keyboard triggered filter

[WeAreAs1 at aol.com]

In a message dated 11/8/99 1:32:11 PM, you wrote:

<<What you are describing sounds like a state-variable filter, with the cutoff
frequency controlled by a keyboard. This will definitely work for feedback
oscillator applications - I was doing this the other day (with a Moog filter) 
to
control the pitch of feedback echoes.>>

Yeah, and a SVF would also have a Bandpass ouput, which might even be the 
most useful one for controlled-feedback experiments.  A very narrow bandpass 
filter might actually allow you to sweep the feedback pitch, almost like an 
oscillator (depending on favorable environmental acoustic factors, of 
course).  You could certainly control the filter's pitch range with some kind 
of CV pedal - this would allow you to sweep through and zero in on various 
strong feedback resonance ranges.  I have my doubts about trying to come up 
with any kind of reliable feedback-pitch-to-CV device, though.

Are you guys making your feedback with open microphones, or are you using 
amplified guitar strings?  This sounds like fun!

Mike B.