Thanks for the tip about the ladder filter. I'll look into that. As for Sallen-key: here are the equations based on component values: http://upload.wikimedia.org/math/6/3/4/6349d6659acb77c5660709e64c7a39d7.png http://upload.wikimedia.org/math/2/4/4/244c18b3c78db258742ae2b6b1f828e9.png What I am look...

I am working on some analog filters right now, and was wondering if anyone knew anything about the filters used in old analog synths. Passive or active? What type of active filter? I don't think it would be Sallen-Key, as then Q (resonance), and cutoff frequency are intertwined. Does anyone know any...