Liquid filter

3 filter modes are available: 2-pole band-pass, 2-pole low-pass, and 4-pole low-pass.

Self-oscillation is available for all modes and produces a clean sine-wave on the LP4 output. Unlike many classic 4-pole designs, this filter does not suffer from “loudness drop” when resonance is increased. The resonance loudness compensation circuit brings a slight tone coloration reminiscent of the Roland SH/Jupiter filters, with a very round and “liquid” resonance.

The 4-pole low-pass output is additionally sent to a VCA. This makes Ripples a good “final stage” module for an inexpensive/space-constrained subtractive synthesis synth voice.


  • Cutoff frequency, 18Hz to 18kHz
  • Resonance (self oscillation at 80%)
  • Attenuverter on Frequency CV

Inputs and outputs

  • Signal in
  • Frequency CV 1 (1V/Oct)
  • Resonance CV. Self oscillation starts at 4V. Control voltages above 5V are non-linearly compressed, for fine control of resonance overdrive
  • Frequency CV 2 (with bipolar attenuator, from -1V/Oct to 1V/Oct)
  • VCA level. Control voltages above 5V are non-linearly compressed.
  • 2-pole BP output
  • 2-pole LP output
  • 4-pole LP output
  • 4-pole LP output attenuated by VCA

Technical characteristics

  • Fully analog, based on SSM2164 low noise/distortion quad VCA chip, and LM13700 OTA for that extra bit of non-linearity.
  • Frequency CV inputs impedance: 100k.
  • Audio input impedance: 75k.
  • Resonance and VCA CV input impedance: 30k.
  • Open-source hardware.

  • 35 mA +12V
  • 35 mA -12V
  • 0 mA 5V
  • 20 mm deep
  • Ø 4.45 (102 Votes) Average Rating

This Module is currently available.

$199 submitted Apr 9th 2013, 14:10 by pichenettes | last Change Mar 1st, 19:51 by pichenettes
Specs are approved by the manufacturer

Date Region Description Price Seller
USAMutable Instruments RIPPLES filter in great condition. Works precisely as it ...$125.00 View
SwitzerlandThe overall condition of this Mutable instruments Ripples is like new ###t...€120,00wav909 View
EUMI Ripples w/custom original art alu panel (DIY) x 2 More modules for s...€100,00Darylc View
EUDIY Ripples with dark panel, EU wide shipping included, only 2 months old ...€105,00synthetictheory View
EUDIY Ripples shipping from Berlin/GER it is actually this version: https:...€100,00lpzw_modules View
USAOriginal Mutable Instruments Ripples with minimal rash. comes in original bo...$160.00nrg242 View
USA Mutable Instruments Ripples with Grayscale faceplate and white Rogan knobs. ...$195.00 View
USAThis product has been played/demoed in store, used to make promotional materi...$199.07 View

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