Yahoo Groups archive

Cgs synth

Index last updated: 2026-04-28 23:16 UTC

Thread

Stiner-Parker VCF help.

Stiner-Parker VCF help.

2004-05-01 by earthtodylan2000

Hi,
I'm new to the Ken Stone projects. I've built a small collection of
Blacet modules(BZ,TM, I/O,MW,DSCX2). Ken's modules seem
really great.

Can someone tell me If all the parts for the Stiner-Parker filter
are easy to source?

And what are the controls and in's and outs for the module.

CV, audio, etc,

Thanks

Re: Stiner-Parker VCF help.

2004-05-01 by Luís Marka

I took half the parts for a Steiner VCF from a broken PC power supply...
Very, very easy to get parts.

----- Original Message -----
Show quoted textHide quoted text
From: "earthtodylan2000" <earthtodylan2000@...>
To: <cgs_synth@yahoogroups.com>
Sent: Saturday, May 01, 2004 5:17 PM
Subject: [cgs_synth] Stiner-Parker VCF help.


> Hi,
> I'm new to the Ken Stone projects. I've built a small collection of
> Blacet modules(BZ,TM, I/O,MW,DSCX2). Ken's modules seem
> really great.
>
> Can someone tell me If all the parts for the Stiner-Parker filter
> are easy to source?
>
> And what are the controls and in's and outs for the module.
>
> CV, audio, etc,
>
> Thanks
>
>
>
> See the following URLS for the CGS Modular Synth home page:
> Main: http://www.cgs.synth.net/
> Secondary: http://otherunicorn.0catch.com/synth/
> Yahoo! Groups Links
>
>
>
>
>
>

Re: Stiner-Parker VCF help.

2004-05-01 by bbluthang

hi
the only parts that may be hard to source are the transistors,
depends upon where you live.
i think you can substitute many trannies here, i used c1815 and a1015.

4 ins - cv, lopass, bandpass, hipass.
1 out
pots - freq, res and level (optional)

the steiner vcf is my most used module, along with the super psycho
(which is always connected to the steiner anyway)
andrew
Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, "earthtodylan2000"
<earthtodylan2000@y...> wrote:
> Hi,
> I'm new to the Ken Stone projects. I've built a small collection
of
> Blacet modules(BZ,TM, I/O,MW,DSCX2). Ken's modules seem
> really great.
>
> Can someone tell me If all the parts for the Stiner-Parker filter
> are easy to source?
>
> And what are the controls and in's and outs for the module.
>
> CV, audio, etc,
>
> Thanks

Re: Stiner-Parker VCF help. CV control.

2004-05-02 by earthtodylan2000

Thanks for the info.

Can you add CV in's to control the Frequency, Resonance, and
Level?

Show quoted textHide quoted text

--- In cgs_synth@yahoogroups.com, "bbluthang"
<jumpswine@h...> wrote:
> hi
> the only parts that may be hard to source are the transistors,
> depends upon where you live.
> i think you can substitute many trannies here, i used c1815
and a1015.
>
> 4 ins - cv, lopass, bandpass, hipass.
> 1 out
> pots - freq, res and level (optional)
>
> the steiner vcf is my most used module, along with the super
psycho
> (which is always connected to the steiner anyway)
> andrew
>
> --- In cgs_synth@yahoogroups.com, "earthtodylan2000"
> <earthtodylan2000@y...> wrote:
> > Hi,
> > I'm new to the Ken Stone projects. I've built a small
collection
> of
> > Blacet modules(BZ,TM, I/O,MW,DSCX2). Ken's modules
seem
> > really great.
> >
> > Can someone tell me If all the parts for the Stiner-Parker filter
> > are easy to source?
> >
> > And what are the controls and in's and outs for the module.
> >
> > CV, audio, etc,
> >
> > Thanks

Re: Stiner-Parker VCF help. CV control.

