Behringer System 100 121 VCF
Legendary dual analog low-pass filter for Eurorack
16 HP Eurorack module
The Behringer System 100 121 Dual VCF is an analog dual voltage-controlled filter module for Eurorack, featuring two independent 4-pole low-pass filters with resonance, fixed high-pass filter switching, and three signal inputs and three CV modulation inputs per filter. Inspired by the classic Roland System 100, it delivers warm, resonant analog filtering capable of everything from subtle tone shaping to screaming self-oscillation.
Features
- Two fully independent analog voltage-controlled low-pass filters
- Three signal inputs per VCF with individual level attenuators
- CUTOFF slider from 20 Hz to 20 kHz
- Resonance control capable of self-oscillation
- Fixed high-pass filter switchable: OFF, 1 kHz, 2 kHz, 5 kHz
- Three CV modulation inputs per VCF with individual level attenuators
- 1V/octave CV tracking on MOD IN
- CV range 0V to +10V
- AC-coupled signal inputs and outputs
- Maximum input and output level +16 dBu
- Output noise below -64 dBu (22 Hz - 22 kHz)
- Standard Eurorack power via 16-pin to 10-pin cable included
Controls & Jacks (36)
- VCF 1 Signal Input 1 — Audio input 1 for VCF 1, 3.5 mm TS jack
- VCF 1 Signal Input 2 — Adjust the high-pass filter for VCF 1 from OFF, 1 (1 kHz), 2 (2 kHz), or 3 (5 kHz)
- VCF 1 Signal Input 3 1 — Audio input 2 for VCF 1, 3.5 mm TS jack
- VCF 1 Signal Input 3 2 — Audio input 3 for VCF 1, 3.5 mm TS jack
- VCF 1 Signal Input 1 Level — Adjust the cutoff frequency of the low-pass filter for VCF 1 (20 Hz to 20 kHz)
- VCF 1 Signal Input 2 Level — Adjust the level of the signal connected to Signal Input 2 of VCF 1
- VCF 2 Signal Input 1 — Audio input 1 for VCF 2, 3.5 mm TS jack
- VCF 2 Signal Input 2 — Audio input 2 for VCF 2, 3.5 mm TS jack
- VCF 2 Signal Input 3 1 — Audio input 3 for VCF 2, 3.5 mm TS jack
- VCF 2 Signal Input 3 2 — Audio input 3 for VCF 2, 3.5 mm TS jack
- VCF 1 Output — Filtered audio output for VCF 1, 3.5 mm TS jack
- VCF 1 Resonance — Boost the resonance frequencies selected with the Cutoff slider, potentially causing VCF oscillation for VCF 1
- VCF 1 Signal Input 3 Level 1 — Adjust the level of the signal connected to Signal Input 1 of VCF 1
- VCF 2 Cutoff Frequency — Adjust the cutoff frequency of the low-pass filter for VCF 2 (20 Hz to 20 kHz)
- VCF 1 Mod Input 3 Level — Attenuate the voltage connected to Mod Input 3 for VCF 1
- VCF 1 Mod Input 1 — Control voltage input 1 for VCF 1 cutoff frequency modulation, 3.5 mm TS jack
- VCF 2 Signal Input 1 Level — Adjust the level of the signal connected to Signal Input 1 of VCF 2
- VCF 1 Mod Input 3 — Control voltage input 3 for VCF 1 cutoff frequency modulation, 3.5 mm TS jack
- VCF 2 Signal Input 2 Level — Adjust the level of the signal connected to Signal Input 2 of VCF 2
- VCF 2 Mod Input 1 — Control voltage input 1 for VCF 2 cutoff frequency modulation, 3.5 mm TS jack
- VCF 1 Signal Input 2 Level — Adjust the level of the signal connected to Signal Input 2 of VCF 1
- VCF 2 Signal Input 3 Level — Adjust the level of the signal connected to Signal Input 3 of VCF 2
- VCF 2 Resonance — Boost the resonance frequencies selected with the Cutoff slider, potentially causing VCF oscillation for VCF 2
- VCF 2 Mod Input 1 Level — Attenuate the voltage connected to Mod Input 1 for VCF 2
- VCF 2 Mod Input 2 Level — Attenuate the voltage connected to Mod Input 2 for VCF 2
- VCF 1 Signal Input 3 Level 2 — Adjust the level of the signal connected to Signal Input 3 of VCF 1
- VCF 2 Mod Input 3 Level — Attenuate the voltage connected to Mod Input 3 for VCF 2
- VCF 2 Mod Input 2 — Control voltage input 2 for VCF 2 cutoff frequency modulation, 3.5 mm TS jack
- VCF 1 Mod Input 2 — Control voltage input 2 for VCF 1 cutoff frequency modulation, 3.5 mm TS jack
- VCF 2 Mod Input 3 — Control voltage input 3 for VCF 2 cutoff frequency modulation, 3.5 mm TS jack
- VCF 1 Mod Input 1 Level — Attenuate the voltage connected to Mod Input 1 for VCF 1
- VCF 1 Mod Input 2 Level — Attenuate the voltage connected to Mod Input 2 for VCF 1
- VCF 2 Output — Filtered audio output for VCF 2, 3.5 mm TS jack
- VCF 2 Fixed HPF — Adjust the high-pass filter for VCF 2 from OFF, 1 (1 kHz), 2 (2 kHz), or 3 (5 kHz)
- VCF 1 Cutoff Frequency — Adjust the cutoff frequency of the low-pass filter for VCF 1 (20 Hz to 20 kHz)
- VCF 1 Fixed HPF — Adjust the high-pass filter for VCF 1 from OFF, 1 (1 kHz), 2 (2 kHz), or 3 (5 kHz)
How-To Guides
- Classic Low-Pass Filter Sweep
- VCF as Sine Wave Oscillator
- Dual VCF in Series for Steeper Filtering
- Envelope-Controlled Filter
- LFO Filter Wobble
- Bandpass-Style Filter Using HPF and LPF Together
- Parallel Dual Filter for Stereo or Layered Texture
- Resonant Noise Percussion
- Three-Source Mixer into Single Filter
- LFO Cutoff Sweep into Fixed HPF for Spectral Motion
Explore the interactive System 100 121 VCF panel on BleepDex — tap any control to learn what it does.
