Serge Modular Stereo VCFQ

This is a stereo implementation of the classic Serge Variable Q Filter, expanding the original VCFQ concept into a dual-channel format.

The Variable Q VCF is a flexible, general-purpose filter offering simultaneous low-pass, band-pass, and high-pass outputs. Resonance, or Q, can be adjusted manually or via control voltage, and each input includes level control, allowing the filter to be driven into saturation for more aggressive or percussive results.

A dedicated Trigger input allows the filter to ring when pulsed, producing damped, resonant tones that range from sharp clicks to woody percussion and bell-like sounds. The character of this response is shaped by the cutoff frequency and Q, making it useful for tuned percussion, resonant accents, and complex tonal shaping.

An AUX input is summed into both channels without attenuation, making it suitable for adding mono sources into the stereo signal path.

This Eurorack version is based on Serge Tcherepnin’s original 1976 VCFQ design, built with high-quality VCAs for improved audio performance. It occupies 18 hp, draws approximately 50 mA on both +12 V and -12 V rails, and has a depth under 25 mm, making it suitable for skiff cases.

• 18 HP 25 mm deep

Filter

Found Sound Australia Pty Ltd.
110 Albert St
Brunswick East, VIC 3057
Australia