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Synthrotek MST VC Low Pass Filter

Synthrotek is pleased to offer a complete line of eurorack synthesizer modules, power, cases and accessories in both complete units kits and panels & pcbs. We now offer a very complete analog modular monophonic voice with many accompanying utility modules. This new complete voice is the product of a collaboration with synth guru George Mattson, who now joins us in releasing our new MST (Mattson – Synthrotek) line of premium modules.

MST VC Low Pass Filter 1v/o Tuning Instructions
Things you will need:

  • 1v/o cv source (midi-cv with a keyboard, oscillator with a Hz readout)
  • The MST VC Low Pass Filter
  • Patch cables
  • Chromatic tuner (we use Pitchlab Pro, its free for Android and IOS)
  • Small flathead screwdriver

Patch Setup:

  1. Plug your 1v/o source into the 1v/o jack in the MST VC Low Pass Filter
  1. Plug the -24db output of the filter to an amp or speakers, something where you can hear it.
  1. Turn All Knobs to the Full CCW position.

Tuning Instructions:

  1. Set your 1v/o source to 0v, which we will call C1.
  1. Turn the Resonance knob all the way CW.
  1. Slowly turn the Cutoff knob CW until you can hear the Filter self oscillating, and keep turning until the pitch reads ~32.7 Hz, C1.
  1. Set your 1v/o source to 1v, which will be C2.
  1. Flip the Filter over and adjust the trim pot until the pitch is ~65.4 Hz, C2.
  1. Set your 1v/o source to 2v, and check that the filter is now at C3, 130.8Hz.


The MST Low Pass Filter is a precision analog dual slope output 2 & 4 pole filter. Simultaneous -12 DB and -24 DB outputs with CV control over all parameters. Can be used as a 1V/O sine wave oscillator


Manual control of cutoff frequency

Manual Control of Resonance (Q)

1V/O input for clean sine wave output

CV Frequency input w/ attenuator

Resonance CV input w/ attenuator

Audio input

Simultaneous -12 db and -24 db/octave outputs


Current draw: V+ max 23.5mA, V- max 15.5mA

Width: 6HP  Depth: 3.5cm (1.75 in)