.6;      // measured

// variables used inside interrupt service declared as voilatile
volatile byte icnt;              // var inside interrupt
volatile byte icnt1;             // var inside interrupt
volatile byte c4ms;              // counter incremented all 4ms
volatile unsigned long phaccu;   // pahse accumulator
volatile unsigned long tword_m;  // dds tuning word m

void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output
  Serial.begin(115200);        // connect to the serial port
  Serial.println("DDS Test");

  pinMode(6, OUTPUT);      // sets the digital pin as output
  pinMode(7, OUTPUT);      // sets the digital pin as output
  pinMode(11, OUTPUT);     // pin11= PWM  output / frequency output

  Setup_timer2();

  // disable interrupts to avoid timing distortion
  cbi (TIMSK0,TOIE0);              // disable Timer0 !!! delay() is now not available
  sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt

  dfreq=1000.0;                    // initial output frequency = 1000.o Hz


*****What is happening here??*****


  tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word 

}
void loop()
{
  while(1) {
     if (c4ms > 250) {                 // timer / wait fou a full second
      c4ms=0;
      dfreq=analogRead(0);             // read Poti on analog pin 0 to adjust output frequency from 0..1023 Hz

      cbi (TIMSK2,TOIE2);              // disble Timer2 Interrupt
      tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word
      sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt 

      Serial.print(dfreq);
      Serial.print("  ");
      Serial.println(tword_m);
    }

   sbi(PORTD,6); // Test / set PORTD,7 high to observe timing with a scope
   cbi(PORTD,6); // Test /reset PORTD,7 high to observe timing with a scope
  }
 }
//******************************************************************
// timer2 setup
// set prscaler to 1, PWM mode to phase correct PWM,  16000000/510 = 31372.55 Hz clock
void Setup_timer2() {

// Timer2 Clock Prescaler to : 1
  sbi (TCCR2B, CS20);
  cbi (TCCR2B, CS21);
  cbi (TCCR2B, CS22);

  // Timer2 PWM Mode set to Phase Correct PWM
  cbi (TCCR2A, COM2A0);  // clear Compare Match
  sbi (TCCR2A, COM2A1);

  sbi (TCCR2A, WGM20);  // Mode 1  / Phase Correct PWM
  cbi (TCCR2A, WGM21);
  cbi (TCCR2B, WGM22);
}

//******************************************************************
// Timer2 Interrupt Service at 31372,550 KHz = 32uSec
// this is the timebase REFCLOCK for the DDS generator
// FOUT = (M (REFCLK)) / (2 exp 32)
// runtime : 8 microseconds ( inclusive push and pop)
ISR(TIMER2_OVF_vect) {

  sbi(PORTD,7);          // Test / set PORTD,7 high to observe timing with a oscope

  phaccu=phaccu+tword_m; // soft DDS, phase accu with 32 bits
  icnt=phaccu >> 24;     // use upper 8 bits for phase accu as frequency information
                         // read value fron ROM sine table and send to PWM DAC
  OCR2A=pgm_read_byte_near(sine256 + icnt);    

  if(icnt1++ == 125) {  // increment variable c4ms all 4 milliseconds
    c4ms++;
    icnt1=0;
   }   

 cbi(PORTD,7);            // reset PORTD,7
}



On Feb 17, 2012, at 5:31 PM, Gordon JC Pearc e wrote:

> On 17/02/12 20:59, dan snazelle wrote:
>> Ok lets say I have a  program (on an Avr or pic) that has a few different variables.
> 
> <snip>
> 
> Dan, I hope you don't mind me answering your off-list questions on-list.  If you do, tough, it's a bit late now ;-)
> 
> The reason I want to tackle it on-list is because I want some constructive (hopefully) criticism of my project.
> 
> Firstly take a look at this article:
> 
> http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-generator/
> 
> This is what a lot of my AVR synthesis stuff is based on.  Where possible I tried to keep it in line with the Arduino environment but for the more outr? experiments I needed to go to bare metal because things had already hooked ISRs that I needed.
> 
> Okay, now you asked me about fmtoy.  Let's look at that:
> https://github.com/gordonjcp/gyoza/blob/master/fmtoy/fmtoy.pde
> 
> The first few lines define various preprocessor things, and some lookup tables to go into flash including an 8-bit sine and floating point pitch-in-Hz table.
> 
> Next there's a struct that contains patch data, and an array of values that comprise the eight "stock" patches - note that N_PATCH is one less than the number of patches!
> 
> We can skip over lots of horrible global variables.
> 
> set_env() calculates the envelope parameters from the current patch
> set_patch() copies a patch from flash to RAM
> 
> In setup() there is some cruft used when I was driving an analogue resonant filter from fmtoy - yes, it was pretty awesome.  No, it didn't work very well.
> 
> Okay, in the main loop there is a *horrible* buggy MIDI parser that accepts note on, note off, and some continuous controllers.  They are inadequately documented.
> 
> Line 366 to 385 calculate the oscillator pitch, envelope levels and phase and ultimately the timing word for the oscillators
> 
> Line 418 and down is the PWM ISR that actually does the sound generation.  Now from reading the sine DDS article you should know that Arduino pin 11 (PWM2A) is the PWM output and needs to be lowpass filtered and fed to an amp.
> 
> Every 32 times round the loop, we fire the update flag to tell it to update the voice every (roughly) 1ms
> 
> Each operator adds the timing word value to the phase accumulator, and takes the top bits as the pointer to the sine table.  So we calculate the offset into the table from the phase accumulator plus the feedback (or Op1) amount, and wrap by taking it modulo 256 (doing  & 0xff would maybe be faster, if the compiler doesn't optimise this).
> 
> Line 430 calculates the amount of feedback to apply, by multiplying the output, adding the feedback, and shifting right by 8 bits to scale it back down to an unsigned byte.
> 
> Line 441 does a trick to keep the DC offset steady even though we're using unsigned numbers because the AVR8 family only support unsigned int multiply
> 
> Lines 444-447 put it back into a sensible range and ensure that the output value is clipped rather than going off-scale which would cause it to "wrap around" with very objectionable noises.
> 
> Finally, the value is written to OCR2A where it sets the output PWM width, and hence the "DAC" voltage.
> 
> So you asked me:
> 1) Where the output is defined - it's defined in setup() and actually created in the ISR at the end.  For practical purposes, noises come out on pin 11.
> 
> 2) It looks for MIDI on the serial port.  In this case, it actually receives at 57600bps so you will need something to take MIDI and connect to a serial port.
> Grab this: http://www.gjcp.net/~gordonjcp/alsabridge.c and compile it with the instructions at the top of the file.  It's crap but it works.
> You could also hook up an optoisolator and use it with MIDI directly if you set the baud rate.
> 
> 3) You could convert it to look for CV and gate.  Use the analogue inputs for CV (I guess you need to clip to 5V, or scale by 2) and work out the relationship between the input voltage and pitch.  Probably 1024 steps will give you accurate enough pitch tracking.  Use a GPIO pin for gate, and remove all the note queuing stuff from lines 211 to 260.  Then figure out where to handle your CV on in there somewhere.
> 
> Hope this helps.  I welcome any comments or suggestions, but not half as much as I welcome patches ;-)
> 
> -- 
> Gordon JC Pearce MM0YEQ
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From music.maker at gte.net  Sun Feb 19 16:27:08 2012
From: music.maker at gte.net (Scott Gravenhorst)
Date: Sun, 19 Feb 2012 08:27:08 -0700
Subject: [sdiy] Filter frequency cutoff with linear response?
Message-ID: <201202191627.q1JGR8Hd009742@linux7.lan>


Justin Owen <juzowen at gmail.com> wrote:
>Is there a 'musically useful' reason (in the widest possible 
>definition...) to have a filter frequency cutoff control with a 
>linear response? 
>
>No? Why not?
>

For what it might be worth, the PAiA Fatman uses linear control for
both the filter and the VCOs.  Seems to work musically for me.

-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
-- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
-- Some Random Electronics Bits:
jovianpyx.dyndns.org:8080/public/electronics/
-- When the going gets tough, the tough use the command line.



From juzowen at gmail.com  Sun Feb 19 17:00:56 2012
From: juzowen at gmail.com (Justin Owen)
Date: Sun, 19 Feb 2012 16:00:56 +0000
Subject: [sdiy] Filter frequency cutoff with linear response?
Message-ID: <4f411cba.4651b40a.7b5c.731c@mx.google.com>

Is there a 'musically useful' reason (in the widest possible definition...) to have a filter frequency cutoff control with a linear response?

No? Why not?

Thanks. 



From ol.gillet at gmail.com  Sun Feb 19 17:14:56 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Sun, 19 Feb 2012 17:14:56 +0100
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
References: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
Message-ID: <CAJoLJ5WAS1+TO2AvpRDEUXCnU++wTvBaepa115t7PvzmQ5k+5w@mail.gmail.com>

> Is there a 'musically useful' reason (in the widest possible definition...) to have a filter frequency cutoff control with a linear response?

I see one, albeit a very convoluted one:

Let's say you use are using a filter at self-oscillation like a sine
oscillator. You want to do FM with this oscillator, so you need to
apply a linear modulation on pitch (the oscillator frequency must go
between f_0 - f_fm and f_0 + f_fm, and you won't get that symmetry if
the modulation signal gets into the expo converter!).

That's why VCOs have both linear and exponential pitch control -
exponential for "musical" control, and linear for true FM effects. If
you consider a filter as a sine VCO, it might be useful to do it too.


From Stromeko at nexgo.de  Sun Feb 19 18:20:28 2012
From: Stromeko at nexgo.de (ASSI)
Date: Sun, 19 Feb 2012 18:20:28 +0100
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
References: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
Message-ID: <17731997.pBcEJ1PDdK@rainer>

On Sunday 19 February 2012, 16:00:56, Justin Owen wrote:
> Is there a 'musically useful' reason (in the widest possible
> definition...) to have a filter frequency cutoff control with a linear
> response?

Just as with VCO, when you want to do FM or detune with constant beat 
frequency instead of constant interval, then you need a linear control.  Of 
course if you can't afford an extra control the exponential is likely more 
useful.


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

SD adaptations for Waldorf Q V3.00R3 and Q+ V3.54R2:
http://Synth.Stromeko.net/Downloads.html#WaldorfSDada



From jays at aracnet.com  Sun Feb 19 19:33:06 2012
From: jays at aracnet.com (Jay Schwichtenberg)
Date: Sun, 19 Feb 2012 10:33:06 -0800
Subject: [sdiy] audio effects in C??
In-Reply-To: <BLU0-SMTP14284D75F4725BE10AF0E9DC8610@phx.gbl>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>	<4F3ED52C.7060709@gjcp.net>
	<BLU0-SMTP14284D75F4725BE10AF0E9DC8610@phx.gbl>
Message-ID: <000d01ccef34$ec07e520$c417af60$@com>

There are a couple of books that you may find interesting if you can find
them. Both unfortunately are out of print.

A Digit Signal processing Primer by Steiglitz, Addison-Wesley
Interfacing with C by Howard Hutchings, Butterworth Heinemann

While both get into some of the theory and math they aren't as complexe as
most DSP books.

Jay S.

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
Sent: Saturday, February 18, 2012 7:42 PM
To: Gordon JC Pearc e
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] audio effects in C??

thanks a lot for the help

you know, one of the big problems for me is that you mention this as your
starting point:

>
http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-gener
ator/


that code has a lot of stuff in it that makes very little sense to me


anyone care to help me through it?


it is very dense...many variables have non descriptive names, the comments
are pretty sparse, etc.

I would love to get to grips with it though.


here is the code:


-------------

/*
 *
 * DDS Sine Generator mit ATMEGS 168
 * Timer2 generates the  31250 KHz Clock Interrupt
 *
 * KHM 2009 /  Martin Nawrath
 * Kunsthochschule fuer Medien Koeln
 * Academy of Media Arts Cologne

 */

#include "avr/pgmspace.h"

// table of 256 sine values / one sine period / stored in flash memory
PROGMEM  prog_uchar sine256[]  = {
 
127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,
184,187,190,192,195,198,200,203,205,208,210,212,215,217,219,221,223,225,227,
229,231,233,234,236,238,239,240,
 
242,243,244,245,247,248,249,249,250,251,252,252,253,253,253,254,254,254,254,
254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,
239,238,236,234,233,231,229,227,225,223,
 
221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,
173,170,167,164,161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,
115,111,108,105,102,99,96,93,90,87,84,81,78,
 
76,73,70,67,64,62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,1
8,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0,0,0,0,0,1,1,1,2,2,3,4,5,5,
6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,
 
33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,90,93,96,9
9,102,105,108,111,115,118,121,124

};
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))

int ledPin = 13;                 // LED pin 7
int testPin = 7;
int t2Pin = 6;
byte bb;




double dfreq;
// const double refclk=31372.549;  // =16MHz / 510
const double refclk=31376.6;      // measured

// variables used inside interrupt service declared as voilatile
volatile byte icnt;              // var inside interrupt
volatile byte icnt1;             // var inside interrupt
volatile byte c4ms;              // counter incremented all 4ms
volatile unsigned long phaccu;   // pahse accumulator
volatile unsigned long tword_m;  // dds tuning word m

void setup()
{
  pinMode(ledPin, OUTPUT);      // sets the digital pin as output
  Serial.begin(115200);        // connect to the serial port
  Serial.println("DDS Test");

  pinMode(6, OUTPUT);      // sets the digital pin as output
  pinMode(7, OUTPUT);      // sets the digital pin as output
  pinMode(11, OUTPUT);     // pin11= PWM  output / frequency output

  Setup_timer2();

  // disable interrupts to avoid timing distortion
  cbi (TIMSK0,TOIE0);              // disable Timer0 !!! delay() is now not
available
  sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt

  dfreq=1000.0;                    // initial output frequency = 1000.o Hz


*****What is happening here??*****


  tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word 

}
void loop()
{
  while(1) {
     if (c4ms > 250) {                 // timer / wait fou a full second
      c4ms=0;
      dfreq=analogRead(0);             // read Poti on analog pin 0 to
adjust output frequency from 0..1023 Hz

      cbi (TIMSK2,TOIE2);              // disble Timer2 Interrupt
      tword_m=pow(2,32)*dfreq/refclk;  // calulate DDS new tuning word
      sbi (TIMSK2,TOIE2);              // enable Timer2 Interrupt 

      Serial.print(dfreq);
      Serial.print("  ");
      Serial.println(tword_m);
    }

   sbi(PORTD,6); // Test / set PORTD,7 high to observe timing with a scope
   cbi(PORTD,6); // Test /reset PORTD,7 high to observe timing with a scope
  }
 }
//******************************************************************
// timer2 setup
// set prscaler to 1, PWM mode to phase correct PWM,  16000000/510 =
31372.55 Hz clock
void Setup_timer2() {

// Timer2 Clock Prescaler to : 1
  sbi (TCCR2B, CS20);
  cbi (TCCR2B, CS21);
  cbi (TCCR2B, CS22);

  // Timer2 PWM Mode set to Phase Correct PWM
  cbi (TCCR2A, COM2A0);  // clear Compare Match
  sbi (TCCR2A, COM2A1);

  sbi (TCCR2A, WGM20);  // Mode 1  / Phase Correct PWM
  cbi (TCCR2A, WGM21);
  cbi (TCCR2B, WGM22);
}

//******************************************************************
// Timer2 Interrupt Service at 31372,550 KHz = 32uSec
// this is the timebase REFCLOCK for the DDS generator
// FOUT = (M (REFCLK)) / (2 exp 32)
// runtime : 8 microseconds ( inclusive push and pop)
ISR(TIMER2_OVF_vect) {

  sbi(PORTD,7);          // Test / set PORTD,7 high to observe timing with a
oscope

  phaccu=phaccu+tword_m; // soft DDS, phase accu with 32 bits
  icnt=phaccu >> 24;     // use upper 8 bits for phase accu as frequency
information
                         // read value fron ROM sine table and send to PWM
DAC
  OCR2A=pgm_read_byte_near(sine256 + icnt);    

  if(icnt1++ == 125) {  // increment variable c4ms all 4 milliseconds
    c4ms++;
    icnt1=0;
   }   

 cbi(PORTD,7);            // reset PORTD,7
}



On Feb 17, 2012, at 5:31 PM, Gordon JC Pearc e wrote:

> On 17/02/12 20:59, dan snazelle wrote:
>> Ok lets say I have a  program (on an Avr or pic) that has a few different
variables.
> 
> <snip>
> 
> Dan, I hope you don't mind me answering your off-list questions on-list.
If you do, tough, it's a bit late now ;-)
> 
> The reason I want to tackle it on-list is because I want some constructive
(hopefully) criticism of my project.
> 
> Firstly take a look at this article:
> 
>
http://interface.khm.de/index.php/lab/experiments/arduino-dds-sinewave-gener
ator/
> 
> This is what a lot of my AVR synthesis stuff is based on.  Where possible
I tried to keep it in line with the Arduino environment but for the more
outr? experiments I needed to go to bare metal because things had already
hooked ISRs that I needed.
> 
> Okay, now you asked me about fmtoy.  Let's look at that:
> https://github.com/gordonjcp/gyoza/blob/master/fmtoy/fmtoy.pde
> 
> The first few lines define various preprocessor things, and some lookup
tables to go into flash including an 8-bit sine and floating point
pitch-in-Hz table.
> 
> Next there's a struct that contains patch data, and an array of values
that comprise the eight "stock" patches - note that N_PATCH is one less than
the number of patches!
> 
> We can skip over lots of horrible global variables.
> 
> set_env() calculates the envelope parameters from the current patch
> set_patch() copies a patch from flash to RAM
> 
> In setup() there is some cruft used when I was driving an analogue
resonant filter from fmtoy - yes, it was pretty awesome.  No, it didn't work
very well.
> 
> Okay, in the main loop there is a *horrible* buggy MIDI parser that
accepts note on, note off, and some continuous controllers.  They are
inadequately documented.
> 
> Line 366 to 385 calculate the oscillator pitch, envelope levels and phase
and ultimately the timing word for the oscillators
> 
> Line 418 and down is the PWM ISR that actually does the sound generation.
Now from reading the sine DDS article you should know that Arduino pin 11
(PWM2A) is the PWM output and needs to be lowpass filtered and fed to an
amp.
> 
> Every 32 times round the loop, we fire the update flag to tell it to
update the voice every (roughly) 1ms
> 
> Each operator adds the timing word value to the phase accumulator, and
takes the top bits as the pointer to the sine table.  So we calculate the
offset into the table from the phase accumulator plus the feedback (or Op1)
amount, and wrap by taking it modulo 256 (doing  & 0xff would maybe be
faster, if the compiler doesn't optimise this).
> 
> Line 430 calculates the amount of feedback to apply, by multiplying the
output, adding the feedback, and shifting right by 8 bits to scale it back
down to an unsigned byte.
> 
> Line 441 does a trick to keep the DC offset steady even though we're using
unsigned numbers because the AVR8 family only support unsigned int multiply
> 
> Lines 444-447 put it back into a sensible range and ensure that the output
value is clipped rather than going off-scale which would cause it to "wrap
around" with very objectionable noises.
> 
> Finally, the value is written to OCR2A where it sets the output PWM width,
and hence the "DAC" voltage.
> 
> So you asked me:
> 1) Where the output is defined - it's defined in setup() and actually
created in the ISR at the end.  For practical purposes, noises come out on
pin 11.
> 
> 2) It looks for MIDI on the serial port.  In this case, it actually
receives at 57600bps so you will need something to take MIDI and connect to
a serial port.
> Grab this: http://www.gjcp.net/~gordonjcp/alsabridge.c and compile it with
the instructions at the top of the file.  It's crap but it works.
> You could also hook up an optoisolator and use it with MIDI directly if
you set the baud rate.
> 
> 3) You could convert it to look for CV and gate.  Use the analogue inputs
for CV (I guess you need to clip to 5V, or scale by 2) and work out the
relationship between the input voltage and pitch.  Probably 1024 steps will
give you accurate enough pitch tracking.  Use a GPIO pin for gate, and
remove all the note queuing stuff from lines 211 to 260.  Then figure out
where to handle your CV on in there somewhere.
> 
> Hope this helps.  I welcome any comments or suggestions, but not half as
much as I welcome patches ;-)
> 
> -- 
> Gordon JC Pearce MM0YEQ
> 
> 
> 
> 
> 
> 
> 
> _______________________________________________
> 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 mail.ubc.ca  Sun Feb 19 19:38:57 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Sun, 19 Feb 2012 10:38:57 -0800
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
References: <4f411cba.4651b40a.7b5c.731c@mx.google.com>
Message-ID: <1E363C2C3F4248F387B41ED2B06F8661@galvanox01>

> Is there a 'musically useful' reason (in the widest possible 
> definition...) to have a filter frequency cutoff control with 
> a linear response?

I know that there are linear (Hz/V) VCOs, but I've not heard of a linear
VCF.  However, it would give a more limited and useful range of cutoff
control than most VCFs, and could still be controlled exponentially with an
exponential envelope.

Verdict: Why not?  Try it and see if you like it.



From mr at analogue.org  Sun Feb 19 21:20:12 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Sun, 19 Feb 2012 21:20:12 +0100
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <201202191627.q1JGR8Hd009742@linux7.lan>
References: <201202191627.q1JGR8Hd009742@linux7.lan>
Message-ID: <CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>

On 19 February 2012 16:27, Scott Gravenhorst <music.maker at gte.net> wrote:
> For what it might be worth, the PAiA Fatman uses linear control for
> both the filter and the VCOs. ?Seems to work musically for me.

Smooth and even sweeps with exponentially falling envelopes. ("musical")
Uneven sweeps with saw/triangle LFOs. ("unmusical?") :-)

The (linear) filter FM discussion is interesting though. A few
hardwired synths have the possibility to modulate the VCF in the audio
range with VCOs (Prophet poly-mod style). This is an important way of
expanding the VCO-VCF-VCA architecture possibilities. But is there any
of these synths that does this VCF modulation linearly?

/mr


From matt at smiffytech.com  Sun Feb 19 21:27:44 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Mon, 20 Feb 2012 06:57:44 +1030
Subject: [sdiy] audio effects in C??
In-Reply-To: <000d01ccef34$ec07e520$c417af60$@com>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>	<4F3ED52C.7060709@gjcp.net>	<BLU0-SMTP14284D75F4725BE10AF0E9DC8610@phx.gbl>
	<000d01ccef34$ec07e520$c417af60$@com>
Message-ID: <4F415B40.9070001@smiffytech.com>

Quoth Jay Schwichtenberg at 20/02/12 05:03...
> There are a couple of books that you may find interesting if you can find
> them. Both unfortunately are out of print.
>
> A Digit Signal processing Primer by Steiglitz, Addison-Wesley
> Interfacing with C by Howard Hutchings, Butterworth Heinemann

Both have multiple copies available through www.abebooks.com (I just 
grabbed myself one of each for just over $20 the pair, including 
shipping to Australia.)

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From ol.gillet at gmail.com  Sun Feb 19 21:32:25 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Sun, 19 Feb 2012 21:32:25 +0100
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>
References: <201202191627.q1JGR8Hd009742@linux7.lan>
	<CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>
Message-ID: <CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>

> The (linear) filter FM discussion is interesting though. A few
> hardwired synths have the possibility to modulate the VCF in the audio
> range with VCOs (Prophet poly-mod style). This is an important way of
> expanding the VCO-VCF-VCA architecture possibilities. But is there any
> of these synths that does this VCF modulation linearly?

The Doepfer Dark Energy does it.

Olivier


From subjectivity at hotmail.com  Sun Feb 19 21:32:56 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Sun, 19 Feb 2012 15:32:56 -0500
Subject: [sdiy] audio effects in C??
In-Reply-To: <4F415B40.9070001@smiffytech.com>
References: <BLU0-SMTP89B7334B567BAEE3228911C8630@phx.gbl>
	<4F3ED52C.7060709@gjcp.net>
	<BLU0-SMTP14284D75F4725BE10AF0E9DC8610@phx.gbl>
	<000d01ccef34$ec07e520$c417af60$@com>
	<4F415B40.9070001@smiffytech.com>
Message-ID: <BLU0-SMTP447B2E1AF2E99F639149B75C8610@phx.gbl>

I just bought both as well!!


Thnx

Sent from my iPhone 

On Feb 19, 2012, at 3:27 PM, Matthew Smith <matt at smiffytech.com> wrote:

> Quoth Jay Schwichtenberg at 20/02/12 05:03...
>> There are a couple of books that you may find interesting if you can find
>> them. Both unfortunately are out of print.
>> 
>> A Digit Signal processing Primer by Steiglitz, Addison-Wesley
>> Interfacing with C by Howard Hutchings, Butterworth Heinemann
> 
> Both have multiple copies available through www.abebooks.com (I just grabbed myself one of each for just over $20 the pair, including shipping to Australia.)
> 
> -- 
> Matthew Smith
> 
> Business: http://www.smiffytech.com
> Blog:     http://www.smiffysplace.com
> Linkedin: http://www.linkedin.com/in/smiffy
> Flickr:   http://www.flickr.com/photos/msmiffy
> Twitter:  http://twitter.com/smiffy
> 
> ABN 16 391 203 815
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From subjectivity at hotmail.com  Sun Feb 19 22:14:11 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Sun, 19 Feb 2012 16:14:11 -0500
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>
References: <201202191627.q1JGR8Hd009742@linux7.lan>
	<CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>
	<CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>
Message-ID: <BLU0-SMTP48A7ACAA409653C733C45BC8610@phx.gbl>



On Feb 19, 2012, at 3:32 PM, Olivier Gillet wrote:

>> The (linear) filter FM discussion is interesting though. A few
>> hardwired synths have the possibility to modulate the VCF in the audio
>> range with VCOs (Prophet poly-mod style). This is an important way of
>> expanding the VCO-VCF-VCA architecture possibilities. But is there any
>> of these synths that does this VCF modulation linearly?
> 
> The Doepfer Dark Energy does it.
> 
> Olivier
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


I might as well plug my own product ;)

The Snazzy FX "Tracer City" filter box has the option to route CV or audio signals to the filter cutoff (there is an onboard oscillator which can go LFO or Osc range...as well as an envelope
follower and psuedo random modulator and Two 1/4 jacks in the back for inputting audio or CV)


ALLl such modulators/jacks can be switched to provide Linear or Expo modulation of the filter

 (there are a bunch of toggles labelled A/B to serve this purpose)

this is the one feature of the box that few people seem to understand and or use!

http://snazzyfx.com/tracercity.html



From fanwander at mnet-online.de  Mon Feb 20 14:19:37 2012
From: fanwander at mnet-online.de (Florian Anwander)
Date: Mon, 20 Feb 2012 14:19:37 +0100
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>
References: <201202191627.q1JGR8Hd009742@linux7.lan>	<CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>
	<CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>
Message-ID: <4F424869.6080303@mnet-online.de>

Am 19.02.2012 21:32, schrieb Olivier Gillet:
>> But is there any
>> of these synths that does this VCF modulation linearly?
>
> The Doepfer Dark Energy does it.
???
The DE is based on a CEM 3394, so most of the 3394 based synths should 
do that: AX60, SixTrak, MAX, M1000...


From pic24hj at gmail.com  Mon Feb 20 15:05:05 2012
From: pic24hj at gmail.com (KD KD)
Date: Mon, 20 Feb 2012 15:05:05 +0100
Subject: [sdiy] Bob Moog and Don Buchla both get a mention
In-Reply-To: <7781A3C5-B8CD-4EAB-888E-5386ADE9B190@ece.gatech.edu>
References: <7781A3C5-B8CD-4EAB-888E-5386ADE9B190@ece.gatech.edu>
Message-ID: <CADYQ7+iEQyAiedBXTY8-pkvkt+yQLYMQAn5Z9OvV6p-cUt_0Hg@mail.gmail.com>

Its a hard cold truth new designs don't pay off unless it has USB, Midi,
or keys in terms of time and investment. Thanks for the article link!

Adolpho Sax had some serious hard life as it seams..it's like painters
who become recognized after they are dead....

2012/2/13, Lanterman, Aaron <lanterma at ece.gatech.edu>:
> Cool article:
>
> http://www.theatlantic.com/entertainment/archive/2012/02/why-is-it-so-hard-for-new-musical-instruments-to-catch-on/252668/
>
> I confess I didn't know anything about the fascinating history of the
> saxophone...
>
> - Aaron
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


From harrybissell at wowway.com  Mon Feb 20 16:15:47 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 20 Feb 2012 10:15:47 -0500 (EST)
Subject: [sdiy] Slightly OT: Workspace lighting
In-Reply-To: <1794909.GNQGlUDu3E@rainer>
Message-ID: <505021164.455826.1329750947760.JavaMail.root@md01.wow.synacor.com>

I use two 40W cool white fluorescents and one 100W incandescent bulb in an aluminum reflector
about 4' above the (rather small) work surface. The indandescent and fluorescent mix gives good color rendering.

A swing-arm magnifying lamp (circular fluorescent) is available at need... more need these days than previously :^(

I just got my stereo microscope set up... I neede an illuminator. A USB ring-light from Deal Extreme and a tiny 120 USB
adapter plug filled the bill for under $10

H^) harry


----- Original Message -----
From: ASSI <Stromeko at nexgo.de>
To: synth-diy at dropmix.xs4all.nl
Sent: Sat, 18 Feb 2012 09:09:02 -0500 (EST)
Subject: Re: [sdiy] Slightly OT: Workspace lighting

On Saturday 18 February 2012, 12:56:32, Justin Owen wrote:
> So - what recommendations for bulb/light types/brands, etc. for a nice,
> bright, clean working environment.

I've installed a specular luminaire with a single T8/58W fluorescent tube 
with an electronic ballast directly over the work desk.  It took a bit of 
searching catalogs and finding a source, but it was well worth the effort 
and not much pricier than a "normal" light fixture would have been.

Daylight (or "bright white") might be a better choice for the for the work 
area, but warm-white mixes better with the other lights in my room.  A tri-
phosphor tube would give even better color rendering, but I guess by the 
time the tube needs to be replaced I should be able to drop in an LED strip.  
Depending on where the light fixture gets installed and how much area needs 
to be lit, you might need a different configuration.  They are usually 
optimized for specific ceiling heights or distance from the desk surface, so 
you need to check the datasheets (yes, they should have one).

These are all 2x58W for whatever reason I can't find any single tube 
fixtures on UK sites... :-)

http://www.wirefield.co.uk/product.asp?catId=8&ranId=104

http://www.tlc-
direct.co.uk/Main_Index/Lighting_Menu_Index/Lighting_Fluorescent_Index/Modular_Fittings/index.html


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

Waldorf MIDI Implementation & additional documentation:
http://Synth.Stromeko.net/Downloads.html#WaldorfDocs

_______________________________________________
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 Feb 20 17:53:49 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 20 Feb 2012 16:53:49 +0000
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <4F424869.6080303@mnet-online.de>
References: <201202191627.q1JGR8Hd009742@linux7.lan>	<CAP92RBVh4gr+_uj=Mb3+TWywtkNFtvk7Ap=yy9ZagbXhNPOt+A@mail.gmail.com>
	<CAJoLJ5Wxw_z0ej80HgpDy3rwrpZSZj81BfE=CX37Av5iTgPU=w@mail.gmail.com>
	<4F424869.6080303@mnet-online.de>
Message-ID: <113B9E95-32E5-4C00-8195-A7BD4AD745BB@electricdruid.net>


On 20 Feb 2012, at 13:19, Florian Anwander wrote:

> Am 19.02.2012 21:32, schrieb Olivier Gillet:
>>> But is there any
>>> of these synths that does this VCF modulation linearly?
>> 
>> The Doepfer Dark Energy does it.
> ???
> The DE is based on a CEM 3394, so most of the 3394 based synths should do that: AX60, SixTrak, MAX, M1000...

