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Cgs synth

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Re: CGS48 - VCO -- some questions

2006-03-10 by c10h14no2i

> i just finished the whole cabling
> stuff (except the "Waveshape Pot", where i am puzzled up, where to
> connect it..
>
> middle pin to PCB (SPW)
> left side (CCW) to Ground
> right side (CW) to SP+
>
> am i right with this assumption ?
>

yes, if you are looking at the back of the pot w/ the pins facing up.
I wire mine w/ pins facing down, so I have to think of it in reverse.
CCW right, CW left


> Not to forget ... i still have the "have-to-touch TL072" thingie
> before the VCO works, anybody got a _good_ idea of that ? it works
> after touching,
> even CV works (was using FM AC instead of CV, because CV is not wired
> 100% right ..
>

For the tl072, if you've double and trippled checked all of the
components in that part of the circuit, I'd just replace the 072. Its
hard to say if could be the one on the bottom left or the top left.
The pro sp trimmer connects to the tl072 on the top left. And if
you're getting CV's and FM to work, then the one on the bottom left
might be good. I'd replace both of them.

(I had one module that didn't work, which had 4 ic's.. One IC smoked,
another got hot. I checked all the components again and again,
re-heated all the solders. I replaced the IC that smoked.. It fried
again. I replaced that IC as well as the one that got hot. The IC
fried again. I checked all components again and again.. finally
replaced all 4 IC's and it worked!)
Someone who knows what they are doing might have a more direct answer.

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