M 504

Low Pass 

Ladder Filter 

This VOLTAGE CONTROLLED LOW PASS FILTER is a traditional ladder-type filter, switchable 12/18/24 dB/oct with voltage controllable cutoff frequency and regeneration.

M 505

Voltage Controlled Multi Mode Filter

The MULTI MODE FILTER features low pass, high pass, band pass (12 dB/oct each) and notch mode (6 dB/oct), which are available simultaneously as well as combined at the mixed output, where the filter mode is voltage controlled. Cutoff frequency and resonance are voltage controllable too.

M 509

Low Pass/Band Pass 

Polivoks Type Filter  

The VOLTAGE CONTROLLED LOW PASS/BAND PASS FILTER is inspired by the filter part of the famous Formanta Radio Factory Polivoks synthesizer from 1982. 

It features a switchable band pass/low pass filter with voltage controllable cutoff frequency and as an enhancement of the original voltage controlled regeneration.

Filter slope in low pass mode is 12 dB/oct, in band pass mode 6 dB/oct.

M 517 

Coupled Dual Voltage Controlled

High Pass/Low Pass Filter

This module combines two VOLTAGE CONTROLLED FILTER circuits in one triple-width unit. The two identical filters are switchable high pass/low pass filters with independent controls for cutoff frequency and regeneration. 

The four-mode combinator allows using the filters as – two separate filters (”stereo mode“) – two filters in series (”maximum slope“) – notch/band reject mode – band pass mode. 

The balance between filter 1 and 2 and the bandwidth are voltage controllable. 

An additional jack combines both filters' audio outputs.

M 517 S

Voltage Controlled

High Pass/Low Pass Filter

The SINGLE VOLTAGE CONTROLLED FILTER is one half of the 517 module without the combinator part, featuring a single high pass/low pass filter with voltage controllable cutoff frequency and regeneration.