I was just having a look at the CEM3394 datasheet, and they did it that way for exactly the reason predicted - linear FM of the filter. The cutoff CV is exponential (3/8V per octave) but the chip also includes a filter modulation VCA from the VCO triangle output, and that input is linear.
Presumably Florian is right; since this is a feature of the chip, you'd expect the other synths based on it to have the same characteristic.
Interestingly, none of the CEM3396, CEM3378, CEM3379, or the CEM3372 include this feature - the only filter cutoff CV input is fed through an exponential convertor block in all cases.

T.





From juzowen at gmail.com  Mon Feb 20 18:29:17 2012
From: juzowen at gmail.com (Justin Owen)
Date: Mon, 20 Feb 2012 17:29:17 +0000
Subject: [sdiy] Filter frequency cutoff with linear response?
Message-ID: <4f4282ef.214eb40a.2c0d.ffffdddc@mx.google.com>

On 20 Feb 2012, at 13:19, Florian Anwander wrote:

> Am 19.02.2012 21:32, schrieb Olivier Gillet:
>>> But is there any
>>> of these synths that does this VCF modulation linearly?

>> The Doepfer Dark Energy does it.
>> ???
>> The DE is based on a CEM 3394, so most of the 3394 based synths should do that: AX60, SixTrak, MAX, M1000...

> I was just having a look at the CEM3394 datasheet, and they did it that way for exactly the reason predicted - linear FM of the filter. The cutoff CV is exponential (3/8V per octave) but the chip also includes a filter modulation VCA from the VCO triangle output, and that input is linear.

So assuming that CV control of Frequency Cutoff on the 3394 (I haven't looked at the data sheet) is handled via a VCA - it appears they've made a decision to use a Linear response for the other cutoff modulation source...

...is that a correct assumption? 

Curiouser and curiouser.



From juzowen at gmail.com  Mon Feb 20 18:39:45 2012
From: juzowen at gmail.com (Justin Owen)
Date: Mon, 20 Feb 2012 17:39:45 +0000
Subject: [sdiy] Simple fix or filthy kludge?
Message-ID: <4f428562.6560b40a.24b9.ffffe0d0@mx.google.com>

I'm trying to diagnose/troubleshoot a problem I'm having with one bit of a circuit that has become very susceptible to external loads (at least I think that's what it is...).

Plugging stuff into inputs, attaching test probes - it's not very happy and it's causing one particular integrator to swing down to the negative rail. Odd - not seen behaviour like this before.

I noticed this seems to solve it completely: http://www.sdiy.org/juz/input_ground_01.pdf

All I've done is add a 1K resistor between the Ground input of my input jacks and Ground. Never had to do this before because I've never had a problem like this before.

Elegant (temporary?) solution or dirty kludge that'll potentially cause more problems? 

Thanks.



From juzowen at gmail.com  Mon Feb 20 18:49:28 2012
From: juzowen at gmail.com (Justin Owen)
Date: Mon, 20 Feb 2012 17:49:28 +0000
Subject: [sdiy] A (slightly) better VRef?
Message-ID: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>

Sorry to be flooding the list like this...

Hoping for some VRef advice: http://www.sdiy.org/juz/voltage_reference_01.pdf
 
For VRefs I've always used the 2xR voltage divider into an op-amp buffer shown in Ex. 1. It's simple, it works but I've been wondering if there might be a small step up?

Would there be any advantage in using Ex. 2 over Ex. 1?

Is there something else you'd suggest that was better than 1 but not necessarily up to LM317 level?

Thanks again.  





From Stromeko at nexgo.de  Mon Feb 20 19:13:11 2012
From: Stromeko at nexgo.de (ASSI)
Date: Mon, 20 Feb 2012 19:13:11 +0100
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>
References: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>
Message-ID: <1599373.gMDOZWQ2Ag@rainer>

On Monday 20 February 2012, 17:49:28, Justin Owen wrote:
> For VRefs I've always used the 2xR voltage divider into an op-amp buffer
> shown in Ex. 1. It's simple, it works but I've been wondering if there
> might be a small step up?
> 
> Would there be any advantage in using Ex. 2 over Ex. 1?

It all depends on what you define a "reference".  If the rails are regulated 
and your reference is supposed to track them, then Ex.1 is fine.  You might 
want to filter both input and output and tack R1||R2 into the feedback loop 
to minimize offset drift, but the trait of that reference is that whatever 
the supply does, the reference will follow.  You should also keep an eye on 
where those voltages come from you feed the divider with, they should go 
back directly to the rail regulators.

If on the other hand you want an absolute reference voltage, then this is 
not the circuit to use.  In fact you shouldn't be using Ex.2, either.  These 
days there is little to no reason to employ something like this, a proper 
fixed reference IC (or adjustable is you prefer) will give you a much more 
stable reference.


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

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



From tom at electricdruid.net  Mon Feb 20 19:18:34 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Mon, 20 Feb 2012 18:18:34 +0000
Subject: [sdiy] Filter frequency cutoff with linear response?
In-Reply-To: <4f4282ef.214eb40a.2c0d.ffffdddc@mx.google.com>
References: <4f4282ef.214eb40a.2c0d.ffffdddc@mx.google.com>
Message-ID: <5B296378-A809-40AF-904B-4019E470F62C@electricdruid.net>


On 20 Feb 2012, at 17:29, Justin Owen wrote:

> On 20 Feb 2012, at 13:19, Florian Anwander wrote:
> 
>> Am 19.02.2012 21:32, schrieb Olivier Gillet:
>>>> But is there any
>>>> of these synths that does this VCF modulation linearly?
> 
>>> The Doepfer Dark Energy does it.
>>> ???
>>> The DE is based on a CEM 3394, so most of the 3394 based synths should do that: AX60, SixTrak, MAX, M1000...
> 
>> I was just having a look at the CEM3394 datasheet, and they did it that way for exactly the reason predicted - linear FM of the filter. The cutoff CV is exponential (3/8V per octave) but the chip also includes a filter modulation VCA from the VCO triangle output, and that input is linear.
> 
> So assuming that CV control of Frequency Cutoff on the 3394 (I haven't looked at the data sheet) is handled via a VCA - it appears they've made a decision to use a Linear response for the other cutoff modulation source...
> 
> ...is that a correct assumption?
> 
> Curiouser and curiouser.

Filter Freq CV is done the usual way with an exponential convertor. The VCF modulation is taken from the VCO triangle output, via a Modulation Amount VCA, to the exponential convertor's "Iref" - current reference, presumably. At least, that's how it's shown on the datasheet diagram.

It's definitely a choice to use linear FM for the VCO-to-VCF modulation path rather than just doing things the simple way. On this chip the VCO outputs aren't available directly, but they could have provided a triangle output (at no cost bar one pin) and left you you to add a mixer to feed it into the Filter Freq CV input if you wanted that feature. But instead they went to the trouble of adding both a VCA and a linear FM input. They must have thought it was worth it.

Part of the reason for that is that the voice is based on a single VCO, so doing this allows you to get both filter FM and two "oscillator" FM (one is really the filter making a sine wave). Hence it adds a fair bit of versatility to an otherwise simple synth architecture. And since it was intended to be controlled by a uP, they didn't have to worry about filter tracking so much - it'll be compensated in software tuning tables - making decent-sounding filter FM a realistic possibility.

T.
 

From dixon at mail.ubc.ca  Mon Feb 20 21:06:50 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 20 Feb 2012 12:06:50 -0800
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <1599373.gMDOZWQ2Ag@rainer>
References: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>
	<1599373.gMDOZWQ2Ag@rainer>
Message-ID: <74C283B3681D4FFD8CF72DB5938F081A@galvanox01>

> If on the other hand you want an absolute reference voltage, 
> then this is not the circuit to use.  In fact you shouldn't 
> be using Ex.2, either.  These days there is little to no 
> reason to employ something like this, a proper fixed 
> reference IC (or adjustable is you prefer) will give you a 
> much more stable reference.

I concur.  Use a REF02 or one of it's siblings for this application.



From davekendall at ntlworld.com  Mon Feb 20 21:21:54 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Mon, 20 Feb 2012 20:21:54 +0000
Subject: [sdiy] Using D-Sub connectors as patching elements
Message-ID: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>

Hi all.

How robust are, for example 9-pin D-Sub connectors for repeated 
connections, compared to say a 3.5mm mini-jack, or a 1/4" jack in a 
patching environment?
I've used 9-pin D-sub patchfields back in the day, for RS232 control of 
VTRs and other similar usage, but the typical amount of re-patching in 
that application is probably very minimal compared to modular synth 
usage, where connections are made and re-made an order of magnitude 
more times.

Does anyone have any experience of heavy D-sub patching use to share, 
or alternatively any suggestions for a practical 8-way connector system 
for patchbay-style free patching?

cheers,
Dave




From harrybissell at wowway.com  Mon Feb 20 21:54:24 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Mon, 20 Feb 2012 15:54:24 -0500 (EST)
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
Message-ID: <1978690046.463584.1329771264001.JavaMail.root@md01.wow.synacor.com>

everything old is new again...   :^)

there are very good D-subs with machined pins etc, and cheap ones with stamped contacts.

If you were at system design level right now, I'd consider making some internal bus to handle
the polyphonic interconnects (analog switches and something like the ARP2500 matirx switches ?)
and make the external connection with a banana jack or something like that.

This ~has~ been discussed on-list but i can't think of a key word to search on...

You might consider RJ-45 style connectors, the jacks are fairly robust, and the plugs (cables)
easily replaced...

H^) harry


----- Original Message -----
From: Dave Kendall <davekendall at ntlworld.com>
To: synthdiy diy <synth-diy at dropmix.xs4all.nl>
Sent: Mon, 20 Feb 2012 15:21:54 -0500 (EST)
Subject: [sdiy] Using D-Sub connectors as patching elements

Hi all.

How robust are, for example 9-pin D-Sub connectors for repeated 
connections, compared to say a 3.5mm mini-jack, or a 1/4" jack in a 
patching environment?
I've used 9-pin D-sub patchfields back in the day, for RS232 control of 
VTRs and other similar usage, but the typical amount of re-patching in 
that application is probably very minimal compared to modular synth 
usage, where connections are made and re-made an order of magnitude 
more times.

Does anyone have any experience of heavy D-sub patching use to share, 
or alternatively any suggestions for a practical 8-way connector system 
for patchbay-style free patching?

cheers,
Dave


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

-- 
Harry Bissell & Nora Abdullah 4eva


From mr at analogue.org  Mon Feb 20 22:12:12 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Mon, 20 Feb 2012 22:12:12 +0100
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <74C283B3681D4FFD8CF72DB5938F081A@galvanox01>
References: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>
	<1599373.gMDOZWQ2Ag@rainer>
	<74C283B3681D4FFD8CF72DB5938F081A@galvanox01>
Message-ID: <CAP92RBWSq=_YatSfCigbaMMicOyqY8KuY4RErnMSSP2DpVh94Q@mail.gmail.com>

On 20 February 2012 21:06, David G Dixon <dixon at mail.ubc.ca> wrote:
>> a proper fixed reference IC (or adjustable is you prefer) will give
>> you a much more stable reference.
>
> I concur. ?Use a REF02 or one of it's siblings for this application.

Or something like a TL431 for a fraction of the price.

/mr


From dingebre at 3dphysics.net  Mon Feb 20 22:22:27 2012
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Mon, 20 Feb 2012 14:22:27 -0700
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
References: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
Message-ID: <004201ccf015$bf3c47c0$3db4d740$@3dphysics.net>

The Tinysizer by Audio Tommy at http://www.anyware-instruments.de/ uses 3M
8500 series board mount sockets for patching. I've got a Tinysizer and using
breadboard wires like these
http://www.seeedstudio.com/depot/breadboard-jumper-wire-70pcs-pack-p-234.htm
l?cPath=175_187 or the ones that ship with it work great and the connectors
seem to be very robust and reliable.

David


>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
>> bounces at dropmix.xs4all.nl] On Behalf Of Dave Kendall
>> Sent: Monday, February 20, 2012 1:22 PM
>> To: synthdiy diy
>> Subject: [sdiy] Using D-Sub connectors as patching elements
>> 
>> Hi all.
>> 
>> How robust are, for example 9-pin D-Sub connectors for repeated
>> connections, compared to say a 3.5mm mini-jack, or a 1/4" jack in a
>> patching environment?
>> I've used 9-pin D-sub patchfields back in the day, for RS232 control of
VTRs
>> and other similar usage, but the typical amount of re-patching in that
>> application is probably very minimal compared to modular synth usage,
>> where connections are made and re-made an order of magnitude more
>> times.
>> 
>> Does anyone have any experience of heavy D-sub patching use to share, or
>> alternatively any suggestions for a practical 8-way connector system for
>> patchbay-style free patching?
>> 
>> 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  Mon Feb 20 23:09:04 2012
From: dingebre at 3dphysics.net (David Ingebretsen)
Date: Mon, 20 Feb 2012 15:09:04 -0700
Subject: [sdiy] corrected link RE: Using D-Sub connectors as patching
	elements
Message-ID: <005701ccf01c$425578b0$c7006a10$@3dphysics.net>

Sorry, here is the correct SeeedStudio link:

http://www.seeedstudio.com/depot/breadboard-jumper-wire-70pcs-pack-p-234.htm
l?cPath=175_187

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: Monday, February 20, 2012 2:22 PM
>> To: 'Dave Kendall'; 'synthdiy diy'
>> Subject: Re: [sdiy] Using D-Sub connectors as patching elements
>> 
>> The Tinysizer by Audio Tommy at http://www.anyware-instruments.de/
>> uses 3M
>> 8500 series board mount sockets for patching. I've got a Tinysizer and
using
>> breadboard wires like these
>> http://www.seeedstudio.com/depot/breadboard-jumper-wire-70pcs-pack-
>> p-234.htm
>> l?cPath=175_187 or the ones that ship with it work great and the
>> connectors seem to be very robust and reliable.
>> 
>> David
>> 
>> 
>> >> -----Original Message-----
>> >> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
>> >> bounces at dropmix.xs4all.nl] On Behalf Of Dave Kendall
>> >> Sent: Monday, February 20, 2012 1:22 PM
>> >> To: synthdiy diy
>> >> Subject: [sdiy] Using D-Sub connectors as patching elements
>> >>
>> >> Hi all.
>> >>
>> >> How robust are, for example 9-pin D-Sub connectors for repeated
>> >> connections, compared to say a 3.5mm mini-jack, or a 1/4" jack in a
>> >> patching environment?
>> >> I've used 9-pin D-sub patchfields back in the day, for RS232 control
>> >> of
>> VTRs
>> >> and other similar usage, but the typical amount of re-patching in
>> >> that application is probably very minimal compared to modular synth
>> >> usage, where connections are made and re-made an order of magnitude
>> >> more times.
>> >>
>> >> Does anyone have any experience of heavy D-sub patching use to share,
>> >> or alternatively any suggestions for a practical 8-way connector
>> >> system for patchbay-style free patching?
>> >>
>> >> 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 dixon at mail.ubc.ca  Tue Feb 21 01:01:28 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 20 Feb 2012 16:01:28 -0800
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
References: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
Message-ID: <7DF400856EC54CB8A7A31B80095F0B67@galvanox01>

> How robust are, for example 9-pin D-Sub connectors for 
> repeated connections, compared to say a 3.5mm mini-jack, or a 
> 1/4" jack in a patching environment?
> I've used 9-pin D-sub patchfields back in the day, for RS232 
> control of VTRs and other similar usage, but the typical 
> amount of re-patching in that application is probably very 
> minimal compared to modular synth usage, where connections 
> are made and re-made an order of magnitude more times.
> 
> Does anyone have any experience of heavy D-sub patching use 
> to share, or alternatively any suggestions for a practical 
> 8-way connector system for patchbay-style free patching?

I don't know about that, but have you looked at the Anyware Tinysizer synth?
It basically uses solderless breadboard-type patchbays.  I think it works
pretty well.



From dixon at mail.ubc.ca  Tue Feb 21 01:06:56 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Mon, 20 Feb 2012 16:06:56 -0800
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <CAP92RBWSq=_YatSfCigbaMMicOyqY8KuY4RErnMSSP2DpVh94Q@mail.gmail.com>
References: <4f4287a9.e54cb40a.0e5e.ffffe309@mx.google.com>
	<1599373.gMDOZWQ2Ag@rainer>
	<74C283B3681D4FFD8CF72DB5938F081A@galvanox01>
	<CAP92RBWSq=_YatSfCigbaMMicOyqY8KuY4RErnMSSP2DpVh94Q@mail.gmail.com>
Message-ID: <4025D92EBE1148169F9B2B1EE4CDBE39@galvanox01>

> > I concur. ?Use a REF02 or one of it's siblings for this application.
> 
> Or something like a TL431 for a fraction of the price.

Absolutely.  Heck, even 78L0X is better than using the rails.



From aym-htnys at teaser.fr  Tue Feb 21 08:13:56 2012
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Tue, 21 Feb 2012 08:13:56 +0100
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
References: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
Message-ID: <20120221071356.GA16049@aym.net2.nerim.net>

On 2012-02-20 20:21 +0000, Dave Kendall wrote:

> How robust are, for example 9-pin D-Sub connectors for repeated
> connections, compared to say a 3.5mm mini-jack, or a 1/4" jack in a
> patching environment?

No actual experience but I've looked at them with a polyphonic
modular in mind. Even the expensive Cannon ones are rated for
very few cycles, something like 250.

Modular jacks (RJ45) are even worse.

Round DIN connnectors are not even spec'd. Always a good sign.
;-)

> Does anyone have any experience of heavy D-sub patching use to
> share, or alternatively any suggestions for a practical 8-way
> connector system for patchbay-style free patching?

I think I would give 8-way DINs a try, expecting to have to
replace broken female contacts from time to time. At least
they're round so the panel cut-out is easy to make.

A simple test jig :

  1 kHz --o J1.1     J2.1 o-+
                            |
        +-o J1.2     J2.2 o-+
        |
        +-o J1.3     J2.3 o-+
                            |
        +-o J1.4     J2.4 o-+
        |
        +-o J1.5     J2.5 o-+
                            |
        +-o J1.6     J2.6 o-+
        |
        +-o J1.7     J2.7 o-+
                            |
Speaker --o J1.8     J2.8 o-+

Repeatedly plug and unplug a patch cord between J1 and J2 until
signal stops passing and you'll get an idea of the failure rate.

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


From paul at fitvideo.co.uk  Tue Feb 21 08:16:55 2012
From: paul at fitvideo.co.uk (=?utf-8?b?UGF1bCBCdXJucw==?=)
Date: Tue, 21 Feb 2012 02:16:55 -0500
Subject: [sdiy] Using D-Sub connectors as patching elements
Message-ID: <20120221021655.5xodvnopsks4scws@webmail.talktalkbusiness.co.uk>

morning,
I realise this is an aside, however re the Anyware Tinysizer synth, 
they look suspiciously like floppy drive headers to me, hence a 
conversation between myself and Howard Scarr who owns a Tinysizer to 
use M/F floppy drive stand offs to increase the longevity of the 
connections built in to the synth. I would rather plug a stand off in 
one of the headers, use and abuse it, and when the connectivity failed 
, just replace it with a new one every so often. I also discussed 
building some kind of break out box for a proper patchbay , which was 
not to his taste but would be to mine. 

regards

paul burns


Quoting David G Dixon <dixon at mail.ubc.ca>:
> > How robust are, for example 9-pin D-Sub connectors for
> > repeated connections, compared to say a 3.5mm mini-jack, or a
> > 1/4" jack in a patching environment?
> > I've used 9-pin D-sub patchfields back in the day, for RS232
> > control of VTRs and other similar usage, but the typical
> > amount of re-patching in that application is probably very
> > minimal compared to modular synth usage, where connections
> > are made and re-made an order of magnitude more times. 
> >
> > Does anyone have any experience of heavy D-sub patching use
> > to share, or alternatively any suggestions for a practical
> > 8-way connector system for patchbay-style free patching?
>
> I don't know about that, but have you looked at the Anyware Tinysizer synth?
> It basically uses solderless breadboard-type patchbays.  I think it works
> pretty well. 
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>


regards

Paul Burns



From davekendall at ntlworld.com  Tue Feb 21 11:25:28 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Tue, 21 Feb 2012 10:25:28 +0000
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <20120221021655.5xodvnopsks4scws@webmail.talktalkbusiness.co.uk>
References: <20120221021655.5xodvnopsks4scws@webmail.talktalkbusiness.co.uk>
Message-ID: <60361BEB-5C76-11E1-A93D-000393A85F9E@ntlworld.com>

Hi All.

Many thanks for the advice from everyone. I *was* thinking of a 
polyphonic modular, so 8 simultaneous connections in the one 
plug/socket would be optimum. As Harry said, nothing new under the sun 
I guess...... was it really that obvious?  ;-)
Andre - will try the test rig for 8-way DINs. As I'm toying with the 
idea of memories, going down the logic switching route would make sense 
in the long run, but the idea of an old-style open-architecture modular 
is certainly appealing, and possibly much simpler to implement -  more 
wiring, but less electronics.

cheers and thanks all,
Dave



From davekendall at ntlworld.com  Tue Feb 21 11:45:01 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Tue, 21 Feb 2012 10:45:01 +0000
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <20120221071356.GA16049@aym.net2.nerim.net>
References: <87B717EA-5C00-11E1-A2EA-000393A85F9E@ntlworld.com>
	<20120221071356.GA16049@aym.net2.nerim.net>
Message-ID: <1B687F3D-5C79-11E1-9F8A-000393A85F9E@ntlworld.com>


On Feb 21, 2012, at 07:13, Andre Majorel wrote:
> I think I would give 8-way DINs a try

Just looked at the datasheet for an 8-pin DIN free plug that digikey 
stock, and it's rated at 5000 cycles!
A dollar a pop in quantity too.... looks very encouraging!

cheers,
Dave



From chris at chrismusic.de  Tue Feb 21 12:05:21 2012
From: chris at chrismusic.de (ChristianH)
Date: Tue, 21 Feb 2012 12:05:21 +0100
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <1B687F3D-5C79-11E1-9F8A-000393A85F9E@ntlworld.com>
References: <20120221071356.GA16049@aym.net2.nerim.net>
	<1B687F3D-5C79-11E1-9F8A-000393A85F9E@ntlworld.com>
Message-ID: <20120221115346.9827.CHRIS@chrismusic.de>

On Tue, 21 Feb 2012 10:45:01 +0000 Dave Kendall <davekendall at ntlworld.com> wrote:

> 
> On Feb 21, 2012, at 07:13, Andre Majorel wrote:
> > I think I would give 8-way DINs a try
> 
> Just looked at the datasheet for an 8-pin DIN free plug that digikey 
> stock, and it's rated at 5000 cycles!

And you think that is much?

Ok, this may be an academic calculation - but assume a dozen patch
changes a day, so after a year it's starting to have problems.
I wouldn't consider that good enough, not even for diy. Unless I know
it's going to be used significantly less - as they say, YMMV.

Christian



From harrybissell at wowway.com  Tue Feb 21 15:31:32 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 21 Feb 2012 09:31:32 -0500 (EST)
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <7DF400856EC54CB8A7A31B80095F0B67@galvanox01>
Message-ID: <1343598858.477421.1329834692038.JavaMail.root@md01.wow.synacor.com>

LOL (in a really really large font !!!)

and how reliable are the solderless breadboards ?   :^)

H^) harry


----- Original Message -----
From: David G Dixon <dixon at mail.ubc.ca>
To: 'Dave Kendall' <davekendall at ntlworld.com>, 'synthdiy diy' <synth-diy at dropmix.xs4all.nl>
Sent: Mon, 20 Feb 2012 19:01:28 -0500 (EST)
Subject: Re: [sdiy] Using D-Sub connectors as patching elements

> How robust are, for example 9-pin D-Sub connectors for 
> repeated connections, compared to say a 3.5mm mini-jack, or a 
> 1/4" jack in a patching environment?
> I've used 9-pin D-sub patchfields back in the day, for RS232 
> control of VTRs and other similar usage, but the typical 
> amount of re-patching in that application is probably very 
> minimal compared to modular synth usage, where connections 
> are made and re-made an order of magnitude more times.
> 
> Does anyone have any experience of heavy D-sub patching use 
> to share, or alternatively any suggestions for a practical 
> 8-way connector system for patchbay-style free patching?

I don't know about that, but have you looked at the Anyware Tinysizer synth?
It basically uses solderless breadboard-type patchbays.  I think it works
pretty well.

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

-- 
Harry Bissell & Nora Abdullah 4eva


From aym-htnys at teaser.fr  Tue Feb 21 16:21:09 2012
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Tue, 21 Feb 2012 16:21:09 +0100
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <20120221115346.9827.CHRIS@chrismusic.de>
References: <20120221071356.GA16049@aym.net2.nerim.net>
	<1B687F3D-5C79-11E1-9F8A-000393A85F9E@ntlworld.com>
	<20120221115346.9827.CHRIS@chrismusic.de>
Message-ID: <20120221152109.GB16049@aym.net2.nerim.net>

On 2012-02-21 12:05 +0100, ChristianH wrote:
> On Tue, 21 Feb 2012 10:45:01 +0000 Dave Kendall <davekendall at ntlworld.com> wrote:
> > On Feb 21, 2012, at 07:13, Andre Majorel wrote:
> > > I think I would give 8-way DINs a try
> > 
> > Just looked at the datasheet for an 8-pin DIN free plug that digikey 
> > stock, and it's rated at 5000 cycles!

What's the rating on the socket ? For DINs, the female part of
the contact is the one whose mechanical properties (clearance
and elasticity) are the most critical and simultaneously the one
that is worked the hardest (flexion).

> And you think that is much?
> 
> Ok, this may be an academic calculation - but assume a dozen patch
> changes a day, so after a year it's starting to have problems.
> I wouldn't consider that good enough, not even for diy. Unless I know
> it's going to be used significantly less - as they say, YMMV.

It's a difficult problem. Round industrial connectors are
prohibitively expensive and some patch points won't be used 5000
times in your life time.

Tiptop Audio use 8-way mini-DINs in their polyphonic modules. I
expect they're even less reliable than regular DINs. It will be
interesting to see how well they hold.

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


From harrybissell at wowway.com  Tue Feb 21 16:43:56 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Tue, 21 Feb 2012 10:43:56 -0500 (EST)
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <20120221152109.GB16049@aym.net2.nerim.net>
Message-ID: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>

How about D-SUB 9 pin Males on the modules, and female to female cables, THIS way you throw out
a worn cable. If you use screw-machined male plugs, the pins should be good for many many cycles...

Unfortunately the D-sub cables are not so common anymore...

H^) harry

----- Original Message -----
From: Andre Majorel <aym-htnys at teaser.fr>
To: synth-diy at dropmix.xs4all.nl
Sent: Tue, 21 Feb 2012 10:21:09 -0500 (EST)
Subject: Re: [sdiy] Using D-Sub connectors as patching elements

On 2012-02-21 12:05 +0100, ChristianH wrote:
> On Tue, 21 Feb 2012 10:45:01 +0000 Dave Kendall <davekendall at ntlworld.com> wrote:
> > On Feb 21, 2012, at 07:13, Andre Majorel wrote:
> > > I think I would give 8-way DINs a try
> > 
> > Just looked at the datasheet for an 8-pin DIN free plug that digikey 
> > stock, and it's rated at 5000 cycles!

What's the rating on the socket ? For DINs, the female part of
the contact is the one whose mechanical properties (clearance
and elasticity) are the most critical and simultaneously the one
that is worked the hardest (flexion).

> And you think that is much?
> 
> Ok, this may be an academic calculation - but assume a dozen patch
> changes a day, so after a year it's starting to have problems.
> I wouldn't consider that good enough, not even for diy. Unless I know
> it's going to be used significantly less - as they say, YMMV.

It's a difficult problem. Round industrial connectors are
prohibitively expensive and some patch points won't be used 5000
times in your life time.

Tiptop Audio use 8-way mini-DINs in their polyphonic modules. I
expect they're even less reliable than regular DINs. It will be
interesting to see how well they hold.

-- 
Andr? Majorel http://www.teaser.fr/~amajorel/
_______________________________________________
Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
http://dropmix.xs4all.nl/mailman/listinfo/synth-diy

-- 
Harry Bissell & Nora Abdullah 4eva


From pfperry at melbpc.org.au  Wed Feb 22 01:15:58 2012
From: pfperry at melbpc.org.au (Paul Perry)
Date: Wed, 22 Feb 2012 11:15:58 +1100
Subject: [sdiy] Using D-Sub connectors as patching elements
References: <1343598858.477421.1329834692038.JavaMail.root@md01.wow.synacor.com>
Message-ID: <9432623D4DCF43278D0D1B3DA96A6AEA@ownerf0d9273f5>

+1 on that 72 point LOL, Harry!
I don't even use solderless breadboards for breadboarding.

paul perry Melbourne Australia

----- Original Message ----- 
From: "Harry Bissell" <
> LOL (in a really really large font !!!)
> 
> and how reliable are the solderless breadboards ?   :^)
> H^) harry
> 



From eric.wood74 at gmail.com  Wed Feb 22 07:56:11 2012
From: eric.wood74 at gmail.com (Eric Wood)
Date: Wed, 22 Feb 2012 00:56:11 -0600
Subject: [sdiy] Wizard Wogglebug
Message-ID: <65F40718-EEB1-4960-8040-2083713EE974@gmail.com>

Hey all,
I purchased a Wiard Wogglebug PCB several years ago and it has no markings on it other than the component silkscreen markings. I know there are several versions of this PCB out there; how do I determine which version I have so I can put this thing together?
Thanks,
Eric

Sent from my iPhone

From don at till.com  Wed Feb 22 08:39:27 2012
From: don at till.com (Donald Tillman)
Date: Tue, 21 Feb 2012 23:39:27 -0800
Subject: [sdiy] Today's Google Doodle...
Message-ID: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>

... honors Heinrich Hertz.

  -- Don

--
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com






From juzowen at gmail.com  Wed Feb 22 11:03:54 2012
From: juzowen at gmail.com (Justin Owen)
Date: Wed, 22 Feb 2012 10:03:54 +0000
Subject: [sdiy] A (slightly) better VRef?
Message-ID: <4f44bd8e.8a0eb40a.2914.fffff846@mx.google.com>

-----Original Message-----
From: David G Dixon [dixon at mail.ubc.ca]
Received: 21.02.2012 00:09:25
To: 'Mattias Rickardsson'
Cc: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] A (slightly) better VRef?

>>> I concur. ?Use a REF02 or one of it's siblings for this application.
 
>> Or something like a TL431 for a fraction of the price.

> Absolutely.  Heck, even 78L0X is better than using the rails.

OK, consider me warned :)

So, for something like the REF02 are you using that as your central, stable VRef and runnning your other VRefs of of that? e.g. if you need a stable +3.5V and +1.25V and -1.25V - you'd create them from the stable +5V of the REF02?

What then are you using to create those 'sub' VRefs?

Thanks.



From obl64 at ix.netcom.com  Wed Feb 22 11:16:48 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Wed, 22 Feb 2012 04:16:48 -0600
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <4f44bd8e.8a0eb40a.2914.fffff846@mx.google.com>
References: <4f44bd8e.8a0eb40a.2914.fffff846@mx.google.com>
Message-ID: <4F44C090.4020402@ix.netcom.com>



On 2/22/2012 4:03 AM, Justin Owen wrote:
> -----Original Message-----
> From: David G Dixon [dixon at mail.ubc.ca]
> Received: 21.02.2012 00:09:25
> To: 'Mattias Rickardsson'
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] A (slightly) better VRef?
>
>>>> I concur.  Use a REF02 or one of it's siblings for this application.
>
>>> Or something like a TL431 for a fraction of the price.
>
>> Absolutely.  Heck, even 78L0X is better than using the rails.
>
> OK, consider me warned :)
>
> So, for something like the REF02 are you using that as your central, stable VRef and runnning your other VRefs of of that? e.g. if you need a stable +3.5V and +1.25V and -1.25V - you'd create them from the stable +5V of the REF02?
>
> What then are you using to create those 'sub' VRefs?
>
> Thanks.

Sure thing Justin. You can use one reference IC and derive other "vrefs" 
using resistor dividers and op-amp buffers/inverters off of that.

