PAIA Synthespin Mk II

[toneman]

Looks like those 2 wrong-value resistors are in the voltage control area of the filter/LFO.

check the manual here:

http://www.paia.com/talk/viewtopic.php?f=6&t=211


actual pdf here:

http://www.paia.com/talk/download/file.php?id=191&sid=0adda2cc2dfb28a71ae6ddeccfa75e77


read the theory-of-operation about how the voltage from the reference and the pots add/subtract.

don't seem to be any 330K resistors in the circuit??

sounds like a biasing problem with the LFO range.

T

[Electron Tornado]

I have that document. That's what I used to verify the components on the PCB. I changed the two resistors and cap that were wrong. They are all "downstream" of the LFO, so had no effect on the LFO speed.

I need to re-check the wiring and re-heat the solder joints for everything in the LFO section. If none of that helps, then my only guess is the problem is one of the caps is bad, part of the IC is bad, or the transistor is bad. The LFO is oscillating, however, but the frequency range is too high.

[toneman]

C12 is the timing cap for the LFO.

T

[Electron Tornado]

C12 is the timing cap for the LFO.

T

I tried a few different values for C12. Changing it from 0.005uf to 0.02uf got the speed into a much better range.

Thanks to everyone for their help.