ASM1 filter self oscillation

[Troy Sheets]

Well, without any special mods, my ASM1 VCF does self oscillate, but it
is an interesting, "raspy" self oscillation.  It sounds completely
different than the 4-pole self-oscillation on my Odyssey, which I would
suspect is a pretty pure sine wave. 

The ASM-1 self-ocillation is a real sound though, and it is stable and
tunalbe to a keyboard CV.

-troy


> 
> I have been experimenting with a VC Q circuit for my ASM1 VCF I found in
> Chamberlin's Musical Applications of Microprocessors.  I think this is
> right out of Electronotes.  One of my goals is to get the filter to self
> oscillate at a high Q setting with no signal input.  I realize that there
> is a Q limiter in the feedback path.  So if I take it out, does anybody
> know if a state variable filter can self oscillate in a controllable manner
> like its' 4 pole LPF conterparts?  Or is there something about this circuit
> that makes this impossible?
> 
> John Speth
> 

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