Possibly goofy idea...

[Dan Gendreau]

> I haven't seen this one (but that doesn't mean it doesn't exist)...
>From what you describe, I believe the Roland SH-101 does part of this. The
only thing it wont allow you to do is control the VCO from a separate
source...

The SH101 allows you to route some amount(0-100%) of the Keyboard CV into
the filter cutoff CV. When it is set to 100% KCV->VCF Cutoff and you turn
off the VCOs and put the VCF Resonance into self oscillation you get a sine
wave oscillator that tracks the pitch of the keyboard.

I wouldnt bother creating a custom keypad for this. You should be able to
just take a standard analog keyboard or Midi/CV source and route the pitch
CV into your Fatman Filter Cutoff CV.

Just a thought,
-Dan G.