README from GitHub, MIT

Am MOD

Unofficial SD card mod for the Akai MPC Sample

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Am MOD is a community mod for the Akai MPC Sample (firmware 1.3.0.12) that starts from the SD card. On top of the stock app it adds a step sequencer on the pads, a chord mode, typing names with the pads, scale lighting, search across folders, batch copy, a per-pad EQ, resampling, recording from the rear inputs and more. Nothing is flashed: the mod runs a patched copy of the stock app in RAM, and the stock app starts as usual without the card.

Chords mode: pads play chords in the project key

_{Recorded in the Virtual MPC Sample emulator running the stock firmware with the mod; the pads on the right show the colours the app sends.}

Unofficial project. Not affiliated with, endorsed by or supported by inMusic Brands or Akai Professional. No firmware and no Akai code are in this repository or in the release packages: the mod patches the copy of the app already on your MPC Sample. Use at your own risk. See NOTICE.

What's new in r27q

Back up samples and projects before updating.

Degrees layout. Sample → Tune → Play → Lights → K1 Layout: Degrees. The 16 pads of 16 Levels Tune play only notes of the key, one degree per pad (C Major: C D E F G A B C…); Transpose16 moves by degrees. The tonic, IV and V have their own colours. New defaults in Scale and Degrees: tonic Red, key notes Cyan, IV Violet, V Yellow.
Search. K2 Search in: Folder, Library, SD Card or All. The first matches appear under the query, preview is on by default, K3 sets its volume. The encoder press enters a letter; with Encoder input, +/− move the cursor and Erase deletes. Shift+Erase clears; the last query is remembered.
Erase in the name window deletes in both input modes.
Rear Routing and Mod Settings look like stock lists and panels; confirmations use the stock frame.
Splash with “MOD” at the height of “Am” and smooth version text.
Clearer messages instead of technical “… unavailable” errors.

r27q includes everything from r27p (Rear recording and monitoring, Knob FX priority) and r27n (Preview from end, Steps length and grid, eight colours).

All r27q changes · Mod Settings · Testing status · Roadmap and ideas

Thanks to Leusha, mxt1iga and all testers.

Features

Confirmed: checked on a real MPC Sample. Trial: automated and emulator checks passed; a hardware check is still pending.

Feature	Where	Status
Readable K1–K3 panel: parameter names and values always visible, amber focus, `S` marks for Shift functions	all standard screens	confirmed
Type names with the pads (phone keypad: ABC on pad 14, DEF on 15…, delete on 16)	Save Project / Save Sample, Search	confirmed
Orig Note of a sample, project Key / Scale	Sample → Tune → Shift+K1; Project → Key/Scale	confirmed
Scale lighting for 16 Levels Tune: Monochrome / Piano / Scale colours, Transpose16	Sample → Tune/Play/Lights	partly confirmed
Degrees: 16 Levels pads play only key notes, tonic/IV/V colours	Lights → K1 Layout	trial
Steps: 16-step sequencer on the physical pads, grid 1/4…1/64 and triplets, velocity, mute steps, copy/paste	Shift+SEQ → B2 Steps	confirmed
Events editor with Chop / 16 Levels choice and audition, event move on the grid	Step Edit / Steps	confirmed
Poly: chords recorded and edited as separate notes	Seq	confirmed
Search samples and projects in Folder / Subfolders / Library, preview, load to a pad	Sample Select / Open Project → Shift+B3	confirmed (basic)
Batch Copy of up to 16 sounds with automatic or manual targets	Sample → Shift+Erase → B2	confirmed
Resample a pad (with Pad Link and Bypass) or a sequence to another pad	Shift+Pad 11	confirmed
Power key asks, saves a separate copy of the project to SD, powers off	power key	confirmed
Per-pad EQ: one band, 6 types + Bypass, ±18 dB, live spectrum behind the curve	Sample → B3 Filter → Filter Env → EQ	confirmed
Stereo → Mono (left or right channel to a new pad)	Sample → Shift+B3	trial
Chords: 8 scale degrees, 6/7/maj7/9, Maj/Min/Dim/Aug/Sus4, octave, inversion, latch, arpeggiator, chord repeat with Note Repeat; recorded as normal Tune events	16 Levels Tune → Chop	trial
OptoCat/Warm: optical-style compression, Gain −6…+6 dB, Shift Attack/Release/Knee; paw follows red GR, shared Bypass	Shift+Pad5 → B2 Type; B1 Warm	trial
Am MOD sequence pads: Default + eight colours; selected pulses once per bar at Stop, playing once per beat, queued twice per beat; visible background and stable brightness of other pads	Seq → Shift+K1 (Am MOD)	trial
Batch Extract chops to separate samples	Chop → Shift+B2	confirmed
Rear recording: Rear L, Rear R or L + R to pads; monitoring with pan and level	Sample Record → B2 Routing; Input Config → Shift+B2	trial
Preview from end of a sample or slice	hold STOP + pad in Sample / Chop	trial
Mod Settings: pad lighting, waveform tint, system colours, cursor pulse	Project → Mod Settings	trial

Every feature with its controls and status: docs/FEATURES.md. Build history: CHANGELOG.md.

In action

Steps	Typing names with the pads
Scale lighting	Search
Batch Copy	Pad EQ
Resample a pad

Install

[!IMPORTANT] Before installing or updating Am MOD, I recommend backing up all projects and samples from the SD card to your computer or another drive. The installer's backup of autorun/ does not include your projects or samples.

