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CGS13 Gated Comparator troubleshooting advice . .

CGS13 Gated Comparator troubleshooting advice . .

2011-06-21 by Adam Scramstad

Hi all -


I just finished building a "Best of CGS" SWAMP Sequener Panel
(flipping awesome BTW). But I'm having some difficulty w/ the CGS13
Gated Comparator module...... there appears to be a few issues. I have
never used a module like this (it's seem very unique - and I love
that) so ANY advice or experience with building and troubleshooting
this module would be greatly appreciated.

Issues found:

1 - Whenever the CV "SENS" knob is turned counter clockwise below 2-
oclock.... the "COMP OUT" LED turns on and a voltage is produced at
the "COMP OUT" jack.

2 - If an external clock is patched into the "CLOCK" input and you
turn the CV "SENS" knob below 2-oclock.... then each of the 8x stages
will light in turn sequentially following the clock pulse.

3 - If you create a "Loop Sequence".... then whenever "Stage 8" lights
up - the "COMP OUT" light/jack will light up along with it (at the
same time)


SO basically COMP OUT & Stage 8 seemed linked somehow - and the CV
SENS knob seem too sensitive (100k lin)

Any ideas?

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-21 by sasami@hotkey.net.au

>1 - Whenever the CV "SENS" knob is turned counter clockwise below 2-
>oclock.... the "COMP OUT" LED turns on and a voltage is produced at
>the "COMP OUT" jack.

You are merely setting the detection point below the range of the incoming
signal (or 0V if there is not signal). It is not a fault.

>2 - If an external clock is patched into the "CLOCK" input and you
>turn the CV "SENS" knob below 2-oclock.... then each of the 8x stages
>will light in turn sequentially following the clock pulse.

Not surprising. See above. You are simply clocking a High into all the stages.

>3 - If you create a "Loop Sequence".... then whenever "Stage 8" lights
>up - the "COMP OUT" light/jack will light up along with it (at the
>same time)

Correct, as the COMP OUT is now connected to Stage 8, and mimmicing it.

>SO basically COMP OUT & Stage 8 seemed linked somehow - and the CV
>SENS knob seem too sensitive (100k lin)

If you want to change the sense, increase the value of the resistor between
the CCW end of the pot and the negative rail.
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-22 by Adam Scramstad

Hi Ken,

First off - thank you for your input and info :)

OK..... for example:

1 - if you capture 1x pulse & loop it - then turn all stage cv/knobs
to "zero".....
2 - then monitor the CV at the "MIX" OUT .....
..... why does the voltage jump/increase as it passes through stage 8?
Seems like with all stage knobs on zero . . then there should be NO
change in the voltage out at the "MIX" out?

Is this just part of the way the "KLEE" style sequencer works?

Thanks again - and still having a blast w/ this project :)

- Adam
Show quoted textHide quoted text
On Jun 21, 2011, at 5:47 PM, sasami@... wrote:

> >1 - Whenever the CV "SENS" knob is turned counter clockwise below 2-
> >oclock.... the "COMP OUT" LED turns on and a voltage is produced at
> >the "COMP OUT" jack.
>
> You are merely setting the detection point below the range of the
> incoming
> signal (or 0V if there is not signal). It is not a fault.
>
> >2 - If an external clock is patched into the "CLOCK" input and you
> >turn the CV "SENS" knob below 2-oclock.... then each of the 8x stages
> >will light in turn sequentially following the clock pulse.
>
> Not surprising. See above. You are simply clocking a High into all
> the stages.
>
> >3 - If you create a "Loop Sequence".... then whenever "Stage 8"
> lights
> >up - the "COMP OUT" light/jack will light up along with it (at the
> >same time)
>
> Correct, as the COMP OUT is now connected to Stage 8, and mimmicing
> it.
>
> >SO basically COMP OUT & Stage 8 seemed linked somehow - and the CV
> >SENS knob seem too sensitive (100k lin)
>
> If you want to change the sense, increase the value of the resistor
> between
> the CCW end of the pot and the negative rail.
> __________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/
> ~sasami/>
>
>
>



[Non-text portions of this message have been removed]

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-22 by sasami@hotkey.net.au

>OK..... for example:
>
>1 - if you capture 1x pulse & loop it - then turn all stage cv/knobs
>to "zero".....
>2 - then monitor the CV at the "MIX" OUT .....
>..... why does the voltage jump/increase as it passes through stage 8?
>Seems like with all stage knobs on zero . . then there should be NO
>change in the voltage out at the "MIX" out?

