121 Dual VCF

The Behringer 121 Dual VCF brings the revered filtering power of the classic Roland System-100M into the modern Eurorack world. This module is a faithful, all-analog recreation of the original 121 module, featuring two independent 24 dB/octave low-pass filters. The voltage-controlled filter (VCF) is one of the most critical components in subtractive synthesis, responsible for shaping the tonal character of a sound, and having two of them in a single module opens up a vast range of sonic possibilities, from stereo filtering to complex series or parallel sound sculpting.

Each filter in the 121 Dual VCF provides that classic, warm, and musical sound characteristic of vintage Japanese synthesizers. Both filters have manual controls for cutoff frequency and resonance, allowing you to dial in everything from gentle high-frequency roll-offs to sharp, self-oscillating resonant peaks. To bring the filters to life, each has three CV inputs for modulating the cutoff frequency, allowing you to control them with envelopes, LFOs, sequencers, or any other CV source. This dual design is perfect for processing two separate sound sources independently, or for routing a single source through both filters in series for an aggressive 48 dB/octave slope.

Features

• Authentic recreation of the legendary Roland System-100M 121 Dual VCF module.
• Contains two independent 24 dB/octave low-pass filters.
• Classic all-analog circuitry for warm, rich, and musical filtering.
• Manual controls for Cutoff Frequency and Resonance for each filter.
• Three CV inputs per filter for extensive modulation possibilities.
• High resonance settings allow the filters to self-oscillate and act as sine wave generators.
• Ideal for stereo processing or series/parallel filter configurations.
• Eurorack-compatible format for easy integration into any modular setup.