electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
  Jez Adventures in Sound
Please visit the chat
 Forum index » DIY Hardware and Software » Ken Stone designs - CGS
CGS-34 Analog Shift Register
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [19 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
funkyfarm



Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3

PostPosted: Sat Jul 26, 2008 7:32 pm    Post subject: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

I'm sure i've put 1% resistors where needed, but i've always been disappointing when it come to drive several VCO with this "cv delay"... (fed by 1v/oct keyboard)

theoretically, can we use it with a LFO, in order to get "quadrature" waveform, or something ala ThreePhase LFO ?

how do you use it ?

http://www.cgs.synth.net/modules/cgs34_asr.html
Back to top
View user's profile Send private message
andrewF



Joined: Dec 29, 2006
Posts: 1174
Location: australia
Audio files: 4

PostPosted: Mon Jul 28, 2008 4:32 am    Post subject: Reply with quote  Mark this post and the followings unread

I usually use two in series with the 3rd output of one module connected to the input of the other. All the stage outputs go to VCOs and VCFs

have you read Serge's suggestions for using the ASR?
http://www.cyndustries.com/synapse/synapse.cfm?pc=35&folder=sept1976&pic=19
and
http://www.cyndustries.com/synapse/synapse.cfm?pc=35&folder=sept1976&pic=20

The circuit design is not the same as the CGS but the functionality is basically the same.
Back to top
View user's profile Send private message Visit poster's website
ericcoleridge



Joined: Jan 16, 2007
Posts: 885
Location: NYC

PostPosted: Tue Jul 29, 2008 10:23 am    Post subject: Reply with quote  Mark this post and the followings unread

I feed the CV Input of the ASR a S+H signal, then take the 3 outputs and feed them into a mixer, and use the mixer output to control a VCO. Or I may take some of the mixer output and feed it back into the S+H input.

Creates very interesting semi-random melodic patterns. It's fun and a different way and outcome from a straightforward S+H.
Back to top
View user's profile Send private message
bearblock



Joined: Sep 27, 2006
Posts: 90
Location: uk
Audio files: 1

PostPosted: Tue Jul 29, 2008 10:45 am    Post subject: Reply with quote  Mark this post and the followings unread

i also had some trouble getting my ASR to track accurately enough for melodic stuff... and i used 0.1% resistors. ended up having to install some trim pots around the input amp, now it's much better. my guess would be that the output impedance of my midi-cv converter isn't what the circuit expects to see? haven't done any math to back that up though.

Quote:
theoretically, can we use it with a LFO, in order to get "quadrature" waveform, or something ala ThreePhase LFO ?


in theory, but you would need more than 3 stages, like 100 or so Wink
Back to top
View user's profile Send private message Visit poster's website
funkyfarm



Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3

PostPosted: Sun Aug 03, 2008 6:35 pm    Post subject: Reply with quote  Mark this post and the followings unread

bearblock wrote:
i also had some trouble getting my ASR to track accurately enough for melodic stuff... and i used 0.1% resistors. ended up having to install some trim pots around the input amp, now it's much better.


maybe i should do that too.

bearblock wrote:
Quote:
theoretically, can we use it with a LFO, in order to get "quadrature" waveform, or something ala ThreePhase LFO ?


in theory, but you would need more than 3 stages, like 100 or so Wink


3 stages, three outputs, no ?


0°, 120° and 240°

Quote:
Creates very interesting semi-random melodic patterns. It's fun and a different way and outcome from a straightforward S+H.


hmm, semi-random melodic patterns...i'll try, but i used to see this module in a funny tempered echo/arpeggiator style...maybe i'll have to run outputs trough the oncoming quad cv quantizer...

http://electro-music.com/forum/topic-21931.html
Back to top
View user's profile Send private message
ericcoleridge



Joined: Jan 16, 2007
Posts: 885
Location: NYC

PostPosted: Sun Aug 03, 2008 7:12 pm    Post subject: Reply with quote  Mark this post and the followings unread

funkyfarm wrote:

hmm, semi-random melodic patterns...i'll try, but i used to see this module in a funny tempered echo/arpeggiator style...