Have you accidentally added the Comp Out into the mixer? It should not be
connected.

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

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-22 by Adam Scramstad

On Jun 22, 2011, at 12:46 AM, sasami@... wrote:
Show quoted textHide quoted text
> >Have you accidentally added the Comp Out into the mixer? It should
> not be
> connected.
>
> Ken
>
No, it doesn't look like it.

On Jun 22, 2011, at 12:47 AM, sasami@... wrote:

> Or is pot 8 properly grounded?
>
The ground wire comes off of pot #8 (non cw leg) and goes to the pcb
ground shown in the diagram.

I wasn't sure where to attach the ground wire from the COMP OUT LED
(on the diagram it says "to LED RETURN") - so I attached it to the
ground that has the "wire strap" on the pcb (near the Q8 out).

For the MANUAL LOOP switch, I followed the diagram and wired one side
of the switch to "Gate 8 Out" - then put a 15k resistor on the center
leg that goes to pin 2 of the LM393 (I used an NTE 943M instead of the
LM393, that's all the shop had in stock) - then the last leg of the
switch went to the same "+VE" on the pcb as the LOOP ENABLE Switch.


- Adam

[Non-text portions of this message have been removed]

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-22 by sasami@hotkey.net.au

The wiring all sounds right.

Ken



>
>
>On Jun 22, 2011, at 12:46 AM, sasami@... wrote:
>
>> >Have you accidentally added the Comp Out into the mixer? It should
>> not be
>> connected.
>>
>> Ken
>>
>No, it doesn't look like it.
>
>On Jun 22, 2011, at 12:47 AM, sasami@... wrote:
>
>> Or is pot 8 properly grounded?
>>
>The ground wire comes off of pot #8 (non cw leg) and goes to the pcb
>ground shown in the diagram.
>
>I wasn't sure where to attach the ground wire from the COMP OUT LED
>(on the diagram it says "to LED RETURN") - so I attached it to the
>ground that has the "wire strap" on the pcb (near the Q8 out).
>
>For the MANUAL LOOP switch, I followed the diagram and wired one side
>of the switch to "Gate 8 Out" - then put a 15k resistor on the center
>leg that goes to pin 2 of the LM393 (I used an NTE 943M instead of the
>LM393, that's all the shop had in stock) - then the last leg of the
>switch went to the same "+VE" on the pcb as the LOOP ENABLE Switch.
>
>
>- Adam
>
_______________________________________________________________________
Ken Stone sasami@... otherunicorn@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Re: CGS13 Gated Comparator troubleshooting advice . .

2011-06-22 by Adam Scramstad

Thanks Ken for double checking, I appreciate it.

All inputs/outputs, switches & knobs seem to function as they should.
I'll spend some time using & getting familiar w/ this module . . .
especially the "looping" and how each stage is added etc.

Every module in this SWAMP Sequencer Panel works awesome w/ my other
Serge gear :)

Best,

- Adam
Show quoted textHide quoted text
On Jun 22, 2011, at 2:47 PM, sasami@... wrote:

> The wiring all sounds right.
>
> Ken
>
> >
> >
> >On Jun 22, 2011, at 12:46 AM, sasami@... wrote:
> >
> >> >Have you accidentally added the Comp Out into the mixer? It should
> >> not be
> >> connected.
> >>
> >> Ken
> >>
> >No, it doesn't look like it.
> >
> >On Jun 22, 2011, at 12:47 AM, sasami@... wrote:
> >
> >> Or is pot 8 properly grounded?
> >>
> >The ground wire comes off of pot #8 (non cw leg) and goes to the pcb
> >ground shown in the diagram.
> >
> >I wasn't sure where to attach the ground wire from the COMP OUT LED
> >(on the diagram it says "to LED RETURN") - so I attached it to the
> >ground that has the "wire strap" on the pcb (near the Q8 out).
> >
> >For the MANUAL LOOP switch, I followed the diagram and wired one side
> >of the switch to "Gate 8 Out" - then put a 15k resistor on the center
> >leg that goes to pin 2 of the LM393 (I used an NTE 943M instead of
> the
> >LM393, that's all the shop had in stock) - then the last leg of the
> >switch went to the same "+VE" on the pcb as the LOOP ENABLE Switch.
> >
> >
> >- Adam
> >
> __________________________________________________________
> Ken Stone sasami@... otherunicorn@...
> Modular Synth PCBs for sale <http://www.cgs.synth.net/>
> Australian Miniature Horses & Ponies <http://www.blaze.net.au/
> ~sasami/>
>
>
>



[Non-text portions of this message have been removed]

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