A analogue voltage controlled Filter for modular Eurorack Synthesizers based losely on the Korg MS-20 Filter from 1978 with a frew extras

Features

• Blend between the 12 dB-Lowpass and the 6 dB-Highpass filters
• Switch between three different types of resonance
  • Symmetric clipping with two anti-parallel diodes (classical MS-20 behaviour)
  • Asymmetric clipping with one diode (weird/wild)
  • No diode clipping (loud, self-oscillating behaviour)
• CV Input with Attenuverter and a bicolor LED to display the incoming signal. The Attenuverter allows you to e.g. turn positive control voltages into negative control voltages, which is useful for the Highpass mode
• Drive controls the level, but has a wider range than just a passive control

Sound Demo

Watch the video for a short demo of the breadboarded circuit