Sun Jan 16 22:01:07 EST 2011


Instead of the traditional gain-settable integrator, use a fixed gain
double (leaky) integrator, and 2 variable feedback.  1 for cutoff
frequency and 1 for Q.  Would this work?

I'm thinking: what about driving the input diode of the LM13700
directly using the filtered PWM?  As long as we limit the current this
should work just fine.  EDIT: nope, it's not a diode.