Elektron Octatrack MKI custom firmware

octabam

A remixer that builds one Octatrack firmware image from your own OS 1.40C and the community modules you choose: new effects (a shared delay and reverb bus, filters, modulation), new machines, stem recording to the card, USB audio and MIDI additions. Several projects here are built on it.

Writing a non-official OS can leave the unit unusable and puts the warranty in question. Read the recovery path before flashing.

LATEST SEEN OCTABAM43 · 6 OCT 2026

Modwerk

Formerly Octamod: a browser app that builds a custom OS 1.40C from your own OS file and the modules you pick from its library (effects, machines, MIDI and USB, system), with a forum and a developer SDK. It also covers the Digitakt and Digitone mk1.

Experimental. Custom firmware can make the unit unusable, cause data loss and affect the warranty: back up projects and samples and keep the original OS.

elekloader

A mod loader for Elektron firmware: you pick .elemod mods and supply the official OS file, and it builds a custom OS on your computer (in the browser, or as a Windows or macOS app). On the Octatrack it works with OS 1.40C; it also supports the Digitakt and Digitone.

Mods built on elekloader's own core have run on an MKII, not yet on an MKI. Recovering an Octatrack needs a 5-pin DIN MIDI interface.

LATEST SEEN v0.4.0 · 6 OCT 2026

Octakit

Replaces the 4 Parts per bank with 256 Kits per project, as on the Machinedrum and Monomachine, with gestures to load, save and copy Kits. Old projects' Parts move to the first 64 Kits. Builds come from the author's browser patcher and your own OS 1.40C.

Development builds: back up your projects and avoid critical work. Going back to stock may lose Kit data. It takes 3.6% of the flex sample memory.

octemu

An Octatrack emulator for macOS that is also a workshop for firmware customizations built from your own OS 1.40C: a RECEIVE machine that mixes up to six tracks, class-compliant USB MIDI, and 16 channels of USB audio out (the eight tracks in stereo).

Use at your own risk: the author takes no responsibility for damage to the unit or data loss on the card. USB audio is only tested on macOS.

Octatrick

Four octabam modules for OS 1.40C: a two-operator FM synth machine (paraphonic up to 4 voices, with chords), a scale quantizer with root and glide, a DIRECT pattern jump and a tuner. Its build adds USB MIDI, 20-channel USB audio out and USB audio in.

Unofficial, outside Elektron's licence terms and warranty. Back up your card before flashing.

LATEST SEEN v2.9 · 6 OCT 2026

OT Kyoti FW

Features and bug fixes for OS 1.40C that keep the stock feel: mute modes with FX tails, a clock-locked direct pattern jump, a side-chain compressor, reloading a track from the card while playing, S900 and SP-1200 style repitch and more, alone or combined as KYOTI V1.0.

For personal study, flash at your own risk and keep the official .syx for recovery. The side-chain compressor and repitch replace the Spring Reverb.

LATEST SEEN v1.0 · 6 OCT 2026

midisc

A patch for OS 1.40C (MIDISC2.0) that adds scene locks to MIDI tracks, so scenes and the crossfader also drive MIDI values and follow pattern and Part changes. Rebuilt from your own OS file.

A modified OS can brick the unit: flash at your own risk.

LATEST SEEN v2.0 · 6 OCT 2026

octa-bt-pt

A tool that builds a patched OS 1.40C with your own defaults: effect parameter values and the FX1/FX2 effects of new projects, plus a fix for an AMF bug. It patches values, not code.

A modified OS can leave the unit unusable until you recover it and puts the warranty in question. OS 1.40C only; the build tools run on macOS only for now.

PassOS

An octabam-based firmware for the Octatrack MKI: MIDI tracks get the Digitone II's 36 scales on 12 roots, with every note snapped to the scale, plus an optional guard that asks before STOP and PLAY stop the sequencer.

MKI only. Have a 5-pin DIN MIDI interface working before you flash: it is the only recovery path if a flash goes wrong.

LATEST SEEN v1.0 · 6 OCT 2026