I have been slaving since 2am (no sleep) over a design that occurred to me as my dogs barking woke me up to the twilight of a Colbert report rerun;
I want to 'do' an envelope-controlled filter with a parametric eq as the filter; the idea is to have total control over your Q, resonance, and filter sweep range.
The EQ is based off of GEOFEX's article, here
, and will be controlled by a rectifier/photoresistor circuit.
I have something 'working' in front of me, but the sweep is simply far too short right now... I used some photoresistors I had around, but I think I need to order a few
The end result should be an envelope filter with a peak or notch, as subtle or apparent as possible
I am also working on a whole new idea for the filter that uses an all-pass phase shifting filter to do the notching/peaking, but the eq circuit itself needs a lot of work as-is