2004-05-02 by Luís Marka

For CV the level, you better use a VCA. Resonance CV is a bit tricky, you
could use a LDR excited by a LED, or an OTA. I never tried these. And
frequency CV is already built in the filter (CV In is exactly this: the CV
for frequency).

----- Original Message -----
Show quoted textHide quoted text
From: "earthtodylan2000" <earthtodylan2000@...>
To: <cgs_synth@yahoogroups.com>
Sent: Sunday, May 02, 2004 3:58 PM
Subject: [cgs_synth] Re: Stiner-Parker VCF help. CV control.


> Thanks for the info.
>
> Can you add CV in's to control the Frequency, Resonance, and
> Level?
>
>
> --- In cgs_synth@yahoogroups.com, "bbluthang"
> <jumpswine@h...> wrote:
> > hi
> > the only parts that may be hard to source are the transistors,
> > depends upon where you live.
> > i think you can substitute many trannies here, i used c1815
> and a1015.
> >
> > 4 ins - cv, lopass, bandpass, hipass.
> > 1 out
> > pots - freq, res and level (optional)
> >
> > the steiner vcf is my most used module, along with the super
> psycho
> > (which is always connected to the steiner anyway)
> > andrew
> >
> > --- In cgs_synth@yahoogroups.com, "earthtodylan2000"
> > <earthtodylan2000@y...> wrote:
> > > Hi,
> > > I'm new to the Ken Stone projects. I've built a small
> collection
> > of
> > > Blacet modules(BZ,TM, I/O,MW,DSCX2). Ken's modules
> seem
> > > really great.
> > >
> > > Can someone tell me If all the parts for the Stiner-Parker filter
> > > are easy to source?
> > >
> > > And what are the controls and in's and outs for the module.
> > >
> > > CV, audio, etc,
> > >
> > > Thanks
>
>
>
> See the following URLS for the CGS Modular Synth home page:
> Main: http://www.cgs.synth.net/
> Secondary: http://otherunicorn.0catch.com/synth/
> Yahoo! Groups Links
>
>
>
>
>
>

Re: Stiner-Parker VCF help. CV control.

2004-05-02 by sasami@hotkey.net.au

>Thanks for the info.
>
>Can you add CV in's to control the Frequency, Resonance, and
>Level?

CV already has one. The others can't be CV controlled, short of adding CV
circuitry (e.g. run the output through a VCA)

Ken

_______________________________________________________________________
Ken Stone sasami@... or ken@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: Stiner-Parker VCF help. CV control.

2004-05-03 by earthtodylan2000

Wait...what control do you mean by "CV already has one"?
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> >Thanks for the info.
> >
> >Can you add CV in's to control the Frequency, Resonance,
and
> >Level?
>
> The others can't be CV controlled, short of adding CV
> circuitry (e.g. run the output through a VCA)
>
> Ken
>
>
__________________________________________________
_____________________
> Ken Stone sasami@h... or ken@c...
> Modular Synth PCBs for sale
<http://www.blaze.net.au/~sasami/synth/>
> Australian Miniature Horses & Ponies
<http://www.blaze.net.au/~sasami/>

Re: Stiner-Parker VCF help. CV control.

2004-05-03 by sasami@hotkey.net.au

Frequency already has a CV control

>Wait...what control do you mean by "CV already has one"?
>
>
>
>
>
>--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
>> >Thanks for the info.
>> >
>> >Can you add CV in's to control the Frequency, Resonance,
>and
>> >Level?
>>
>> The others can't be CV controlled, short of adding CV
>> circuitry (e.g. run the output through a VCA)
>>
>> Ken
>>
>>
>__________________________________________________
>_____________________
>> Ken Stone sasami@h... or ken@c...
>> Modular Synth PCBs for sale
><http://www.blaze.net.au/~sasami/synth/>
>> Australian Miniature Horses & Ponies
><http://www.blaze.net.au/~sasami/>
>
>
>
>
>See the following URLS for the CGS Modular Synth home page:
>Main: http://www.cgs.synth.net/
>Secondary: http://otherunicorn.0catch.com/synth/
>Yahoo! Groups Links
>
>
>
>
>
>
_______________________________________________________________________
Ken Stone sasami@... or ken@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

