MOTM

I am very excited about this as well. I have been poking around with 
it off and on trying to get it to work as I wish on a breadboard, but 
so far it does not.

It will go into self-oscillation. The idea of the pair of 420's is not 
too far off, but the sound qualities are very different.  The filter 
has a very distinct "howl" to it when the Q gets up there.  I have an 
OSCar and it sound pretty fantastic on that. 

Earlier this year another list member came up with a circuit that 
could generate separation voltages.  The OSCar filter as I had been 
trying to get work as CV for:

Cutoff
Resonance
Separation
Overdrive

The original OSCar circuit will overdrive pretty easily, and it has 
some nice distortion that adds to the characteristic howl.

In addition there would need to be switches for

Slope:
12 db
18 db
24 db

Mode:
Lowpass
Bandpass
Highpass

So that is the though anyhow, but so far it is not behaving itself in 
the lab.  I am a software guy, not a hardware guy, and I am doing this 
mostly to amuse myself.  Some of the difficulties include the fact 
that the OSCar schematics are hand drawn, missing some part 
descriptions, and (I believe) wrong in some parts.  So one day it will 
probably work, till then it is just a science experiment.

Bruce