top of page
W121 Low-Pass Filter

W121 Low-Pass Filter

The 2144 Low-Pass Filter features the SSI2144 IC, the official and improved reissue of the legendary SSM2044 filter IC used in many classic synthesizers.


With its unmistakably silky-smooth top-end and liquid-like mid-range; it is widely regarded as being one of the best sounding filters ever made.


A wide range of modulation possibilities also adds versatility.



  • Four-pole 24dB/octave low-pass filter.
  • Manually controllable resonance and cutoff frequency.
  • Frequency range greater than audio range (> 20Hz to 20kHz).
  • Capable of self-oscillation i.e. producing a sine wave output.
  • Thermally compensated 1V/octave input.
  • Numerous modulation possibilities including FM and resonance CV inputs (0V to 10V input range).
  • Ergonomic design.
  • Hand-built and tested in the UK.



  • Model number: W121
  • Format: Eurorack
  • Width: 10HP
  • Depth: approx. 40mm
  • Power consumption:
    • +12V: 30mA
    • -12V: 30mA
    • +5V: 0mA





Please see our Delivery Policy for more information.

    Excluding VAT