pt2395 delay update

2004-05-04 by Ryan Williams

hi all,

just an update on the pt2395 delay I'm working on. I decided that I
didn't like the filters that the datasheet uses. I bought a couple of
LTC1063 - 5th order switched cap filters from linear technology (mostly
out of curiosity). These are $6 each, but they seem do a pretty good
job. I have my 74hc4046 clocking the delay chip, the switched cap
filters are clocked by the same clock divided by 4. This is giving about
16khz for the bandwidth when the clock is at maximum, and about 6.25khz
at the longer delay times. I can't see any clock noise on my scope,
atleast not any noise that I can say is coming from the switching. I
suspect that setting the bandwidth by the delay clock should help me get
some longer delays without so much distortion, but I've got to make some
adjustments before I can test it with long delay times.

This was my second version of the delay to build. In the first one, I
tried using the filters from the datasheet, but modified for about a
10khz cutoff frequency, That didn't work as well as I'd hoped. It sounds
quite a bit better with the LTC1063 filters. Noise doesn't seem to be
much of a problem, and I haven't added the compander yet. The first
version was all on a breadboard with only one ground (noise was
horrible, so deffinently don't do that).

now, just to add a reset trigger input and a VCA for the feedback.

..Ryan

Re: pt2395 delay update

2004-05-04 by Fernando

Great and exciting news, thank you! 16kHz it's very good I think.

What's the minimum delay time (approx.) that you can get at max clock freq?

Fernando
Show quoted textHide quoted text
> just an update on the pt2395 delay I'm working on. I decided that I
> didn't like the filters that the datasheet uses. I bought a couple of
> LTC1063 - 5th order switched cap filters from linear technology (mostly
> out of curiosity). These are $6 each, but they seem do a pretty good
> job.

Re: Stiner-Parker VCF help. CV control.

2004-05-04 by lammspam

I think this means the filter's cutoff frequency can be controlled
by injecting a CV into the filter via a pot. You'd wire say 5V DC to
one
lug of a 100K linear pot, the middle tap to the CV in of the filter,
and the
remaining lug to ground. Now, turn the knob and you will hear the
cutoff
frequency sweep.

As far as adding CV control of audio inputs and resonance: I have
wired up
CV control of resonance and audio input levels (HP/BP/LP) to my
CGS Steiner filter. it's pretty easy to do, but does require adding
some
external VCA's to Ken's design as Ken suggests below.

I am happy with the way it sounds after the mods. BTW, I have some of
the
VCA PCB's and Chips for sale if you want to try this mod, although
you could
probably use pretty much any 4 good VCA's and it'd work.

You can find info on the mod here:
http://www.charlielamm.com/synth/steiner/index.php

Info on the VCA's for this is here:
http://www.charlielamm.com/synth/duallinearvca.php
--Charlie Lamm
Show quoted textHide quoted text
--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> Frequency already has a CV control
>
> >Wait...what control do you mean by "CV already has one"?
> >
> >
> >
> >
> >
> >--- In cgs_synth@yahoogroups.com, sasami@h... wrote:
> >> >Thanks for the info.
> >> >
> >> >Can you add CV in's to control the Frequency, Resonance,
> >and
> >> >Level?
> >>
> >> The others can't be CV controlled, short of adding CV
> >> circuitry (e.g. run the output through a VCA)
> >>
> >> Ken
> >>
> >>
> >__________________________________________________
> >_____________________
> >> Ken Stone sasami@h... or ken@c...
> >> Modular Synth PCBs for sale
> ><http://www.blaze.net.au/~sasami/synth/>
> >> Australian Miniature Horses & Ponies
> ><http://www.blaze.net.au/~sasami/>
> >
> >
> >
> >
> >See the following URLS for the CGS Modular Synth home page:
> >Main: http://www.cgs.synth.net/
> >Secondary: http://otherunicorn.0catch.com/synth/
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
____________________________________________________________
___________
> Ken Stone sasami@h... or ken@c...
> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
> Australian Miniature Horses & Ponies <http://www
.blaze.net.au/~sasami/>