Check out the app notes for REF-02 et-al for additional ideas.

- Oren


From obl64 at ix.netcom.com  Wed Feb 22 11:18:11 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Wed, 22 Feb 2012 04:18:11 -0600
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
Message-ID: <4F44C0E3.70808@ix.netcom.com>



On 2/22/2012 1:39 AM, Donald Tillman wrote:
> ... honors Heinrich Hertz.
>
>    -- Don
>
> --
> Don Tillman
> Palo Alto, California
> don at till.com
> http://www.till.com
>
>

Yes - complete with little AM and FM thrown in ;-)


From colin at colinfraser.com  Wed Feb 22 11:40:20 2012
From: colin at colinfraser.com (Colin f)
Date: Wed, 22 Feb 2012 10:40:20 -0000
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <4F44C0E3.70808@ix.netcom.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com>
Message-ID: <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>

Huh ?
Where ?
Ah... 
I just realised that setting a pointless Google background picture means you
miss out on Google Doodles.

Cheers,
Colin f



> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl 
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Oren Leavitt
> Sent: 22 February 2012 10:18
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Today's Google Doodle...
> 
> 
> 
> On 2/22/2012 1:39 AM, Donald Tillman wrote:
> > ... honors Heinrich Hertz.
> >
> >    -- Don
> >
> > --
> > Don Tillman
> > Palo Alto, California
> > don at till.com
> > http://www.till.com
> >
> >
> 
> Yes - complete with little AM and FM thrown in ;-) 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From ol.gillet at gmail.com  Wed Feb 22 12:20:42 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Wed, 22 Feb 2012 12:20:42 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com> <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
Message-ID: <CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>

"Sinewaves" drawn with bits of ellipses. That slope at zero crossings. Arghhhhh.

Even the "back to back diodes" soft limiter of the MS20 filter isn't that harsh.


From antoniotuzzi at gmail.com  Wed Feb 22 12:28:21 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Wed, 22 Feb 2012 12:28:21 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
Message-ID: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>

Hello friends,

I received a defective juno
with the standard defects to some of the 80017a

but there is more: all the panel controls are working 

all the buttons are working but:
key 2 for the bank number and 4 for the patch number  are not working

the keyboard is most defective part. 
non working:
12 keys octave 1
12 keys octave 2
10 keys octave 3
7 keys octave 4
3 keys octave 5
0 keys octave 6  (is only the final C)

I cannot find any "binary rule" (reading the schematics) that brings this defect

Do I have to blame immediatly the CPU?
both keys and buttons are connected the IC 7 8 and 9
and the PB bus of the cpu

thanks 
Antonio


PS
(the synth is working using MIDI in)




From fanwander at mnet-online.de  Wed Feb 22 12:42:14 2012
From: fanwander at mnet-online.de (Florian Anwander)
Date: Wed, 22 Feb 2012 12:42:14 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
Message-ID: <4F44D496.3060009@mnet-online.de>

Am 22.02.2012 12:28, schrieb Antonio Tuzzi:
> all the buttons are working but:
> key 2 for the bank number and 4 for the patch number  are not working
>
> the keyboard is most defective part.
> non working:
> 12 keys octave 1
> 12 keys octave 2
> 10 keys octave 3
> 7 keys octave 4
> 3 keys octave 5
> 0 keys octave 6  (is only the final C)
>
> I cannot find any "binary rule" (reading the schematics) that brings this defect
How dirty is this 106 inside? May a drink was spilled on the 
synth/keyboard pcb.

Florian


From antoniotuzzi at gmail.com  Wed Feb 22 12:57:18 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Wed, 22 Feb 2012 12:57:18 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <4F44D496.3060009@mnet-online.de>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
	<4F44D496.3060009@mnet-online.de>
Message-ID: <FC887D24-6C7F-4C23-B32C-5B59703295D2@gmail.com>


>> all the buttons are working but:
>> key 2 for the bank number and 4 for the patch number  are not working
>> 
>> the keyboard is most defective part.
>> non working:
>> 12 keys octave 1
>> 12 keys octave 2
>> 10 keys octave 3
>> 7 keys octave 4
>> 3 keys octave 5
>> 0 keys octave 6  (is only the final C)
>> 
>> I cannot find any "binary rule" (reading the schematics) that brings this defect
> How dirty is this 106 inside? May a drink was spilled on the synth/keyboard pcb.
> 
> 

Hi Florian!

I'd love such a simple solution!! but outside the synth is superclean
anyway I'm going to open it ASAP... :D

thanks

Antonio

From mr at analogue.org  Wed Feb 22 13:37:01 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 22 Feb 2012 13:37:01 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com> <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
Message-ID: <CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>

On 22 February 2012 12:20, Olivier Gillet <ol.gillet at gmail.com> wrote:
> "Sinewaves" drawn with bits of ellipses. That slope at zero crossings. Arghhhhh.

Exactly... it's really awful! Can't see why people keep doing that,
even in quite technically serious contexts. :-)

/mr  -  sineophile


From ol.gillet at gmail.com  Wed Feb 22 14:18:42 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Wed, 22 Feb 2012 14:18:42 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com> <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
Message-ID: <CAJoLJ5VZTixrK9QRvAYz0d8iTmvrHFwOsKCBzJqS+YfQTgKVMA@mail.gmail.com>

http://i40.tinypic.com/10zvmee.png

Now if I had a modular setup I would totally patch that and take a
scope snapshot :)

On Wed, Feb 22, 2012 at 1:37 PM, Mattias Rickardsson <mr at analogue.org> wrote:
> On 22 February 2012 12:20, Olivier Gillet <ol.gillet at gmail.com> wrote:
>> "Sinewaves" drawn with bits of ellipses. That slope at zero crossings. Arghhhhh.
>
> Exactly... it's really awful! Can't see why people keep doing that,
> even in quite technically serious contexts. :-)
>
> /mr ?- ?sineophile


From tom at electricdruid.net  Wed Feb 22 15:08:03 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Wed, 22 Feb 2012 14:08:03 +0000
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com>
	<C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
Message-ID: <3173D56F-0842-40E4-B8B4-120634216839@electricdruid.net>


On 22 Feb 2012, at 12:37, Mattias Rickardsson wrote:

> On 22 February 2012 12:20, Olivier Gillet <ol.gillet at gmail.com> wrote:
>> "Sinewaves" drawn with bits of ellipses. That slope at zero crossings. Arghhhhh.
> 
> Exactly... it's really awful! Can't see why people keep doing that,
> even in quite technically serious contexts. :-)

I know why people keep doing it. Because every drawing package includes a tool for doing ellipses, and none that I've ever seen include a tool for doing sine curves.

Anyway, why does the google waveform have to be a sinewave? Can't it honour Hertz with plenty of odd harmonics thrown in?

T.




From subjectivity at hotmail.com  Wed Feb 22 15:21:52 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Wed, 22 Feb 2012 09:21:52 -0500
Subject: [sdiy] (OT)Electrify your brain with 9v
Message-ID: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>

http://gizmodo.com/5882754/how-to-electrify-your-brain-to-be-smarter-with-a-9+volt-battery




From barryklein at cox.net  Wed Feb 22 17:59:57 2012
From: barryklein at cox.net (Barry Klein)
Date: Wed, 22 Feb 2012 08:59:57 -0800
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>
Message-ID: <002401ccf183$67db5920$37920b60$@cox.net>


I researched this a bit as it is supposed to improve one's memory and mine's
pretty sucky.
First off, the human body model (brain model?) resistance is such that you
need a higher voltage than 9V, but I suppose you could use a booster
circuit.
Only need 1.5-2mA.
But just found this website:
http://www.techzonics.com/unusual-fortean-paranormal.htm
Kinda mind boggling....

Barry


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Dan Snazelle
Sent: Wednesday, February 22, 2012 06:22
To: synthdiy diy
Subject: [sdiy] (OT)Electrify your brain with 9v

http://gizmodo.com/5882754/how-to-electrify-your-brain-to-be-smarter-with-a-
9+volt-battery


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Synth-diy mailing list
Synth-diy at dropmix.xs4all.nl
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From igg.debus at t-online.de  Wed Feb 22 18:35:52 2012
From: igg.debus at t-online.de (Ingo Debus)
Date: Wed, 22 Feb 2012 18:35:52 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <3173D56F-0842-40E4-B8B4-120634216839@electricdruid.net>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com>
	<C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
	<3173D56F-0842-40E4-B8B4-120634216839@electricdruid.net>
Message-ID: <AC47254A-CAE5-4637-8684-0070C5817D59@t-online.de>


Am 22.02.2012 um 15:08 schrieb Tom Wiltshire:

> Anyway, why does the google waveform have to be a sinewave? Can't it honour Hertz with plenty of odd harmonics thrown in?

I think the letters from the word Google are hidden in there. The big blue positive half-wave is the G and so on.

Ingo

From gsn10 at hotmail.com  Wed Feb 22 18:44:54 2012
From: gsn10 at hotmail.com (Scott Nordlund)
Date: Wed, 22 Feb 2012 12:44:54 -0500
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <002401ccf183$67db5920$37920b60$@cox.net>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>,
	<002401ccf183$67db5920$37920b60$@cox.net>
Message-ID: <SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>


----------------------------------------
> From: barryklein at cox.net
> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
> Date: Wed, 22 Feb 2012 08:59:57 -0800
> Subject: Re: [sdiy] (OT)Electrify your brain with 9v
>
>
> I researched this a bit as it is supposed to improve one's memory and mine's
> pretty sucky.
> First off, the human body model (brain model?) resistance is such that you
> need a higher voltage than 9V, but I suppose you could use a booster
> circuit.
> Only need 1.5-2mA.
> But just found this website:
> http://www.techzonics.com/unusual-fortean-paranormal.htm
> Kinda mind boggling....
>
> Barry?
Wow! I'd love to spend $6985 on something built with a Radio Shack breadboard and hot glue. I hope everyone is paying attention here, because this is clearly the way forward. VHS case "project boxes" with built-in tinfoil hats!?Mica TO-3 insulators as jewelry! This guy has all the best ideas. Throw in some HTML blink and marquee tags and he'd really show those reptilian NWO bastards who's boss! 		 	   		  

From ka4hjh at gmail.com  Wed Feb 22 18:53:01 2012
From: ka4hjh at gmail.com (KA4HJH)
Date: Wed, 22 Feb 2012 12:53:01 -0500
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <002401ccf183$67db5920$37920b60$@cox.net>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>
	<002401ccf183$67db5920$37920b60$@cox.net>
Message-ID: <p06240801cb6adaa5a8a3@[192.168.1.66]>

>I researched this a bit as it is supposed to improve one's memory and mine's
>pretty sucky.
>First off, the human body model (brain model?) resistance is such that you
>need a higher voltage than 9V, but I suppose you could use a booster
>circuit.
>Only need 1.5-2mA.
>But just found this website:
>http://www.techzonics.com/unusual-fortean-paranormal.htm
>Kinda mind boggling....

I like "The ULTIMO BRAINWAVE ANALYSIS & BIOFEEDBACK / BIOCONTROL DEVICE"
with the circuit done entirely on a solderless breadboard. Oh wait, there's
a bunch of them made like that. This guy is so clueless he can't make a PC
board.

It's mind-boggling all right. That anyone would fall for this stuff.

Somehow I suspect he's not one of those golden-eared audiophiles.

-- 

Terry Bowman, KA4HJH
"The Mac Doctor"


From nitro2k01 at gmail.com  Wed Feb 22 18:53:35 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Wed, 22 Feb 2012 18:53:35 +0100
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
Message-ID: <CABacs=DtN3ASHzXpOPmV2_wa67KpJTePjOK90HvBsWvQmq6kQQ@mail.gmail.com>

On 22 February 2012 18:44, Scott Nordlund <gsn10 at hotmail.com> wrote:
>
> ----------------------------------------
>> From: barryklein at cox.net
>> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
>> Date: Wed, 22 Feb 2012 08:59:57 -0800
>> Subject: Re: [sdiy] (OT)Electrify your brain with 9v
>>
>>
>> I researched this a bit as it is supposed to improve one's memory and mine's
>> pretty sucky.
>> First off, the human body model (brain model?) resistance is such that you
>> need a higher voltage than 9V, but I suppose you could use a booster
>> circuit.
>> Only need 1.5-2mA.
>> But just found this website:
>> http://www.techzonics.com/unusual-fortean-paranormal.htm
>> Kinda mind boggling....
>>
>> Barry
> Wow! I'd love to spend $6985 on something built with a Radio Shack breadboard and hot glue. I hope everyone is paying attention here, because this is clearly the way forward. VHS case "project boxes" with built-in tinfoil hats!?Mica TO-3 insulators as jewelry! This guy has all the best ideas. Throw in some HTML blink and marquee tags and he'd really show those reptilian NWO bastards who's boss!

Maybe one could simply sell synthesizers as a 2 in 1 alien repellent
and mind harmonizer. Just consider the unexploited market...

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From nvawter at media.mit.edu  Wed Feb 22 19:07:59 2012
From: nvawter at media.mit.edu (nvawter at media.mit.edu)
Date: Wed, 22 Feb 2012 13:07:59 -0500
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>,
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
Message-ID: <20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>


I love statements like this:
"In fact, Ancient Roman physicians (Galen) placed torpedo fish, known  
for their electric charges, to the foreheads of sufferers of migraine  
headaches and depression."

because there is soooo much opportunity for deception.
e.g.

How many physicians did this?  1 (Galen)?  Or many?  Or all?

How often did they do it!!!?  Once?  everyday?  numerous times?  a few times?
we don't even know!  The grammar just obliterates all possibility of  
comprehension.

How many fish?  1?  Millions?
How many sufferers?  1?  Thousands?  GAH!



hahahaha also the bit about 333Hz is hilarious.  hoo boy...




Quoting Scott Nordlund <gsn10 at hotmail.com>:

>
> ----------------------------------------
>> From: barryklein at cox.net
>> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
>> Date: Wed, 22 Feb 2012 08:59:57 -0800
>> Subject: Re: [sdiy] (OT)Electrify your brain with 9v
>>
>>
>> I researched this a bit as it is supposed to improve one's memory and mine's
>> pretty sucky.
>> First off, the human body model (brain model?) resistance is such that you
>> need a higher voltage than 9V, but I suppose you could use a booster
>> circuit.
>> Only need 1.5-2mA.
>> But just found this website:
>> http://www.techzonics.com/unusual-fortean-paranormal.htm
>> Kinda mind boggling....
>>
>> Barry?
> Wow! I'd love to spend $6985 on something built with a Radio Shack  
> breadboard and hot glue. I hope everyone is paying attention here,  
> because this is clearly the way forward. VHS case "project boxes"  
> with built-in tinfoil hats!?Mica TO-3 insulators as jewelry! This  
> guy has all the best ideas. Throw in some HTML blink and marquee  
> tags and he'd really show those reptilian NWO bastards who's boss!
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>



From mr at analogue.org  Wed Feb 22 19:21:14 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Wed, 22 Feb 2012 19:21:14 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <CANoTfUK_-08NDNbbjtDhDTyR9yVJ-uZpnJKQ0vdO+ayKR_cL3A@mail.gmail.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com> <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
	<3173D56F-0842-40E4-B8B4-120634216839@electricdruid.net>
	<CANoTfUK_-08NDNbbjtDhDTyR9yVJ-uZpnJKQ0vdO+ayKR_cL3A@mail.gmail.com>
Message-ID: <CAP92RBW2N68=0a9Dq8t+0fjys+gGPXzyE+ZzfqOz0r7swrL7nQ@mail.gmail.com>

On 22 February 2012 18:40, John Marshall <wa7bsr at gmail.com> wrote:
> It just Hertz for me to see semi-circles trying to be sine waves.

Period. ;-)

/mr


From nitro2k01 at gmail.com  Wed Feb 22 19:38:36 2012
From: nitro2k01 at gmail.com (=?UTF-8?B?T3ZlIFJpZMOp?=)
Date: Wed, 22 Feb 2012 19:38:36 +0100
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
	<20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
Message-ID: <CABacs=AKafPTyMvNOJpGwA3XfPY7tSM+h0ik7SURUb7=SFMBxw@mail.gmail.com>

On 22 February 2012 19:07,  <nvawter at media.mit.edu> wrote:
>
> I love statements like this:
> "In fact, Ancient Roman physicians (Galen) placed torpedo fish, known for
> their electric charges, to the foreheads of sufferers of migraine headaches
> and depression."
>
> because there is soooo much opportunity for deception.
> e.g.
>
> How many physicians did this? ?1 (Galen)? ?Or many? ?Or all?
>
> How often did they do it!!!? ?Once? ?everyday? ?numerous times? ?a few
> times?
> we don't even know! ?The grammar just obliterates all possibility of
> comprehension.
>
> How many fish? ?1? ?Millions?
> How many sufferers? ?1? ?Thousands? ?GAH!
>
>
>
> hahahaha also the bit about 333Hz is hilarious. ?hoo boy...

And this has to be the best disclaimer ever:

NOTE: If psychic powers exist, this extremely low frequency amplifier
may be useful to amplify psychic powers. We do not claim that psychic
powers exist or that if they exist, they can be proven.

-- 
/Ove

Blog: <http://blog.gg8.se/>

"Here is Evergreen City. Evergreen? is the color of green forever."


From Barry.L.Klein at wdc.com  Wed Feb 22 19:39:18 2012
From: Barry.L.Klein at wdc.com (Barry Klein)
Date: Wed, 22 Feb 2012 18:39:18 +0000
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>,
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
	<20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
Message-ID: <83EEDB9AA00D6B449EB022CF4EFEC3232B301678@wdscexmb03.sc.wdc.com>

Actually I googled it and there's a lot supporting the statement or at least repeating the suggestion:
http://www.google.com/#hl=en&gs_nf=1&cp=52&gs_id=3&xhr=t&q=Ancient+Roman+physicians+(Galen)+placed+torpedo+fish&pf=p&output=search&sclient=psy-ab&rlz=1W1ADSA_enUS468&pbx=1&oq=Ancient+Roman+physicians+(Galen)+placed+torpedo+fish&aq=f&aqi=&aql=&gs_sm=&gs_upl=&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=1aef0db0b8ed3188&biw=1280&bih=845

Maybe we should sell Torpedo fish?  Or sell aquariums with 6 quadrant voltage sensors connected to a modular synth with Torpedo fish, for $15K or so?

Barry


-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of nvawter at media.mit.edu
Sent: Wednesday, February 22, 2012 10:08 AM
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] (OT)Electrify your brain with 9v


I love statements like this:
"In fact, Ancient Roman physicians (Galen) placed torpedo fish, known for their electric charges, to the foreheads of sufferers of migraine headaches and depression."

because there is soooo much opportunity for deception.
e.g.

How many physicians did this?  1 (Galen)?  Or many?  Or all?

How often did they do it!!!?  Once?  everyday?  numerous times?  a few times?
we don't even know!  The grammar just obliterates all possibility of comprehension.

How many fish?  1?  Millions?
How many sufferers?  1?  Thousands?  GAH!



hahahaha also the bit about 333Hz is hilarious.  hoo boy...




Quoting Scott Nordlund <gsn10 at hotmail.com>:

>
> ----------------------------------------
>> From: barryklein at cox.net
>> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
>> Date: Wed, 22 Feb 2012 08:59:57 -0800
>> Subject: Re: [sdiy] (OT)Electrify your brain with 9v
>>
>>
>> I researched this a bit as it is supposed to improve one's memory and 
>> mine's pretty sucky.
>> First off, the human body model (brain model?) resistance is such 
>> that you need a higher voltage than 9V, but I suppose you could use a 
>> booster circuit.
>> Only need 1.5-2mA.
>> But just found this website:
>> http://www.techzonics.com/unusual-fortean-paranormal.htm
>> Kinda mind boggling....
>>
>> Barry
> Wow! I'd love to spend $6985 on something built with a Radio Shack 
> breadboard and hot glue. I hope everyone is paying attention here, 
> because this is clearly the way forward. VHS case "project boxes"
> with built-in tinfoil hats!?Mica TO-3 insulators as jewelry! This guy 
> has all the best ideas. Throw in some HTML blink and marquee tags and 
> he'd really show those reptilian NWO bastards who's boss!
> _______________________________________________
> 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 mail.ubc.ca  Wed Feb 22 21:25:30 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Wed, 22 Feb 2012 12:25:30 -0800
Subject: [sdiy] A (slightly) better VRef?
In-Reply-To: <4f44bd8e.8a0eb40a.2914.fffff846@mx.google.com>
References: <4f44bd8e.8a0eb40a.2914.fffff846@mx.google.com>
Message-ID: <E28CA8FF24D34524B411452927766C9C@galvanox01>

> So, for something like the REF02 are you using that as your 
> central, stable VRef and runnning your other VRefs of of 
> that? e.g. if you need a stable +3.5V and +1.25V and -1.25V - 
> you'd create them from the stable +5V of the REF02?
> 
> What then are you using to create those 'sub' VRefs?

Once you've got one (say, +5V) voltage reference, you can use dividers and
opamp voltage followers or inverters to get whatever voltage you want.



From dixon at mail.ubc.ca  Wed Feb 22 21:28:14 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Wed, 22 Feb 2012 12:28:14 -0800
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com><4F44C0E3.70808@ix.netcom.com>
	<C80D3B809CEC4E1D90BA6651EE5E2DE6@zen><CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
Message-ID: <A0D268C835824497AE85794CA0F89153@galvanox01>

> > "Sinewaves" drawn with bits of ellipses. That slope at zero 
> crossings. Arghhhhh.
> 
> Exactly... it's really awful! Can't see why people keep doing 
> that, even in quite technically serious contexts. :-)

I know, right?  Why can't everyone be as dorky and obsessive as us?  It just
makes me SO MAD!!!!

:)



From davekendall at ntlworld.com  Wed Feb 22 23:33:15 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Wed, 22 Feb 2012 22:33:15 +0000
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>
References: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>
Message-ID: <360C52F8-5DA5-11E1-ADE2-000393A85F9E@ntlworld.com>


On Feb 21, 2012, at 15:43, Harry Bissell wrote:

> How about D-SUB 9 pin Males on the modules, and female to female 
> cables, THIS way you throw out
> a worn cable. If you use screw-machined male plugs, the pins should be 
> good for many many cycles...
>
> Unfortunately the D-sub cables are not so common anymore...
>
> H^) harry

That seems like a good idea. I may have access to a load of NOS D-sub 
components that were in storage at an A/V place I've worked at.
They probably don't want/need those parts anymore, so it could be a 
cheap and worthwhile experiment (if soldering time is not included in 
that.....)

cheers,
Dave


>
> ----- Original Message -----
> From: Andre Majorel <aym-htnys at teaser.fr>
> To: synth-diy at dropmix.xs4all.nl
> Sent: Tue, 21 Feb 2012 10:21:09 -0500 (EST)
> Subject: Re: [sdiy] Using D-Sub connectors as patching elements
>
> On 2012-02-21 12:05 +0100, ChristianH wrote:
>> On Tue, 21 Feb 2012 10:45:01 +0000 Dave Kendall 
>> <davekendall at ntlworld.com> wrote:
>>> On Feb 21, 2012, at 07:13, Andre Majorel wrote:
>>>> I think I would give 8-way DINs a try
>>>
>>> Just looked at the datasheet for an 8-pin DIN free plug that digikey
>>> stock, and it's rated at 5000 cycles!
>
> What's the rating on the socket ? For DINs, the female part of
> the contact is the one whose mechanical properties (clearance
> and elasticity) are the most critical and simultaneously the one
> that is worked the hardest (flexion).
>
>> And you think that is much?
>>
>> Ok, this may be an academic calculation - but assume a dozen patch
>> changes a day, so after a year it's starting to have problems.
>> I wouldn't consider that good enough, not even for diy. Unless I know
>> it's going to be used significantly less - as they say, YMMV.
>
> It's a difficult problem. Round industrial connectors are
> prohibitively expensive and some patch points won't be used 5000
> times in your life time.
>
> Tiptop Audio use 8-way mini-DINs in their polyphonic modules. I
> expect they're even less reliable than regular DINs. It will be
> interesting to see how well they hold.
>
> -- 
> Andr? Majorel http://www.teaser.fr/~amajorel/
> _______________________________________________
> 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 music.maker at gte.net  Wed Feb 22 23:45:00 2012
From: music.maker at gte.net (Scott Gravenhorst)
Date: Wed, 22 Feb 2012 15:45:00 -0700
Subject: [sdiy] Today's Google Doodle...
Message-ID: <201202222345.q1MNj0ix029021@linux7.lan>


Tim Parkhurst <tim.parkhurst at gmail.com> wrote:
>On Tue, Feb 21, 2012 at 11:39 PM, Donald Tillman <don at till.com> wrote:
>> ... honors Heinrich Hertz.
>>
>> ?-- Don
>>
>
>Hey, look - circular waveforms...
>
>
>Tim (veterans may remember that particular conflagration) Servo

Hmm...  I seem to remember it being about "spiral" waveforms...


-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
-- FPGA MIDI Synth Info: jovianpyx.dyndns.org:8080/public/FPGA_synth/
-- FatMan Mods Etc.: jovianpyx.dyndns.org:8080/public/fatman/
-- Some Random Electronics Bits: jovianpyx.dyndns.org:8080/public/electronics/
-- When the going gets tough, the tough use the command line.



From davekendall at ntlworld.com  Wed Feb 22 23:45:18 2012
From: davekendall at ntlworld.com (Dave Kendall)
Date: Wed, 22 Feb 2012 22:45:18 +0000
Subject: [sdiy] Mundorf capacitors - how much snake oil do they contain?
Message-ID: <E521588C-5DA6-11E1-ADE2-000393A85F9E@ntlworld.com>

Hi all.

They do seem excessively pricey to say the least (*cough*)....... 
Anyone here know of any technical documents on whether there is any 
noticeable/measurable difference using them in synth or audio circuits 
instead of regular, reasonable quality caps?
R.G Keen has a great article on the Geofex site on carbon comp 
resistors;
http://www.geofex.com/article_folders/carbon_comp/carboncomp.htm

Anyone know of anything comparable on capacitors?

cheers,
Dave



From lanterma at ece.gatech.edu  Wed Feb 22 23:45:54 2012
From: lanterma at ece.gatech.edu (Lanterman, Aaron)
Date: Wed, 22 Feb 2012 22:45:54 +0000
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <83EEDB9AA00D6B449EB022CF4EFEC3232B301678@wdscexmb03.sc.wdc.com>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>,
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
	<20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
	<83EEDB9AA00D6B449EB022CF4EFEC3232B301678@wdscexmb03.sc.wdc.com>
Message-ID: <2F409D33-2FFF-4304-B5AE-0B45097658F0@ece.gatech.edu>

On Feb 22, 2012, at 1:39 PM, Barry Klein wrote:

> Maybe we should sell Torpedo fish?  Or sell aquariums with 6 quadrant voltage sensors connected to a modular synth with Torpedo fish, for $15K or so?

Well, there's this, by my GTCMT colleagues:

http://www.youtube.com/watch?v=ReUsWd2hWQU

And kind of related, here's Laurie Anderson playing for the fish at the Atlanta Aquarium. I didn't see her do this but I saw her give a talk at Tech about doing this. ;)

http://www.youtube.com/watch?v=90X_L0YUzPU

- Aaron

From obl64 at ix.netcom.com  Wed Feb 22 23:58:39 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Wed, 22 Feb 2012 16:58:39 -0600
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <360C52F8-5DA5-11E1-ADE2-000393A85F9E@ntlworld.com>
References: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>
	<360C52F8-5DA5-11E1-ADE2-000393A85F9E@ntlworld.com>
Message-ID: <4F45731F.3030904@ix.netcom.com>



On 2/22/2012 4:33 PM, Dave Kendall wrote:
>
> On Feb 21, 2012, at 15:43, Harry Bissell wrote:
>
>> How about D-SUB 9 pin Males on the modules, and female to female
>> cables, THIS way you throw out
>> a worn cable. If you use screw-machined male plugs, the pins should be
>> good for many many cycles...
>>
>> Unfortunately the D-sub cables are not so common anymore...
>>
>> H^) harry
>
> That seems like a good idea. I may have access to a load of NOS D-sub
> components that were in storage at an A/V place I've worked at.
> They probably don't want/need those parts anymore, so it could be a
> cheap and worthwhile experiment (if soldering time is not included in
> that.....)
>
> cheers,
> Dave
>
>

Speaking of D-Subs as patch connections. I have been entertaining the 
idea of using 9 pin D-Subs in an 8 voice patchable polysynth. Each pin 
routing signal/CV for single voice.
Maybe 8 ASM-1 type synths.

- Oren

>>
>> ----- Original Message -----
>> From: Andre Majorel <aym-htnys at teaser.fr>
>> To: synth-diy at dropmix.xs4all.nl
>> Sent: Tue, 21 Feb 2012 10:21:09 -0500 (EST)
>> Subject: Re: [sdiy] Using D-Sub connectors as patching elements
>>
>> On 2012-02-21 12:05 +0100, ChristianH wrote:
>>> On Tue, 21 Feb 2012 10:45:01 +0000 Dave Kendall
>>> <davekendall at ntlworld.com> wrote:
>>>> On Feb 21, 2012, at 07:13, Andre Majorel wrote:
>>>>> I think I would give 8-way DINs a try
>>>>
>>>> Just looked at the datasheet for an 8-pin DIN free plug that digikey
>>>> stock, and it's rated at 5000 cycles!
>>
>> What's the rating on the socket ? For DINs, the female part of
>> the contact is the one whose mechanical properties (clearance
>> and elasticity) are the most critical and simultaneously the one
>> that is worked the hardest (flexion).
>>
>>> And you think that is much?
>>>
>>> Ok, this may be an academic calculation - but assume a dozen patch
>>> changes a day, so after a year it's starting to have problems.
>>> I wouldn't consider that good enough, not even for diy. Unless I know
>>> it's going to be used significantly less - as they say, YMMV.
>>
>> It's a difficult problem. Round industrial connectors are
>> prohibitively expensive and some patch points won't be used 5000
>> times in your life time.
>>
>> Tiptop Audio use 8-way mini-DINs in their polyphonic modules. I
>> expect they're even less reliable than regular DINs. It will be
>> interesting to see how well they hold.
>>
>> --
>> Andr? Majorel http://www.teaser.fr/~amajorel/
>> _______________________________________________
>> 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
>


From tim.parkhurst at gmail.com  Thu Feb 23 00:02:08 2012
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Wed, 22 Feb 2012 15:02:08 -0800
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
Message-ID: <CACDGQT9oym7xtKY03zM1TC5D6atEwvbner9tS7HTOxtANfb3HA@mail.gmail.com>

On Tue, Feb 21, 2012 at 11:39 PM, Donald Tillman <don at till.com> wrote:
> ... honors Heinrich Hertz.
>
> ?-- Don
>

Hey, look - circular waveforms...


Tim (veterans may remember that particular conflagration) Servo
---
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From richard at wentk.com  Thu Feb 23 03:43:02 2012
From: richard at wentk.com (Richard Wentk)
Date: Thu, 23 Feb 2012 02:43:02 +0000
Subject: [sdiy] (OT)Electrify your brain with 9v
In-Reply-To: <20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
References: <BLU0-SMTP161FE3009C453E4A12A688CC8640@phx.gbl>,
	<002401ccf183$67db5920$37920b60$@cox.net>
	<SNT104-W15B8C0F72F159E6D33A017B4640@phx.gbl>
	<20120222130759.15696fz6qsjbdtrz@webmail.media.mit.edu>
Message-ID: <07AD58A4-654F-40C6-B781-1E33982DF9CC@wentk.com>

"No person on Earth likes being attacked by feral rats!"

Superb.

