Matrix VCF

The Matrix VCF is no ordinary filter. What AJH Synth delivered here is the result of two years of meticulous development – sixteen different filter types with two distinct resonance models per type, totaling an extraordinary thirty-two filter variations. Not just an Oberheim Matrix 12 filter clone, but an evolution that takes the classic design into a new ballpark.

The Matrix VCF features the rare and highly sought-after Oberheim Matrix 12 filter topology, expanded with several additional modes and new tonal possibilities. The sixteen filter types are clearly indicated by illuminated LEDs on the front panel, with filter selection possible via both manual control and external CV. The low-pass, high-pass, band-pass, notch, and combination filters are all here, plus AJH added a four-pole all-pass phaser mode not found in the original Matrix 12.

The Matrix VCF, features something called the “P-Vox” switch. Engaging this mode completely transforms the resonance behavior, introducing distortion and overdrive inspired by Soviet Polivoks circuits. When P-Vox is activated, all sixteen filter types can be pushed into self-oscillation, producing harmonically rich waveforms far beyond the usual sine waves. This effectively doubles your filter palette to thirty-two distinct variations, ranging from smooth and musical to screaming and aggressive.

The interface is as straightforward as can be and should leave very few riddles behind. Six solid control knobs manage frequency, mode selection, resonance, CV levels, and input/output levels. There’s a row of sixteen LEDs that provide visual feedback about which filter type is currently active – definitely helpful when using external CV to switch between modes. Speaking of CV, the module offers you six CV inputs, including a 1V/Oct input that lets you use the filter as a tracking oscillator when in self-oscillation mode. A built-in VCA on the output is also there with a peak LED that helps you dial in your signal levels without unwanted distortion.

In use, the Matrix VCF is capable of a whole host of classic filter tones – and then there’s the more unusual complex combination filters like “Three Pole High Pass combined with One Pole Low Pass” to create unique timbral sounds rarely found in other filter designs. When P-Vox mode is engaged, even familiar filter types take on new life with a distinctly raw, analog character. This is simply an outstanding selection of filters, housed in a premium module.

Features:

• 16 distinct filter modes based on Oberheim Matrix 12 topology
• P-Vox (Polivoks) resonance distortion circuit doubles the sonic palette to 32 filter variations
• Visual feedback via 16 LEDs showing the active filter type
• Manual and CV-controllable filter type selection
• Multiple CV inputs for frequency control (1V/Oct, 1/3, 2/3, Freq CV)
• Self-oscillation capability in P-Vox mode with 1V/Oct tracking
• Integrated VCA with dedicated CV input
• Input and output level controls with peak LED indicator
• All-analog signal path with premium components