The AJH Synth Matrix VCF at a glance

With the Matrix VCF, AJH Synth has created a special treat, as the module contains all the filter models of the famous Oberheim Matrix 12 synthesizer from 1985. The original Matrix 12 filter already offers an impressive 15 characteristics, which are divided into lowpass, bandpass, highpass, allpass and notch with 1-4 poles, including a few combinations. In this Eurorack version, a four-pole all-pass filter has been added to the circuit, making 16 filter models available. Almost all filter modes tend to self-oscillate; if the P-Vox Mode switch is in the upper position, the softer, Matrix 12-typical resonance behavior is used. In the lower position, the resonance is fed through the crazy and only partially predictable Polivoks circuit, which ensures a much more aggressive resonance behavior. The various filters can be accessed using the mode control, which is equipped with its own control voltage input. This allows you to select a different filter for each new note or glide through the filter modes using an envelope. To modulate the filter, there are three tracking inputs (1V/oct, 2V/oct, 0.66V/oct), an FCV input with attenuator and a CV input for resonance. Thanks to the integrated VCA, the Matrix VCF can also be used as the last module in the signal path, depending on Patch ; the VCA is only active when a cable is plugged into the CV input. Depending on the setup, this can save an additional VCA.