Richard

On 22 Feb 2012, at 18:07, nvawter at media.mit.edu wrote:

> 
> I love statements like this:
> "In fact, Ancient Roman physicians (Galen) placed torpedo fish, known for their electric charges, to the foreheads of sufferers of migraine headaches and depression."
> 
> because there is soooo much opportunity for deception.
> e.g.
> 
> How many physicians did this?  1 (Galen)?  Or many?  Or all?
> 
> How often did they do it!!!?  Once?  everyday?  numerous times?  a few times?
> we don't even know!  The grammar just obliterates all possibility of comprehension.
> 
> How many fish?  1?  Millions?
> How many sufferers?  1?  Thousands?  GAH!
> 
> 
> 
> hahahaha also the bit about 333Hz is hilarious.  hoo boy...
> 
> 
> 
> 
> Quoting Scott Nordlund <gsn10 at hotmail.com>:
> 
>> 
>> ----------------------------------------
>>> From: barryklein at cox.net
>>> To: subjectivity at hotmail.com; synth-diy at dropmix.xs4all.nl
>>> Date: Wed, 22 Feb 2012 08:59:57 -0800
>>> Subject: Re: [sdiy] (OT)Electrify your brain with 9v
>>> 
>>> 
>>> I researched this a bit as it is supposed to improve one's memory and mine's
>>> pretty sucky.
>>> First off, the human body model (brain model?) resistance is such that you
>>> need a higher voltage than 9V, but I suppose you could use a booster
>>> circuit.
>>> Only need 1.5-2mA.
>>> But just found this website:
>>> http://www.techzonics.com/unusual-fortean-paranormal.htm
>>> Kinda mind boggling....
>>> 
>>> Barry 
>> Wow! I'd love to spend $6985 on something built with a Radio Shack breadboard and hot glue. I hope everyone is paying attention here, because this is clearly the way forward. VHS case "project boxes" with built-in tinfoil hats! Mica TO-3 insulators as jewelry! This guy has all the best ideas. Throw in some HTML blink and marquee tags and he'd really show those reptilian NWO bastards who's boss!
>> _______________________________________________
>> 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 ijfritz at comcast.net  Thu Feb 23 04:45:01 2012
From: ijfritz at comcast.net (Ian Fritz)
Date: Wed, 22 Feb 2012 20:45:01 -0700
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <201202222345.q1MNj0ix029021@linux7.lan>
References: <201202222345.q1MNj0ix029021@linux7.lan>
Message-ID: <6.2.1.2.2.20120222204337.023484d8@mail.comcast.net>

Which, once again, are very much real!

Ian



At 03:45 PM 2/22/2012, Scott Gravenhorst wrote:

>Hmm...  I seem to remember it being about "spiral" waveforms...



From don at till.com  Thu Feb 23 04:57:30 2012
From: don at till.com (Donald Tillman)
Date: Wed, 22 Feb 2012 19:57:30 -0800
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <AC47254A-CAE5-4637-8684-0070C5817D59@t-online.de>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com>
	<C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
	<3173D56F-0842-40E4-B8B4-120634216839@electricdruid.net>
	<AC47254A-CAE5-4637-8684-0070C5817D59@t-online.de>
Message-ID: <44FBF8A4-A44F-442E-A532-B1C53AA17984@till.com>

On Feb 22, 2012, at 9:35 AM, Ingo Debus wrote:

> Am 22.02.2012 um 15:08 schrieb Tom Wiltshire:
> 
>> Anyway, why does the google waveform have to be a sinewave? Can't it honour Hertz with plenty of odd harmonics thrown in?
> 
> I think the letters from the word Google are hidden in there. The big blue positive half-wave is the G and so on.


I think its also a bit of an homage to Walt Disney:

   'Soundtrack' Intermission - Fantasia
   http://www.youtube.com/watch?v=NTM48pwoXAo

  -- Don

--
Don Tillman
Palo Alto, California
don at till.com
http://www.till.com






From antoniotuzzi at gmail.com  Thu Feb 23 09:50:53 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Thu, 23 Feb 2012 09:50:53 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
Message-ID: <FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>

so...
was not a cpu fault but the keyboard pcb with interrupted traces
(you all were right!)

http://img46.imageshack.us/img46/6109/img1560el.jpg
http://img33.imageshack.us/img33/1269/img1562xn.jpg

but WHY?!

corrosion ? is in 6 different spots
drag from keys ? (a couple of spot presents kind of scratches) (but keys don't touch the pcb!)

I'm quite sure nobody opened the keyboard before

for the 2 button in the front panel, are simply failing switches

Thank you
Antonio
 

On 22/feb/2012, at 12.28, Antonio Tuzzi wrote:

> Hello friends,
> 
> I received a defective juno
> with the standard defects to some of the 80017a
> 
> but there is more: all the panel controls are working 
> 
> all the buttons are working but:
> key 2 for the bank number and 4 for the patch number  are not working
> 
> the keyboard is most defective part. 
> non working:
> 12 keys octave 1
> 12 keys octave 2
> 10 keys octave 3
> 7 keys octave 4
> 3 keys octave 5
> 0 keys octave 6  (is only the final C)
> 
> I cannot find any "binary rule" (reading the schematics) that brings this defect
> 
> Do I have to blame immediatly the CPU?
> both keys and buttons are connected the IC 7 8 and 9
> and the PB bus of the cpu
> 
> thanks 
> Antonio
> 
> 
> PS
> (the synth is working using MIDI in)
> 
> 



From tom at electricdruid.net  Thu Feb 23 11:45:45 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Thu, 23 Feb 2012 10:45:45 +0000
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
	<FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
Message-ID: <42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>

Those images look like someone scratched the soldermask off to get a probe onto the keyboard PCB.
I think someone definitely opened the keyboard before. No way that happened by any kind of accident.

T.

On 23 Feb 2012, at 08:50, Antonio Tuzzi wrote:

> so...
> was not a cpu fault but the keyboard pcb with interrupted traces
> (you all were right!)
> 
> http://img46.imageshack.us/img46/6109/img1560el.jpg
> http://img33.imageshack.us/img33/1269/img1562xn.jpg
> 
> but WHY?!
> 
> corrosion ? is in 6 different spots
> drag from keys ? (a couple of spot presents kind of scratches) (but keys don't touch the pcb!)
> 
> I'm quite sure nobody opened the keyboard before
> 
> for the 2 button in the front panel, are simply failing switches
> 
> Thank you
> Antonio



From colin at colinfraser.com  Thu Feb 23 11:53:17 2012
From: colin at colinfraser.com (Colin f)
Date: Thu, 23 Feb 2012 10:53:17 -0000
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com><FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
	<42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>
Message-ID: <707E66EEB11A4097B3112CBE1CF3E790@zen>

 
> Those images look like someone scratched the soldermask off 
> to get a probe onto the keyboard PCB.
> I think someone definitely opened the keyboard before. No way 
> that happened by any kind of accident.

Either that, or it belonged to a big Keith Emerson fan, and those are knife
marks ;-)
Was the synth full of Hammond patches ?

Cheers,
Colin f




From antoniotuzzi at gmail.com  Thu Feb 23 12:07:07 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Thu, 23 Feb 2012 12:07:07 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <707E66EEB11A4097B3112CBE1CF3E790@zen>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com><FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
	<42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>
	<707E66EEB11A4097B3112CBE1CF3E790@zen>
Message-ID: <D32122C1-6615-4404-A97D-8BB22980DF65@gmail.com>


On 23/feb/2012, at 11.53, Colin f wrote:

> 
>> Those images look like someone scratched the soldermask off 
>> to get a probe onto the keyboard PCB.
>> I think someone definitely opened the keyboard before. No way 
>> that happened by any kind of accident.
> 
> Either that, or it belonged to a big Keith Emerson fan, and those are knife
> marks ;-)
> Was the synth full of Hammond patches ?
> 

HAHAHA
ROFL


> Cheers,
> Colin f
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From antoniotuzzi at gmail.com  Thu Feb 23 12:14:03 2012
From: antoniotuzzi at gmail.com (Antonio Tuzzi)
Date: Thu, 23 Feb 2012 12:14:03 +0100
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <D32122C1-6615-4404-A97D-8BB22980DF65@gmail.com>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com><FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
	<42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>
	<707E66EEB11A4097B3112CBE1CF3E790@zen>
	<D32122C1-6615-4404-A97D-8BB22980DF65@gmail.com>
Message-ID: <29749FDA-D92C-4BF2-9A2B-5A87859C99D8@gmail.com>

Or better

could have been a very angry girlfriend or fan (HATE)


about 5 years ago I repaired an Oberheim m1000 missing one of the eprom: 
After a group separation,  probably a sabotage... 

(I swear!)

antonio


On 23/feb/2012, at 12.07, Antonio Tuzzi wrote:

> 
> On 23/feb/2012, at 11.53, Colin f wrote:
> 
>> 
>>> Those images look like someone scratched the soldermask off 
>>> to get a probe onto the keyboard PCB.
>>> I think someone definitely opened the keyboard before. No way 
>>> that happened by any kind of accident.
>> 
>> Either that, or it belonged to a big Keith Emerson fan, and those are knife
>> marks ;-)
>> Was the synth full of Hammond patches ?
>> 
> 
> HAHAHA
> ROFL
> 
> 
>> Cheers,
>> Colin f
>> 
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From geoffprince at talktalk.net  Thu Feb 23 12:50:54 2012
From: geoffprince at talktalk.net (Geoff)
Date: Thu, 23 Feb 2012 11:50:54 -0000
Subject: [sdiy] cute hand held scopes on eBay
Message-ID: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net>

Hi all,

has anybody tried one of these very cute hand held digital storage scopes
found on ebay?

single channel..

http://www.ebay.co.uk/itm/120846225927?ssPageName=STRK:MEWAX:IT&_trksid=p398
4.m1438.l2649#ht_4240wt_1026

four channel..

http://www.ebay.co.uk/itm/120846227053?ssPageName=STRK:MEWAX:IT&_trksid=p398
4.m1438.l2649#ht_4106wt_1029


Geoff~



From dfevans at sekrit.eu  Thu Feb 23 12:57:04 2012
From: dfevans at sekrit.eu (David Evans)
Date: Thu, 23 Feb 2012 11:57:04 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net>
Message-ID: <F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu>

On 23 Feb 2012, at 11:50, Geoff wrote:

> Hi all,
> 
> has anybody tried one of these very cute hand held digital storage scopes
> found on ebay?
> 
> single channel..
> 
> http://www.ebay.co.uk/itm/120846225927?ssPageName=STRK:MEWAX:IT&_trksid=p398
> 4.m1438.l2649#ht_4240wt_1026
> 

The DSO nano is fairly well-known and was talked about on here a few weeks ago. I have one; it's OK but a bit cheesy given it's single-channel.

> four channel..
> 
> http://www.ebay.co.uk/itm/120846227053?ssPageName=STRK:MEWAX:IT&_trksid=p398
> 4.m1438.l2649#ht_4106wt_1029
> 

I have not used the DSO quad.




From 21pointy at tpg.com.au  Thu Feb 23 13:03:03 2012
From: 21pointy at tpg.com.au (Adam Inglis)
Date: Thu, 23 Feb 2012 22:03:03 +1000
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <707E66EEB11A4097B3112CBE1CF3E790@zen>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com><FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com>
	<42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net>
	<707E66EEB11A4097B3112CBE1CF3E790@zen>
Message-ID: <5F0EFF96-2722-427E-BEE9-2CA33BF1D302@tpg.com.au>


On 23/02/2012, at 8:53 PM, Colin f wrote:

>
>> Those images look like someone scratched the soldermask off
>> to get a probe onto the keyboard PCB.
>> I think someone definitely opened the keyboard before. No way
>> that happened by any kind of accident.
>
> Either that, or it belonged to a big Keith Emerson fan, and those  
> are knife
> marks ;-)
> Was the synth full of Hammond patches ?
>
> Cheers,
> Colin f


!!!!!!!!
Oh sh#t I just fell off my chair....



















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



From tom at electricdruid.net  Thu Feb 23 14:57:44 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Thu, 23 Feb 2012 13:57:44 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net>
	<F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu>
Message-ID: <2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>


On 23 Feb 2012, at 11:57, David Evans wrote:

> On 23 Feb 2012, at 11:50, Geoff wrote:
> 
>> Hi all,
>> 
>> has anybody tried one of these very cute hand held digital storage scopes
>> found on ebay?
>> 
>> single channel..
>> 
>> http://www.ebay.co.uk/itm/120846225927?ssPageName=STRK:MEWAX:IT&_trksid=p398
>> 4.m1438.l2649#ht_4240wt_1026
>> 
> 
> The DSO nano is fairly well-known and was talked about on here a few weeks ago. I have one; it's OK but a bit cheesy given it's single-channel.
> 
>> four channel..
>> 
>> http://www.ebay.co.uk/itm/120846227053?ssPageName=STRK:MEWAX:IT&_trksid=p398
>> 4.m1438.l2649#ht_4106wt_1029
>> 
> 
> I have not used the DSO quad.

It sounds like there have been considerable improvements to the firmware since the earlier versions:

	http://www.seeedstudio.com/blog/tag/dso-nano/

I haven't used one, but I like the idea of an open-source oscilloscope. If there's a feature you don't need, replace it with one you want - ace.

Tom



From grant at musictechnologiesgroup.com  Thu Feb 23 15:33:47 2012
From: grant at musictechnologiesgroup.com (MTG)
Date: Thu, 23 Feb 2012 06:33:47 -0800
Subject: [sdiy] juno 106 (illogical) behaviour
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com><FBCCFB0D-823E-4FAE-ACBA-05C1BB456F76@gmail.com><42690B72-8BB3-471D-B946-0C960635059F@electricdruid.net><707E66EEB11A4097B3112CBE1CF3E790@zen>
	<5F0EFF96-2722-427E-BEE9-2CA33BF1D302@tpg.com.au>
Message-ID: <CDFA6502E64B4B67973EFA013C41B785@LIFEBOOK>

Perhaps the circuit board is cracked?

GB
www.musictechnologiesgroup.com


----- Original Message ----- 
From: "Adam Inglis" <21pointy at tpg.com.au>
To: "Colin f" <colin at colinfraser.com>
Cc: "'synthdiy diy'" <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, February 23, 2012 4:03 AM
Subject: Re: [sdiy] juno 106 (illogical) behaviour


> 
> On 23/02/2012, at 8:53 PM, Colin f wrote:
> 
>>
>>> Those images look like someone scratched the soldermask off
>>> to get a probe onto the keyboard PCB.
>>> I think someone definitely opened the keyboard before. No way
>>> that happened by any kind of accident.
>>
>> Either that, or it belonged to a big Keith Emerson fan, and those  
>> are knife
>> marks ;-)
>> Was the synth full of Hammond patches ?
>>
>> Cheers,
>> Colin f
> 
> 
> !!!!!!!!
> Oh sh#t I just fell off my chair....
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>>
>>
>> _______________________________________________
>> 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 dfevans at sekrit.eu  Thu Feb 23 15:36:47 2012
From: dfevans at sekrit.eu (David Evans)
Date: Thu, 23 Feb 2012 14:36:47 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net>
	<F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu>
	<2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>
Message-ID: <EE8B1C9E-B723-44A1-9ACF-22CC7046BC9C@sekrit.eu>

On 23 Feb 2012, at 13:57, Tom Wiltshire wrote:

> It sounds like there have been considerable improvements to the firmware since the earlier versions:
> 
> 	http://www.seeedstudio.com/blog/tag/dso-nano/
> 

Yes. I haven't looked at this in about a year, having BenF firmware in mine. It made a big difference!

> I haven't used one, but I like the idea of an open-source oscilloscope. If there's a feature you don't need, replace it with one you want - ace.
> 

Yes. Although the firmware is the expected embedded maze of pain, the toolchain is easy enough to get together and then you can, in theory at least, "do stuff".




From rburnett at richieburnett.co.uk  Thu Feb 23 16:22:00 2012
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Thu, 23 Feb 2012 15:22:00 -0000 (GMT)
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6
	C29AF0B889F@sekrit.eu>
	<2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>
Message-ID: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>

>> The DSO nano is fairly well-known and was talked about on here a few weeks
>> ago. I have one; it's OK but a bit cheesy given it's single-channel.

I think the linear interpolation between sample points would be my biggest
gripe!  For example, this picture of a 500kHz sinewave:

http://toolboom.com/content_image/content/5210/IMG_2417.JPG

from the many photos at this page:

http://toolboom.com/en/Articles/DSO-Nano-DSO201-Pocket-Sized-Digital-Oscilloscope-Review.html

I know this is a dirt-cheap low-end product, and i'm spoiled having a Agilent
DSO on my desk here.  However, if someone would program proper sinc
interpolation into this it would at least be able to display the sampled
waveforms correctly up to its front-end's bandwidth limit.

-Richie,


From srmaietta at yahoo.com  Thu Feb 23 18:17:08 2012
From: srmaietta at yahoo.com (Steve Maietta)
Date: Thu, 23 Feb 2012 09:17:08 -0800 (PST)
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
Message-ID: <1330017428.3517.YahooMailClassic@web65905.mail.ac4.yahoo.com>

Thise "sine" waves look bad yes, but that's at 500Khz..  So for RF, okay its not going to work.. But perhaps for synth use they do a "good enogh" job?  For tuning circuits, trimming waveshapes etc??

good S-DIY bench/pocket tool?

~Steve



--- On Thu, 2/23/12, Richie Burnett <rburnett at richieburnett.co.uk> wrote:

> From: Richie Burnett <rburnett at richieburnett.co.uk>
> Subject: Re: [sdiy] cute hand held scopes on eBay
> To: synth-diy at dropmix.xs4all.nl
> Date: Thursday, February 23, 2012, 10:22 AM
> >> The DSO nano is fairly
> well-known and was talked about on here a few weeks
> >> ago. I have one; it's OK but a bit cheesy given
> it's single-channel.
> 
> I think the linear interpolation between sample points would
> be my biggest
> gripe!? For example, this picture of a 500kHz
> sinewave:
> 
> http://toolboom.com/content_image/content/5210/IMG_2417.JPG
> 
> from the many photos at this page:
> 
> http://toolboom.com/en/Articles/DSO-Nano-DSO201-Pocket-Sized-Digital-Oscilloscope-Review.html
> 
> I know this is a dirt-cheap low-end product, and i'm spoiled
> having a Agilent
> DSO on my desk here.? However, if someone would program
> proper sinc
> interpolation into this it would at least be able to display
> the sampled
> waveforms correctly up to its front-end's bandwidth limit.
> 
> -Richie,
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From neil.johnson97 at ntlworld.com  Thu Feb 23 18:45:25 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Thu, 23 Feb 2012 17:45:25 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <1330017428.3517.YahooMailClassic@web65905.mail.ac4.yahoo.com>
References: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<1330017428.3517.YahooMailClassic@web65905.mail.ac4.yahoo.com>
Message-ID: <CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>

Steve Maietta wrote:
> Thise "sine" waves look bad yes, but that's at 500Khz..  So for RF, okay its not going to work.. But perhaps for synth use they do a "good enogh" job?  For tuning circuits, trimming waveshapes etc??

The pictures on the webpage Rich linked to are quite astounding.
Sure, it might show you a wiggly line, but I wouldn't trust it any
further than that.  Definitely not for making any measurements.

Try observing the reset pulse from the comparator in a sawtooth VCO.
Its typically a few microseconds.  Say, the ASM-1.... should sit at
the negative rail, then up to 0V for a few microseconds while the
capacitor discharges, then back to V-.  You *might* see something with
this toy.  You might not.  Or something that you can't say whether is
correct or not.

Heck, even that 500Hz square wave on the review site -- what's with
the over/undershoot?  Is that in the circuit, the probe, or the scope?

> good S-DIY bench/pocket tool?

Not in my opinion.  A waste of money, unless you want it for some
artistic purpose.
Better save up and get a decent analogue scope and decent probes.  Or
if you need to capture occasional events or need to dump out dataplots
to a printer or a PC get a decent DSO.

This issue has been discussed on the list several times over the
years.  Rigol and OWON seem quite popular.  Or be lucky on eBay or a
reseller for a second-hand Tektronix or HP/Agilent.

Cheers,
Neil
-- 
Modules and more: http://www.cesyg.com
Homepage: http://www.njohnson.co.uk


From davebr at earthlink.net  Thu Feb 23 19:02:43 2012
From: davebr at earthlink.net (Dave Brown)
Date: Thu, 23 Feb 2012 10:02:43 -0800
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>
References: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>	<1330017428.3517.YahooMailClassic@web65905.mail.ac4.yahoo.com>
	<CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>
Message-ID: <006001ccf255$57c4f7d0$074ee770$@earthlink.net>

I built the AVR scope into a module in my synth
http://modularsynthesis.com/modules/DJB-019/djb019.htm  I show a 300 KHz
square wave image which is fairly decent.

I use it with a slow timebase to show an envelope generator output, or to
set a frequency (it's pretty decent at that).  I would not want to use it
for troubleshooting simply because of the difficulty of the controls.
Besides using multiple channels, I'm always changing the timescale and
trigger, and pushing little buttons to do that is a pain.  I do know someone
that does use this scope for troubleshooting though but they have more
patience than I.  One of the software revisions enables cascading multiple
AVR scopes for multiple channels.

David J. Brown
Email davebr at earthlink.net
Website http://modularsynthesis.com

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Neil Johnson
Sent: Thursday, February 23, 2012 9:45 AM
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] cute hand held scopes on eBay

Steve Maietta wrote:
> Thise "sine" waves look bad yes, but that's at 500Khz..  So for RF, okay
its not going to work.. But perhaps for synth use they do a "good enogh"
job?  For tuning circuits, trimming waveshapes etc??





From mr at analogue.org  Thu Feb 23 20:20:30 2012
From: mr at analogue.org (Mattias Rickardsson)
Date: Thu, 23 Feb 2012 20:20:30 +0100
Subject: [sdiy] Today's Google Doodle...
In-Reply-To: <A0D268C835824497AE85794CA0F89153@galvanox01>
References: <725F495D-6E52-44AC-A65D-21CA1380F42D@till.com>
	<4F44C0E3.70808@ix.netcom.com> <C80D3B809CEC4E1D90BA6651EE5E2DE6@zen>
	<CAJoLJ5VZxw5MObsGkHRAXrFRVXstAS3WMnXz1uo=tFAij5wwqA@mail.gmail.com>
	<CAP92RBVcLFdXS8P0KUZtMYp45_f+A5CVs+XHp-5_ozynbt757Q@mail.gmail.com>
	<A0D268C835824497AE85794CA0F89153@galvanox01>
Message-ID: <CAP92RBUDz32kfLDSnEuwbGr+P0h0b-tsJX5bRxxPw9XwcEgsEQ@mail.gmail.com>

On 22 February 2012 21:28, David G Dixon <dixon at mail.ubc.ca> wrote:
>>> "Sinewaves" drawn with bits of ellipses. That slope at zero
>>> crossings. Arghhhhh.
>>
>> Exactly... it's really awful! Can't see why people keep doing
>> that, even in quite technically serious contexts. :-)
>
> I know, right? ?Why can't everyone be as dorky and obsessive as us? ?It just
> makes me SO MAD!!!! :)

Yeah! At least they could pick a smaller bit of the ellipse. Everyone
should know that the maximum slope should be 1:1 if that half ellipse
is 1 high and Pi long... 8-)

/mr


From srmaietta at yahoo.com  Thu Feb 23 20:35:44 2012
From: srmaietta at yahoo.com (Steve Maietta)
Date: Thu, 23 Feb 2012 11:35:44 -0800 (PST)
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>
Message-ID: <1330025744.34603.YahooMailClassic@web65906.mail.ac4.yahoo.com>

Well thanks for the explanation.


ASM-1.. you don't say..  haha

~Steve
aka The ASM-1 Orphanage.  On my third. 



--- On Thu, 2/23/12, Neil Johnson <neil.johnson97 at ntlworld.com> wrote:

> From: Neil Johnson <neil.johnson97 at ntlworld.com>
> Subject: Re: [sdiy] cute hand held scopes on eBay
> To: synth-diy at dropmix.xs4all.nl
> Date: Thursday, February 23, 2012, 12:45 PM
> Steve Maietta wrote:
> > Thise "sine" waves look bad yes, but that's at
> 500Khz..? So for RF, okay its not going to work.. But
> perhaps for synth use they do a "good enogh" job?? For
> tuning circuits, trimming waveshapes etc??
> 
> The pictures on the webpage Rich linked to are quite
> astounding.
> Sure, it might show you a wiggly line, but I wouldn't trust
> it any
> further than that.? Definitely not for making any
> measurements.
> 
> Try observing the reset pulse from the comparator in a
> sawtooth VCO.
> Its typically a few microseconds.? Say, the ASM-1....
> should sit at
> the negative rail, then up to 0V for a few microseconds
> while the
> capacitor discharges, then back to V-.? You *might* see
> something with
> this toy.? You might not.? Or something that you
> can't say whether is
> correct or not.
> 
> Heck, even that 500Hz square wave on the review site --
> what's with
> the over/undershoot?? Is that in the circuit, the
> probe, or the scope?
> 
> > good S-DIY bench/pocket tool?
> 
> Not in my opinion.? A waste of money, unless you want
> it for some
> artistic purpose.
> Better save up and get a decent analogue scope and decent
> probes.? Or
> if you need to capture occasional events or need to dump out
> dataplots
> to a printer or a PC get a decent DSO.
> 
> This issue has been discussed on the list several times over
> the
> years.? Rigol and OWON seem quite popular.? Or be
> lucky on eBay or a
> reseller for a second-hand Tektronix or HP/Agilent.
> 
> Cheers,
> Neil
> -- 
> Modules and more: http://www.cesyg.com
> Homepage: http://www.njohnson.co.uk
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From dfevans at sekrit.eu  Thu Feb 23 20:44:56 2012
From: dfevans at sekrit.eu (David Evans)
Date: Thu, 23 Feb 2012 19:44:56 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>
References: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<1330017428.3517.YahooMailClassic@web65905.mail.ac4.yahoo.com>
	<CAEaByMT_Y7WcQWiXq=tavCxBPncm96DkBhTB68uJr0Y7pisK8Q@mail.gmail.com>
Message-ID: <B3CEE01C-73D4-492D-830B-85B7FC028F03@sekrit.eu>

On 23 Feb 2012, at 17:45, Neil Johnson wrote:

[ out of order for clarity ]

> Heck, even that 500Hz square wave on the review site -- what's with
> the over/undershoot?  Is that in the circuit, the probe, or the scope?
> 

Wow, that is terrible and nothing like what I've seen. Had I this experience I'd have not much good to say about the thing. However, this photo illustrates how bad it is for some!

> The pictures on the webpage Rich linked to are quite astounding.
> Sure, it might show you a wiggly line, but I wouldn't trust it any
> further than that.  Definitely not for making any measurements.
> 

I think that a "wiggly line" is a bit uncharitable. I've used it for frequency/period measurements and it's worked well for that.

> Try observing the reset pulse from the comparator in a sawtooth VCO.
> Its typically a few microseconds.

Yeah, that sort of thing might lead you into trouble.

> get a decent analogue scope and decent probes.  Or
> if you need to capture occasional events or need to dump out dataplots
> to a printer or a PC get a decent DSO.
> 

Always good advice.




From tom at electricdruid.net  Thu Feb 23 21:22:08 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Thu, 23 Feb 2012 20:22:08 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6
	C29AF0B889F@sekrit.eu>
	<2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>
	<55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
Message-ID: <9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>


On 23 Feb 2012, at 15:22, Richie Burnett wrote:

>>> The DSO nano is fairly well-known and was talked about on here a few weeks
>>> ago. I have one; it's OK but a bit cheesy given it's single-channel.
> 
> I think the linear interpolation between sample points would be my biggest
> gripe!  For example, this picture of a 500kHz sinewave:
> 
> http://toolboom.com/content_image/content/5210/IMG_2417.JPG
> 
> from the many photos at this page:
> 
> http://toolboom.com/en/Articles/DSO-Nano-DSO201-Pocket-Sized-Digital-Oscilloscope-Review.html
> 
> I know this is a dirt-cheap low-end product, and i'm spoiled having a Agilent
> DSO on my desk here.  However, if someone would program proper sinc
> interpolation into this it would at least be able to display the sampled
> waveforms correctly up to its front-end's bandwidth limit.

I quite like the fact that my own digital scope just puts linear sections between samples. It makes it obvious that I'm zoomed in to the limit of the data, and that I shouldn't go making assumptions about what's inbetween those few points. Dot mode does this too, but the display isn't so clear.
If I had a beautiful-looking sinc-interpolated image to look at, I might well start confusing it with reality, and I definitely wouldn't be able to tell where the actual datapoints were.
Tastes differ, I guess.

Tom




From matt at smiffytech.com  Thu Feb 23 21:32:12 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Fri, 24 Feb 2012 07:02:12 +1030
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6	C29AF0B889F@sekrit.eu>	<2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net>	<55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>
Message-ID: <4F46A24C.1050908@smiffytech.com>

Quoth Tom Wiltshire at 24/02/12 06:52...
...
> I quite like the fact that my own digital scope just puts linear sections between samples. It makes it obvious that I'm zoomed in to the limit of the data, and that I shouldn't go making assumptions about what's inbetween those few points. Dot mode does this too, but the display isn't so clear.
> If I had a beautiful-looking sinc-interpolated image to look at, I might well start confusing it with reality, and I definitely wouldn't be able to tell where the actual datapoints were.
> Tastes differ, I guess.

OK, no use for anyone who is colour-blind, but no reason firmware 
couldn't be configured to show data points in a different colour from 
calculated points. Just like on a "real" graph.

My ancient HP 1741A, however, only comes in slightly fuzzy green ;-)

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From aym-htnys at teaser.fr  Thu Feb 23 22:05:22 2012
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Thu, 23 Feb 2012 22:05:22 +0100
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <4F45731F.3030904@ix.netcom.com>
References: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>
	<360C52F8-5DA5-11E1-ADE2-000393A85F9E@ntlworld.com>
	<4F45731F.3030904@ix.netcom.com>
Message-ID: <20120223210522.GC16049@aym.net2.nerim.net>

On 2012-02-22 16:58 -0600, Oren Leavitt wrote:
> On 2/22/2012 4:33 PM, Dave Kendall wrote:
> >On Feb 21, 2012, at 15:43, Harry Bissell wrote:
> >
> >>How about D-SUB 9 pin Males on the modules, and female to
> >>female cables, THIS way you throw out a worn cable. If you
> >>use screw-machined male plugs, the pins should be good for
> >>many many cycles...
> >>
> >>Unfortunately the D-sub cables are not so common anymore...
> >
> >That seems like a good idea.

Seconded. One problem with sub-D is size, though. Rewirable
plugs are about 31 x 16 mm, twice the footprint of a DIN or
phone jack. Moulded plugs are close to parity with 22 x 11 mm.

> > I may have access to a load of NOS D-sub components that
> > were in storage at an A/V place I've worked at. They
> > probably don't want/need those parts anymore, so it could be
> > a cheap and worthwhile experiment (if soldering time is not
> > included in that.....)

Alternatively, there are IDC sub-D.

> Speaking of D-Subs as patch connections. I have been entertaining
> the idea of using 9 pin D-Subs in an 8 voice patchable polysynth.
> Each pin routing signal/CV for single voice.
> Maybe 8 ASM-1 type synths.

Wouldn't eight ASM-1 boards have too many LFOs and way too few
VCAs ?

