Tone generator
91 wheels
Mechanical frequencies (gear ratios), 27 buses, terminal taper and crosstalk, wiring and compartments. The wheels are shared between the keys.
M-VAVE FM-1 · tonewheel organ · after setBfree
fm1-wheel
A complete tonewheel organ for the FM-1: 91 wheels, contact matrix, scanner, tube preamp, reverb and Leslie. The same code runs on the device and in the browser.
Version 0.2.0 · firmware in development · device and emulator builds validated; FM-1 test pending.
What fm1-wheel is
It is not a per-voice organ: it is a shared tonewheel generator, like the original instrument. The timbre comes from the wheels, the contacts, the drawbars and the analogue chain.
setBfree chain
From scanner to Leslie
V1–V3/C1–C3 scanner vibrato/chorus, tube preamp, Schroeder reverb and Leslie with Doppler, reflections and acceleration.
FM-1
27 keys + MIDI
Built-in keyboard, USB-MIDI and TRS-MIDI. Drawbar-key mode turns the keys into drawbar controls while an external controller keeps playing.
Start in three steps
You can listen now in the browser, or install on the FM-1 when the device is connected.
Install
Connect the FM-1 with a USB data cable and use the web installer in Chrome/Edge. The installer can also restore the official firmware.
Play
The 27 keys play the upper manual. An external MIDI controller can play upper, lower and pedal on channels 1, 2 and 3.
Edit
Press GLO: the keys stop playing and push/pull the drawbars. External MIDI keeps sounding.
Drawbar-key mode
With the mode on, each flat / natural pair controls one drawbar of the selected manual. The black key pushes in (decreases); the white key pulls out (increases). The bar fills from top to bottom: 8 is fully pulled out, at maximum volume. All 18 control keys light equally; the others stay dark.
GLO toggles the mode. External MIDI keeps playing — the built-in keyboard becomes the registration control.
F3, C4, F4 and C5 are ignored. D#5, E5, F5, F#5 and G5 are free.
| Pair | Drawbar |
|---|---|
| F#3 / G3 | 16' |
| G#3 / A3 | 5⅓' |
| A#3 / B3 | 8' |
| C#4 / D4 | 4' |
| D#4 / E4 | 2⅔' |
| F#4 / G4 | 2' |
| G#4 / A4 | 1⅗' |
| A#4 / B4 | 1⅓' |
| C#5 / D5 | 1' |
Controls on the FM-1
The labels printed on the device are the originals; the screen shows the real function.
| Control | Function |
|---|---|
| SELECT | drawbar page: 0–3, 4–7, 8 + percussion |
| ALGO / EDIT | manual: UPPER, LOWER, PEDAL |
| PRESET | eight factory registrations |
| K1–K4 | the four bars on the current page; on page 3, the 1' bar and percussion |
| FX | drive on/off |
| ENV / ARP | percussion on/off; 2nd/3rd harmonic |
| LFO | vibrato/chorus OFF → V1 → C1 → V2 → C2 → V3 → C3 |
| PLAY | rotor STOP → SLOW → FAST |
| SEQ | reverb OFF → 30% → 60% → 100% |
| GLO | drawbar-key mode |
| SAVE | write settings to flash |
| OCT− / OCT+ | transpose the built-in keyboard |
| MASTER | output volume |
The full manual covers the MIDI table, what is saved and troubleshooting: Português · English.
Take it to the FM-1
Package 0.2.0, web installer and direct download. Connect with a USB data cable; installing is at your own risk.
Source, base and licence
fm1-wheel is free software. The code, the DSP port and the documentation are on GitHub.
Base projects
setBfree (GPL-2.0-or-later) — DSP and algorithms.
fm1-base (MPL-2.0) — platform, host simulator, emulator and installer.
felucca-bsp (MPL-2.0) — AC79 layer, boot and loader.
Felucca (GPL-3.0-only) — firmware/UX reference.
Licence and credits
The combined firmware is GPL-3.0-or-later. See LICENSING.md and LICENSES/.
Built with OpenCode and DeepSeek V4.1 Flash, under human direction and review.