Pre-distortion Diodes for Moog Ladder Filter

[Michael B. Irwin]

Magnus,
Thanks for your helpful advice. Is the major source of distortion in the
Moog ladder (under normal operating conditions) distortion from the
input differential amp stage or distortion due to instantaneous
modulation of the filter cutoff frequency by the audio signal? If the
signal-induced modulation is the dominant effect, it would be
interesting to take a 24 dB/oct OTA VCF and feed some of the audio
output back into a control voltage input in an attempt to produce a
controllable amount of warm-sounding distortion in a low-noise VCF.