SyntHack OS
Unofficial, modular firmware mods for the Elektron Syntakt (OS 1.41). Each mod is a small patch applied to the stock OS you download from elektron.se — no firmware is distributed here.
Not affiliated with Elektron. Modified firmware can make your device unusable and may void your warranty. Learn the recovery procedure before flashing. Use at your own risk.
Status: v0.8.0 — seven mods running on real hardware.
Features
| Feature | Status | What it does |
|---|---|---|
| Master compressor | ✅ v0.5.0 | Bus compressor on the analog master (via the master VCAs). Digitakt-style curves. THR · ATK · REL · MUP · RAT + gain-reduction meter + ON/OFF switch on the FX track SYN page, values in dB / ms / ratio. Saved per pattern, or global with SYN global. |
| Dual mono input | ✅ v0.5.0 | With EXTERNAL IN set to mono, IN L and IN R get independent levels on the External Mixer page. |
| Boot splash | ✅ v0.8.0 | "SyntHack" logo and version after the official intro. Boot time unchanged. |
| Mod area | ✅ infra | 64 KB of RAM for mod code, stored compressed and unpacked at boot. |
| Readable parameter values | ✅ v0.5.0 | Hz, dB, ms and % instead of 0–127: filters, envelopes, levels, sends, delay and reverb, on every track and the FX track. Computed from the same data the DSP uses; analog parts measured on the device. |
| Beat repeat | ✅ v0.6.0 | Sequencer stutter on all tracks (analog too): hold retrig keys 13/14 on the FX track to loop the last 1/16 … 1 bar (rates RPT1/RPT2 on the TRIG page, saved with the kit) and resume in time. |
| Third send FX | ✅ v0.8.0 | SND3 on every track (AMP page 1, next to DEL and REV; PAN moves to page 2) into a chorus, flanger, phaser or crusher, with its own page (REVERB tab, page 2) saved with the kit, independent return level and a send into the delay. |
| PIN lock | ⬜ planned | Optional PIN at power-on, as a theft deterrent. Recovery via OS reflash stays possible. |
| Dual mono v2 | ⬜ planned | Separate IN L / IN R pages with their own FX sends. |
| New LFO shapes · 3rd LFO / mod matrix | ⬜ planned | |
| Arpeggiator · Euclidean circle UI | ⬜ planned | |
| Resampling to SP TWINSHOT · advanced sampler | ⬜ planned | |
| New machines: RISER / DOWNFILTER, SY SWARM+ | ⬜ planned | Requires custom audio-engine code (CPU #2). |
| Web builder | ⬜ planned | Pick mods in the browser, build your .syx locally. |
Roadmap
flowchart LR
A["Foundations ✅<br/>unpack/repack · emulator<br/>build tool · recovery"] --> B["First mods ✅<br/>splash · dual mono<br/>master compressor"]
B --> C["UI & usability<br/>readable values ✅ · PIN lock<br/>dual mono v2"]
C --> D["FX & performance<br/>beat repeat ✅ · third send FX ✅<br/>arp · euclidean UI · LFOs"]
D --> E["Engine mods<br/>new machines · sampler<br/>resampling"]
B -.-> W["Web builder"]
How it works
tools/unpack— unpack/repack the.syx(wraps elektron-firmware-tool).mods/<name>/patch.json— where to patch, a hash of the expected original bytes, and our new bytes.tools/build/build.py— stock OS + chosen mods → verified.syx(refuses wrong OS, overlaps, protected sections).tools/emu— ColdFire emulator (Unicorn + our EMAC model). Every mod is tested against the original code before flashing.
Technical findings: docs/. Writing your own mod: docs/modding-guide.md.
Build your OS
Requires Python 3, WSL/Linux and your own Syntakt_OS1.41.syx (see firmware/README.md).
bash tools/unpack/setup_eft.sh # once (WSL/Linux)
git config core.hooksPath tools/hooks # once: blocks firmware files from commits
python tools/build/build.py --stock firmware/Syntakt_OS1.41.syx \
mods/splash mods/dual-mono mods/modarea mods/vparams mods/master-comp mods/readable-values mods/beat-repeat \
mods/fx3 -o out/synthack.syx
Flash out/synthack.syx with Elektron Transfer (USB, Drop page). To go back, flash the stock OS the same way.
Contributing
Issues and pull requests are welcome — see CONTRIBUTING.md. Please don't post mods or instructions on Elektronauts (forbidden there); use GitHub.
License
MIT for everything in this repository (LICENSE). See LEGAL.md.