Behringer System 100 121 Dual VCF, $69!

The Behringer System 100 121 Dual VCF (Voltage Controlled Filter) module is part of Behringer’s Eurorack series inspired by the classic Roland System 100M. This module features two independent voltage-controlled filters, each with multiple filter modes, providing comprehensive sound-shaping capabilities. The 121 module is designed to offer rich, analog filtering for modular synthesizer enthusiasts.

Key Features:

Dual Voltage Controlled Filters:

  • Two Independent VCFs: The 121 module includes two separate VCFs, each with its own set of controls and outputs, allowing for versatile sound shaping and filtering options.
  • Multi-Mode Filters: Each VCF can operate in low-pass, high-pass, and band-pass modes, providing a wide range of tonal possibilities.

Filter Controls:

  • Cutoff Frequency Control: Each VCF has a dedicated cutoff frequency knob, allowing for precise adjustment of the filter’s cutoff point.
  • Resonance Control: Each VCF features a resonance control knob, emphasizing frequencies around the cutoff point to create pronounced filter sweeps and harmonic content.
  • CV Inputs: Multiple control voltage (CV) inputs for modulating the cutoff frequency and resonance, enabling dynamic and evolving filter effects.

Sound Characteristics:

  • Rich Analog Filtering: The 121 module delivers warm, rich analog filter tones characteristic of classic synthesizers.
  • Versatile Sound Shaping: Capable of producing a wide range of filter effects, from subtle tone shaping to aggressive, resonant sweeps.


  • Sound Design: Ideal for sound designers looking to shape and control the tonal characteristics of their sounds with precision.
  • Modular Synthesis: Perfect for modular synth enthusiasts who need versatile filtering capabilities in their systems.
  • Live Performance: Suitable for live performances, offering hands-on control over filter settings for dynamic and expressive sound manipulation.


  • Width: 16 HP
  • Depth: 35 mm
  • Power Consumption: 60 mA (+12V), 55 mA (-12V)
  • Inputs: CV inputs for cutoff frequency and resonance modulation, audio inputs for each VCF
  • Outputs: Audio outputs for each filter mode (low-pass, high-pass, band-pass) for both VCFs
  • Controls: Cutoff frequency and resonance knobs for each VCF

Country of Manufacture:

  • China: The Behringer System 100 121 module is manufactured in China, ensuring affordability while maintaining quality standards.

Notable Features:

  • Dual independent voltage-controlled filters
  • Multi-mode filtering (low-pass, high-pass, band-pass) for each VCF
  • Cutoff frequency and resonance controls for precise filter shaping
  • Multiple CV inputs for dynamic modulation
  • Compact and durable design

Notable Users:

While specific high-profile users of the Behringer System 100 121 module may not be extensively documented, it is popular among:

  • Modular Synth Enthusiasts: Those who appreciate versatile and affordable VCF modules for their Eurorack systems.
  • Sound Designers: Professionals who require advanced filtering capabilities for creating complex and evolving sounds.
  • Electronic Musicians: Artists who use modular synthesizers to explore dynamic and innovative soundscapes.

The Behringer System 100 121 Dual VCF module is a powerful and versatile addition to any Eurorack modular synthesizer system. With its dual independent voltage-controlled filters, multi-mode filtering options, and extensive modulation capabilities, the 121 module provides essential tools for shaping and controlling the tonal characteristics of your sounds. Whether you’re a sound designer, modular synth enthusiast, or electronic musician, this module offers the precision and flexibility needed to enhance your creative process and performance capabilities. Its compact design and high-quality construction make it an excellent choice for those looking to expand their Eurorack setup with reliable and multi-functional filtering options.

If adding a shirt please indicate size at checkout, thanks!