Cgs synth

The +6V is only there as part of a bus system I was using in some of my
panels that did require +6V - old Serge stuff mostly. 6 volts is not used in
any CGS board.

One known cause of scratchiness showing with pots is if there is a DC signal
involved. I don't know if the following will help or be a total failure, but
try placing a 10uF electro in series with the pot to block any DC component.
Before you do though, us a multimeter to work out which end is more positive
so you get the cap in the right way around.

Ken

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>ok so i went out and bought a new pot just to drop in in case the pot
>i had was bad. seemed it was. i dropped it in and still its scratchy.
>is it possible that i am wiring the legs of the pot up wrong? whilst
>trawling the message archives i noted that ken advises that the third
>leg of the pot is not connected hence i havent grounded it.
>
>i was about to try peng's suggestions but then i realised i have
>nothing connected to the +6v pad.
>
>i run the ground to the frequency pot then run the ground across to
>some perfboard where ive tied in the grounds of the input output and
>volume pot. the 6v connector isnt used at all!
>
>--- In cgs_synth@yahoogroups.com, "peng3002" <peng3002@y...> wrote:
>>
>> Hold up before replacing the pot. I had a similar problem ith the Res
>> pot. It actually came from other pots/jacks not being grounded. Next
>> to the power supply header there is a "6V" hole on the pcb. Make sure
>> if your using this hole to run a ground line to pots/jacks to solder
>> a link to the ground trace right next to it. Cleared up my crackle
>> problems, maybe it'll work for you.
>>
>> As far as output levels go...I took out the link and replaced it with
>> a 390K resistor.
>>
>> As a side note: I think Ken says to breadboard first. This is great
>> advice. For instance: I built the pulse divider and it works
>> perfectly, but it puts out 13-15volts and I would have preferred
>> 5volts. It's simply a matter of changing some resistors to get the
>> output level I want, but after everything is wired solder work can be
>> a little awkward.
>>
>> Phil
>>
>>
>> --- In cgs_synth@yahoogroups.com, "hiriseau" <sean@p...> wrote:
>> >
>> > thanks i will get another one pronto, its a sealed pot so nothing i
>> > can really do about it. and its only a couple of dollars to get a
>> new
>> > one.
>> >
>> > with the level, considering that i will be using the filter in a
>> tweak
>> > hard on the fly sort of role, would i be better off using the trim
>> pot
>> > to set the output level and then attenuator on the input, so that i
>> > don't kill any club sound systems and peoples ears?
>> >
>> > --- In cgs_synth@yahoogroups.com, sasami@h... wrote:
>> > > >the resonance pot is EXTREMELY crackly whenever i move it.
>> > >
>> > > That's a dud pot. It isn't a solder issue, but rather dust or
>> > "corrosion" on
>> > > the pot resistive strip. A shot of electrolube contact cleaner may
>> > help. A
>> > > better pot is the best solution.
>> > >
>> > > >secondly, levels. i have the link in and i have a 50k log pot in
>> (the
>> > > >same 9mm alpha) and it doesnt seem to be working too well. it is
>> low
>> > > >in volume then BANG heaps of volume. my suspicion is that i
>> should be
>> > > >using a linear pot instead of a log pot. this is what it sounds
>> like
>> > > >http://users.bigpond.net.au/xpander/level.mp3 would i be better
>> off
>> > > >using the pot as an attenuator on the input stage, and using a
>> trim
>> > > >pot on the level to tweak it to where i want?
>> > >
>> > > Yes, a linear pot would probably be better. In fact, I rarely use
>> > log pots
>> > > in synthesizers at all.
>> > >
>> > > Ken
>> > >
>> > >
>> ______________________________________________________________________
>> _
>> > > Ken Stone sasami@h... or sasami@c...
>> > > Modular Synth PCBs for sale
>> <http://www.blaze.net.au/~sasami/synth/>
>> > > Australian Miniature Horses & Ponies
>> <http://www.blaze.net.au/~sasami/>
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>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
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_______________________________________________________________________
Ken Stone sasami@... or sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>