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


From obl64 at ix.netcom.com  Thu Feb 23 22:18:42 2012
From: obl64 at ix.netcom.com (Oren Leavitt)
Date: Thu, 23 Feb 2012 15:18:42 -0600
Subject: [sdiy] Using D-Sub connectors as patching elements
In-Reply-To: <20120223210522.GC16049@aym.net2.nerim.net>
References: <728325607.479333.1329839036152.JavaMail.root@md01.wow.synacor.com>
	<360C52F8-5DA5-11E1-ADE2-000393A85F9E@ntlworld.com>
	<4F45731F.3030904@ix.netcom.com>
	<20120223210522.GC16049@aym.net2.nerim.net>
Message-ID: <4F46AD32.2020907@ix.netcom.com>



On 2/23/2012 3:05 PM, Andre Majorel wrote:
> On 2012-02-22 16:58 -0600, Oren Leavitt wrote:
>> On 2/22/2012 4:33 PM, Dave Kendall wrote:
>>> On Feb 21, 2012, at 15:43, Harry Bissell wrote:
>>>
>>>> How about D-SUB 9 pin Males on the modules, and female to
>>>> female cables, THIS way you throw out a worn cable. If you
>>>> use screw-machined male plugs, the pins should be good for
>>>> many many cycles...
>>>>
>>>> Unfortunately the D-sub cables are not so common anymore...
>>>
>>> That seems like a good idea.
>
> Seconded. One problem with sub-D is size, though. Rewirable
> plugs are about 31 x 16 mm, twice the footprint of a DIN or
> phone jack. Moulded plugs are close to parity with 22 x 11 mm.
>
>>> I may have access to a load of NOS D-sub components that
>>> were in storage at an A/V place I've worked at. They
>>> probably don't want/need those parts anymore, so it could be
>>> a cheap and worthwhile experiment (if soldering time is not
>>> included in that.....)
>
> Alternatively, there are IDC sub-D.
>
>> Speaking of D-Subs as patch connections. I have been entertaining
>> the idea of using 9 pin D-Subs in an 8 voice patchable polysynth.
>> Each pin routing signal/CV for single voice.
>> Maybe 8 ASM-1 type synths.
>
> Wouldn't eight ASM-1 boards have too many LFOs and way too few
> VCAs ?
>

It's an idea. It's a given that there would be some adjustments needed 
for a polysynth - definitely don't need that many LFOs or noise sources.

- Oren


From rburnett at richieburnett.co.uk  Thu Feb 23 22:27:06 2012
From: rburnett at richieburnett.co.uk (Richie Burnett)
Date: Thu, 23 Feb 2012 21:27:06 -0000
Subject: [sdiy] cute hand held scopes on eBay
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu><2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net><55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>
Message-ID: <232EBD613DE04988BD50AB4B3879104E@homepc002>

Hi Tom, and all.

> I quite like the fact that my own digital scope just puts linear sections 
> between samples. It makes it obvious that I'm zoomed in to the limit of 
> the data, and that I shouldn't go making assumptions about what's 
> inbetween those few points. Dot mode does this too, but the display isn't 
> so clear.

My point regarding the sinc-interpolation is that it is technically the 
correct way to display a continuous waveform in between the discrete sample 
points.  Assuming the signal in question has been properly band-limited 
before being sampled (by front-end analogue anti-aliasing filter), then 
sinc-interpolation actually reconstructs the original continuous-time signal 
from the discrete sample points.

> If I had a beautiful-looking sinc-interpolated image to look at, I might 
> well start confusing it with reality, and I definitely wouldn't be able to 
> tell where the actual datapoints were.
> Tastes differ, I guess.

It's not confusing anything for reality, it is reality.  Done properly sinc 
interpolation will show you the original band-limited signal by drawing a 
continuous smooth line through the sample points.

The thing is that sinc-interpolation isn't actually that hard to do.  It is 
just post-processing of the sampled data before it is displayed on the 
screen.  That's why I think that it is a shame that the ARM DSO product is 
let down in this final step of displaying the captured data!

-Richie, 



From dfevans at sekrit.eu  Thu Feb 23 22:37:22 2012
From: dfevans at sekrit.eu (David Evans)
Date: Thu, 23 Feb 2012 21:37:22 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <232EBD613DE04988BD50AB4B3879104E@homepc002>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu><2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net><55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>
	<232EBD613DE04988BD50AB4B3879104E@homepc002>
Message-ID: <0964F2E4-76C2-47C6-B5D8-433CE00C294A@sekrit.eu>

On 23 Feb 2012, at 21:27, Richie Burnett wrote:

> The thing is that sinc-interpolation isn't actually that hard to do.  It is just post-processing of the sampled data before it is displayed on the screen.  That's why I think that it is a shame that the ARM DSO product is let down in this final step of displaying the captured data!
> 

I can't recall if the Benf firmware does it, but if not then adding it might be easy enough. (Certainly I recall the stock firmware being crap in all sorts of ways!)




From sounddoctorin at imt.net  Thu Feb 23 22:56:19 2012
From: sounddoctorin at imt.net (Bob Weigel)
Date: Thu, 23 Feb 2012 14:56:19 -0700
Subject: [sdiy] juno 106 (illogical) behaviour
In-Reply-To: <4F44D496.3060009@mnet-online.de>
References: <3DDE2FEA-766B-49AB-A4CC-1CBC69E11FB9@gmail.com>
	<4F44D496.3060009@mnet-online.de>
Message-ID: <4F46B603.1040104@imt.net>

On 2/22/2012 4:42 AM, Florian Anwander wrote:
> Am 22.02.2012 12:28, schrieb Antonio Tuzzi:
>> all the buttons are working but:
>> key 2 for the bank number and 4 for the patch number  are not working
>>
>> the keyboard is most defective part.
>> non working:
>> 12 keys octave 1
>> 12 keys octave 2
>> 10 keys octave 3
>> 7 keys octave 4
>> 3 keys octave 5
>> 0 keys octave 6  (is only the final C)
>>
>> I cannot find any "binary rule" (reading the schematics) that brings 
>> this defect
> How dirty is this 106 inside? May a drink was spilled on the 
> synth/keyboard pcb.
>
> Florian
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
Check the contacts and see if the resistance with two probes lying side 
by side is around 700 ohm or less.  If it's a lot more then there's your 
problem.  My website covers both the cleaning/trimming possibilities 
which sometimes works, or the outright 'refacing' of the contacts with 
better than original material it appears.  The contact disks I sell on 
the site also.  sounddoctorin.com/synthtec/parts/key.htm has 'good news' 
links for keyboards that suffer this issue.

-- 
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 tom at electricdruid.net  Fri Feb 24 01:03:16 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 24 Feb 2012 00:03:16 +0000
Subject: [sdiy] cute hand held scopes on eBay
In-Reply-To: <232EBD613DE04988BD50AB4B3879104E@homepc002>
References: <9fnr6q$b20670@out1.ip05ir2.opaltelecom.net><F5ECE2D8-ED19-4641-9BFF-6C29AF0B889F@sekrit.eu><2D5D3EFF-93D9-49BC-A68C-2B7D570A1911@electricdruid.net><55323.128.240.229.68.1330010520.squirrel@www.richieburnett.co.uk>
	<9BD8E3D9-86A8-4EF9-B8B9-B900454146C5@electricdruid.net>
	<232EBD613DE04988BD50AB4B3879104E@homepc002>
Message-ID: <8472E859-5E82-43DF-ACF5-5121F71AD7A1@electricdruid.net>

Hi Richie,

On 23 Feb 2012, at 21:27, Richie Burnett wrote:

> Hi Tom, and all.
> 
>> I quite like the fact that my own digital scope just puts linear sections between samples. It makes it obvious that I'm zoomed in to the limit of the data, and that I shouldn't go making assumptions about what's inbetween those few points. Dot mode does this too, but the display isn't so clear.
> 
> My point regarding the sinc-interpolation is that it is technically the correct way to display a continuous waveform in between the discrete sample points.  Assuming the signal in question has been properly band-limited before being sampled (by front-end analogue anti-aliasing filter), then sinc-interpolation actually reconstructs the original continuous-time signal from the discrete sample points.

I understand that it's technically correct. I just like the technically-incorrect way because it reminds me that what I'm seeing is sampled, not continuous. The sinc interp gets me back to a continuous signal, which isn't what I'm viewing. I'm looking at a load of samples of my input.

>> If I had a beautiful-looking sinc-interpolated image to look at, I might well start confusing it with reality, and I definitely wouldn't be able to tell where the actual datapoints were.
>> Tastes differ, I guess.
> 
> It's not confusing anything for reality, it is reality.  Done properly sinc interpolation will show you the original band-limited signal by drawing a continuous smooth line through the sample points.

That assumes that I didn't lose anything of interest when the signal went through that front-end anti-alising filter. I agree that what the sinc-interp shows is what the scope's AD sees, but what the scope's AD sees isn't necessarily the same as what I feed in, if I push it.

> The thing is that sinc-interpolation isn't actually that hard to do.  It is just post-processing of the sampled data before it is displayed on the screen.  That's why I think that it is a shame that the ARM DSO product is let down in this final step of displaying the captured data!

Hey, it's firmware. We should be able to have lines, dots, lines with dots in different colours, or full sinc interp on some menu somewhere! Everyone's happy!


Tom





From subjectivity at hotmail.com  Fri Feb 24 15:19:57 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Fri, 24 Feb 2012 09:19:57 -0500
Subject: [sdiy] Avr32???
Message-ID: <BLU0-SMTP335EBC9A877631E81E76B9DC86A0@phx.gbl>

Anyone here have experience using these for synth applications?


I was reading that it has dsp features. 
Looked interesting.


Thanks

Sent from my iPhone


From goaqihai at yahoo.co.uk  Fri Feb 24 15:35:21 2012
From: goaqihai at yahoo.co.uk (ganesha)
Date: Fri, 24 Feb 2012 14:35:21 +0000 (GMT)
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com>
	<CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com>
	<BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5>
Message-ID: <1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>

Hi,

I have 2 questions about summing buffers
If you take this schematic:

http://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Op-Amp_Summing_Amplifier.svg/200px-Op-Amp_Summing_Amplifier.svg.png


-Most of the schematics I've seen so far use large resistor values of f.e. 100K for resistors R1- Rn and Rf. 
Is there a specific reason to use 100K 0,1% instead of? small resistor values like for example 1K 0,1%? If they both are high precision resistors of 0,1% I would think the result would be exactly the same?

-In some schematics I've seen a small capacitor in parallel with resistor Rf. Can someone explain when it is better to add a capacitor?

Thanks.



From maillist at tellun.com  Fri Feb 24 19:43:05 2012
From: maillist at tellun.com (Scott Juskiw)
Date: Fri, 24 Feb 2012 11:43:05 -0700
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se>
	<A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net>
	<1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com>
	<CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com>
	<BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5>
	<1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
Message-ID: <6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com>

For the inverting summer shown in that schematic the input impedance is R1. If you use 1K for R1 then your input impedance is 1K which might not work very well (depends on what is driving this circuit). If the output impedance of the driving circuit is also 1K then you are only getting half the voltage at your inverting summer output. Not good.

Capacitor across Rf forms a low pass filter, helps dampen any high frequency oscillations at the output.

On 2012-02-24, at 7:35 AM, ganesha wrote:

> Hi,
> 
> I have 2 questions about summing buffers
> If you take this schematic:
> 
> http://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Op-Amp_Summing_Amplifier.svg/200px-Op-Amp_Summing_Amplifier.svg.png
> 
> 
> -Most of the schematics I've seen so far use large resistor values of f.e. 100K for resistors R1- Rn and Rf. 
> Is there a specific reason to use 100K 0,1% instead of  small resistor values like for example 1K 0,1%? If they both are high precision resistors of 0,1% I would think the result would be exactly the same?
> 
> -In some schematics I've seen a small capacitor in parallel with resistor Rf. Can someone explain when it is better to add a capacitor?
> 
> Thanks.
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From patchell at cox.net  Fri Feb 24 20:07:29 2012
From: patchell at cox.net (James Patchell)
Date: Fri, 24 Feb 2012 11:07:29 -0800
Subject: [sdiy] Avr32???
In-Reply-To: <BLU0-SMTP335EBC9A877631E81E76B9DC86A0@phx.gbl>
References: <BLU0-SMTP335EBC9A877631E81E76B9DC86A0@phx.gbl>
Message-ID: <4F47DFF1.10207@cox.net>

I have very minimal experience.  I bought an eval board a few years ago, 
and played with it.  It is a very powerful little processor.  The 
hardware looks similar to the ARM,  but it is much faster, or so it 
would seem from reading Atmel Lit.  I have been itching to do something 
with one of these myself.

Best thing about it, it has a very nice set of GNU tools that are FREE!

-Jim

On 2/24/2012 6:19 AM, Dan Snazelle wrote:
> Anyone here have experience using these for synth applications?
>
>
> I was reading that it has dsp features.
> Looked interesting.
>
>
> Thanks
>
> Sent from my iPhone
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From ijfritz at comcast.net  Fri Feb 24 20:14:25 2012
From: ijfritz at comcast.net (Ian Fritz)
Date: Fri, 24 Feb 2012 12:14:25 -0700
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se>
	<A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net>
	<1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com>
	<CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com>
	<BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5>
	<1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
	<6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com>
Message-ID: <6.2.1.2.2.20120224121020.02448c38@mail.comcast.net>


>
>Capacitor across Rf forms a low pass filter, helps dampen any high 
>frequency oscillations at the output.

People often write this but it isn't quite true.  The feedback cap 
stabilizes the circuit by compensating for opamp nonidealities, not by 
acting as a LP filter.  IOW you can't clculate the cap size just from the 
frequency of the spurious oscillations.  There is a good TI writeup about 
this online somewhere.

Ian 



From dixon at mail.ubc.ca  Fri Feb 24 20:36:33 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Fri, 24 Feb 2012 12:36:33 -0700
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <6.2.1.2.2.20120224121020.02448c38@mail.comcast.net>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com><CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com><BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5><1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com><6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com>
	<6.2.1.2.2.20120224121020.02448c38@mail.comcast.net>
Message-ID: <4FFA6278D1BF4F4C8B709F5E8D3049A0@galvanox01>

> >Capacitor across Rf forms a low pass filter, helps dampen any high 
> >frequency oscillations at the output.
> 
> People often write this but it isn't quite true.  The 
> feedback cap stabilizes the circuit by compensating for opamp 
> nonidealities, not by acting as a LP filter.  IOW you can't 
> clculate the cap size just from the frequency of the spurious 
> oscillations.  There is a good TI writeup about this online somewhere.

I've been reading up on this stuff myself -- break points and loop gain and
all the rest of it -- but I must confess that when I've got spurious
oscillations in a circuit, I use good old trial and error to find the cap
value which eliminates them.



From ebrombaugh1 at cox.net  Fri Feb 24 21:11:44 2012
From: ebrombaugh1 at cox.net (Eric Brombaugh)
Date: Fri, 24 Feb 2012 13:11:44 -0700
Subject: [sdiy] Avr32???
In-Reply-To: <4F47DFF1.10207@cox.net>
References: <BLU0-SMTP335EBC9A877631E81E76B9DC86A0@phx.gbl>
	<4F47DFF1.10207@cox.net>
Message-ID: <4F47EF00.8040906@cox.net>

I remember looking at these a few years back and being somewhat 
underwhelmed at the time. It looks like there have been some additions 
and improvements in the product line since I last checked though. There 
have been a few DIY projects published on the web that are based on 
these parts but overall they don't seem to get much attention.

The DSP capabilities are reasonably useful, but not up to the standards 
of a true DSP with zero-overhead looping and parallel operand 
prefetching so filtering operations will suffer in comparison to devices 
like the dsPIC, 56k and TMS320.

Feature-wise they have a good selection of peripherals and packages. The 
UC3C variants have an FPU which could come in handy, but the smallest 
package for those is 64-pin and you really have to go to the 144-pin 
parts to get the most from the I/O and those are expensive. UC3B parts 
have smaller packages and lower prices but also lack peripherals (I2S & 
12-bit ADCs) that would be useful for audio. Interrupt architecture 
looks pretty good and goodness but they've got a lot of shadow registers 
for fast context switches.

Max clock speed is 66MHz which doesn't compare favorably with some of 
the common ARM products out there, and Flash memory access requires wait 
states at speeds above 33MHz (something that's fairly common in ARM 
parts too), so I don't quite see where the "much faster" comparison 
comes from.

Atmel AVR devtools are well regarded and free as well, so that's a big 
advantage.

Pricing looks a bit on the high side compared to some of the newer ARM 
Cortex M stuff that's coming on line lately.

Definitely worth consideration, but by no means a slam-dunk win over 
other architectures.

Eric

On 02/24/2012 12:07 PM, James Patchell wrote:
> I have very minimal experience. I bought an eval board a few years ago,
> and played with it. It is a very powerful little processor. The hardware
> looks similar to the ARM, but it is much faster, or so it would seem
> from reading Atmel Lit. I have been itching to do something with one of
> these myself.
>
> Best thing about it, it has a very nice set of GNU tools that are FREE!
>
> -Jim
>
> On 2/24/2012 6:19 AM, Dan Snazelle wrote:
>> Anyone here have experience using these for synth applications?
>>
>> I was reading that it has dsp features.
>> Looked interesting.


From ol.gillet at gmail.com  Fri Feb 24 21:38:28 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Fri, 24 Feb 2012 21:38:28 +0100
Subject: [sdiy] Avr32???
In-Reply-To: <4F47EF00.8040906@cox.net>
References: <BLU0-SMTP335EBC9A877631E81E76B9DC86A0@phx.gbl>
	<4F47DFF1.10207@cox.net> <4F47EF00.8040906@cox.net>
Message-ID: <CAJoLJ5W3tgjGmwvHjoSHY1PB8osNSCiPnoeB0BOn=sD_OS3j-g@mail.gmail.com>

This guy rolled his own AVR32 devboard presumably for synth applications:
http://tolaemon.com/scoreb/

No code/demo beyond the basic drivers, though...

On Fri, Feb 24, 2012 at 9:11 PM, Eric Brombaugh <ebrombaugh1 at cox.net> wrote:
> I remember looking at these a few years back and being somewhat underwhelmed
> at the time. It looks like there have been some additions and improvements
> in the product line since I last checked though. There have been a few DIY
> projects published on the web that are based on these parts but overall they
> don't seem to get much attention.
>
> The DSP capabilities are reasonably useful, but not up to the standards of a
> true DSP with zero-overhead looping and parallel operand prefetching so
> filtering operations will suffer in comparison to devices like the dsPIC,
> 56k and TMS320.
>
> Feature-wise they have a good selection of peripherals and packages. The
> UC3C variants have an FPU which could come in handy, but the smallest
> package for those is 64-pin and you really have to go to the 144-pin parts
> to get the most from the I/O and those are expensive. UC3B parts have
> smaller packages and lower prices but also lack peripherals (I2S & 12-bit
> ADCs) that would be useful for audio. Interrupt architecture looks pretty
> good and goodness but they've got a lot of shadow registers for fast context
> switches.
>
> Max clock speed is 66MHz which doesn't compare favorably with some of the
> common ARM products out there, and Flash memory access requires wait states
> at speeds above 33MHz (something that's fairly common in ARM parts too), so
> I don't quite see where the "much faster" comparison comes from.
>
> Atmel AVR devtools are well regarded and free as well, so that's a big
> advantage.
>
> Pricing looks a bit on the high side compared to some of the newer ARM
> Cortex M stuff that's coming on line lately.
>
> Definitely worth consideration, but by no means a slam-dunk win over other
> architectures.
>
> Eric
>
>
> On 02/24/2012 12:07 PM, James Patchell wrote:
>>
>> I have very minimal experience. I bought an eval board a few years ago,
>> and played with it. It is a very powerful little processor. The hardware
>> looks similar to the ARM, but it is much faster, or so it would seem
>> from reading Atmel Lit. I have been itching to do something with one of
>> these myself.
>>
>> Best thing about it, it has a very nice set of GNU tools that are FREE!
>>
>> -Jim
>>
>> On 2/24/2012 6:19 AM, Dan Snazelle wrote:
>>>
>>> Anyone here have experience using these for synth applications?
>>>
>>> I was reading that it has dsp features.
>>> Looked interesting.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From tom at electricdruid.net  Fri Feb 24 21:49:59 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Fri, 24 Feb 2012 20:49:59 +0000
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com>
	<CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com>
	<BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5>
	<1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
Message-ID: <0F830CF1-B82E-41F3-A19F-CAF0158558A2@electricdruid.net>


On 24 Feb 2012, at 14:35, ganesha wrote:

> Hi,
> 
> I have 2 questions about summing buffers
> If you take this schematic:
> 
> http://upload.wikimedia.org/wikipedia/commons/thumb/3/3e/Op-Amp_Summing_Amplifier.svg/200px-Op-Amp_Summing_Amplifier.svg.png
> 
> 
> -Most of the schematics I've seen so far use large resistor values of f.e. 100K for resistors R1- Rn and Rf. 
> Is there a specific reason to use 100K 0,1% instead of  small resistor values like for example 1K 0,1%? If they both are high precision resistors of 0,1% I would think the result would be exactly the same?

0.1% is very high precision, I'd say. 1% is easily good enough, and not that long ago 5% would have been normal. There's no need to go crazy for a audio mixer. Maybe for an instrumentation application, but not a mixer.

Scott J mentioned the input impedance issue, but otherwise the equations for the op-amp all work out the same. I remember doing an experiment with a 741 when I was first learning about op-amps. I built an inverting amp using 100R, 1K, 10K, 100K, 1M and 10M resistors. What I learned was that apart from the two extremes, I couldn't hear any difference. The extremes were noisy. I also learned that the 10K, 47K, and 100K values that I commonly saw in circuits were right in the middle of the range, and so I've used similar values ever since.

> -In some schematics I've seen a small capacitor in parallel with resistor Rf. Can someone explain when it is better to add a capacitor?

In general, it's better to add the capacitor. After all, in general you're not trying to amplify radio waves, so you might as well tame the top end. I usually leave space in a circuit to add the cap, even if sometimes I don't fit it. Stick in something that rolls everything off above whatever you regard as the top end of audio (15KHz, 20KHz, 25KHz?) and you're done. I tend to use a fairly low value for this since I'm not a fan of crisp bright treble anyway, and a lot of 'warm', 'analogue' gear has a frequency response that basically nosedives above 10KHz!

HTH,
Tom

From neil.johnson97 at ntlworld.com  Fri Feb 24 22:49:50 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Fri, 24 Feb 2012 21:49:50 +0000
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <4FFA6278D1BF4F4C8B709F5E8D3049A0@galvanox01>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com><CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com><BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5><1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com><6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com>
	<6.2.1.2.2.20120224121020.02448c38@mail.comcast.net>
	<4FFA6278D1BF4F4C8B709F5E8D3049A0@galvanox01>
Message-ID: <4F4805FE.8070006@ntlworld.com>

Hi,

Scott Juskiw wrote:
>>> Capacitor across Rf forms a low pass filter, helps dampen any high
>>> frequency oscillations at the output.

Ian Fritz wrote:
>> People often write this but it isn't quite true.  The
>> feedback cap stabilizes the circuit by compensating for opamp
>> nonidealities, not by acting as a LP filter.  IOW you can't
>> clculate the cap size just from the frequency of the spurious
>> oscillations.  There is a good TI writeup about this online somewhere.

David G Dixon wrote:
> I've been reading up on this stuff myself -- break points and loop gain and
> all the rest of it -- but I must confess that when I've got spurious
> oscillations in a circuit, I use good old trial and error to find the cap
> value which eliminates them.

Walt Jung has a nice little write-up about this in his "IC Op-Amp 
Handbook", section 3.3.1.

Cheers,
Neil
-- 
Modules and more :: www.cesyg.com
Homepage :: www.njohnson.co.uk ::


From dixon at mail.ubc.ca  Sat Feb 25 00:50:01 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Fri, 24 Feb 2012 16:50:01 -0700
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <0F830CF1-B82E-41F3-A19F-CAF0158558A2@electricdruid.net>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com><CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com><BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5><1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com>
	<0F830CF1-B82E-41F3-A19F-CAF0158558A2@electricdruid.net>
Message-ID: <09F29DD3A157453D853A16C85E9D8C01@galvanox01>

> Scott J mentioned the input impedance issue, but otherwise 
> the equations for the op-amp all work out the same. I 
> remember doing an experiment with a 741 when I was first 
> learning about op-amps. I built an inverting amp using 100R, 
> 1K, 10K, 100K, 1M and 10M resistors. What I learned was that 
> apart from the two extremes, I couldn't hear any difference. 
> The extremes were noisy. I also learned that the 10K, 47K, 
> and 100K values that I commonly saw in circuits were right in 
> the middle of the range, and so I've used similar values ever since.

At 100R, you'll get excessive current noise.  At 1M or 10M, you'll get
excessive Johnson noise (I think that's what it's called).

I tend to use mostly 100k in my home-built through-hole circuits, but have
found that 10k to 30k is better in SMD circuits.  I still don't know why,
but figure it may have to do with layout issues.

> In general, it's better to add the capacitor. After all, in 
> general you're not trying to amplify radio waves, so you 
> might as well tame the top end. I usually leave space in a 
> circuit to add the cap, even if sometimes I don't fit it. 
> Stick in something that rolls everything off above whatever 
> you regard as the top end of audio (15KHz, 20KHz, 25KHz?) and 
> you're done. I tend to use a fairly low value for this since 
> I'm not a fan of crisp bright treble anyway, and a lot of 
> 'warm', 'analogue' gear has a frequency response that 
> basically nosedives above 10KHz!

I too almost always make room for caps next to the inverting and output pins
of opamps, which is very easy to do in my layout style.  However, bear in
mind that there are a few situations where you definitely do not want to use
feedback capacitors -- on unity-gain inverters in filter cores, for example
-- as they can sometimes introduce spurious behaviour.  Experiment!



From dixon at mail.ubc.ca  Sat Feb 25 00:51:41 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Fri, 24 Feb 2012 16:51:41 -0700
Subject: [sdiy] Newbie questions about summing buffers
In-Reply-To: <4F4805FE.8070006@ntlworld.com>
References: <EE034063-081D-478F-B015-5A412E43EB7D@yahoo.se><A3B3DFBD-E131-4985-96B0-072A9BE0EF1E@VacoLoco.net><1324578984.51187.YahooMailNeo@web25705.mail.ukl.yahoo.com><CAMnyfQnppH8i9y2wLXWAnCKDAr8s0KaQVoyB3weX5-5Uu-a3eA@mail.gmail.com><BAA3D4CA148E45D8ACD6792F54177504@ownerf0d9273f5><1330094121.50918.YahooMailNeo@web171410.mail.ir2.yahoo.com><6CC22A1A-A2D1-4214-BFFD-4940AD281D13@tellun.com><6.2.1.2.2.20120224121020.02448c38@mail.comcast.net><4FFA6278D1BF4F4C8B709F5E8D3049A0@galvanox01>
	<4F4805FE.8070006@ntlworld.com>
Message-ID: <775D012A646C49A6871804604F4DAE36@galvanox01>

> David G Dixon wrote:
> > I've been reading up on this stuff myself

> Walt Jung has a nice little write-up about this in his "IC 
> Op-Amp Handbook", section 3.3.1.

That's exactly what I've been reading!



From subjectivity at hotmail.com  Sat Feb 25 03:36:02 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Sat, 25 Feb 2012 02:36:02 -0000
Subject: [sdiy] sine wave floating point conversion issue
Message-ID: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>

If I have a value in my program that is putting out floating point values (to make a sine wave) between 0.0 and 1.0

I would like to get these values into an integer value of between 0 and 255 for my dac routine.

i tried changing the type and multiplying the value and then dividing it, but then i ended up with negative and positive values....


here is the routine which MAKES the sine

	

void loop () {
  int FREQUENCY=25+analogRead(0);
  float sample;
   int j; 

	for(j = 0; j < NUM_SAMPLES; j++) {

		

  		sample = sin(2 * PI * FREQUENCY * j / SAMPLING_RATE);


sample is the value which is a float and puts out the number I want to transform into something usable for the dacOutput function.


This has shown me I need to get better and basic type conversion, etc


thanks





From subjectivity at hotmail.com  Sat Feb 25 04:15:32 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Fri, 24 Feb 2012 22:15:32 -0500
Subject: [sdiy] sine wave floating point conversion issue
In-Reply-To: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
Message-ID: <BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>

that should be
> 
> If I have a value in my program that is putting out floating point values (to make a sine wave) between "-1.0 and 1.0"





On Dec 31, 2000, at 7:51 PM, dan snazelle wrote:

> If I have a value in my program that is putting out floating point values (to make a sine wave) between 0.0 and 1.0
> 
> I would like to get these values into an integer value of between 0 and 255 for my dac routine.
> 
> i tried changing the type and multiplying the value and then dividing it, but then i ended up with negative and positive values....
> 
> 
> here is the routine which MAKES the sine
> 
> 	
> 
> void loop () {
>  int FREQUENCY=25+analogRead(0);
>  float sample;
>   int j; 
> 
> 	for(j = 0; j < NUM_SAMPLES; j++) {
> 
> 		
> 
>  		sample = sin(2 * PI * FREQUENCY * j / SAMPLING_RATE);
> 
> 
> sample is the value which is a float and puts out the number I want to transform into something usable for the dacOutput function.
> 
> 
> This has shown me I need to get better and basic type conversion, etc
> 
> 
> thanks
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 



From jays at aracnet.com  Sat Feb 25 04:20:24 2012
From: jays at aracnet.com (Jay Schwichtenberg)
Date: Fri, 24 Feb 2012 19:20:24 -0800
Subject: [sdiy] sine wave floating point conversion issue
In-Reply-To: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
Message-ID: <000701ccf36c$69e5b0e0$3db112a0$@com>

Dan,

Try:
	sine_int = (int) ((((sine_float + 1.0) * 256.0) - 1.0) / 2.0);

Jay S.

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
Sent: Sunday, December 31, 2000 4:52 PM
To: synthdiy diy
Subject: [sdiy] sine wave floating point conversion issue

If I have a value in my program that is putting out floating point values
(to make a sine wave) between 0.0 and 1.0

I would like to get these values into an integer value of between 0 and 255
for my dac routine.

i tried changing the type and multiplying the value and then dividing it,
but then i ended up with negative and positive values....


here is the routine which MAKES the sine

	

void loop () {
  int FREQUENCY=25+analogRead(0);
  float sample;
   int j; 

	for(j = 0; j < NUM_SAMPLES; j++) {

		

  		sample = sin(2 * PI * FREQUENCY * j / SAMPLING_RATE);


sample is the value which is a float and puts out the number I want to
transform into something usable for the dacOutput function.


This has shown me I need to get better and basic type conversion, etc


thanks



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




From veronica at merryfield.ca  Sat Feb 25 04:29:42 2012
From: veronica at merryfield.ca (Veronica Merryfield)
Date: Fri, 24 Feb 2012 19:29:42 -0800
Subject: [sdiy] sine wave floating point conversion issue
In-Reply-To: <000701ccf36c$69e5b0e0$3db112a0$@com>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<000701ccf36c$69e5b0e0$3db112a0$@com>
Message-ID: <37E5F14A-2162-4430-8AE4-1D9E3B941D05@merryfield.ca>

Divide is often expensive (although not always).

unsigned char DacValue = (unsigned char)((sample*127.5)+127.5);

On 2012-02-24, at 7:20 PM, Jay Schwichtenberg wrote:

> Dan,
> 
> Try:
> 	sine_int = (int) ((((sine_float + 1.0) * 256.0) - 1.0) / 2.0);
> 
> Jay S.
> 
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
> Sent: Sunday, December 31, 2000 4:52 PM
> To: synthdiy diy
> Subject: [sdiy] sine wave floating point conversion issue
> 
> If I have a value in my program that is putting out floating point values
> (to make a sine wave) between 0.0 and 1.0
> 
> I would like to get these values into an integer value of between 0 and 255
> for my dac routine.
> 
> i tried changing the type and multiplying the value and then dividing it,
> but then i ended up with negative and positive values....
> 
> 
> here is the routine which MAKES the sine
> 
> 	
> 
> void loop () {
>  int FREQUENCY=25+analogRead(0);
>  float sample;
>   int j; 
> 
> 	for(j = 0; j < NUM_SAMPLES; j++) {
> 
> 		
> 
>  		sample = sin(2 * PI * FREQUENCY * j / SAMPLING_RATE);
> 
> 
> sample is the value which is a float and puts out the number I want to
> transform into something usable for the dacOutput function.
> 
> 
> This has shown me I need to get better and basic type conversion, etc
> 
> 
> 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 subjectivity at hotmail.com  Sat Feb 25 05:42:07 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Fri, 24 Feb 2012 23:42:07 -0500
Subject: [sdiy] sine wave floating point conversion issue
In-Reply-To: <37E5F14A-2162-4430-8AE4-1D9E3B941D05@merryfield.ca>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<000701ccf36c$69e5b0e0$3db112a0$@com>
	<37E5F14A-2162-4430-8AE4-1D9E3B941D05@merryfield.ca>
Message-ID: <BLU0-SMTP64B50F75CDEED9B87703C8C86B0@phx.gbl>

Thanks everyone!!!

