Cgs synth

Apply a voltage into the PWM input. If the triangle wave isn't happening
within the comparator's range, there will be no output.

Ken

>The triangle out is working, but square out is not. There isn't much
>to what converts the triangle to square, so I thought I could figure
>it out. While looking around for bad solders or anything else I had
>my headphones plugged into the square out. I started to get a tone..
>definitely a square wave. I figured out that if my thumb was touching
>pin 8 on the tl072 and the area around sync in or the 100p cap, I
>would get square wave. From there I figured out that if I touch pin 3
>of the lm311(sync in) and +v the square wave works, however it
>distorts the saw out.
>I accidentally discovered that if I short the 100k resistor just right
>of the 311 it produces a tone out of the sq. out(though it sounds
>different). Its connected to a bunch of stuff on the pcb, including
>the output of the ca3140.
>
>Ive checked the components all around those portions of the circuit.
>I dont understand why messing w/the sync would make the output from
>the square work. Should I be looking around the tl072, or the lm311?
>
>Any clues what the cause might be?
>
>thanks
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>The CGS Modular Synth home page: http://www.cgs.synth.net/
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>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/>