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CGS051 (WRS) & CGS055 (ASM) question(s)

CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-17 by phijel

Hello

Currently building these (linked together)

this is the panel (modcan A format) I designed for it :

https://farm2.staticflickr.com/1546/26217580190_b2abc30812_b.jpg

Any feedback on this layout ?

Also, after rereading the docs, I was wondering my idea to have one switch per stage is worth it (instead of a global switch), and if this would be easily doable considering I already soldered the pins sockets to link the boards together.

Also I noticed the pad C on the ASM seems to be directly connected to +15V. Is this normal ?

Thanks !

Philippe

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-17 by Ken Stone

Pad C in the CGS55 is connected to 14.4 volts. It acts as a HIGH for the CGS51, when the parts in the outlined area containing the TL074 are omitted.

"A switch could be placed between the C pads, allowing the switch matrix to be isolated from the weighted random board when the switch matrix is needed without the random function."
There isn't provision in the circuitry for individual switches. It's all or nothing.
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On Mon, Apr 18, 2016 at 8:11 AM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

Hello


Currently building these (linked together)

this is the panel (modcan A format) I designed for it :


Any feedback on this layout ?

Also, after rereading the docs, I was wondering my idea to have one switch per stage is worth it (instead of a global switch), and if this would be easily doable considering I already soldered the pins sockets to link the boards together.

Also I noticed the pad C on the ASM seems to be directly connected to +15V. Is this normal ?

Thanks !

Philippe




--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-18 by phijel

I see, thanks Ken

I found the diode just after the +15V was dead, so that's why I had a continuity and the same voltage on the C pad

btw, my PSU delivers +15,48V on the positive rail and -15,54V on the negative. As the +14,4V only relies on the diode resistance apparently, I have +15,19 instead of +14,4 (and -0.74V instead of -0.6V). Would that be a problem for the circuit or the chips ?

Another question I had about the WRS: I don't find anything in the docs or the schematic aboutt how should I wire the pots for the inputs. Are they supposed to be simple attenuators, or sending fixed voltages in parallel with the inputs (as there a 8 of those) ?

Thanks

Philippe

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-18 by Ken Stone

Are those PSU voltages with the PSU under load or not? It really is a little too high for CMOS. Adjust the PSU if you can. The 0.74 drop is fine.

The pots are wired between +VE and 0V, with the wipers going to the resistors, so yes, they are for sending fixed voltages in parallel with the CV inputs.
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On Tue, Apr 19, 2016 at 1:49 AM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

I see, thanks Ken


I found the diode just after the +15V was dead, so that's why I had a continuity and the same voltage on the C pad

btw, my PSU delivers +15,48V on the positive rail and -15,54V on the negative. As the +14,4V only relies on the diode resistance apparently, I have +15,19 instead of +14,4 (and -0.74V instead of -0.6V). Would that be a problem for the circuit or the chips ?

Another question I had about the WRS: I don't find anything in the docs or the schematic aboutt how should I wire the pots for the inputs. Are they supposed to be simple attenuators, or sending fixed voltages in parallel with the inputs (as there a 8 of those) ?

Thanks

Philippe




--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-19 by phijel

Yes under load (+/- 20 modules)

It's a Cynthia majors PSU, it's been a while since I opened it, and I remember there's a kind of protective hood on top that needs very specific screwdriver to be removed - not sure the trimmers (if any) can be easily accessed - I'll check again

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-19 by Ken Stone

Make sure your meter is accurate first.

On Tue, Apr 19, 2016 at 5:53 PM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

Yes under load (+/- 20 modules)

It's a Cynthia majors PSU, it's been a while since I opened it, and I remember there's a kind of protective hood on top that needs very specific screwdriver to be removed - not sure the trimmers (if any) can be easily accessed - I'll check again




--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-19 by phijel

I'm happy to report back I finished the module(s) and they are working 100% ;-)

I love it, it's a fantastic combo, and I'm sure it will get a lot of use in my setup

Thanks !

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-27 by phijel

One thing I also noticed though about the CV outputs on the WRS, they are varying in a random fashion, but they are always at audio rate, no matter what signal I send to the CV ins, even slow ones. Is it normal ? Does this have something to do with the unspecified components values ? I used the values suggested in the docs, (100k for RA, 10k for RB, nothing for RC, 47nF for CA, 47nF for CB). If yes, what component should I modify to lower the CV out rate if possible ?


Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-27 by Ken Stone

the variation rate depends entirely on the frequency of the signal at the CLK (Clock) input.
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On Thu, Apr 28, 2016 at 5:34 AM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

One thing I also noticed though about the CV outputs on the WRS, they are varying in a random fashion, but they are always at audio rate, no matter what signal I send to the CV ins, even slow ones. Is it normal ? Does this have something to do with the unspecified components values ? I used the values suggested in the docs, (100k for RA, 10k for RB, nothing for RC, 47nF for CA, 47nF for CB). If yes, what component should I modify to lower the CV out rate if possible ?






