electronics for a diy ribbon controller

[Mike]

Puentstein wrote:
> 
> In a message dated 98-02-26 01:15:48 EST, Puentstein at AOL.COM writes:
> 
> <<  What kind of old moog do you have?
>  Prodigy, Source and Minimoog.
> Funny,  after connecting my proto-ribbon thingy to any of these, seems I gain
> a nasty-sounding fast audio freq. Lfo mod effect! (WHIRRR!!  - old sci-fi
> movie...)
> Any ideas as to what might cause this?
>  (the ribbon works, at least.  Thanx all!)
> The synths all sound just fine, btw, when they are connected to each other,
> (cv out to cv in, etc).
> 
>  Randy
Randy 
This almost has to be from 60 hertz hum getting mixed in with your
control voltage outputs. The output from controllers like ribbon
controllers and keyboards is supposed to be DC, and any hum voltage will
result in FM modulation of what they are controlling. Might want to
shield the circuit and/or passively low pass filter the output to help
eliminate the problem.

Mike Granger