[!IMPORTANT] FAT32 / MS-DOS (FAT32) is available experimentally starting with r26e; exFAT remains supported. FAT32 requires a package r26e or newer (r27q is current) and installer 1.0.2+, or a manual copy of that package's complete autorun/. FAT32 has been checked in test images and the emulator; physical MPC testing is still pending. The published r26d and earlier packages require exFAT; updating only the installer does not add FAT32 support to an old package.

Use a card volume name such as MPC or MPCSAMPLE. Only ASCII letters, digits, ., _ and - are supported; spaces and Cyrillic letters in the card name prevent startup. This restriction applies to the card name, not your sample/project names.

Check the filesystem before installing: Finder → select the SD volume → ⌘I → Format on macOS; drive Properties → File system on Windows. Installer 1.0.2+ checks the filesystem, card name and package compatibility before writing.

No reformatting is needed to install the current release on an existing FAT32 card. Keep your projects and samples; replace the mod's autorun/ folder with the complete new version. The installer backs up the previous folder and does not format or convert cards. FAT32 has a limit of 4 GiB minus 1 byte per file.

You need an MPC Sample on firmware 1.3.0.12 (the mod checks the app's SHA-256 and refuses to start on any other version) and a compatible SD card with a supported volume name: exFAT, or experimental FAT32 starting with r26e.

Installer (Windows): download MPC-Sample-Mod-Installer.exe and the am-mod-*.zip package from Releases, run the installer, pick the zip (or press Latest release) and the SD card, press Install.

Installer (macOS / Linux / Windows with Python 3.8+):

python3 installer/mpc_mod_installer.py                 # window
python3 installer/mpc_mod_installer.py cards           # list cards
python3 installer/mpc_mod_installer.py install am-mod-r27q.zip --card E:
python3 installer/mpc_mod_installer.py install --latest --card /Volumes/MPC
python3 installer/mpc_mod_installer.py remove --card E:

The installer writes only autorun/ and MPC_MOD_VERSION.json on the card. It checks the package, backs up the previous autorun/ to ~/AM-Mod-Backups/, writes the files that start the mod last, and verifies everything it wrote. It never formats the card and never touches MPC-Sample/ (your projects and samples).

By hand: unzip the package and copy its autorun folder to the root of the card.

Use

Insert the card and power on the MPC, or insert it into a running MPC. The mod starts by itself. Preparation time depends on the card and project. If a start ever hangs at 0 %, power on without the card, wait for the normal screen, then insert it.

The mod shows the Am MOD splash while preparing the app, with the version and repository address. Do not power off or remove the card during preparation. The splash has no artificial minimum display time.
The mod checks the stock app and its own files before it starts; on any mismatch the stock app keeps running.
Work as usual. Save projects and samples to External (the SD card): in the mod, Internal storage is temporary and is lost when the mod stops.
Save to External and use the power key to switch off. Remove the card only after shutdown. Start without the mod card to use the stock app.

The power key also works in the mod: it asks, saves a project copy to the card and powers off. Do not pull the card while the mod is starting, saving or shutting down.

Try it without the device

Virtual MPC Sample runs the stock firmware in QEMU with the whole device in your browser, and runs SD autorun packages the way the MPC does. The GIFs above were recorded there:

python3 lab.py autorun am-mod-r27q.zip --no-reboot --yes

Emulator runs are useful for development, but they are not a hardware test: timing, audio latency, battery and USB audio differ from the device.

Build from source

Requirements: Linux or WSL, Python 3, AArch64 GCC/binutils and your own local copy of the stock firmware 1.3.0.12; the expected SHA-256 of the app is b6584cba76e416e432ad202509099d34373dc2c3d6a8fb625f5678bf0193b508. The firmware image, updater, extracted partitions and rootfs are not part of this repository; paths to the rootfs used by the checks (/home/user/mpc-rootfs-user-20260808 in the scripts) need adjusting.

Order: get the local inputs with the expected hashes → build sd-clone-trial (the loader) → build the value patches in sd-k-value-peek → build the current sd-mod-session revision. sd-mod-session/build_chords_candidate.py compiles the app library (phone-input.so); verify_*.py run scoped checks. These research scripts depend on frozen earlier build outputs, verified preceding packages and your local firmware/rootfs; they are not a standalone fresh-checkout build. r27q was assembled with package_r27q.py over the verified r27p package. refresh_release_docs.py can refresh documentation from an explicit verified base ZIP while asserting unchanged autorun bytes. ARM/QEMU checks (verify_*.py, check_*.c) use clearly marked adapters and do not replace a hardware run.

Folder	Contents
`sd-mod-session/`	the current mod: sources (`src/`), build and package scripts, checks, feature docs
`sd-clone-trial/`	the loader: runs a verified copy of the stock app in RAM and restores the stock app
`sd-k-value-peek/`	the first display patches (K1–K3 values)
`installer/`	the SD card installer and its tests
`virtual-mpc/`	an early browser model of the UI (not an emulator)
`research/`, `docs/`	reverse-engineering notes and scripts, history of the stages

Most technical documents are in Russian.

Legal

Akai Professional and MPC are trademarks of inMusic Brands, Inc., used here only to name the device the mod runs on.
No firmware, Akai code, factory content or Akai artwork is distributed. The mod copies the app that is on your device and patches that copy in RAM; it never writes the firmware or the boot loader.
Release packages include xdg-dbus-proxy (LGPL-2.1-or-later) with its source.
Details: NOTICE.md.

License

MIT. Contributions: CONTRIBUTING.md.