--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-28 by phijel

Thanks Ken but maybe I wasn't clear enough in my post, so let me reformulate :

- the clock IN is slow
- the CV IN's are slow
- the CV OUT's are varying slowly indeed, and at a rate depending on the clock rate, so no problem there
- but it's the internal rate of these CV OUT's that's fast (all 4 of them), and make them more sound like oscillators (indeed slowly varying ones) instead of slow CV sources




Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-28 by Ken Stone

You must have some sort of construction error that is shorting the internal VCO to the outputs, or the 4013 that selects them.
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On Thu, Apr 28, 2016 at 3:42 PM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

Thanks Ken but maybe I wasn't clear enough in my post, so let me reformulate :


- the clock IN is slow
- the CV IN's are slow
- the CV OUT's are varying slowly indeed, and at a rate depending on the clock rate, so no problem there
- but it's the internal rate of these CV OUT's that's fast (all 4 of them), and make them more sound like oscillators (indeed slowly varying ones) instead of slow CV sources







--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-28 by Ken Stone

Or maybe I'm still misunderstanding still, and you are poking around in the internal works where things are behaving as they should.

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On Thu, Apr 28, 2016 at 6:00 PM, Ken Stone <otherunicorn@...> wrote:
You must have some sort of construction error that is shorting the internal VCO to the outputs, or the 4013 that selects them.

On Thu, Apr 28, 2016 at 3:42 PM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

Thanks Ken but maybe I wasn't clear enough in my post, so let me reformulate :


- the clock IN is slow
- the CV IN's are slow
- the CV OUT's are varying slowly indeed, and at a rate depending on the clock rate, so no problem there
- but it's the internal rate of these CV OUT's that's fast (all 4 of them), and make them more sound like oscillators (indeed slowly varying ones) instead of slow CV sources







--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>



--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-28 by phijel

Hello again

I made a small vid about it here :

CGS 051 WRS
CGS 051 WRS
Troubleshooting the WRS (CGS051) The 4 CV OUT (bottom) are following each other closely, and doesn't seem related to the CV IN's (top) - Is this the normal ...
View on www.youtube.com
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Sorry for the bad quality - screen capture, but i think it might clarify some things.

I'm only showing 3 CV IN's and 3 CV out's + the clock (I can monitor 8 signals max)

I think the micro oscillation (making the CV out act as oscillators when amplified) is the "warble" you're talking about in the docs - so probably normal.

The 4 CV OUT (bottom) are following each other closely, and doesn't seem related to the CV IN's (top)

They also stop working when the weight knobs are set to 0 (fully CCW), despite the fact that the fluctuating voltages keep entering the CV IN's.

The vertical scale of the display is approx. -1 V to 5 V

Does this CV out behaviour look normal to you ?

Thanks !

Philippe

Re: CGS051 (WRS) & CGS055 (ASM) question(s)

2016-04-28 by Ken Stone

It's been 12 years since I designed the thing, and I really don't remember a lot about it. It may be the warble I was talking about. If changing the value of CA does effect it, I guess it is.

As for a 0V input, yes, it stops the clock. The following text is from the web page. I think the description is not quite right, as a 0v input simply prevents any more clock signals from getting through. The description suggests it simply disables that input, but I can't see how that would work.

"There is an over-ride condition where an external clock pulse is ignored. If one of the weight determining CVs is below around 0.5 volts, it is deemed to be effectively zero - in other words, an unwanted state. The comparator detects this condition and blocks the clock pulse, so the second multiplexer holds the previous state. This may mess up the perceived weighing of that particular state, but it is preferable to selecting a state to which nothing is connected, thus the unit can be used to switch between 2, 3 or 4 different inputs as required."
Show quoted textHide quoted text
On Thu, Apr 28, 2016 at 11:26 PM, philippe@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:

Hello again


I made a small vid about it here :

CGS 051 WRS
CGS 051 WRS
Troubleshooting the WRS (CGS051) The 4 CV OUT (bottom) are following each other closely, and doesn't seem related to the CV IN's (top) - Is this the normal ...
Preview by Yahoo


Sorry for the bad quality - screen capture, but i think it might clarify some things.

I'm only showing 3 CV IN's and 3 CV out's + the clock (I can monitor 8 signals max)

I think the micro oscillation (making the CV out act as oscillators when amplified) is the "warble" you're talking about in the docs - so probably normal.

The 4 CV OUT (bottom) are following each other closely, and doesn't seem related to the CV IN's (top)

They also stop working when the weight knobs are set to 0 (fully CCW), despite the fact that the fluctuating voltages keep entering the CV IN's.

The vertical scale of the display is approx. -1 V to 5 V

Does this CV out behaviour look normal to you ?

Thanks !

Philippe




--
Ken Stone otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>

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