pronuciation? RE: [sdiy] Restoring a Pro-One, need simple electronic advice

[Colin f]

> Well, In my case, knowing how to pronounce the chip name is a 
> start.....
> still it does not tell me what to do with it !
> 
> It's sad that you lost any infos about the mod Colin, it's 
> exactly what I
> needed!
> If ever, you find it, let me know ! Wise guys like we are 
> always have some
> backups , do you?? !! :)

The Pro-One mod wheel pot has the modulation signal at one end, ground at
the other, and the wiper feeds a variable amount of the mod signal back into
the synth.
You need to replace the modulation signal at one end of the pot with a fixed
voltage, so you get a CV proportional to the mod wheel position from the
wiper. Then you need a DC coupled VCA (this was half the 13700 and a buffer
op-amp). You take the original modulation signal that went to one end of the
pot, and feed it to the VCA input. The VCA output goes back into the synth
where the wheel wiper used to go. The CV coming from your modified wheel now
controls the VCA, with an input jack to over-ride it with an external CV.

If someone wants to lend me a Pro-One for a few months, I'm sure I could
come up with a working circuit ;-)

Cheers,
Colin f