Re: pt2395 delay update

2004-05-05 by Ryan Williams

Fernando wrote:
> Great and exciting news, thank you! 16kHz it's very good I think.
>
> What's the minimum delay time (approx.) that you can get at max clock freq?
>
> Fernando

hi Fernando,

I don't really have a good method of measuring exactly how short the
delay can be. Currently I plan on having a switch that selects either
the 64k or 256k ram which will be labeled short and long modes. If you
clock the chip too fast, it gets all messed up and starts spitting out
garbage (I have no idea if this could damage the chip, but it hasn't
yet). I will probably setup some kind of trimmer so that I'll be able to
adjust the CV input of the 4046 to allow a maximum clock frequency
slightly less that the PT2395 will accept.

For the moment, I'm using the resistor values on the 4046 that Ken had
labeled on the development board. the capacitor for the 4046 is a 33pF.
This doesn't allow the shortest or longests delays that I want with a CV
range of 0-5V. My guess is that it currently gives around 50ms-80ms in
64k/short mode. when sending it a sound from an envelope that has very
short attack and decay you can hear the echo still. I know this can be
improved quite a bit because in my first version, I couldn't hear the
echo. This part of the circuit is what I'll be working on just as soon
as final exams are over in school...

another note about the LTC1063 filters. They add several parts to the
circuit. Running of +-7.5V (which is the maximum allowed). I use two
adjustable regulators LM337L and LM317L. several additional bypass
capacitors are needed to keep the noise down on the LTC1063s. A opamp
buffer is also needed between the delay output and the output filter's
input. Thats the only way, I could figure out how to get rid of the DC
offset from the delay IC. A capacitor alone wasn't working...

Re: pt2395 delay update

2004-05-05 by Ryan Williams

Ryan Williams wrote:
>>Great and exciting news, thank you! 16kHz it's very good I think.

I think I spoke too soon. I had to listen quietly when I was testing
last night. There is some distortion at this bandwidth. I think I'll
have to adjust that some.

Re: pt2395 delay update

2004-05-05 by Fernando

Hi Ryan + all,

I'm interested in using it at/over flanger-like frequency (less than a millisecond)
This would allow to play with analog physical modelling if the freq of the delay is voltage
controllable and we can achieve very short delays...
Great that you are experimenting with it!
I suppose that apart from filters, some kind of dynamic processing (compression/
expansion) would help to get a cleaner signal...

Best wishes,

Fernando

Ryan Williams <destrukto@g...> wrote:
Show quoted textHide quoted text
> Fernando wrote:
> > Great and exciting news, thank you! 16kHz it's very good I think.
> >
> > What's the minimum delay time (approx.) that you can get at max clock freq?
> >
> > Fernando
>
> hi Fernando,
>
> I don't really have a good method of measuring exactly how short the
> delay can be. Currently I plan on having a switch that selects either
> the 64k or 256k ram which will be labeled short and long modes. If you
> clock the chip too fast, it gets all messed up and starts spitting out
> garbage (I have no idea if this could damage the chip, but it hasn't
> yet). I will probably setup some kind of trimmer so that I'll be able to
> adjust the CV input of the 4046 to allow a maximum clock frequency
> slightly less that the PT2395 will accept.
>
> For the moment, I'm using the resistor values on the 4046 that Ken had
> labeled on the development board. the capacitor for the 4046 is a 33pF.
> This doesn't allow the shortest or longests delays that I want with a CV
> range of 0-5V. My guess is that it currently gives around 50ms-80ms in
> 64k/short mode. when sending it a sound from an envelope that has very
> short attack and decay you can hear the echo still. I know this can be
> improved quite a bit because in my first version, I couldn't hear the
> echo. This part of the circuit is what I'll be working on just as soon
> as final exams are over in school...
>
> another note about the LTC1063 filters. They add several parts to the
> circuit. Running of +-7.5V (which is the maximum allowed). I use two
> adjustable regulators LM337L and LM317L. several additional bypass
> capacitors are needed to keep the noise down on the LTC1063s. A opamp
> buffer is also needed between the delay output and the output filter's
> input. Thats the only way, I could figure out how to get rid of the DC
> offset from the delay IC. A capacitor alone wasn't working...

