Mutable Instruments Beads goes open source: code and hardware files released

The code for Beads, the last Eurorack module from Mutable Instruments, went public overnight on 11 to 12 October 2026. Mutable founder Émilie Gillet pushed it to the official GitHub repository for Mutable modules, together with the hardware design files. The news was spotted by Synth Anatomy. For Beads owners, it opens the door to alternative firmware; for manufacturers, it is a green light to build on the design.

What has been released

Beads was the only recent Mutable module whose code had stayed closed. The beads folder in the repository now holds:

• the full firmware: signal processing, user interface, CV reading, calibration, bootloader and factory test tools;
• the hardware design files (the hardware_design folder).

On licensing, the repository README puts the code for the STM32-based modules, Beads included, under the MIT licence: anyone can read, modify and reuse it, commercial products included, as long as the author credit is kept. The hardware falls under CC BY-SA 3.0, which requires credit and sharing derivatives under the same licence.

The README warns that the code is provided as is: it builds on a desktop platform, but has not been verified to build and run on the module. Install at your own risk.

In other words, this is not an update to flash tomorrow morning, but a starting point for developers.

Beads at a glance

Beads is a texture synthesizer released in February 2021 as the successor to Clouds. It is built on granular synthesis: the module records incoming audio into a buffer, then plays it back as thousands of very short fragments, called grains, whose position, length, envelope and pitch you control. It can also run as a delay, with a reverb at the end of the chain.

Each grain parameter has an attenurandomizer: one control sets either the amount of incoming CV (the control voltage sent by another module) or a dose of randomness drawn for every new grain. The buffer holds from 4 seconds (48 kHz, 16-bit, stereo) to 32 seconds (24 kHz, µ-law, mono), depending on which of the four quality modes is selected; these include a Clouds emulation and a cassette emulation.

Source: the official archived Mutable Instruments documentation. To see what 14 HP and 100 mA mean for your case, our guide Eurorack explained: what to know before buying your first case walks through the maths.

Who is it for?

First, Beads owners. Every other Mutable module gained alternative firmware once its code was open: the official documentation lists several, including Parasites for Clouds, which adds resonator and reverb modes. Beads may follow the same path, but nothing has been announced yet.

Next, developers and DIY builders: the complete code of a stereo granular processor, written by one of the format’s best-known designers, is a rare study resource. Finally, manufacturers, whom the licence allows to build their own versions, provided they keep the credit and share the hardware changes.

How much does it cost?

The code and files are free. The module itself has not been made since December 2022, when Mutable Instruments closed: it no longer has a list price and is only found second-hand.

What does it compete with?

• Mutable Instruments Clouds: the predecessor, open for years and built in many versions by other makers. Beads keeps a mode that emulates it, with finer control over the grains.
• Make Noise Morphagene and Instruō Arbhar: two granular processors still in production, the first geared to tape-style microsound editing, the second designed as a granular instrument in its own right.
• RYK Modular Side FX: a multi-effects module with a granular engine among its effects, released this week and covered here.

Beads keeps the edge on depth of grain control; opening the code mainly gives it a second life. More new releases in the format are in our Eurorack modules section, and free software tools in free and open source.