Sent from my iPhone

On Feb 24, 2012, at 10:29 PM, Veronica Merryfield <veronica at merryfield.ca> wrote:

> Divide is often expensive (although not always).
> 
> unsigned char DacValue = (unsigned char)((sample*127.5)+127.5);
> 
> On 2012-02-24, at 7:20 PM, Jay Schwichtenberg wrote:
> 
>> Dan,
>> 
>> Try:
>>    sine_int = (int) ((((sine_float + 1.0) * 256.0) - 1.0) / 2.0);
>> 
>> Jay S.
>> 
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
>> Sent: Sunday, December 31, 2000 4:52 PM
>> To: synthdiy diy
>> Subject: [sdiy] sine wave floating point conversion issue
>> 
>> If I have a value in my program that is putting out floating point values
>> (to make a sine wave) between 0.0 and 1.0
>> 
>> I would like to get these values into an integer value of between 0 and 255
>> for my dac routine.
>> 
>> i tried changing the type and multiplying the value and then dividing it,
>> but then i ended up with negative and positive values....
>> 
>> 
>> here is the routine which MAKES the sine
>> 
>>    
>> 
>> void loop () {
>> int FREQUENCY=25+analogRead(0);
>> float sample;
>>  int j; 
>> 
>>    for(j = 0; j < NUM_SAMPLES; j++) {
>> 
>>        
>> 
>>        sample = sin(2 * PI * FREQUENCY * j / SAMPLING_RATE);
>> 
>> 
>> sample is the value which is a float and puts out the number I want to
>> transform into something usable for the dacOutput function.
>> 
>> 
>> This has shown me I need to get better and basic type conversion, etc
>> 
>> 
>> 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 matt at smiffytech.com  Sat Feb 25 20:52:14 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Sun, 26 Feb 2012 06:22:14 +1030
Subject: [sdiy] sine wave floating point conversion issue
In-Reply-To: <BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
Message-ID: <4F493BEE.1080902@smiffytech.com>

I guess, for the sake of completeness, I should ask if you REALLY want 
to be calculating sines at all, unless you have a way overpowered system 
with more spare CPU cycles than you know what to do with.

Don't know what frequency range you will be working over, but if you 
were to set up an array of 4096 integers, rather than go through the 
heartache of doing infinite series to get your sines, you could do FAR 
less math just figuring out when to grab the next value from the array. 
And, as you go up in frequency, what your increment value is - because 
you sure won't need every single one of 4k samples up the top end of the 
keyboard.

I tend to regard working out sines on the fly to be a case of 
re-calculating the wheel, but then I was brought up on Godfrey & 
Siddon's Four Figure Tables ;-)

By the way, Dan, have you considered using an RTOS for this type of 
work?  Whilst I have yet to implement one, my reading suggests that they 
are far less scary than I had thought - and really wish I'd started 
using them before I had started any of my current projects. If you're 
still using AVRs, FreeRTOS is know to work on the ATMega128 (just enough 
RAM.)

Cheers

M

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From tom at electricdruid.net  Sat Feb 25 22:23:30 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sat, 25 Feb 2012 21:23:30 +0000
Subject: [sdiy] RTOS (was Re:  sine wave floating point conversion issue)
In-Reply-To: <4F493BEE.1080902@smiffytech.com>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
	<4F493BEE.1080902@smiffytech.com>
Message-ID: <54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>

What advantages do you find with a full RTOS, Matthew?

I generally use a tick-based scheduling algorithm without priority and find that sufficient. I'd begin to wonder if I was doing the right thing if it wasn't enough for the task(s) at hand, to be honest. I'd probably try and rethink the problem into a simpler solution rather than use a more powerful structure.

It looks like this:


//=============================================================
//		Process Timing
//=============================================================
// Process Timing bitmasks
#define SCAN_KNOBS		128		// Process analog inputs
#define CHECK_SERIAL		64		// Check for received serial messages
#define CHECK_THING1		32		// Do something
#define CHECK_THING2		16		// Do something

// Set up an array to define the timing
static int process_timing[] = {	0b10100000,
							0b01100000,
							0b10100000,
							0b01110000};
// For what each bit means, see above - I'm not using all the available width, obviously.


	// Set up the Process Timing Clock
	int clock = 0;

	// Loop forever
	while(1)
	{
		// Has the Timer counted the process timing period?
		if (IFS0bits.T1IF == 1) {
			IFS0bits.T1IF = 0;	// Clear period match flag
			// Move onto the next tick of the Process Timing Clock
			clock++;
			clock &= 0x3;		// Wrap around in 2 bits (4 tick cycle)

			// Get the flags from the Process Timing array
			int timing = process_timing[clock];
			// Now we use the flags to determine which processes should run

//=============================================================
//		PROCESS: DO SOMETHING
//=============================================================
		
			if ((timing & CHECK_THING1) > 0) {

				// So do it

			}

//=============================================================
//		PROCESS: DO SOMETHING ELSE
//=============================================================
		
			if ((timing & CHECK_THING2) > 0) {

				// So do it

			}

// Include as many processes as you need.

		}
	}

I have a timer running to provide the timebase for this, and I can set up certain events to occur more frequently than others in the process_timing array. In the example above, for instance, the SCAN_KNOBS and CHECK_SERIAL alternate, CHECK_THING1 happens every time, and CHECK_THING2 only happens every fourth time.
I've mostly used a 1ms timebase, but sometimes used a 0.5ms timebase, with the majority of tasks happening every second cycle.

A structure like this seems to me to provide most of the benefits whilst being extremely simple - unless I'm missing something important? Hence the question.

Thanks,
Tom






On 25 Feb 2012, at 19:52, Matthew Smith wrote:

> I guess, for the sake of completeness, I should ask if you REALLY want to be calculating sines at all, unless you have a way overpowered system with more spare CPU cycles than you know what to do with.
> 
> Don't know what frequency range you will be working over, but if you were to set up an array of 4096 integers, rather than go through the heartache of doing infinite series to get your sines, you could do FAR less math just figuring out when to grab the next value from the array. And, as you go up in frequency, what your increment value is - because you sure won't need every single one of 4k samples up the top end of the keyboard.
> 
> I tend to regard working out sines on the fly to be a case of re-calculating the wheel, but then I was brought up on Godfrey & Siddon's Four Figure Tables ;-)
> 
> By the way, Dan, have you considered using an RTOS for this type of work?  Whilst I have yet to implement one, my reading suggests that they are far less scary than I had thought - and really wish I'd started using them before I had started any of my current projects. If you're still using AVRs, FreeRTOS is know to work on the ATMega128 (just enough RAM.)
> 
> Cheers
> 
> M
> 
> -- 
> Matthew Smith
> 
> Business: http://www.smiffytech.com
> Blog:     http://www.smiffysplace.com
> Linkedin: http://www.linkedin.com/in/smiffy
> Flickr:   http://www.flickr.com/photos/msmiffy
> Twitter:  http://twitter.com/smiffy
> 
> ABN 16 391 203 815
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From ol.gillet at gmail.com  Sat Feb 25 22:45:30 2012
From: ol.gillet at gmail.com (Olivier Gillet)
Date: Sat, 25 Feb 2012 22:45:30 +0100
Subject: [sdiy] RTOS (was Re: sine wave floating point conversion issue)
In-Reply-To: <54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
	<4F493BEE.1080902@smiffytech.com>
	<54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
Message-ID: <CAJoLJ5V0PKXdOBT4w-vCafqMVUwCvg_nq9Zkjawdq=GRRdgf+Q@mail.gmail.com>

This works well under the assumption that each task will complete
rapidly. As soon as a task can unpredictably take more time to
complete (say 10 ms in your case), and you still want the other ones
to be executed on a regular time base, this solution won't work. There
are several options then:
* Do everything time critical in a timer ISR, and everything "slow"
and not time-critical in the main code.
* Allow the "slow" task to return mid-way, for example by using
coroutines http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
. The drawback is that you'll have to sprinkle TASK_SWITCH or whatever
macro you have defined everywhere in your tasks code to indicate where
it's OK to break from.
* Use a proper RTOS.

I personally think that an RTOS is overkill for something at the level
of complexity as a synth project (except maybe if it's a
workstation-style thing). I wouldn't do a quadrocopter without though
:) And in Dan's case, who is doing sound generation or Fxs on an AVR
clocked at 16 MHz, this is close to insane.

Olivier


From williamjf77 at yahoo.com  Sat Feb 25 22:51:07 2012
From: williamjf77 at yahoo.com (william faulkner)
Date: Sat, 25 Feb 2012 13:51:07 -0800 (PST)
Subject: [sdiy] (no subject)
Message-ID: <1330206667.88689.yint-ygo-j2me@web125404.mail.ne1.yahoo.com>


Make alot of money using your computer... http://digitaulis.com/service.link.php?qulGIS=34be7


From matt at smiffytech.com  Sat Feb 25 23:48:08 2012
From: matt at smiffytech.com (Matthew Smith)
Date: Sun, 26 Feb 2012 09:18:08 +1030
Subject: [sdiy] RTOS (was Re: sine wave floating point conversion issue)
In-Reply-To: <54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
	<4F493BEE.1080902@smiffytech.com>
	<54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
Message-ID: <4F496528.9040009@smiffytech.com>

Quoth Tom Wiltshire at 26/02/12 07:53...
> What advantages do you find with a full RTOS, Matthew?

To give a bit of background, I have been developing (mostly on paper,) a 
few microcontroller-based systems, for various purposes, and using 
different families of devices from multiple vendors.

In order to avoid continually re-inventing the wheel, I have started 
building a toolkit of code to write to a specific (external) DAC, 
display stuff on an LCD, interpret data from a rotary encoder, etcetera, 
etcetera. The idea is to create a hardware abstraction layer (HAL) for 
each family, so that the higher level toolkit can talk to a consistent 
API, even if I were to port from, say, AVR, to MSP430, to Kinetis ARM 
Cortex M4.

Writing a scheduler for each of these would mean having to do so for 
each family, due to the ways different interrupts are implemented both 
in the devices themselves, and the different toolchains.

FreeRTOS appears to take care of both HAL and scheduler - someone's 
already done the dirty work. I can just get on and build my toolkit, 
knowing that I've got a consistent API to work with, and a proven 
scheduler to boot.

I can then take the ADSR/LFO code I'm developing on an ATMega128 (the 
last thing I'm doing with AVR, as I'm dumping Atmel in favour of 
Freescale) and shove it, as a module, straight into a Kinetis project.

So, I guess you could say that, for me, it's about flexibility and 
cutting development time over a number of designs.

-- 
Matthew Smith

Business: http://www.smiffytech.com
Blog:     http://www.smiffysplace.com
Linkedin: http://www.linkedin.com/in/smiffy
Flickr:   http://www.flickr.com/photos/msmiffy
Twitter:  http://twitter.com/smiffy

ABN 16 391 203 815


From subjectivity at hotmail.com  Sun Feb 26 00:24:30 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Sat, 25 Feb 2012 18:24:30 -0500
Subject: [sdiy] RTOS (was Re: sine wave floating point conversion issue)
In-Reply-To: <4F496528.9040009@smiffytech.com>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
	<4F493BEE.1080902@smiffytech.com>
	<54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
	<4F496528.9040009@smiffytech.com>
Message-ID: <BLU0-SMTP1804B86BEECDF85E29C0600C86B0@phx.gbl>

Freescale eh? Can anyone vouch for these? What speed? Peripherals? Free C compiler? support online? price


Thanks

Sent from my iPhone

On Feb 25, 2012, at 5:48 PM, Matthew Smith <matt at smiffytech.com> wrote:

> Quoth Tom Wiltshire at 26/02/12 07:53...
>> What advantages do you find with a full RTOS, Matthew?
> 
> To give a bit of background, I have been developing (mostly on paper,) a few microcontroller-based systems, for various purposes, and using different families of devices from multiple vendors.
> 
> In order to avoid continually re-inventing the wheel, I have started building a toolkit of code to write to a specific (external) DAC, display stuff on an LCD, interpret data from a rotary encoder, etcetera, etcetera. The idea is to create a hardware abstraction layer (HAL) for each family, so that the higher level toolkit can talk to a consistent API, even if I were to port from, say, AVR, to MSP430, to Kinetis ARM Cortex M4.
> 
> Writing a scheduler for each of these would mean having to do so for each family, due to the ways different interrupts are implemented both in the devices themselves, and the different toolchains.
> 
> FreeRTOS appears to take care of both HAL and scheduler - someone's already done the dirty work. I can just get on and build my toolkit, knowing that I've got a consistent API to work with, and a proven scheduler to boot.
> 
> I can then take the ADSR/LFO code I'm developing on an ATMega128 (the last thing I'm doing with AVR, as I'm dumping Atmel in favour of Freescale) and shove it, as a module, straight into a Kinetis project.
> 
> So, I guess you could say that, for me, it's about flexibility and cutting development time over a number of designs.
> 
> -- 
> Matthew Smith
> 
> Business: http://www.smiffytech.com
> Blog:     http://www.smiffysplace.com
> Linkedin: http://www.linkedin.com/in/smiffy
> Flickr:   http://www.flickr.com/photos/msmiffy
> Twitter:  http://twitter.com/smiffy
> 
> ABN 16 391 203 815
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From luther.rochester at gmail.com  Sun Feb 26 03:18:18 2012
From: luther.rochester at gmail.com (luther rochester)
Date: Sat, 25 Feb 2012 20:18:18 -0600
Subject: [sdiy] Prophet 600 tuning question
Message-ID: <4F49966A.6070404@gmail.com>

When my 600 tunes up, all 6 voices are in tune with each other and 
scaled fine over octaves. But all notes on the synth are a bit flat. I 
have to keep the Master Tune knob at about +3 in order for it in tune to 
properly to other instruments.

I've read the scaling procedure and it seems relatively painless, but it 
also doesn't seem like it would address this problem. Is there some 
other kind of offset adjustment I can make so keeping the Master Tune at 
0 will mean the synth will be in tune?

Thanks
-- 
./luther


From dougt55 at yahoo.com  Sun Feb 26 06:01:48 2012
From: dougt55 at yahoo.com (Doug Terrebonne)
Date: Sat, 25 Feb 2012 21:01:48 -0800 (PST)
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <4F49966A.6070404@gmail.com>
Message-ID: <1330232508.20356.YahooMailClassic@web181714.mail.ne1.yahoo.com>


Pull off the knob when it is in tune and put it back on so the line is at 12 o'clock. :)

Doug
--- On Sat, 2/25/12, luther rochester <luther.rochester at gmail.com> wrote:

> From: luther rochester <luther.rochester at gmail.com>
> Subject: [sdiy] Prophet 600 tuning question
> To: "'synthdiy diy'" <synth-diy at dropmix.xs4all.nl>
> Date: Saturday, February 25, 2012, 6:18 PM
> When my 600 tunes up, all 6 voices
> are in tune with each other and scaled fine over octaves.
> But all notes on the synth are a bit flat. I have to keep
> the Master Tune knob at about +3 in order for it in tune to
> properly to other instruments.
> 
> I've read the scaling procedure and it seems relatively
> painless, but it also doesn't seem like it would address
> this problem. Is there some other kind of offset adjustment
> I can make so keeping the Master Tune at 0 will mean the
> synth will be in tune?
> 
> Thanks
> -- ./luther
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From veronica at merryfield.ca  Sun Feb 26 07:02:58 2012
From: veronica at merryfield.ca (Veronica Merryfield)
Date: Sat, 25 Feb 2012 22:02:58 -0800
Subject: [sdiy] RTOS (was Re: sine wave floating point conversion issue)
In-Reply-To: <CAJoLJ5V0PKXdOBT4w-vCafqMVUwCvg_nq9Zkjawdq=GRRdgf+Q@mail.gmail.com>
References: <BLU0-SMTP88C806D92D41873988AA23C86B0@phx.gbl>
	<BLU0-SMTP11509EEFFA6FFCA937D8DA2C86B0@phx.gbl>
	<4F493BEE.1080902@smiffytech.com>
	<54B85C2C-812B-4328-9194-CE6685A1F550@electricdruid.net>
	<CAJoLJ5V0PKXdOBT4w-vCafqMVUwCvg_nq9Zkjawdq=GRRdgf+Q@mail.gmail.com>
Message-ID: <29CF755E-B874-4196-B2B6-4E2C808D576F@merryfield.ca>


On 2012-02-25, at 1:45 PM, Olivier Gillet wrote:

> This works well under the assumption that each task will complete
> rapidly. As soon as a task can unpredictably take more time to
> complete (say 10 ms in your case), and you still want the other ones
> to be executed on a regular time base, this solution won't work. There
> are several options then:
> * Do everything time critical in a timer ISR, and everything "slow"
> and not time-critical in the main code.
> * Allow the "slow" task to return mid-way, for example by using
> coroutines http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
> . The drawback is that you'll have to sprinkle TASK_SWITCH or whatever
> macro you have defined everywhere in your tasks code to indicate where
> it's OK to break from.

The usual way to implement this is to create a state machine where the context is managed explicitly in code. I have on many occasions used this technique and on several used one state machine and a number of context structures - serial routines dealing with weigh scales in chemical plants for instance. In our world, handling multiple midi in sources could be done this way.

> * Use a proper RTOS.

The trade off here is the context switching time verses the pre-emption of tasks and the various other features that usually come with an RTOS. Saving the processor state, finding the next task to run, restoring the state and anything else required (cache flush, memory management and such in bigger systems) can take a significant amount of time. Depending on the flavour of RTOS, it might impose constraints on interrupt processing and so on. An RTOS does not guarantee to make real time systems any more real time and often an RTOS requires overhead horse power. Where it can sometime score is if the RTOS exists for different platforms, something Matthew migth benefit from, or where the system are very complex.

> I personally think that an RTOS is overkill for something at the level
> of complexity as a synth project (except maybe if it's a
> workstation-style thing). I wouldn't do a quadrocopter without though
> :) And in Dan's case, who is doing sound generation or Fxs on an AVR
> clocked at 16 MHz, this is close to insane.

More or less. Depending on the quadrocopter, I still might not :) 

From tom at electricdruid.net  Sun Feb 26 14:32:22 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 26 Feb 2012 13:32:22 +0000
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <4F49966A.6070404@gmail.com>
References: <4F49966A.6070404@gmail.com>
Message-ID: <4956B81D-1900-4B44-8065-73E758E7F18F@electricdruid.net>

From looking at the schematics, I'd say there's no simple adjustment for it. Doug's right - moving the knob is probably easiest.

The Master Tune knob seems to be just a control read by the ADC and then used by the uP to adjust the CVs sent to the voices. There's no adjustments for all the voice CVs - the CV comes from the DAC to an S/H cell and then directly to the voice. No summer or anything in between.

Given that the uP is using its own clock frequency as the basic time reference, presumably you could retune the whole instrument a little by tweaking the 8MHz master uP clock. It's possible that this has drifted a bit over the years. Aside from that, I can't really see a way to do it.

T.

On 26 Feb 2012, at 02:18, luther rochester wrote:

> When my 600 tunes up, all 6 voices are in tune with each other and scaled fine over octaves. But all notes on the synth are a bit flat. I have to keep the Master Tune knob at about +3 in order for it in tune to properly to other instruments.
> 
> I've read the scaling procedure and it seems relatively painless, but it also doesn't seem like it would address this problem. Is there some other kind of offset adjustment I can make so keeping the Master Tune at 0 will mean the synth will be in tune?
> 
> Thanks
> -- 
> ./luther
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From terje.winther at wintherstormer.no  Sun Feb 26 15:37:41 2012
From: terje.winther at wintherstormer.no (Terje Winther)
Date: Sun, 26 Feb 2012 15:37:41 +0100
Subject: [sdiy] Old Elektor PCB no#
In-Reply-To: <BB160623-D25E-4CAD-9256-CD9C20EFB66F@VacoLoco.net>
References: <A645BBDD-BAAE-474E-8478-399D907A9743@wintherstormer.no>
	<3325AD88-6317-42CD-BD60-184F9F8298F0@VacoLoco.net>
	<FF1A2FCA-45FD-42A6-B63F-AF8E2BC1C4CE@electricdruid.net>
	<CAP92RBUCQ7YWZs8ERjTuiDi7vbtCjkenec24H4PNoHzEpEaavA@mail.gmail.com>
	<BB160623-D25E-4CAD-9256-CD9C20EFB66F@VacoLoco.net>
Message-ID: <BA7BF81A-B3CF-4E74-8467-2736B5A60B64@wintherstormer.no>

Hi,
I have got two very old Elektor PCBs here, one EPS 82020 and one EPS  
9949-1.
I have no idea what they are for. They look kind of similar to the  
Elektor Formant modular synth series, so I guess this is something  
from the 1977 - 1980 time period.
Where can I find info regarding old Elektor PCB numbers?



Terje Winther
terje.winther at wintherstormer.no
http://www.wintherstormer.no/






From tom at electricdruid.net  Sun Feb 26 16:54:31 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Sun, 26 Feb 2012 15:54:31 +0000
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <4F49966A.6070404@gmail.com>
References: <4F49966A.6070404@gmail.com>
Message-ID: <901F2E34-CF6B-4CFC-A8C4-D132EEFA1214@electricdruid.net>

One other thought - might the pitch bender have gone wonky? 
If the pitch bend were applying a slight downwards bend, that'd give the effect you're seeing.

T.

On 26 Feb 2012, at 02:18, luther rochester wrote:

> When my 600 tunes up, all 6 voices are in tune with each other and scaled fine over octaves. But all notes on the synth are a bit flat. I have to keep the Master Tune knob at about +3 in order for it in tune to properly to other instruments.
> 
> I've read the scaling procedure and it seems relatively painless, but it also doesn't seem like it would address this problem. Is there some other kind of offset adjustment I can make so keeping the Master Tune at 0 will mean the synth will be in tune?
> 
> Thanks
> -- 
> ./luther
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From luther.rochester at gmail.com  Sun Feb 26 17:42:45 2012
From: luther.rochester at gmail.com (luther rochester)
Date: Sun, 26 Feb 2012 10:42:45 -0600
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <901F2E34-CF6B-4CFC-A8C4-D132EEFA1214@electricdruid.net>
References: <4F49966A.6070404@gmail.com>
	<901F2E34-CF6B-4CFC-A8C4-D132EEFA1214@electricdruid.net>
Message-ID: <4F4A6105.50608@gmail.com>

On 2/26/12 9:54 AM, Tom Wiltshire wrote:
> One other thought - might the pitch bender have gone wonky?
> If the pitch bend were applying a slight downwards bend, that'd give the effect you're seeing.


I thought of that too. It definitely bends more in one direction from 
center than the other.

Thanks for the help, gentlemen.
-- 
./luther


From mikegorman at btinternet.com  Sun Feb 26 18:08:45 2012
From: mikegorman at btinternet.com (Mike Gorman)
Date: Sun, 26 Feb 2012 17:08:45 -0000
Subject: [sdiy] Old Elektor PCB no#
In-Reply-To: <BA7BF81A-B3CF-4E74-8467-2736B5A60B64@wintherstormer.no>
References: <A645BBDD-BAAE-474E-8478-399D907A9743@wintherstormer.no>	<3325AD88-6317-42CD-BD60-184F9F8298F0@VacoLoco.net>	<FF1A2FCA-45FD-42A6-B63F-AF8E2BC1C4CE@electricdruid.net>	<CAP92RBUCQ7YWZs8ERjTuiDi7vbtCjkenec24H4PNoHzEpEaavA@mail.gmail.com>	<BB160623-D25E-4CAD-9256-CD9C20EFB66F@VacoLoco.net>
	<BA7BF81A-B3CF-4E74-8467-2736B5A60B64@wintherstormer.no>
Message-ID: <01d101ccf4a9$4c9ade50$e5d09af0$@com>

Hi Terje,

I have a full collection of Elektor, so I've just dug out some details for
these PCB's.

9949-1 is part of a 3 board PCB set for the Luminant LED Audio Level meter
from the July/August 1978 edition. The -1 board was the audio processing
board. There was also a -2 board for the LED drivers and a -3 board for
holding the LED's.

82020 is for a Mini Organ from November 1981. This used an SAA1900 toy organ
chip, which are still available from a few sources (according to a quick
Google search), and a diode matrix keyboard to make a full organ relatively
simply.

I've not come across any definitive lists for the Elektor PCB numbers, but
you can normally look at the eps PCB service from an old magazine to get a
clue to find the right article.

If you come across any more oddments like this, feel free to give me a
shout.

Regards

Mike

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Terje Winther
Sent: 26 February 2012 14:38
To: sdiy DIY
Subject: [sdiy] Old Elektor PCB no#

Hi,
I have got two very old Elektor PCBs here, one EPS 82020 and one EPS  
9949-1.
I have no idea what they are for. They look kind of similar to the  
Elektor Formant modular synth series, so I guess this is something  
from the 1977 - 1980 time period.
Where can I find info regarding old Elektor PCB numbers?



Terje Winther
terje.winther at wintherstormer.no
http://www.wintherstormer.no/




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



From terje.winther at wintherstormer.no  Sun Feb 26 19:08:35 2012
From: terje.winther at wintherstormer.no (Terje Winther)
Date: Sun, 26 Feb 2012 19:08:35 +0100
Subject: [sdiy] Old Elektor PCB no#
In-Reply-To: <01d101ccf4a9$4c9ade50$e5d09af0$@com>
References: <A645BBDD-BAAE-474E-8478-399D907A9743@wintherstormer.no>	<3325AD88-6317-42CD-BD60-184F9F8298F0@VacoLoco.net>	<FF1A2FCA-45FD-42A6-B63F-AF8E2BC1C4CE@electricdruid.net>	<CAP92RBUCQ7YWZs8ERjTuiDi7vbtCjkenec24H4PNoHzEpEaavA@mail.gmail.com>	<BB160623-D25E-4CAD-9256-CD9C20EFB66F@VacoLoco.net>
	<BA7BF81A-B3CF-4E74-8467-2736B5A60B64@wintherstormer.no>
	<01d101ccf4a9$4c9ade50$e5d09af0$@com>
Message-ID: <D419A4D4-5884-45D9-9A17-CC5B81BD447A@wintherstormer.no>

Dear Mike,
Thanks a lot! This what makes the Synth DIY list to good. This means  
that the Mini Organ could be interesting, while I probably just drop  
the LED thing.

Terje


Den 26. feb.. 2012 kl. 18.08 skrev Mike Gorman:

> Hi Terje,
>
> I have a full collection of Elektor, so I've just dug out some  
> details for
> these PCB's.
>
> 9949-1 is part of a 3 board PCB set for the Luminant LED Audio Level  
> meter
> from the July/August 1978 edition. The -1 board was the audio  
> processing
> board. There was also a -2 board for the LED drivers and a -3 board  
> for
> holding the LED's.
>
> 82020 is for a Mini Organ from November 1981. This used an SAA1900  
> toy organ
> chip, which are still available from a few sources (according to a  
> quick
> Google search), and a diode matrix keyboard to make a full organ  
> relatively
> simply.
>
> I've not come across any definitive lists for the Elektor PCB  
> numbers, but
> you can normally look at the eps PCB service from an old magazine to  
> get a
> clue to find the right article.
>
> If you come across any more oddments like this, feel free to give me a
> shout.
>
> Regards
>
> Mike
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Terje  
> Winther
> Sent: 26 February 2012 14:38
> To: sdiy DIY
> Subject: [sdiy] Old Elektor PCB no#
>
> Hi,
> I have got two very old Elektor PCBs here, one EPS 82020 and one EPS
> 9949-1.
> I have no idea what they are for. They look kind of similar to the
> Elektor Formant modular synth series, so I guess this is something
> from the 1977 - 1980 time period.
> Where can I find info regarding old Elektor PCB numbers?
>
>
>
> Terje Winther
> terje.winther at wintherstormer.no
> http://www.wintherstormer.no/
>
>
>
>
> _______________________________________________
> 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
>

Terje Winther
terje.winther at wintherstormer.no
http://www.wintherstormer.no/






From rtarcan at superonline.com  Sun Feb 26 20:21:35 2012
From: rtarcan at superonline.com (rtarcan)
Date: Sun, 26 Feb 2012 21:21:35 +0200
Subject: [sdiy] Prphet600 problems
Message-ID: <4F4A863F.4030408@superonline.com>

Hi
I purchassed a broken Prophet-600 from EBAY and make it work(After some 
multiplexer changed). But there is still problems with it I think.

1-Frequency knob of VCO'S  controls octave not linearly
For example  when F-knob shows segment3,  pitch is  1 octave above 0 
segment, when shows  segment4 pitch is 1 octave above segment3. After 
segment6 pitch remains at 4 octave costant and knob does'nt kontrol the 
pitch.
2- It always retune  when I switched on.

The other knobs works well and pitch tracking is good when I  play .

If is this standart for a Prophet-600?

Thanks


From luther.rochester at gmail.com  Sun Feb 26 22:46:27 2012
From: luther.rochester at gmail.com (luther rochester)
Date: Sun, 26 Feb 2012 15:46:27 -0600
Subject: [sdiy] Prphet600 problems
In-Reply-To: <4F4A863F.4030408@superonline.com>
References: <4F4A863F.4030408@superonline.com>
Message-ID: <4F4AA833.2070700@gmail.com>

On 2/26/12 1:21 PM, rtarcan wrote:
> Hi
> I purchassed a broken Prophet-600 from EBAY and make it work(After some
> multiplexer changed). But there is still problems with it I think.
>
> 1-Frequency knob of VCO'S controls octave not linearly
> For example when F-knob shows segment3, pitch is 1 octave above 0
> segment, when shows segment4 pitch is 1 octave above segment3. After
> segment6 pitch remains at 4 octave costant and knob does'nt kontrol the
> pitch.
> 2- It always retune when I switched on.
>
> The other knobs works well and pitch tracking is good when I play .
>
> If is this standart for a Prophet-600?



Both of these are standard operation for the Prophet 600, at least mine 
works the same.


-- 
./luther


From luther.rochester at gmail.com  Mon Feb 27 05:57:33 2012
From: luther.rochester at gmail.com (luther rochester)
Date: Sun, 26 Feb 2012 22:57:33 -0600
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <4F4A6105.50608@gmail.com>
References: <4F49966A.6070404@gmail.com>
	<901F2E34-CF6B-4CFC-A8C4-D132EEFA1214@electricdruid.net>
	<4F4A6105.50608@gmail.com>
Message-ID: <4F4B0D3D.8080201@gmail.com>

On 2/26/12 10:42 AM, luther rochester wrote:
> On 2/26/12 9:54 AM, Tom Wiltshire wrote:
>> One other thought - might the pitch bender have gone wonky?
>> If the pitch bend were applying a slight downwards bend, that'd give
>> the effect you're seeing.


So, this was exactly the cause. I found in the manual that there's an 
adjustment for the pitch wheel via a screw going down the center of the 
pot shaft. A little tweaking of that and everything is a-ok in tune.


-- 
./luther


From admin at bugbrand.co.uk  Tue Feb 28 11:40:02 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Tue, 28 Feb 2012 10:40:02 +0000
Subject: [sdiy] Powerline LC filters etc.
Message-ID: <4F4CAF02.7010308@bugbrand.co.uk>

I would like no learn more about using LC filters for power-line noise 
suppression. On this front, therefore, a couple of questions::

- can anyone recommend a good source of info - a book or a particular 
site - google has got me a bit confused/overloaded
- I've been looking at the Murata BNX devices - 
http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if 
you look at the BNX002-01, you see a schematic diagram (similar is used 
on several other devices).
I am curious about i) having an inductor in the ground line and ii) how 
you may calculate suitable values for the caps & inductors (as I say, 
linkage to a book/site with info on these areas would be fantastic too).
Of course, these devices seem to be designed with some specific areas of 
importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions 
everything being aligned in the same direction) so perhaps it is best to 
use these parts 'off the shelf' rather than trying to DIY - but, still, 
I would love to understand better.

