Eurorack Serge Variable SLOPE (VCFS) Full Kit


Officially licensed Serge Filter in Eurorack! Full DIY Kit with Random Source build documentation.

EU Price  does not include EU VAT.

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It contains all components required for a complete build, right down to rack screws and power cable. We selected and used the parts as specced by Random*Source. Random Source have created a step by step build doc for this project

SERGE MODULAR FOR EURORACK – Under licence from Serge Tcherepnin

“Serge Modular” is an analogue modular synthesizer system developed by French composer and electronic designer Serge Tcherepnin in the 1970s at The California Institute of the Arts. Serge’s vision to create a “people’s synthesizers” led to a unique modular music system with an iconic design.

In collaboration with and under licence from Serge Tcherepnin, Random*Source offers a range of Serge modules, combining the original Serge circuits with the advantages of today’s technology. The modules on this page are in Eurorack (3U) format – modules in the classic Serge dimension (“4U” panel height) and the typical banana jacks can be found here.


The Serge Extended Variable Slope filter (VCFS) is a unique filter of the Serge system, covering a wide range of sonic character. According to the 1983 Serge catalogue, the “VARIABLE SLOPE VCF (VCFS) allows the amount of filtering to be dynamically controlled, from barely perceptible filtering to highly resonant, sharp cut-offs. With the variable slope control in the center position, the VCFS acts as a typical flat-response VCF, with high, low, and band~pass outputs available simultaneously. The slope of the cut-off is 12 db/octave. As the control is moved toward the maximum position, the resonance of the filter increases, so that the cut-off becomes sharper.”

Now – for the first time and licenced by Serge – the VCFS is available as DIY kit for Euro.

Build documentation: Serge VCFS BOM / Build doc
  • Under licence from and in cooperation with Serge Tcherepnin
  • Designed for High-end VCAs (THAT2180C)
  • The kit is supplied with the following capacitors as per the Random Source BOM
    • Ceramic Bypass Caps
    • C0G caps for positions C5, C6, C9
    • Polystyrene caps for positions C7, C8
    • Wima Film cap for position C10
    • Nichicon Gold Electrolytic cap in position C1, C2
  • New Q knob for increased resonance
  • No wiring needed
  • Eurorack format (3U), 14 hp
  • Power consumption: 40mA @ +12V, 40mA @ -12V
  • Module depth: < 40mm (1.5″)