Eurorack modules

The project follows Mutable Instruments’ path: an idea first takes shape as a VCV Rack module, and only moves to Eurorack once it is clear enough to live in a physical module. It has been paused since July 2026, after the production file for the first board was approved. I do not have the time to do everything at once, and other projects have taken priority; I also have less appetite for it, with the feeling that this market is saturated and that the road to a finished module is longer than I thought.

No demo: the VCV modules are in a private repository, and the board has been neither photographed assembled nor recorded.

A four-channel VCA that chains to its neighbours

The first module is a four-channel VCA. On the hardware side, it takes Veils v1.1 by Mutable Instruments, whose files are published under CC BY-SA 3.0, and adds one thing: a bus linking several modules placed side by side, so that one module’s input carries on into the next. A STACK switch on channel 1 connects the bus or isolates it. The board is named “Bus.VCA” and marked “2026 v1”.

On the software side, the same VCA exists as a VCV module called “Veils HE”, with the cascade between modules through left and right expanders. Another VCV module, “Quad VCA”, explores a different idea: a generative mixer in which a walker moves the sources between four outputs, set by five parameters (ÉLAN, FLUCTUATION, INERTIE, SOUTIEN, ESPACE).

What is done

• Schematic and circuit board. Veils’ Eagle files imported into KiCad on 27 April 2026; local input cascade, inter-module bus, STACK switch; the V2164 replaced by the SSI2164; standard 16-pin Eurorack power header. The bus cascade was simulated in SPICE on 29 April.
• Manufacturing. Circuit board finalised on 5 May 2026. Bill of materials corrected on 15 July; the production file was approved at the manufacturer for five boards in mid-July 2026. The lists of through-hole parts (jacks, potentiometers, LED sliders, switches) are ready; the knobs are planned as 3D prints.
• VCV modules. “Quad VCA”, in progress from December 2025, front panel redone on 30 May 2026; “Veils HE”, added the same day.

What is not

• The board assembled and measured.
• The front panel. A cutting drawing exists; the front panel has not been ordered.
• Publication. None of the repositories is public; the VCV code is intended to be GPL-3.0-or-later.
• The “zero point” of the generative Quad VCA: a setting where it behaves like an ordinary VCA, so that one has a reference before exploring the movement. Neither ESPACE at 0 nor INERTIE at 1 stops the walker; the question is open.
• A digital module. A working template goes from a gen~ prototype (Max) to a VCV module and then to Daisy firmware; no module has gone through those steps yet.

Where it stands

Paused. Last activity on the board: July 2026 (bill of materials and production file). Last activity on the VCV modules: 30 May 2026.

The published VCV modules from the same workshop have their own page: vcv-osc.

Thanks to Émilie Gillet, whose Mutable Instruments modules are published as open source; Veils is the basis of this board.