Yeah, I don't have enough audio generators yet to try out the echo-like effects as described in the Synapse Serge ASR/arabesque generator article. But I have seen ASRs used in a lot of Buchla, and others, random voltage generators. Check out Marc Verbos's DIY page, and other places, for the Source of Uncertainty schems. That's where I sort of got the idea of mixing the various ASR outputs and using them for CV.

funkyfarm wrote:

maybe i'll have to run outputs trough the oncoming quad cv quantizer...
http://electro-music.com/forum/topic-21931.html


What? Is this really oncoming? I really hope so.
Back to top
View user's profile Send private message
Sine



Joined: Sep 10, 2007
Posts: 111
Location: Netherlands

PostPosted: Wed Aug 06, 2008 6:18 pm    Post subject: Re: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

funkyfarm wrote:
I'm sure i've put 1% resistors where needed, but i've always been disappointing when it come to drive several VCO with this "cv delay"... (fed by 1v/oct keyboard)



Yeah, I had the same problem, when you drive three VCO's them
when you hit the same note four times, tune the vco's and hit the note a fifth time the whole thing jumps out of tune.

Feed it with a constant voltage and clock it with an LFO, then plug a scope in the output and don't be surprised to see something that resembles a staircase.

I went as far as to use CA3140's for the buffer amps, add balance pots for them and select the resistors, that improved it somewhat but the real problem seems to be the 4052's the switches aren't perfect and the voltage drop seems to vary per switch, I ordered a few of them from other brands but I didn't have the time to test them yet.

Also as Ken states this thing is *VERY* sensitive about power line noise, I thought it would be neat to add a few LEDs to the output of the counter to be able to see the steps, bad idea !

I'll swap the muxes tomorrow and let you know how it turns out.
Back to top
View user's profile Send private message
bearblock



Joined: Sep 27, 2006
Posts: 90
Location: uk
Audio files: 1

PostPosted: Thu Aug 07, 2008 1:31 am    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
3 stages, three outputs, no ?


0°, 120° and 240°


no.
the ASR really isn't a "cv delay" in the sense you are thinking. it's more like an multi-stage sample and hold, and sample and hold circuits will mangle any waveform you put through them, unless the sampling rate is a lot higher than the input frequency. with such a fast clock you would need a lot of stages to create more than a couple of degrees of phase shift; you would end up with something like the BBD chips used in old chorus/delay effects.

edit: check out the diagrams on this page http://www.ear-group.net/model_23.html
Back to top
View user's profile Send private message Visit poster's website
funkyfarm



Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3

PostPosted: Thu Aug 07, 2008 2:50 am    Post subject: Re: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

funkyfarm wrote:
i've always been disappointing when it come to drive several VCO with this "cv delay"...


I knew I missed something, so my question !

Quote:
sample and hold circuits will mangle any waveform you put through them


for me, a S&H (without noise) produces some sort of a stepped version of the input.
Back to top
View user's profile Send private message
Sine



Joined: Sep 10, 2007
Posts: 111
Location: Netherlands

PostPosted: Thu Aug 07, 2008 8:11 am    Post subject: Re: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

As promised I tested the module with a few different muxes :

The module with balance pots for the 3140's
Posted Image, might have been reduced in size. Click Image to view fullscreen.

The upper trace is the second output, the lower trace the third

Fairchild muxes :
Posted Image, might have been reduced in size. Click Image to view fullscreen.

Motorola :
Posted Image, might have been reduced in size. Click Image to view fullscreen.

TI
Posted Image, might have been reduced in size. Click Image to view fullscreen.

So these switches are definitely the cause, I have a few DG switches laying around from another project, maybe I'll try something with those.
Back to top
View user's profile Send private message
bearblock



Joined: Sep 27, 2006
Posts: 90
Location: uk
Audio files: 1

PostPosted: Thu Aug 07, 2008 8:15 am    Post subject: Reply with quote  Mark this post and the followings unread

funkyfarm: did you look at the link?
Posted Image, might have been reduced in size. Click Image to view fullscreen.
if you still don't understand, i give up.
Back to top
View user's profile Send private message Visit poster's website
funkyfarm



Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3

PostPosted: Thu Aug 07, 2008 8:21 am    Post subject: Reply with quote  Mark this post and the followings unread

Cool

I understand here "mangle" as stepping waveforms.

I've listened to samples : for sure my ASR doesn't behave like Model23...which makes me sad.

(
Quote:
if you still don't understand, i give up.

most would have given up before !)

Last edited by funkyfarm on Thu Aug 07, 2008 8:45 am; edited 1 time in total
Back to top
View user's profile Send private message
funkyfarm



Joined: Jan 21, 2007
Posts: 583
Location: France
Audio files: 3

PostPosted: Thu Aug 07, 2008 8:45 am    Post subject: Re: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

Sine wrote:
The module with balance pots for the 3140's.


