Small firmware tweaks for the Elektron Model:Cycles and Model:Samples (OS 1.13). No firmware is distributed here: you supply your own .syx, the script applies the tweaks you pick and writes a new file next to it.

Python 3 is the only requirement — or none at all: use the web flasher in Chrome, Edge, Firefox or Safari.

These tweaks are also available as a part of these projects:

• Modded Cycles by 18nelli18 - Model:Cycles only atm.
• Model-TG by TinyAudioGreg - Model:Cycles only atm.

1. Download the original firmware from Elektron and drop the .syx into this folder.

2. Run it:

   • macOS / Linux: ./apply.sh
   • Windows: double-click apply.bat

3. Toggle tweaks by number, press Enter.

4. <name>_mod.syx appears beside the original. Send that one with Elektron Transfer, SysEx Librarian, or any SysEx tool.

The web flasher does the same in a page: drop your .syx, pick the tweaks, download the built file (then send it with Elektron Transfer, the fastest way), or send it straight from the page over USB MIDI in Chrome or Edge. It runs this repository's own tweak.py and mtlib unchanged, in the browser through Pyodide; the firmware never leaves your computer.

To run it locally: python3 -m http.server in this folder, then open http://localhost:8000/flasher/. Published with GitHub Pages from the repository root (.nojekyll keeps mtlib/__init__.py served). After adding or removing a tweak, run python3 flasher/make_manifest.py.

Without the menu:

python3 tweak.py --list                               what is available
python3 tweak.py -i model-cycles_OS1.13.syx --all     everything
python3 tweak.py -i FW.syx -t trig-preview,browser-scroll
python3 tweak.py --verify FW_mod.syx                  recheck a finished file

• Hold TRACK and tap FUNC: the mute mode latches and the FUNC key lights up.
• A short tap on FUNC alone leaves the mode.
• Combinations with FUNC do not leave the mode, including menus such as FUNC + PAGE and holding FUNC to turn the encoders fast.
• TRACK, RETRIG and PATTERN bank select keep working while it is latched.

Holding FUNC to mute tracks behaves exactly as it does in stock firmware.

With the sequencer stopped, hold a step (trig button) and press PAGE: the step sounds with its own note, length, p-locks and sound-lock. The page does not turn. It sounds regardless of the trig condition and probability, and through a muted track.

A selected name in the sound/sample/folder browser scrolls left when it does not fit: about 0.17 s per character, with a ~0.5 s pause at each end. A name that already fits stays put.

Adds a third choice to CONFIG > DEVICE > USB MODE, which now cycles A+M → A16 → MID:

In A16 the channels are, at 48 kHz / 24 bit:

Each channel is exactly what the mixer adds to the main bus, with the same gain curve and master gain, so the 16 channels sum to the stereo mix (short of master-bus clipping). A track muted on the device is silent on its channels; its delay and reverb tail stays on 13–16, as in the stereo mix.

• After flashing the device starts in A+M, which behaves as stock. Pick A16 once; it is kept across power cycles. Switching reconnects the device, so the DAW may need the input device selected again.
• Recording and playback should run on one clock: use the Model as both the input and the output device, or an aggregate device with drift correction (macOS Audio MIDI Setup). Two separate USB devices without drift correction drop host buffers every few minutes.
• Tested on Model:Cycles and Model:Samples hardware with macOS. Windows is untested.

Based on ms-multi-output by Scott Metoyer and the work on it in Modded-Cycles by 18nelli; see Credits.

All four tweaks are independent; any combination works.

Before building:

• the file is parsed in full and every SysEx packet checksum is verified;
• the SHA-256 of the decompressed MAIN OS is matched against the known original, so a different OS version or an already-patched file is refused rather than corrupted;
• every region about to be written has its original bytes confirmed first.

After building, everything is recomputed: packet checksums, container length and content checksum, per-section stream sums, and the HMAC-SHA256 trailer. If any of it disagrees, the file is not offered for flashing.

Only section 3 (MAIN OS) is touched. The bootloader and the updater are carried over byte for byte, so STARTUP MENU recovery stays available and you can always go back to stock firmware.

• Modifying the firmware voids your warranty and could brick your device.
• Tweaks are tested on real Model:Cycles and Model:Samples hardware, but you do this at your own risk.
• Before flashing, make sure you can reach STARTUP MENU: power off, hold FUNC, power on, then 4 ... OS UPGRADE. That is the way back.
• Back your projects up first (#SYSEX DUMP in Transfer, or a project backup).

A .syx is just transport: 7-bit packing with a checksum per packet. Inside is an ELE3 container of four sections; the third, MAIN OS, is compressed with an aPLib variant.

tweak.py unpacks that section, writes the selected byte sets into it and puts everything back together. It does not recompress from scratch: the original stream is decoded into its op list and re-emitted as it was, and only the ops that read or write a changed byte become literals. The result stays as tight as the vendor's own packer and takes a couple of seconds.

apply.sh / apply.bat   launcher
tweak.py               pipeline and menu
mtlib/syx.py           7-bit SysEx transport
mtlib/aplib.py         aPLib codec: decode to ops, re-emit
mtlib/container.py     ELE3: parse, rebuild, checksums, HMAC
tweaks/<firmware>/     the tweaks themselves
flasher/               the web flasher: page, Pyodide glue (web.py), file list

A tweak is plain JSON you can read yourself — offset, expected original bytes, replacement bytes:

{"off": 1344610, "old": "2f02", "new": "4ef9"}

This project is not affiliated with, endorsed by or connected to Elektron Music Machines in any way. Elektron, Model:Cycles and Model:Samples are their trademarks. No Elektron firmware or code is distributed here — the tweaks are applied to a file you supply yourself.

Building scripts are based on elektron-firmware-tool (MIT) by mischa85.

The 16-channel USB audio tweak (usb16) builds on:

• scottmetoyer/ms-multi-output by Scott Metoyer — the original 6-channel USB mod for the Model:Samples and Model:Cycles: the USB driver hook points, the descriptor and queue-head changes, and the method. MIT License, Copyright (c) 2026 Scott Metoyer.
• 18nelli18/Modded-Cycles by 18nelli — the further work on it for the Model:Cycles: keeping USB OS updates working, freeing sprite masks as code space, and the analysis of the USB queue and of the dropouts.

On top of that, usb16 takes the channels after the mixer's VOL and PAN as stereo pairs, adds the delay and reverb returns, moves to 24 bit with the transfer ring in SRAM and a fill-level loop on the packet rate, names the channels, adds the A16 USB mode next to the stock stereo, and covers the Model:Samples as well.

MIT, see LICENSE. The license covers this tooling only, not the firmware it is applied to.

Third-party work this repository builds on: