12 dB State Variable Multimode-Filter with Feedback

The MULTIMODE VCF (Voltage Controlled Filter) module is a state variable filter and offers four filter modes: Lowpass, Bandpass, Notch and Highpass.

The filter module has one audio input with input 1 offering variable attenuation.
Filter cutoff can be controlled manually as well as from CV-sources. CV-1 is adjustable in intensity and intended to be used with an envelope generator. CV 2 has two functions: It accesses the internal Key-CV-voltage provided by the system-bus (when fed by a MIDI/CV-interface). This allows for easy key-tracking for the cutoff-frequency. Tracking-intensity can be adjusted by a trim-potentiometer. An additional front-panel-input allows adding a further CV-source (e.g. LFO) that uses the same potentiometer. To use this input independently, the system-bus-access can be disabled by setting a jumper on the circuit board.

Filter resonance, called emphasis, can also be adjusted manually and by an adjustable CV-input.

http://mfberlin.de/en/modules/multivcf/