Install 0.4.0-beta.3.

Sound / Kit save hotfix: Stage EDIT Push now opens PAD SOURCE or SAVE SOUND. Save reusable User Sound / User Kit presets and reload them from PRESETS. The app version remains 0.4.0-beta.3.

Use the full SD ZIP to install RHYTHMER OS. It contains the app, plug-ins, kits and preset catalogue. Back up the entire card before installation.

Use the full SD ZIP. The native updater may not offer a same-version hotfix. The full package includes the app, plug-ins, current guides and two visual reference sheets.

1. Save your music. Power off the Sample, remove the SD card and back up the entire card, including projects, samples, presets and the existing autorun folder.
2. Check the device is MPC Sample AC50 running stock firmware 1.3.0.12. This release is not an FM-1 installer.
3. Download the full SD ZIP and its SHA-256 file. On macOS, run shasum -a 256 RHYTHMER-OS-0.4.0-beta.3-SD.zip and compare the result.
4. Extract the ZIP. Copy its contents to the card root, keeping autorun/, Rhythmer/ and Samples/ at the top level. Copy all supplied app and plug-in files; preserve your own projects, presets and recordings.
5. Eject the card safely, insert it and start the Sample. Follow the SD launcher. Check the version is 0.4.0-beta.3 before creating your first project.

SD card/
├── autorun/
├── Rhythmer/
│   └── Plugins/
└── Samples/

Keep a way back.

To return to the stock app, power off, remove the card and move autorun/ off the card. Keep your projects, samples and recordings backed up.

Hardware controls, audio performance and install/recovery behavior are still pending owner testing. No break recordings are bundled; load your own loop.

This is independent, unofficial custom firmware, not affiliated with or endorsed by AKAI Professional or inMusic. It is provided without warranty under its component licences. Keep backups and review the test scope before installing.