3140 are used for OUTPUT buffers ? TL074a TL074b TL074c

you're post is amazing !

but you can't swap 4052 for some DG ?!...saying that you still got a lot of blank space on breadboard Smile


Posted Image, might have been reduced in size. Click Image to view fullscreen.
Back to top
View user's profile Send private message
Sine



Joined: Sep 10, 2007
Posts: 111
Location: Netherlands

PostPosted: Thu Aug 07, 2008 9:24 am    Post subject: Re: CGS-34 Analog Shift Register
Subject description: uses
Reply with quote  Mark this post and the followings unread

Quote:


3140 are used for OUTPUT buffers ? TL074a TL074b TL074c


The output indeed is a 074, I used ca3140's for the sample and hold buffers, they have a very high input impedance ( 1.5T ohms (!) ) so It doesn't drain the sample caps as much when using long sample times.

Quote:

but you can't swap 4052 for some DG ?!...saying that you still got a lot of blank space on breadboard Smile


Jup, basically that would be redesigning the whole thing because the DG switches can handle +- 15V so the divider / doubler setup in the ASR isn't really necessary anymore.

I think I'll try the module in It's current form, if it still varys too much to my taste I might try the DG's, after all the biggest difference is about 10mV with the Fairchild muxes.
Back to top
View user's profile Send private message
neandrewthal



Joined: May 11, 2007
Posts: 672
Location: Canada

PostPosted: Mon Aug 11, 2008 9:46 pm    Post subject: Reply with quote  Mark this post and the followings unread

I just read this from Ken's site:

"Being a CV processor, this module requires nice clean power rails. Initially mine was exhibiting slight stepped voltage shifts (resulting in pitch shifts). I traced these to the mass of flashing LEDs in the next module - a module that should have been connected to my "dirty" power supply."

I have my heart set on having it on the same panel as my pulse dividers/boolean logic/digital noise with 14 LEDs Mad It's really the only place I can fit it in my first cabinet at this point and I really want one in each cabinet. Is there anything I can do besides getting a second power supply? Does it help that my power supply is a rock solid power one 5A or does that even make a difference in this situation? Thanks.

_________________
" I went through quite a few trannies til I found one I liked" - Wild Zebra
Back to top
View user's profile Send private message
Sine



Joined: Sep 10, 2007
Posts: 111
Location: Netherlands

PostPosted: Tue Aug 12, 2008 1:59 am    Post subject: Reply with quote  Mark this post and the followings unread

Yes, It is VERY sensitive to powerline noise, I had some LED's on the module and disconnecting them visually affected the output.
Back to top
View user's profile Send private message
neandrewthal



Joined: May 11, 2007
Posts: 672
Location: Canada

PostPosted: Tue Aug 12, 2008 10:03 pm    Post subject: Reply with quote  Mark this post and the followings unread

What If I gave it it's own power line. Directly from the power supply. Would that help?
_________________
" I went through quite a few trannies til I found one I liked" - Wild Zebra
Back to top
View user's profile Send private message
ChrisCoady



Joined: Feb 27, 2010
Posts: 8
Location: NYC

PostPosted: Thu Apr 07, 2011 12:19 am    Post subject: Reply with quote  Mark this post and the followings unread

Hey guys,
I've finished building a pair of ASRs and they sounds great and scale nicely.
When they are recieving a constant voltage and outputting a steady tone there is a wobbling in the frequency though.

In Kens build docs he says:
Connect a constant voltage to the input. Connect one output to a VCO and the Clock input to an LFO or clock running at a few hertz. You should get a constant tone. If there is a stepped warble, one of your ICs has a different offset to the others. You can work out which chip it is by holding your finger on the pins of each chip in turn. Swap the affected chip for another. Repeat if needed until you get a constant tone. I have only had this happen with LM3140/CA3140 chips.


I touch the ICs and I hear a stepping tone but I'm not sure how to identify the bad chip(s). Has anyone experienced this and been able to narrow them down? I am just not sure what to listen for.

Thanks in advance,
Chris Coady
Back to top
View user's profile Send private message
Adam-V



Joined: Jan 29, 2007
Posts: 300
Location: Australia
Audio files: 1

PostPosted: Thu Apr 07, 2011 10:27 pm    Post subject: Reply with quote  Mark this post and the followings unread

Mine does the same thing. I just live with it!

Not much help to you though...

Cheers,
Adam-V

_________________
Digitalis Effect | Fractured Symmetry (www.spiralsect.com)
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [19 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » Ken Stone designs - CGS
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use