Re: pt2395 delay update

2004-05-06 by Ryan Williams

I haven't even tried to mess with the address lines yet. but I can tell
you that you won't get close to that short of a delay using the chip
like the datasheet shows. I will do some experiments with that, as well
as disabling the write line once I'm happy with the bandwidth my circuit
has. I added a compander on it today, sounds a little better, but it
still needs work.

My plan with this circuit is to make an echo module. But, I do think
that super short delays would be nice and I'll let you know what the
shortest ones I get are once I've come a little further along.

Fernando wrote:
Show quoted textHide quoted text
> Hi Ryan + all,
>
> I'm interested in using it at/over flanger-like frequency (less than
> a millisecond) This would allow to play with analog physical
> modelling if the freq of the delay is voltage controllable and we can
> achieve very short delays... Great that you are experimenting with
> it! I suppose that apart from filters, some kind of dynamic
> processing (compression/ expansion) would help to get a cleaner
> signal...
>
> Best wishes,
>
> Fernando

pt2395 delay sound sample

2004-05-08 by Ryan Williams

hi all,

I made some sounds with it for people to hear. Just incase your
wondering, I didn't try to make it musical at all. Infact I'm trying to
show the amount of distortion I get for a few different settings. mostly
justing hitting different Cs.

These are unfiltered inputs from a sawtooth oscillator. I didn't have
the compander hooked up when I recorded. I cant' say that the noise you
hear is from the delay or not because it seems everything I record is as
noisy.

This one uses the switched cap filters clocked by the delay clock
divided by 4. The PT2395 is in short mode/256k. this one doesn't sound
that great.
http://www.sdiy.org/destrukto/mp3/pt2395_div_by_4.mp3

same with divide by 8 for filter clock. This is much better (not
perfect), and I think i'm going to build it as a module like this. max
delay is about 1.5 or 1.6 seconds.
http://www.sdiy.org/destrukto/mp3/pt2395_div_by_8.mp3

This one shows the minimum delay I'm getting. well almost, I had it just
a tad shorter on the breadboard. I still need to adjust the 74hc4046 RC
values a bit. This is 64k/short mode.
http://www.sdiy.org/destrukto/mp3/pt2395_64k_short.mp3

They all sound much nicer with a filtered input, and of course playing a
nice sequence or maybe if someone who could play music was controlling
it. I've been reading a little about delta modulation (the ADC and DAC
it uses) and it seems that the 5th order filters I'm using shouldn't be
needed. One of the advantages for this type of ADC is supposed to be
easy filtering. The data sheet claims that at 4mhz clock, the
samplerate is 500khz. this would mean the sample rate is clock/8, which
is what i'm using for the filter clock. the filter cutoff is clock/100,
so the cutoff should be delay_clock/100. that seems like it should be
more than enough room for a 5th order filter even without an
oversampling converter. anyone know about these things?

about really short delays with cut address line. I decided there was no
reason why I shouldn't test this now. it's only soldering in 1 more
resistor... so I cut A7 and put a 10k in Ra7. this just made the output
very distorted (I suspected it would), but I wonder if that is what was
intended, or if anyone has some other idea about doing this?

,Ryan

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.