Cheers for any pointers,
Tom


-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From guitaricon at verizon.net  Wed Feb 29 02:15:01 2012
From: guitaricon at verizon.net (Jeff Brown)
Date: Tue, 28 Feb 2012 20:15:01 -0500
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <4F4CAF02.7010308@bugbrand.co.uk>
References: <4F4CAF02.7010308@bugbrand.co.uk>
Message-ID: <006a01ccf67f$8fce6750$af6b35f0$@net>

Try searching for "power line filter".  One that I found:

http://www.ecoca.ro/papers/09_ARtim991.pdf

shows a basic LC filter on the 3rd page.  You can also just buy these - even
ones built into a chassis mount female receptacle.
They're also called "EMI filters".  Most medical electronic equipment that
is mains powered has them.

-Jeff

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
Sent: Tuesday, February 28, 2012 5:40 AM
To: Synth-DIY DIY
Subject: [sdiy] Powerline LC filters etc.

I would like no learn more about using LC filters for power-line noise 
suppression. On this front, therefore, a couple of questions::

- can anyone recommend a good source of info - a book or a particular 
site - google has got me a bit confused/overloaded
- I've been looking at the Murata BNX devices - 
http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if 
you look at the BNX002-01, you see a schematic diagram (similar is used 
on several other devices).
I am curious about i) having an inductor in the ground line and ii) how 
you may calculate suitable values for the caps & inductors (as I say, 
linkage to a book/site with info on these areas would be fantastic too).
Of course, these devices seem to be designed with some specific areas of 
importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions 
everything being aligned in the same direction) so perhaps it is best to 
use these parts 'off the shelf' rather than trying to DIY - but, still, 
I would love to understand better.

Cheers for any pointers,
Tom


-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk

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



From farfisa5 at gmail.com  Wed Feb 29 05:13:54 2012
From: farfisa5 at gmail.com (Bob K)
Date: Tue, 28 Feb 2012 20:13:54 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
Message-ID: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>

Hi folks,

So I just went browsing around to look at some simple SPDT toggle switches.

Went to my first choice, Jameco, and saw they had bunch from $1.30 to $1.50

THEN I browsed over to Mouser to see what they had.

After sifting through the drop-down filters (which is a great idea to
include on their website) I found what I was looking for.  SPST
switches from $2.16 to $5.00.

This doesn't seem like an obscene difference in the amount of money
spent on each switch so I'm wondering if Mouser switches really are
better than say, Jameco?

Better metals, contacts, stainless steel yahoo-ma-flubbers?

There's gotta be a metallurgist somewhere around here...

Still, the Mouser stuff sure looks pretty.

Thanks.  :)

-Bob


From list at mikebeauchamp.com  Wed Feb 29 05:29:15 2012
From: list at mikebeauchamp.com (Mike Beauchamp)
Date: Tue, 28 Feb 2012 23:29:15 -0500
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
Message-ID: <1330489755.1688.7.camel@nwwtlaptop>

Hi Bob,
I'm not familiar with the exact switches you are comparing, but
generally I compare the datasheets to see if either give any "expected
life" figures (how many times it can be toggled before it dies). 

When I'm trying to decide on components, I usually order a few samples
of each. Compare them visually, see which one feels more rugged, etc.
If it's a switch, I may mount the contenders and switch them rapidly a
few hundred cycles, checking for any change in play, etc.

Mike


On Tue, 2012-02-28 at 20:13 -0800, Bob K wrote:
> Hi folks,
> 
> So I just went browsing around to look at some simple SPDT toggle switches.
> 
> Went to my first choice, Jameco, and saw they had bunch from $1.30 to $1.50
> 
> THEN I browsed over to Mouser to see what they had.
> 
> After sifting through the drop-down filters (which is a great idea to
> include on their website) I found what I was looking for.  SPST
> switches from $2.16 to $5.00.
> 
> This doesn't seem like an obscene difference in the amount of money
> spent on each switch so I'm wondering if Mouser switches really are
> better than say, Jameco?
> 
> Better metals, contacts, stainless steel yahoo-ma-flubbers?
> 
> There's gotta be a metallurgist somewhere around here...
> 
> Still, the Mouser stuff sure looks pretty.
> 
> Thanks.  :)
> 
> -Bob
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy




From patchell at cox.net  Wed Feb 29 06:09:03 2012
From: patchell at cox.net (James Patchell)
Date: Tue, 28 Feb 2012 21:09:03 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
Message-ID: <4F4DB2EF.1080203@cox.net>

     All I can say about toggle switches, is be careful.  Several years 
ago, I built some sequencer modules .  I used the cheap switches from 
Jameco.  Every single one of those little buggers (256 of them) failed.

At the advice of Paul Schrieber, I got NKK toggle switches.  There were 
a LOT more expensive.  But, the don't FAIL!

-Jim



On 2/28/2012 8:13 PM, Bob K wrote:
> Hi folks,
>
> So I just went browsing around to look at some simple SPDT toggle switches.
>
> Went to my first choice, Jameco, and saw they had bunch from $1.30 to $1.50
>
> THEN I browsed over to Mouser to see what they had.
>
> After sifting through the drop-down filters (which is a great idea to
> include on their website) I found what I was looking for.  SPST
> switches from $2.16 to $5.00.
>
> This doesn't seem like an obscene difference in the amount of money
> spent on each switch so I'm wondering if Mouser switches really are
> better than say, Jameco?
>
> Better metals, contacts, stainless steel yahoo-ma-flubbers?
>
> There's gotta be a metallurgist somewhere around here...
>
> Still, the Mouser stuff sure looks pretty.
>
> Thanks.  :)
>
> -Bob
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From davebr at earthlink.net  Wed Feb 29 07:25:29 2012
From: davebr at earthlink.net (Dave Brown)
Date: Tue, 28 Feb 2012 22:25:29 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
Message-ID: <001f01ccf6aa$eff4c1d0$cfde4570$@earthlink.net>

I used to only buy NKK (along with Switchcraft) but bailed on both when the
prices soared so high.  I've been using Mountain switches which is a Mouser
brand.  I don't know if they are the same ones you are looking at.  I have
been pleased with them and none have failed.  They don't have quite the same
sturdy feel as NKK.  Part numbers are on my parts page.
http://modularsynthesis.com/modules/parts/parts.htm

Dave

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Bob K
Sent: Tuesday, February 28, 2012 8:14 PM
To: synthdiy diy
Subject: [sdiy] are Mouser toggle switches really that good?!

Hi folks,

So I just went browsing around to look at some simple SPDT toggle switches.

Went to my first choice, Jameco, and saw they had bunch from $1.30 to $1.50

THEN I browsed over to Mouser to see what they had.

After sifting through the drop-down filters (which is a great idea to
include on their website) I found what I was looking for.  SPST switches
from $2.16 to $5.00.

This doesn't seem like an obscene difference in the amount of money spent on
each switch so I'm wondering if Mouser switches really are better than say,
Jameco?

Better metals, contacts, stainless steel yahoo-ma-flubbers?

There's gotta be a metallurgist somewhere around here...

Still, the Mouser stuff sure looks pretty.

Thanks.  :)

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




From dixon at mail.ubc.ca  Wed Feb 29 07:27:18 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Tue, 28 Feb 2012 22:27:18 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
Message-ID: <5DB0773F6E6942489D39155598E1FC87@galvanox01>

I really like the Taiway switches that Small Bear Electronics
(www.smallbearelec.com) carries.  They have potted terminals, so they don't
get soft when soldered.  They feel good -- not too stiff, not too loose --
and I've never had an issue with one.  Plus, the price is right.
 

> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl 
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Bob K
> Sent: Tuesday, February 28, 2012 8:14 PM
> To: synthdiy diy
> Subject: [sdiy] are Mouser toggle switches really that good?!
> 
> Hi folks,
> 
> So I just went browsing around to look at some simple SPDT 
> toggle switches.
> 
> Went to my first choice, Jameco, and saw they had bunch from 
> $1.30 to $1.50
> 
> THEN I browsed over to Mouser to see what they had.
> 
> After sifting through the drop-down filters (which is a great 
> idea to include on their website) I found what I was looking 
> for.  SPST switches from $2.16 to $5.00.
> 
> This doesn't seem like an obscene difference in the amount of 
> money spent on each switch so I'm wondering if Mouser 
> switches really are better than say, Jameco?
> 
> Better metals, contacts, stainless steel yahoo-ma-flubbers?
> 
> There's gotta be a metallurgist somewhere around here...
> 
> Still, the Mouser stuff sure looks pretty.
> 
> Thanks.  :)
> 
> -Bob
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy



From nssinc at hevanet.com  Wed Feb 29 08:13:15 2012
From: nssinc at hevanet.com (NSSINC)
Date: Tue, 28 Feb 2012 23:13:15 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <001f01ccf6aa$eff4c1d0$cfde4570$@earthlink.net>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
	<001f01ccf6aa$eff4c1d0$cfde4570$@earthlink.net>
Message-ID: <4F4DD00B.7080704@hevanet.com>


	I have had nothing but bad luck with 'mountain switch'. They failed for 
me mechanically, long before they wear out the contacts or anything. I 
avoid them at all cost now. I use NKK, as others have suggested and have 
no problems. The switches may look similar, but they are not.

-Al


On 02/28/2012 10:25 PM, Dave Brown wrote:
> I used to only buy NKK (along with Switchcraft) but bailed on both when the
> prices soared so high.  I've been using Mountain switches which is a Mouser
> brand.  I don't know if they are the same ones you are looking at.  I have
> been pleased with them and none have failed.  They don't have quite the same
> sturdy feel as NKK.  Part numbers are on my parts page.
> http://modularsynthesis.com/modules/parts/parts.htm
>
> Dave
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Bob K
> Sent: Tuesday, February 28, 2012 8:14 PM
> To: synthdiy diy
> Subject: [sdiy] are Mouser toggle switches really that good?!
>
> Hi folks,
>
> So I just went browsing around to look at some simple SPDT toggle switches.
>
> Went to my first choice, Jameco, and saw they had bunch from $1.30 to $1.50
>
> THEN I browsed over to Mouser to see what they had.
>
> After sifting through the drop-down filters (which is a great idea to
> include on their website) I found what I was looking for.  SPST switches
> from $2.16 to $5.00.
>
> This doesn't seem like an obscene difference in the amount of money spent on
> each switch so I'm wondering if Mouser switches really are better than say,
> Jameco?
>
> Better metals, contacts, stainless steel yahoo-ma-flubbers?
>
> There's gotta be a metallurgist somewhere around here...
>
> Still, the Mouser stuff sure looks pretty.
>
> Thanks.  :)
>
> -Bob
> _______________________________________________
> 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 aym-htnys at teaser.fr  Wed Feb 29 12:35:51 2012
From: aym-htnys at teaser.fr (Andre Majorel)
Date: Wed, 29 Feb 2012 12:35:51 +0100
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <4956B81D-1900-4B44-8065-73E758E7F18F@electricdruid.net>
References: <4F49966A.6070404@gmail.com>
	<4956B81D-1900-4B44-8065-73E758E7F18F@electricdruid.net>
Message-ID: <20120229113550.GA1154@aym.net2.nerim.net>

On 2012-02-26 13:32 +0000, Tom Wiltshire wrote:

> Given that the uP is using its own clock frequency as the
> basic time reference, presumably you could retune the whole
> instrument a little by tweaking the 8MHz master uP clock. It's
> possible that this has drifted a bit over the years. Aside
> from that, I can't really see a way to do it.

f_osc = f(f_cpu) ? The Prophet 600 has DCOs ? Colour me amazed.
It certainly doesn't sound like it.

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


From dougt55 at yahoo.com  Wed Feb 29 14:11:06 2012
From: dougt55 at yahoo.com (Doug Terrebonne)
Date: Wed, 29 Feb 2012 05:11:06 -0800 (PST)
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <20120229113550.GA1154@aym.net2.nerim.net>
References: <4F49966A.6070404@gmail.com>
	<4956B81D-1900-4B44-8065-73E758E7F18F@electricdruid.net>
	<20120229113550.GA1154@aym.net2.nerim.net>
Message-ID: <1330521066.91696.YahooMailRC@web181717.mail.ne1.yahoo.com>

No, it's CEM3340 VCOs. :) It also seems to be a bit picky on which 3340s it 
likes. Some that work fine in my Oberheims don't work in the P-600 for some 
reason...

Doug 
synthparts.com



----- Original Message ----
> From: Andre Majorel <aym-htnys at teaser.fr>
> To: synth-diy at dropmix.xs4all.nl
> Sent: Wed, February 29, 2012 3:35:51 AM
> Subject: Re: [sdiy] Prophet 600 tuning question
> 
> On 2012-02-26 13:32 +0000, Tom Wiltshire wrote:
> 
> > Given that the uP is  using its own clock frequency as the
> > basic time reference, presumably  you could retune the whole
> > instrument a little by tweaking the 8MHz  master uP clock. It's
> > possible that this has drifted a bit over the  years. Aside
> > from that, I can't really see a way to do it.
> 
> f_osc  = f(f_cpu) ? The Prophet 600 has DCOs ? Colour me amazed.
> It certainly  doesn't sound like it.
> 
> -- 
> Andr? Majorel http://www.teaser.fr/~amajorel/
> _______________________________________________
> Synth-diy  mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 


From tom at electricdruid.net  Wed Feb 29 14:57:37 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Wed, 29 Feb 2012 13:57:37 +0000
Subject: [sdiy] Prophet 600 tuning question
In-Reply-To: <20120229113550.GA1154@aym.net2.nerim.net>
References: <4F49966A.6070404@gmail.com>
	<4956B81D-1900-4B44-8065-73E758E7F18F@electricdruid.net>
	<20120229113550.GA1154@aym.net2.nerim.net>
Message-ID: <8BF804DC-370E-4716-8CB8-12D2DEE8E415@electricdruid.net>


On 29 Feb 2012, at 11:35, Andre Majorel wrote:

> On 2012-02-26 13:32 +0000, Tom Wiltshire wrote:
> 
>> Given that the uP is using its own clock frequency as the
>> basic time reference, presumably you could retune the whole
>> instrument a little by tweaking the 8MHz master uP clock. It's
>> possible that this has drifted a bit over the years. Aside
>> from that, I can't really see a way to do it.
> 
> f_osc = f(f_cpu) ? The Prophet 600 has DCOs ? Colour me amazed.
> It certainly doesn't sound like it.

I didn't say that. I just meant that the uP will use some timer to measure the frequency for the tuning routine. That timer will probably depend on the master system clock.
Once it's got tuning tables worked out, it can use them to generate adjusted CVs for the entirely-analog not-entirely-linear VCOs.

I agree about f_osc = f(f_cpu) though. That's true in any uP-tuned synth.

T.





From tom at electricdruid.net  Wed Feb 29 15:19:37 2012
From: tom at electricdruid.net (Tom Wiltshire)
Date: Wed, 29 Feb 2012 14:19:37 +0000
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <1330489755.1688.7.camel@nwwtlaptop>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
	<1330489755.1688.7.camel@nwwtlaptop>
Message-ID: <969688CE-0A58-4DE8-93E7-B82FE8DCA4BE@electricdruid.net>


On 29 Feb 2012, at 04:29, Mike Beauchamp wrote:

> generally I compare the datasheets to see if either give any "expected
> life" figures (how many times it can be toggled before it dies). 

I agree with Mike. Figures for switches vary widely from 10,000 cycles to 10,000,000 or more.
10,000 cycles is once a day for 30 years, which doesn't sound too bad, but if you switch it 30 times a day, you're down to a year, which sounds hopeless.

One example is the Lorlin CK series rotary switches, sometimes used for waveform selection. These say ">10,000 cycles" which is the same as saying "about 10,500 cycles" and which explains why they go funny after a while.

Aim for a million cycles if you can.

T.



From harrybissell at wowway.com  Wed Feb 29 15:33:25 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 29 Feb 2012 09:33:25 -0500 (EST)
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <006a01ccf67f$8fce6750$af6b35f0$@net>
Message-ID: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>

I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
or common mode filters used on DC power system rails ?

In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
to get down as low as 1MHz with any efficiency.

If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
several purposes. In the DC case, the return current to the supply cancels out the current from the supply, 
resulting in a nearly zero flux in the coil (so it will not saturate easily). 

This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
amplifiers etc).

Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.

Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)


----- Original Message -----
From: Jeff Brown <guitaricon at verizon.net>
To: 'Tom Bugs' <admin at bugbrand.co.uk>, 'Synth-DIY DIY' <Synth-diy at dropmix.xs4all.nl>
Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
Subject: Re: [sdiy] Powerline LC filters etc.

Try searching for "power line filter".  One that I found:

http://www.ecoca.ro/papers/09_ARtim991.pdf

shows a basic LC filter on the 3rd page.  You can also just buy these - even
ones built into a chassis mount female receptacle.
They're also called "EMI filters".  Most medical electronic equipment that
is mains powered has them.

-Jeff

-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
Sent: Tuesday, February 28, 2012 5:40 AM
To: Synth-DIY DIY
Subject: [sdiy] Powerline LC filters etc.

I would like no learn more about using LC filters for power-line noise 
suppression. On this front, therefore, a couple of questions::

- can anyone recommend a good source of info - a book or a particular 
site - google has got me a bit confused/overloaded
- I've been looking at the Murata BNX devices - 
http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if 
you look at the BNX002-01, you see a schematic diagram (similar is used 
on several other devices).
I am curious about i) having an inductor in the ground line and ii) how 
you may calculate suitable values for the caps & inductors (as I say, 
linkage to a book/site with info on these areas would be fantastic too).
Of course, these devices seem to be designed with some specific areas of 
importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions 
everything being aligned in the same direction) so perhaps it is best to 
use these parts 'off the shelf' rather than trying to DIY - but, still, 
I would love to understand better.

Cheers for any pointers,
Tom


-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk

_______________________________________________
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 subjectivity at hotmail.com  Wed Feb 29 16:14:01 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Wed, 29 Feb 2012 10:14:01 -0500
Subject: [sdiy] tips for rotary switch removal?
Message-ID: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>

I have an important board that I need to fix which has a 8 way rotary switch which is bad.

so that is 10 pins total to desolder.


every time I have tried to desolder one before I end up damaging the board trying to rip the switch out.

and advice on this?


should i first try to break the switch?


should i crank the temp on my soldering iron when desoldering?

should I use wick? etc


thanks for any help






From subjectivity at hotmail.com  Wed Feb 29 16:50:17 2012
From: subjectivity at hotmail.com (dan snazelle)
Date: Wed, 29 Feb 2012 10:50:17 -0500
Subject: [sdiy] tips for rotary switch removal?
In-Reply-To: <2077873491.661402.1330528859569.JavaMail.root@md01.wow.synacor.com>
References: <2077873491.661402.1330528859569.JavaMail.root@md01.wow.synacor.com>
Message-ID: <BLU0-SMTP317191151DC8635CF9495E5C86F0@phx.gbl>



On Feb 29, 2012, at 10:20 AM, Harry Bissell wrote:

> I've usually had good success with solder wick. I would add some fresh solder to the connections (like tinning)
> so that the solder will melt quickly.
> 
> Cutting the pins is another option...
> 
> is it single sided, through hole, or multilayer ?
> 
> H^) harry
> 







it is a dual  layer board with a ground plane

my usual technique is to use a solder sucker...which works fine for everything but rotaries are always very tough

the ground plane seems to take the heat very quickly and distribute throughout the board

thanks

> 
> ----- Original Message -----
> From: dan snazelle <subjectivity at hotmail.com>
> To: synthdiy diy <synth-diy at dropmix.xs4all.nl>
> Sent: Wed, 29 Feb 2012 10:14:01 -0500 (EST)
> Subject: [sdiy] tips for rotary switch removal?
> 
> I have an important board that I need to fix which has a 8 way rotary switch which is bad.
> 
> so that is 10 pins total to desolder.
> 
> 
> every time I have tried to desolder one before I end up damaging the board trying to rip the switch out.
> 
> and advice on this?
> 
> 
> should i first try to break the switch?
> 
> 
> should i crank the temp on my soldering iron when desoldering?
> 
> should I use wick? etc
> 
> 
> thanks for any help
> 
> 
> 
> 
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 
> -- 
> Harry Bissell & Nora Abdullah 4eva
> 



From synth1 at airmail.net  Wed Feb 29 16:52:16 2012
From: synth1 at airmail.net (Paul Schreiber)
Date: Wed, 29 Feb 2012 09:52:16 -0600
Subject: [sdiy] tips for rotary switch removal?
In-Reply-To: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
References: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
Message-ID: <004101ccf6fa$1cfc3790$56f4a6b0$@airmail.net>

You buy this:

http://www.howardelectronics.com/den-on/sc7000.html

you do not complain about the price. Because once you use it for 30 seconds,
you will kick yourself for not having it years ago.

EASILY the best  $$ you will EVER spend if you solder/desolder a lot (like
FOR A LIVING).

Paul S.
/proud owner for 9 years



-----Original Message-----
From: synth-diy-bounces at dropmix.xs4all.nl
[mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of dan snazelle
Sent: Wednesday, February 29, 2012 9:14 AM
To: synthdiy diy
Subject: [sdiy] tips for rotary switch removal?

I have an important board that I need to fix which has a 8 way rotary switch
which is bad.

so that is 10 pins total to desolder.


every time I have tried to desolder one before I end up damaging the board
trying to rip the switch out.

and advice on this?


should i first try to break the switch?


should i crank the temp on my soldering iron when desoldering?

should I use wick? etc


thanks for any help




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



From fanwander at mnet-online.de  Wed Feb 29 16:59:34 2012
From: fanwander at mnet-online.de (Florian Anwander)
Date: Wed, 29 Feb 2012 16:59:34 +0100
Subject: [sdiy] tips for rotary switch removal?
In-Reply-To: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
References: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
Message-ID: <4F4E4B66.40006@mnet-online.de>

If you plan to modify or repair gear in the future you should consider 
to get a desoldering station.
One of the two Pauls here :-) (I don't remember whether it was Paul 
Perry or Paul Schreiber?) once recommended a DenOn SC7000. Others 
recommend Hakko desoldering stations. Both aren't cheap. I bought the 
DenOn desoldering gun, and it was the best investment I made in any tool 
in the last 10 years.

Florian

Am 29.02.2012 16:14, schrieb dan snazelle:
> I have an important board that I need to fix which has a 8 way rotary switch which is bad.
>
> so that is 10 pins total to desolder.
>
>
> every time I have tried to desolder one before I end up damaging the board trying to rip the switch out.
>
> and advice on this?
>
>
> should i first try to break the switch?
>
>
> should i crank the temp on my soldering iron when desoldering?
>
> should I use wick? etc
>
>
> thanks for any help
>
>
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>



From admin at bugbrand.co.uk  Wed Feb 29 17:00:23 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 16:00:23 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
References: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
Message-ID: <4F4E4B97.4000704@bugbrand.co.uk>

Cheers Harry,

Sorry - lack of clarity due to lack of clarity in my mind.
I was referring to DC power systems.

I'm looking at these areas for two ongoing projects -- first power for 
standalone processing boxes and then also for investigations into DC-DC 
converter based power for the modular.
The troubles I've been coming across may be down to power-line noise or 
(perhaps more likely) due to other fundamental flaws in my 
quasi-engineering approaches////

For the standalones - 9v DC operated boxes powered by wall-warts - now 
that many wall-warts are switchers.
- but I have a feeling that audio noise I was experiencing is actually 
down to my circuit approach rather than due to power-line born noise.
(Douglas Self's book 'Small Signal Audio Design' is useful for these 
areas - very good readability too)

For the modular - I've been trying DC-wall-wart to DC-DC converters to 
local LDO V-regs - the recent discussion on SMPSs gave me some pointers 
for lowering switching noise, but I still feel a bit out of my depth. My 
first build was something of a failure, but that may have been down to 
the choice of DC-DC converter - I have changed type and this seems to 
have improved things greatly. Again, problems may be down to my circuit 
approaches - I was finding that modules would pick-up other module 
signals when un-connected - something I'd never had with linear 
supplies. (at least now I'm learning to put local voltage references in 
for critical parts)

Here's a quick diagram of the approach I'm trying - do let me know if it 
is full of foolish holes...
http://bugbrand.co.uk/images/PowerPlan.jpg - first half is a module with 
DC-DC converters which then has output headers to go to distro boards 
which each have LDO Linear VRegs
- external wall-wart supplying 24V DC
- ? input DC filter ? Murata BNX016-01
- two 20W DC-DC converters (Cincon) with trims to take the output 
voltage up to c.15.5V
- output DC filters - note that the negative side one is connected the 
other way around as detailed in the Murata datasheet
- system ground banana connection comes post DC filters
- headers to take the +/- 15.5V to the distros

- distros then have a pair of LDO Linear V-Regs (a positive and a 
negative type) to regulate down to +/-15V

Does this sound like a sound approach? I'm keen to try to make DC-DC 
converters work, but have had my doubts so far.. They would bring many 
benefits (compactness, worldwide voltages, no mains worries, etc) but 
obviously I don't want to be opening a can of worms.

Cheers!
Tom

On 29/02/2012 14:33, Harry Bissell wrote:
> I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
> or common mode filters used on DC power system rails ?
>
> In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
> of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
> to get down as low as 1MHz with any efficiency.
>
> If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
> several purposes. In the DC case, the return current to the supply cancels out the current from the supply,
> resulting in a nearly zero flux in the coil (so it will not saturate easily).
>
> This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
> but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
> amplifiers etc).
>
> Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.
>
> Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)
>
>
> ----- Original Message -----
> From: Jeff Brown<guitaricon at verizon.net>
> To: 'Tom Bugs'<admin at bugbrand.co.uk>, 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
> Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
> Subject: Re: [sdiy] Powerline LC filters etc.
>
> Try searching for "power line filter".  One that I found:
>
> http://www.ecoca.ro/papers/09_ARtim991.pdf
>
> shows a basic LC filter on the 3rd page.  You can also just buy these - even
> ones built into a chassis mount female receptacle.
> They're also called "EMI filters".  Most medical electronic equipment that
> is mains powered has them.
>
> -Jeff
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
> Sent: Tuesday, February 28, 2012 5:40 AM
> To: Synth-DIY DIY
> Subject: [sdiy] Powerline LC filters etc.
>
> I would like no learn more about using LC filters for power-line noise
> suppression. On this front, therefore, a couple of questions::
>
> - can anyone recommend a good source of info - a book or a particular
> site - google has got me a bit confused/overloaded
> - I've been looking at the Murata BNX devices -
> http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if
> you look at the BNX002-01, you see a schematic diagram (similar is used
> on several other devices).
> I am curious about i) having an inductor in the ground line and ii) how
> you may calculate suitable values for the caps&  inductors (as I say,
> linkage to a book/site with info on these areas would be fantastic too).
> Of course, these devices seem to be designed with some specific areas of
> importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions
> everything being aligned in the same direction) so perhaps it is best to
> use these parts 'off the shelf' rather than trying to DIY - but, still,
> I would love to understand better.
>
> Cheers for any pointers,
> Tom
>
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From fanwander at mnet-online.de  Wed Feb 29 17:00:42 2012
From: fanwander at mnet-online.de (Florian Anwander)
Date: Wed, 29 Feb 2012 17:00:42 +0100
Subject: [sdiy] tips for rotary switch removal?
In-Reply-To: <4F4E4B66.40006@mnet-online.de>
References: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
	<4F4E4B66.40006@mnet-online.de>
Message-ID: <4F4E4BAA.3040208@mnet-online.de>

Am 29.02.2012 16:59, schrieb Florian Anwander:
> One of the two Pauls here :-) (I don't remember whether it was Paul
> Perry or Paul Schreiber?)
ok, I should have refreshed the incoming mail list. It was Paul 
Schreiber :-))))



From admin at bugbrand.co.uk  Wed Feb 29 17:07:02 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 16:07:02 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
References: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
Message-ID: <4F4E4D26.5080300@bugbrand.co.uk>

PS - checking back to the datasheet I linked to yesterday: 
http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf
The BNX016 has 40dB insertion loss at 100kHz - and it is low profile so, 
fingers crossed, it may be useful for me.

On 29/02/2012 14:33, Harry Bissell wrote:
> I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
> or common mode filters used on DC power system rails ?
>
> In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
> of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
> to get down as low as 1MHz with any efficiency.
>
> If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
> several purposes. In the DC case, the return current to the supply cancels out the current from the supply,
> resulting in a nearly zero flux in the coil (so it will not saturate easily).
>
> This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
> but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
> amplifiers etc).
>
> Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.
>
> Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)
>
>
> ----- Original Message -----
> From: Jeff Brown<guitaricon at verizon.net>
> To: 'Tom Bugs'<admin at bugbrand.co.uk>, 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
> Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
> Subject: Re: [sdiy] Powerline LC filters etc.
>
> Try searching for "power line filter".  One that I found:
>
> http://www.ecoca.ro/papers/09_ARtim991.pdf
>
> shows a basic LC filter on the 3rd page.  You can also just buy these - even
> ones built into a chassis mount female receptacle.
> They're also called "EMI filters".  Most medical electronic equipment that
> is mains powered has them.
>
> -Jeff
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
> Sent: Tuesday, February 28, 2012 5:40 AM
> To: Synth-DIY DIY
> Subject: [sdiy] Powerline LC filters etc.
>
> I would like no learn more about using LC filters for power-line noise
> suppression. On this front, therefore, a couple of questions::
>
> - can anyone recommend a good source of info - a book or a particular
> site - google has got me a bit confused/overloaded
> - I've been looking at the Murata BNX devices -
> http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if
> you look at the BNX002-01, you see a schematic diagram (similar is used
> on several other devices).
> I am curious about i) having an inductor in the ground line and ii) how
> you may calculate suitable values for the caps&  inductors (as I say,
> linkage to a book/site with info on these areas would be fantastic too).
> Of course, these devices seem to be designed with some specific areas of
> importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions
> everything being aligned in the same direction) so perhaps it is best to
> use these parts 'off the shelf' rather than trying to DIY - but, still,
> I would love to understand better.
>
> Cheers for any pointers,
> Tom
>
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From harrybissell at wowway.com  Wed Feb 29 17:38:11 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 29 Feb 2012 11:38:11 -0500 (EST)
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <4F4E4B97.4000704@bugbrand.co.uk>
Message-ID: <196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>

Hi Tom

Why are you looking at two DC-DC converters for a bipolar supply and not one with a bipolar output (cost?)

There are potential troubles with two converters, especially if they are the same model.  The switchers may run at'very close to the same frequency, but not exactly. There can be a resulting beat frequency which may be converted to some more offensive frequency by non-linear circuit
elements (essentially, everything in a synth :^).  These new frequency components can be MUCH harder to isolate and filter, and may change
with load etc...  Some switchers include a sync pin so that multiple units can be slaved to the same frequency.

The DC filters are usually better for high frequencies, ie to meets emissions standards.  They need to be chosen with a DC current in mind... if the
current is too big or too small they lose effectivness. This is more a problem for modular where the loads are not fixed.

I'd consider putting the second set of filters on each module, so you can fine tune them individually.

Watch out for the trouble I pointed out earlier... separate ground impedances mean different DC voltage drops, you may create ground loops by
connecting various modules together.

I think your point of 'circuit design' issues is quite good. If you avoid places for the modules to interact by using proper references and
decoupling, you avoid a lot of trouble up front. I use simple zener diode regulators on all my modular front panel pots... to eliminate that
issue. Cheap insurance :^)

H^) harry

----- Original Message -----
From: Tom Bugs <admin at bugbrand.co.uk>
To: 'Synth-DIY DIY' <Synth-diy at dropmix.xs4all.nl>
Sent: Wed, 29 Feb 2012 11:00:23 -0500 (EST)
Subject: Re: [sdiy] Powerline LC filters etc.

