Your MPC Sample. A wider world of sound and groove.
Turn your Sample into an exploratory groovebox — with diverse synth engines, hands-on drums and chopped breaks. Find a sound. Follow a rhythm. Make it yours.
A four-track song group connects drums with melodic parts. Generate a starting point, mutate it while keeping sounds, or work on one track at a time. Repeatable seeds give an idea somewhere to return to.
02
A kit is not a single sound.
Start with a complete Rhythmer Kit, then replace individual pad sounds. Single instruments retain their own presets and sound controls. Different jobs, clearly separated.
03
Generate Acid. Rearrange breaks.
Acid has its own bassline generator. Break turns a loop into playable slices with dedicated pattern generation. Engine-specific pages follow the instrument you are working with.
MORE WAYS TO BUILD A PATTERN
Generate, edit and perform.
Song generation
Generate a four-track group with drum and melodic roles. Adjust energy and seed, then edit the result.
Keep sounds, change patterns
Mutate a song group or focus on one track without replacing its sounds. Undo returns to the previous idea.
Kit and pad editing
Start from a complete Rhythmer Kit, replace individual pad sounds, and shape each part.
ACID GENERATOR / DEDICATED BASSLINES
A new line. Another way to move.
Generate and mutate acid basslines with dedicated density, accent, slide and octave controls. Shape the notes first, then perform the sound.
Two settings pages; the generator manages each track’s seed internally.
Slides, accents and sustained ties from the FM-1 generator lineage.
Bring a loop, prepare sixteen slices, then get hands-on with rolls, A/B source switches, freeze, grain and stretch. Record those moves into the pattern.
Six performance pages built around the pads and three knobs.
Chops, repeat / up / down / shrink, Build, Stretch and Echo.
A/B sources, loop Variation / Drift and sequence-recorded commands.
Uses your own loops. No break recordings bundled. Source length is declared as 1–4 bars; cuts divide the complete loop equally.
Pick an engine. Explore its character, presets and control vocabulary.
What is inside Rhythmer Kit?
36 curated kits from Sophie, Elixir, Hortator, DRUM-X, K-WASUB drum mode, 6W6, 8W8, 9W9, CW-78 and TR-MPC. Kit-only sources are not additional standalone engine entries. The existing Sample Kit workflow remains a separate sampler option.
FIRST SESSION / WATCH & MAKE
Your first groove with RHYTHMER OS.
Find a sound. Build a groove. Make it yours.
Take the engines into your first session: a drum kit, bass, FM-106 chords, an acid phrase and a chopped Think break. Watch the groove come together, then follow the illustrated guide to shape the sounds, balance the tracks and perform a mute jam.
4 BARS / 140 BPM / C MINORWATCH FIRST · FOLLOW AT YOUR OWN PACE
A guided session with RHYTHMER OS for MPC Sample. The guide follows the film, step by step. Use your own permitted break sample.
03 / FROM THE STUDIO
From FM-1 curiosity to MPC Sample possibilities.
I loved exploring open-source engines, building grooves and finding unexpected sounds with RHYTHMER OS on the FM-1. I wanted to bring that freedom and variety to the MPC Sample.
This project builds on Melodee. Much respect to its developers and contributors for sharing a foundation that gives the community room to experiment.
My work focuses on porting and optimizing additional engines for the hardware, integrating them with the existing foundation, and adding my own tools, UI refinements and workflow extensions. The original engine creators deserve the credit for their DSP, ideas and sound.
If you know the stock workflow, this may feel unfamiliar. Give it time, explore, and tell me what gets in the way. There is still plenty to refine.
In search of feel-good rhythms.
LISTEN / OPEN-SOURCE ENGINE PORTS
Twenty engines. Hear them play.
One loop from each engine, with its own screen and sound. Ported and integrated for MPC Sample, and shared for the open-source community.
RHYTHMER builds on the work of open-source creators. The engine ports and integration work are shared so others can explore, adapt and build on them under each project’s licence.
Original synthesis belongs to its authors. Porting, host adaptation and RHYTHMER-specific interface work are documented separately. The OS and engine ports are shared in separate repositories, with original sources, credits and licences retained.
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.
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.
Check the device is MPC Sample AC50 running stock firmware 1.3.0.12. This release is not an FM-1 installer.
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.
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.
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.
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.
SD: complete first-install package. UPDATE: signed app-only archive, not a first-install package. Use the full SD ZIP here. SOURCE / MOVE-SOURCE / SUPPORT-SOURCE: corresponding source for rebuilding, not SD installers.
Support the project
RHYTHMER OS for MPC Sample will be free and open source, and will always stay free.
Your support helps me keep working on this project and other open-source tools.
