Ripples (2020)

Mutable Instruments' analog multimode filter, 2020 panel: high-pass, band-pass and low-pass outputs, a switch for the slope of the band-pass and low-pass, and a VCA on the low-pass output, built on a quad VCA chip with an OTA in the resonance path.

Key features

• HP, BP and LP outputs; the BP and LP slope switched between 12 dB/octave (2-pole) and 24 dB/octave (4-pole), the HP slope varying with resonance
• Two audio inputs mixed: IN 1 through a soft-clipping stage with its level knob (gain 0 to 5), IN 2 always clean
• Frequency CV calibrated for 1 V/Oct tracking of the self-oscillation over 4 octaves, a second frequency CV through the FM attenuverter
• Resonance CV; self-oscillation at about 75 % of the resonance knob
• LEVEL input setting the gain of the LP output (5 V unity); cutoff range 20 Hz to 20 kHz
• Made from May 2020 to November 2022; the design is open source