Cheers Harry,

Sorry - lack of clarity due to lack of clarity in my mind.
I was referring to DC power systems.

I'm looking at these areas for two ongoing projects -- first power for 
standalone processing boxes and then also for investigations into DC-DC 
converter based power for the modular.
The troubles I've been coming across may be down to power-line noise or 
(perhaps more likely) due to other fundamental flaws in my 
quasi-engineering approaches////

For the standalones - 9v DC operated boxes powered by wall-warts - now 
that many wall-warts are switchers.
- but I have a feeling that audio noise I was experiencing is actually 
down to my circuit approach rather than due to power-line born noise.
(Douglas Self's book 'Small Signal Audio Design' is useful for these 
areas - very good readability too)

For the modular - I've been trying DC-wall-wart to DC-DC converters to 
local LDO V-regs - the recent discussion on SMPSs gave me some pointers 
for lowering switching noise, but I still feel a bit out of my depth. My 
first build was something of a failure, but that may have been down to 
the choice of DC-DC converter - I have changed type and this seems to 
have improved things greatly. Again, problems may be down to my circuit 
approaches - I was finding that modules would pick-up other module 
signals when un-connected - something I'd never had with linear 
supplies. (at least now I'm learning to put local voltage references in 
for critical parts)

Here's a quick diagram of the approach I'm trying - do let me know if it 
is full of foolish holes...
http://bugbrand.co.uk/images/PowerPlan.jpg - first half is a module with 
DC-DC converters which then has output headers to go to distro boards 
which each have LDO Linear VRegs
- external wall-wart supplying 24V DC
- ? input DC filter ? Murata BNX016-01
- two 20W DC-DC converters (Cincon) with trims to take the output 
voltage up to c.15.5V
- output DC filters - note that the negative side one is connected the 
other way around as detailed in the Murata datasheet
- system ground banana connection comes post DC filters
- headers to take the +/- 15.5V to the distros

- distros then have a pair of LDO Linear V-Regs (a positive and a 
negative type) to regulate down to +/-15V

Does this sound like a sound approach? I'm keen to try to make DC-DC 
converters work, but have had my doubts so far.. They would bring many 
benefits (compactness, worldwide voltages, no mains worries, etc) but 
obviously I don't want to be opening a can of worms.

Cheers!
Tom

On 29/02/2012 14:33, Harry Bissell wrote:
> I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
> or common mode filters used on DC power system rails ?
>
> In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
> of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
> to get down as low as 1MHz with any efficiency.
>
> If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
> several purposes. In the DC case, the return current to the supply cancels out the current from the supply,
> resulting in a nearly zero flux in the coil (so it will not saturate easily).
>
> This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
> but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
> amplifiers etc).
>
> Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.
>
> Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)
>
>
> ----- Original Message -----
> From: Jeff Brown<guitaricon at verizon.net>
> To: 'Tom Bugs'<admin at bugbrand.co.uk>, 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
> Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
> Subject: Re: [sdiy] Powerline LC filters etc.
>
> Try searching for "power line filter".  One that I found:
>
> http://www.ecoca.ro/papers/09_ARtim991.pdf
>
> shows a basic LC filter on the 3rd page.  You can also just buy these - even
> ones built into a chassis mount female receptacle.
> They're also called "EMI filters".  Most medical electronic equipment that
> is mains powered has them.
>
> -Jeff
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
> Sent: Tuesday, February 28, 2012 5:40 AM
> To: Synth-DIY DIY
> Subject: [sdiy] Powerline LC filters etc.
>
> I would like no learn more about using LC filters for power-line noise
> suppression. On this front, therefore, a couple of questions::
>
> - can anyone recommend a good source of info - a book or a particular
> site - google has got me a bit confused/overloaded
> - I've been looking at the Murata BNX devices -
> http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if
> you look at the BNX002-01, you see a schematic diagram (similar is used
> on several other devices).
> I am curious about i) having an inductor in the ground line and ii) how
> you may calculate suitable values for the caps&  inductors (as I say,
> linkage to a book/site with info on these areas would be fantastic too).
> Of course, these devices seem to be designed with some specific areas of
> importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions
> everything being aligned in the same direction) so perhaps it is best to
> use these parts 'off the shelf' rather than trying to DIY - but, still,
> I would love to understand better.
>
> Cheers for any pointers,
> Tom
>
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.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 harrybissell at wowway.com  Wed Feb 29 17:45:34 2012
From: harrybissell at wowway.com (Harry Bissell)
Date: Wed, 29 Feb 2012 11:45:34 -0500 (EST)
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <4F4E4D26.5080300@bugbrand.co.uk>
Message-ID: <472579294.663487.1330533934291.JavaMail.root@md01.wow.synacor.com>

you'll have to try them and see. If you really get 40db its better than nothing. You need to see what kind of voltage
drops you get as well.

btw if you do create ground loops, you will reduce the effectiveness of the filter and possibly mske the source/sink
currents unequal, making the core move toward saturation. 

It's rarely so 'off the shelf' :^)

Do you need to pass emissions testing ?  (boy i hope not, its a pita)

H^) harry




----- Original Message -----
From: Tom Bugs <admin at bugbrand.co.uk>
To: 'Synth-DIY DIY' <Synth-diy at dropmix.xs4all.nl>
Sent: Wed, 29 Feb 2012 11:07:02 -0500 (EST)
Subject: Re: [sdiy] Powerline LC filters etc.

PS - checking back to the datasheet I linked to yesterday: 
http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf
The BNX016 has 40dB insertion loss at 100kHz - and it is low profile so, 
fingers crossed, it may be useful for me.

On 29/02/2012 14:33, Harry Bissell wrote:
> I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
> or common mode filters used on DC power system rails ?
>
> In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
> of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
> to get down as low as 1MHz with any efficiency.
>
> If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
> several purposes. In the DC case, the return current to the supply cancels out the current from the supply,
> resulting in a nearly zero flux in the coil (so it will not saturate easily).
>
> This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
> but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
> amplifiers etc).
>
> Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.
>
> Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)
>
>
> ----- Original Message -----
> From: Jeff Brown<guitaricon at verizon.net>
> To: 'Tom Bugs'<admin at bugbrand.co.uk>, 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
> Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
> Subject: Re: [sdiy] Powerline LC filters etc.
>
> Try searching for "power line filter".  One that I found:
>
> http://www.ecoca.ro/papers/09_ARtim991.pdf
>
> shows a basic LC filter on the 3rd page.  You can also just buy these - even
> ones built into a chassis mount female receptacle.
> They're also called "EMI filters".  Most medical electronic equipment that
> is mains powered has them.
>
> -Jeff
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
> Sent: Tuesday, February 28, 2012 5:40 AM
> To: Synth-DIY DIY
> Subject: [sdiy] Powerline LC filters etc.
>
> I would like no learn more about using LC filters for power-line noise
> suppression. On this front, therefore, a couple of questions::
>
> - can anyone recommend a good source of info - a book or a particular
> site - google has got me a bit confused/overloaded
> - I've been looking at the Murata BNX devices -
> http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if
> you look at the BNX002-01, you see a schematic diagram (similar is used
> on several other devices).
> I am curious about i) having an inductor in the ground line and ii) how
> you may calculate suitable values for the caps&  inductors (as I say,
> linkage to a book/site with info on these areas would be fantastic too).
> Of course, these devices seem to be designed with some specific areas of
> importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions
> everything being aligned in the same direction) so perhaps it is best to
> use these parts 'off the shelf' rather than trying to DIY - but, still,
> I would love to understand better.
>
> Cheers for any pointers,
> Tom
>
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.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 farfisa5 at gmail.com  Wed Feb 29 18:22:57 2012
From: farfisa5 at gmail.com (Bob K)
Date: Wed, 29 Feb 2012 09:22:57 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <969688CE-0A58-4DE8-93E7-B82FE8DCA4BE@electricdruid.net>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com>
	<1330489755.1688.7.camel@nwwtlaptop>
	<969688CE-0A58-4DE8-93E7-B82FE8DCA4BE@electricdruid.net>
Message-ID: <CANk4Wcjaf3PbRONE+iyTK8FTephek_Dwa9bcy8HCmkN2Rx9ixQ@mail.gmail.com>

Thanks everyone!  Every little bit helps.

So many notes.  So many notes.

Time to buy a case of spiral binders and take advantage of my office's printer.

-Bob

On Wed, Feb 29, 2012 at 6:19 AM, Tom Wiltshire <tom at electricdruid.net> wrote:
>
> On 29 Feb 2012, at 04:29, Mike Beauchamp wrote:
>
>> generally I compare the datasheets to see if either give any "expected
>> life" figures (how many times it can be toggled before it dies).
>
> I agree with Mike. Figures for switches vary widely from 10,000 cycles to 10,000,000 or more.
> 10,000 cycles is once a day for 30 years, which doesn't sound too bad, but if you switch it 30 times a day, you're down to a year, which sounds hopeless.
>
> One example is the Lorlin CK series rotary switches, sometimes used for waveform selection. These say ">10,000 cycles" which is the same as saying "about 10,500 cycles" and which explains why they go funny after a while.
>
> Aim for a million cycles if you can.
>
> T.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


From ijfritz at comcast.net  Wed Feb 29 19:04:07 2012
From: ijfritz at comcast.net (Ian Fritz)
Date: Wed, 29 Feb 2012 11:04:07 -0700
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <196685599.663334.1330533491556.JavaMail.root@md01.wow.syna
	cor.com>
References: <4F4E4B97.4000704@bugbrand.co.uk>
	<196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
Message-ID: <6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>

At 09:38 AM 2/29/2012, Harry Bissell wrote:

>Watch out for the trouble I pointed out earlier... separate ground 
>impedances mean different DC voltage drops, you may create ground loops by
>connecting various modules together.

I wasn't clear on this from the data sheet.  Are these actually wire-wound 
inductors or they ferrites.  Ferrites shouldn't have issues at dc, na?

Ian 



From admin at bugbrand.co.uk  Wed Feb 29 19:07:03 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 18:07:03 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
References: <4F4E4B97.4000704@bugbrand.co.uk>
	<196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
	<6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
Message-ID: <4F4E6947.90402@bugbrand.co.uk>

Ah - eyeballing - they do look like ferrites - maybe I will take one 
apart in the name of science.

(I'll get back later with a reply to Harry's points - cheers)

Tom

On 29/02/2012 18:04, Ian Fritz wrote:
> At 09:38 AM 2/29/2012, Harry Bissell wrote:
>
>> Watch out for the trouble I pointed out earlier... separate ground 
>> impedances mean different DC voltage drops, you may create ground 
>> loops by
>> connecting various modules together.
>
> I wasn't clear on this from the data sheet.  Are these actually 
> wire-wound inductors or they ferrites.  Ferrites shouldn't have issues 
> at dc, na?
>
> Ian
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From admin at bugbrand.co.uk  Wed Feb 29 19:18:32 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 18:18:32 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
References: <4F4E4B97.4000704@bugbrand.co.uk>
	<196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
	<6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
Message-ID: <4F4E6BF8.9040609@bugbrand.co.uk>

Ok - interesting --

I am pretty sure now that these are 'just':
- on the powerline -> input through ferrite to top of cap through 
another ferrite to output
- on the groundline -> input through ferrite to bottom of cap then to output
The cap is just a 10u SMD - maybe 1210 size.

Interesting at $2 + a pop..

Thanks for the lead there Ian!

Cheers for now,
Tom

On 29/02/2012 18:04, Ian Fritz wrote:
> At 09:38 AM 2/29/2012, Harry Bissell wrote:
>
>> Watch out for the trouble I pointed out earlier... separate ground 
>> impedances mean different DC voltage drops, you may create ground 
>> loops by
>> connecting various modules together.
>
> I wasn't clear on this from the data sheet.  Are these actually 
> wire-wound inductors or they ferrites.  Ferrites shouldn't have issues 
> at dc, na?
>
> Ian
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From pic24hj at gmail.com  Wed Feb 29 19:47:35 2012
From: pic24hj at gmail.com (KD KD)
Date: Wed, 29 Feb 2012 19:47:35 +0100
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <4F4E4B97.4000704@bugbrand.co.uk>
References: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
	<4F4E4B97.4000704@bugbrand.co.uk>
Message-ID: <CADYQ7+jhoP1Z-2HC8kXS6MPAhy0rh=c=kx=jra14aNzAGAwaYQ@mail.gmail.com>

> I'm looking at these areas for two ongoing projects -- first power for
> standalone processing boxes and then also for investigations into DC-DC
> converter based power for the modular.

Tom!
Late, but!

One approach you might considder is to go all "AC wallwart". Some major mixing
desk manufacturers does this as well as Alesis once did , it's an easy solution
both economically and electronically and far easier to comply to all
those FCC, etc
regulations.

Reg
KD


From tim.parkhurst at gmail.com  Wed Feb 29 20:50:17 2012
From: tim.parkhurst at gmail.com (Tim Parkhurst)
Date: Wed, 29 Feb 2012 11:50:17 -0800
Subject: [sdiy] tips for rotary switch removal?
In-Reply-To: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
References: <BLU0-SMTP192ABD311F85FD535D4A2F0C86F0@phx.gbl>
Message-ID: <CACDGQT_g6D5yA4Vx2NQHqM8FC73H95o7wkbOx_GNihRY96tLZw@mail.gmail.com>

On Wed, Feb 29, 2012 at 7:14 AM, dan snazelle <subjectivity at hotmail.com> wrote:
> I have an important board that I need to fix which has a 8 way rotary switch which is bad.
>
> so that is 10 pins total to desolder.
>
>
> every time I have tried to desolder one before I end up damaging the board trying to rip the switch out.
>
> and advice on this?

Can you clip the leads and remove the switch body? If the switch is
bad anyway, I would just clip the leads, remove the switch body, and
then carefully desolder and remove the remaining bits of pin lead one
at a time (much easier). Would still take Paul's advice on a good
desoldering tool. That's going to be useful in a lot of situations.


Tim (or just hit it with a bigger hammer) Servo
---
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


From admin at bugbrand.co.uk  Wed Feb 29 21:04:04 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 20:04:04 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
References: <196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
Message-ID: <4F4E84B4.4050500@bugbrand.co.uk>

Thanks for the details, Harry.

I have tried bipolar ones, but they don't tend to have trimmable outputs 
- if I'm going with the scheme of having linear regulation on the 
distros then I need to be able to trim the DC-DC converters up a bit (of 
course, it could be that there's really no need to have the linear regs! 
what do you think?)

I did recently read about two converters locking together - hmm - that's 
one to watch, for sure. (in fact, that *could* have been a problem I 
experienced while trying other converters)

Given the possibility that the BNX blocks are simply ferrites, I am 
thinking to have - i) filtering directly after the converters (maybe LC) 
and ii) on the input of each distro / regulator for a 2nd rolloff. I 
could still implement ferrites on the ground line, but have inductors on 
the V+ and V- lines.
Each module already has ferrite beads, but I'm wondering whether to 
change over to using 1210 50mA polyfuses.
While I'm doing this I'm also considering whether to have a major system 
upgrade and implement clean and dirty ground lines - certainly a wise 
move and hopefully I can do it while keeping backwards compatability.

Emissions tests -- hmm, one of those things I have never really looked 
in to  -- below the radar?

Many thanks for the pointers so far, Tom

On 29/02/2012 16:38, Harry Bissell wrote:
> Hi Tom
>
> Why are you looking at two DC-DC converters for a bipolar supply and not one with a bipolar output (cost?)
>
> There are potential troubles with two converters, especially if they are the same model.  The switchers may run at'very close to the same frequency, but not exactly. There can be a resulting beat frequency which may be converted to some more offensive frequency by non-linear circuit
> elements (essentially, everything in a synth :^).  These new frequency components can be MUCH harder to isolate and filter, and may change
> with load etc...  Some switchers include a sync pin so that multiple units can be slaved to the same frequency.
>
> The DC filters are usually better for high frequencies, ie to meets emissions standards.  They need to be chosen with a DC current in mind... if the
> current is too big or too small they lose effectivness. This is more a problem for modular where the loads are not fixed.
>
> I'd consider putting the second set of filters on each module, so you can fine tune them individually.
>
> Watch out for the trouble I pointed out earlier... separate ground impedances mean different DC voltage drops, you may create ground loops by
> connecting various modules together.
>
> I think your point of 'circuit design' issues is quite good. If you avoid places for the modules to interact by using proper references and
> decoupling, you avoid a lot of trouble up front. I use simple zener diode regulators on all my modular front panel pots... to eliminate that
> issue. Cheap insurance :^)
>
> H^) harry
>
> ----- Original Message -----
> From: Tom Bugs<admin at bugbrand.co.uk>
> To: 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
> Sent: Wed, 29 Feb 2012 11:00:23 -0500 (EST)
> Subject: Re: [sdiy] Powerline LC filters etc.
>
> Cheers Harry,
>
> Sorry - lack of clarity due to lack of clarity in my mind.
> I was referring to DC power systems.
>
> I'm looking at these areas for two ongoing projects -- first power for
> standalone processing boxes and then also for investigations into DC-DC
> converter based power for the modular.
> The troubles I've been coming across may be down to power-line noise or
> (perhaps more likely) due to other fundamental flaws in my
> quasi-engineering approaches////
>
> For the standalones - 9v DC operated boxes powered by wall-warts - now
> that many wall-warts are switchers.
> - but I have a feeling that audio noise I was experiencing is actually
> down to my circuit approach rather than due to power-line born noise.
> (Douglas Self's book 'Small Signal Audio Design' is useful for these
> areas - very good readability too)
>
> For the modular - I've been trying DC-wall-wart to DC-DC converters to
> local LDO V-regs - the recent discussion on SMPSs gave me some pointers
> for lowering switching noise, but I still feel a bit out of my depth. My
> first build was something of a failure, but that may have been down to
> the choice of DC-DC converter - I have changed type and this seems to
> have improved things greatly. Again, problems may be down to my circuit
> approaches - I was finding that modules would pick-up other module
> signals when un-connected - something I'd never had with linear
> supplies. (at least now I'm learning to put local voltage references in
> for critical parts)
>
> Here's a quick diagram of the approach I'm trying - do let me know if it
> is full of foolish holes...
> http://bugbrand.co.uk/images/PowerPlan.jpg - first half is a module with
> DC-DC converters which then has output headers to go to distro boards
> which each have LDO Linear VRegs
> - external wall-wart supplying 24V DC
> - ? input DC filter ? Murata BNX016-01
> - two 20W DC-DC converters (Cincon) with trims to take the output
> voltage up to c.15.5V
> - output DC filters - note that the negative side one is connected the
> other way around as detailed in the Murata datasheet
> - system ground banana connection comes post DC filters
> - headers to take the +/- 15.5V to the distros
>
> - distros then have a pair of LDO Linear V-Regs (a positive and a
> negative type) to regulate down to +/-15V
>
> Does this sound like a sound approach? I'm keen to try to make DC-DC
> converters work, but have had my doubts so far.. They would bring many
> benefits (compactness, worldwide voltages, no mains worries, etc) but
> obviously I don't want to be opening a can of worms.
>
> Cheers!
> Tom
>
> On 29/02/2012 14:33, Harry Bissell wrote:
>> I'm not sure I understood the original question. Are we talking about AC Power Line Filters,
>> or common mode filters used on DC power system rails ?
>>
>> In either case, the usual use for these filters is to reduce the passage of EMI (RF) signals in or out
>> of the system. Usually this protection exists for frequencies from the 10MHz and higher range, its rare
>> to get down as low as 1MHz with any efficiency.
>>
>> If I got the original point, the use of an inductor (as part of a common mode choke) in the ground has
>> several purposes. In the DC case, the return current to the supply cancels out the current from the supply,
>> resulting in a nearly zero flux in the coil (so it will not saturate easily).
>>
>> This does have the downside that there is impedance in the ground line... OK if the circuit is an "island"
>> but maybe not so good if the circuit needs to be connected to other items in use (such as other modules, effects,
>> amplifiers etc).
>>
>> Its a very complex issue... what is good for one unit may totally screw up the rest of a larger system.
>>
>> Tom... what is the filter supposed to do for you ?  (then we can dive deeper :^)
>>
>>
>> ----- Original Message -----
>> From: Jeff Brown<guitaricon at verizon.net>
>> To: 'Tom Bugs'<admin at bugbrand.co.uk>, 'Synth-DIY DIY'<Synth-diy at dropmix.xs4all.nl>
>> Sent: Tue, 28 Feb 2012 20:15:01 -0500 (EST)
>> Subject: Re: [sdiy] Powerline LC filters etc.
>>
>> Try searching for "power line filter".  One that I found:
>>
>> http://www.ecoca.ro/papers/09_ARtim991.pdf
>>
>> shows a basic LC filter on the 3rd page.  You can also just buy these - even
>> ones built into a chassis mount female receptacle.
>> They're also called "EMI filters".  Most medical electronic equipment that
>> is mains powered has them.
>>
>> -Jeff
>>
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Bugs
>> Sent: Tuesday, February 28, 2012 5:40 AM
>> To: Synth-DIY DIY
>> Subject: [sdiy] Powerline LC filters etc.
>>
>> I would like no learn more about using LC filters for power-line noise
>> suppression. On this front, therefore, a couple of questions::
>>
>> - can anyone recommend a good source of info - a book or a particular
>> site - google has got me a bit confused/overloaded
>> - I've been looking at the Murata BNX devices -
>> http://www.mouser.com/catalog/specsheets/Murata%20BNX%20Series.pdf --if
>> you look at the BNX002-01, you see a schematic diagram (similar is used
>> on several other devices).
>> I am curious about i) having an inductor in the ground line and ii) how
>> you may calculate suitable values for the caps&   inductors (as I say,
>> linkage to a book/site with info on these areas would be fantastic too).
>> Of course, these devices seem to be designed with some specific areas of
>> importance (http://www.rapidonline.com/pdf/26-6010e.pdf mentions
>> everything being aligned in the same direction) so perhaps it is best to
>> use these parts 'off the shelf' rather than trying to DIY - but, still,
>> I would love to understand better.
>>
>> Cheers for any pointers,
>> Tom
>>
>>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From admin at bugbrand.co.uk  Wed Feb 29 21:07:08 2012
From: admin at bugbrand.co.uk (Tom Bugs)
Date: Wed, 29 Feb 2012 20:07:08 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <CADYQ7+jhoP1Z-2HC8kXS6MPAhy0rh=c=kx=jra14aNzAGAwaYQ@mail.gmail.com>
References: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
	<4F4E4B97.4000704@bugbrand.co.uk>
	<CADYQ7+jhoP1Z-2HC8kXS6MPAhy0rh=c=kx=jra14aNzAGAwaYQ@mail.gmail.com>
Message-ID: <4F4E856C.1050207@bugbrand.co.uk>

Cheers - I have used AC wallwarts for some projects before, but it is 
hard work to keep stock of different plug/voltage types for worldwide 
usage.
Implementing quite standard wall-warts which can operate 100-240V 
worldwide (simple IEC input) would be ideal - one model does all customers.
Thanks, Tom

On 29/02/2012 18:47, KD KD wrote:
>> I'm looking at these areas for two ongoing projects -- first power for
>> standalone processing boxes and then also for investigations into DC-DC
>> converter based power for the modular.
> Tom!
> Late, but!
>
> One approach you might considder is to go all "AC wallwart". Some major mixing
> desk manufacturers does this as well as Alesis once did , it's an easy solution
> both economically and electronically and far easier to comply to all
> those FCC, etc
> regulations.
>
> Reg
> KD
>

-- 
BugBrand LTD
UK company No. 07199808
VAT No. GB 988 2629 57
1 Ninetree Hill
BRISTOL BS1 3SB
United Kingdom
www.bugbrand.co.uk



From dixon at mail.ubc.ca  Wed Feb 29 21:14:14 2012
From: dixon at mail.ubc.ca (David G Dixon)
Date: Wed, 29 Feb 2012 12:14:14 -0800
Subject: [sdiy] are Mouser toggle switches really that good?!
In-Reply-To: <969688CE-0A58-4DE8-93E7-B82FE8DCA4BE@electricdruid.net>
References: <CANk4WcgV4mc784zGPMeznDxhO7_KSQ-vUo8QkOvAs87z1GdMww@mail.gmail.com><1330489755.1688.7.camel@nwwtlaptop>
	<969688CE-0A58-4DE8-93E7-B82FE8DCA4BE@electricdruid.net>
Message-ID: <C981CE85AD2F4AB9A69942DB9F5A74FB@galvanox01>

> > generally I compare the datasheets to see if either give 
> any "expected life" figures (how many times it can be toggled before it
dies).

On this score, I note that the NKK datasheet specifies 25,000 cycles for
silver-plated, and 50,000 cycles for gold-plated.  The Taiway datasheet
specifies 50,000 cycles.  Hence, on the face of it, the quality of these two
are not that different.  Now, perhaps the real question is, do you believe
the claims in the datasheet?



From mverbos at earthlink.net  Wed Feb 29 22:07:22 2012
From: mverbos at earthlink.net (mark verbos)
Date: Wed, 29 Feb 2012 16:07:22 -0500
Subject: [sdiy] Does anyone know about this EMS keyboard?
Message-ID: <9F33FC41-1C1C-4336-8A37-3E61FCC6C4BF@earthlink.net>

https://secure.flickr.com/photos/45430902 at N07/6080759346/in/photostream/lightbox/

I can figure out what the keys at the bottom do, but what are the other touchplates? Anyone have schematics?
Looks really cool.

Mark

From subjectivity at hotmail.com  Wed Feb 29 22:18:00 2012
From: subjectivity at hotmail.com (Dan Snazelle)
Date: Wed, 29 Feb 2012 16:18:00 -0500
Subject: [sdiy] Does anyone know about this EMS keyboard?
In-Reply-To: <9F33FC41-1C1C-4336-8A37-3E61FCC6C4BF@earthlink.net>
References: <9F33FC41-1C1C-4336-8A37-3E61FCC6C4BF@earthlink.net>
Message-ID: <BLU0-SMTP51B7D4F07B2A594E470619C86F0@phx.gbl>




On Feb 29, 2012, at 4:07 PM, mark verbos <mverbos at earthlink.net> wrote:

> https://secure.flickr.com/photos/45430902 at N07/6080759346/in/photostream/lightbox/
> 
> I can figure out what the keys at the bottom do, but what are the other touchplates? Anyone have schematics?
> Looks really cool.
> 
> Mark
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> 

Thanks for posting that!

From neil.johnson97 at ntlworld.com  Wed Feb 29 22:23:56 2012
From: neil.johnson97 at ntlworld.com (Neil Johnson)
Date: Wed, 29 Feb 2012 21:23:56 +0000
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
References: <4F4E4B97.4000704@bugbrand.co.uk>
	<196685599.663334.1330533491556.JavaMail.root@md01.wow.synacor.com>
	<6.2.1.2.2.20120229110222.0235ed88@mail.comcast.net>
Message-ID: <4F4E976C.9030203@ntlworld.com>

Ian Fritz wrote:
> At 09:38 AM 2/29/2012, Harry Bissell wrote:
>
>> Watch out for the trouble I pointed out earlier... separate ground
>> impedances mean different DC voltage drops, you may create ground
>> loops by
>> connecting various modules together.
>
> I wasn't clear on this from the data sheet. Are these actually
> wire-wound inductors or they ferrites. Ferrites shouldn't have issues at
> dc, na?

It really depends on the type of the filter.  For example, DC 
common-mode chokes used for suppression of RF in DC power inlets are 
quite often wound components, e.g.:

http://www.farnell.com/datasheets/731565.pdf

Cheers,
Neil
-- 
Modules and more :: www.cesyg.com
Homepage :: www.njohnson.co.uk ::


From Stromeko at nexgo.de  Wed Feb 29 22:57:39 2012
From: Stromeko at nexgo.de (ASSI)
Date: Wed, 29 Feb 2012 22:57:39 +0100
Subject: [sdiy] Powerline LC filters etc.
In-Reply-To: <4F4E4B97.4000704@bugbrand.co.uk>
References: <2014423889.660146.1330526005565.JavaMail.root@md01.wow.synacor.com>
	<4F4E4B97.4000704@bugbrand.co.uk>
Message-ID: <3209359.pun3cSHcO6@rainer>

On Wednesday 29 February 2012, 16:00:23, Tom Bugs wrote:
> For the standalones - 9v DC operated boxes powered by wall-warts - now
> that many wall-warts are switchers.
> - but I have a feeling that audio noise I was experiencing is actually
> down to my circuit approach rather than due to power-line born noise.
> (Douglas Self's book 'Small Signal Audio Design' is useful for these
> areas - very good readability too)

I have yet to see a low-wattage wall-wart that has decent RF filtering (or 
any at all) and most of them also have rather high ripple.  I'm not saying 
better ones don't exist, I've just never come across any.  If you've got 
some non-linearity around in your circuit (like a rectifier), you could very 
well be demodulating the RF and have all sorts of unwanted sound-effects 
going on.

So it would be very wise to filter their output and the BNXxxx ones you've 
mentioned look to be good candidates.  The schematic is not very clear, but 
the only way this makes sense to me is if the two inductors closest to the 
source are in fact a common-mode (current compensated) choke and the rest of 
the filter is a pi section for dealing with the RF.  This gives a pretty 
good filter provided that the switching frequency of the source is around 
2MHz, which is what they seem to be optimized for.  It could very well be 
much lower in reality, which would then require different (and more bulky) 
inductive components.  The best place to put this filter would actually be 
directly at the output of the switcher and then follow with a twisted pair 
to the input to your circuit, where you'd put a decoupling / buffer cap 
pair.

> http://bugbrand.co.uk/images/PowerPlan.jpg - first half is a module with
> DC-DC converters which then has output headers to go to distro boards
> which each have LDO Linear VRegs
> - external wall-wart supplying 24V DC
> - ? input DC filter ? Murata BNX016-01
> - two 20W DC-DC converters (Cincon) with trims to take the output
> voltage up to c.15.5V

Doing a cascade of AC/DC -- DC/DC is not very efficient at those close 
voltages, but it may be unavoidable if you need to use a wall wart.

Pairing up two DC/DC in tandem has some (probably unintended) consequences: 
as Harry already mentioned, if they are in close proximity they might beat 
against or lock onto each other, which would produce wholly unexpected 
voltage variations.  Even if they don't do that, you must consider that the 
regulation on either side is completely independent of the other and large 
asymmetric load transients might provoke excursions on the other side that 
the LDO might have a hard time catching.  This depends a lot on what modules 
you will connect and how symmetric the load is in the first place, of 
course.

> - output DC filters - note that the negative side one is connected the
> other way around as detailed in the Murata datasheet
> - system ground banana connection comes post DC filters
> - headers to take the +/- 15.5V to the distros
> 
> - distros then have a pair of LDO Linear V-Regs (a positive and a
> negative type) to regulate down to +/-15V

You should probably give the regulators a bit more headroom and just use a 
16V or 17V output from the DC/DC, in any case trimming the output is not 
something I'd want to do.

> Does this sound like a sound approach? I'm keen to try to make DC-DC
> converters work, but have had my doubts so far.. They would bring many
> benefits (compactness, worldwide voltages, no mains worries, etc) but
> obviously I don't want to be opening a can of worms.

Before settling on that solution, ask yourself again if not dealing with 
mains in the cabinet is worth the added trouble with the wall-wart.  Even if 
you supply a good one, inevitably someone else will decide that they plug 
their super-noisy model into your modular and it's still your problem.  All 
things considered I'd personally prefer a filtered IEC inlet connected to a 
good closed-frame dual-output supply.  Another possible solution might be 
wall-wart into a really good filter and then point-of-load generation of 
voltages, i.e. instead of having a beefy +-15V supply you'd go for many 
small ones that can just supply a single module or a handful.  If the input 
range of the POL converter covers 9-40V (or at least 20V-36V), you can just 
plug them into about any power distribution you might encounter in a modular 
with a simple adapter.


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

Wavetables for the Waldorf Blofeld:
http://Synth.Stromeko.net/Downloads.html#BlofeldUserWavetables



