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Cgs synth

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Message

Re: cgs65 cv issues

2007-12-07 by prophei

--- In cgs_synth@yahoogroups.com, "bbluthang" <jumpswine@...> wrote:
>
> Have you tried to set it up as per Ken`s instructions?
>
> SetInitial Gain pot to 0, no CV in, feed in an audio signal and
> adjust the trimmer until you cannot hear anything on the output.
>
> Once you have done this, plug in a CV signal and adjust initial Gain
> to get it VCAing as you like.
>
> If you have tried all this, and still no effect. What voltage are
> you getting on pin 1 and does it change when you adjust the initial
> Gain pot? (It should!)
> cheers
> Andrew

i just went to test pin 1 of the lm358, and found nothing there. then i somehow blew the
ferrite bead (i had a resistor here) located next to the cv inputs to the board. i have no idea
how i did this, and want to think it was pure coincidence (tho this may be a rather unlikely
thing). all i have ever been able to measure around this ic has been positive and negative
power (on pins 8 and 4 respectively).

i replaced the blown bead (resistor) mentioned above and then swapped the lm358 for a
5532 i had sitting here to see what would happen. this chip gave me actual readings on
the pins. pin one was registering a 12.5. i still was unable to get anything to work
properly, and noticed that the 5532 seemed rather warm, so i pulled it and quit for now.

i sit here scratching my head yet again.

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