FM-1 Firmwares 30 firmwares

The M-VAVE FM-1 is a ~$70 pocket FM synthesizer whose six-operator engine is, underneath, Dexed running on a JieLi SoC. Its updates travel over USB-MIDI SysEx with no cryptographic signature — just checksums. In six weeks the community turned that detail into a full alternative-firmware scene: grooveboxes, SP-1200-style samplers, a Prophet-5, kalimbas, and even Doom.

This is the catalog: every firmware we found, with its author, license, which classic synths it emulates, its status, and what it’s a fork of. Closed-source and paid ones are here too, labeled as such — the community hub only lists GPL; we list everything. Data as of October 9, 2026 — the scene ships releases daily, so treat this as a snapshot, not a mirror.

How to install

Open the firmware’s web installer in Chrome or Edge (they speak Web MIDI).
Connect the FM-1 over USB, then hit Connect and Install.
A minute later the synth reboots as a different instrument.

The same mechanism takes you back to the official V15 firmware whenever you want. The community’s golden rule: flash custom-over-custom only after returning to stock, and back up with each firmware’s editor before switching.

What if it bricks? It can — I documented it with my own corpse. Hold OCT− at power-on (USB rescue); the other two rescue ladders are in the ecosystem page.

Screenshots in each entry come from each project’s repository or site (GPL unless noted), with their source linked.

at a glance

Firmware	Version	Updated	Status	Type	License	Author	Fork of	Emulates
FM-1+VA (Baud Girl)	vFM-1_096	2026-10-06	stable	synth · groovebox	closed (GPL promised)	Madeline (Baud Girl)	—	Corrected DX7: the stock Dexed 6-operator FM with 4 factory bugs fixed (wide detune, slow LFOs, algorithms 4/6, stuck notes) · ’90s VA supersaw: BLEP oscillators with a Super mode of 7 detuned copies, drift, sub, and a multimode ZDF filter +1 more
Felucca	v1.4.1	2026-10-09	stable	synth · groovebox	GPL-3.0	Leo Kuroshita (Hügelton Instruments)	—	DX7 (6-operator FM, Dexed/msfa core, .syx bank import) · Casio CZ (phase distortion) +3 more
SLOOP	v2.5	2026-10-09	beta	groovebox · sampler	GPL-3.0	isod89	Felucca	DX7 (FM6 with SysEx import, 27-patch bank + cartridge) · Mutable Rings / DaisySP (nylon and steel guitars, sitar, tanpura, tabla, steel pan) +3 more
sloopDX	v3.4	2026-10-09	beta	synth · groovebox	GPL-3.0	Sven Trogus (zvenson, DesignBurg)	SLOOP	Yamaha DX7 (Dexed/msfa core ported to integer C, verified sample by sample) · DX7 .syx banks (8 × 32 = 256 voices from standard bulk dumps) +1 more
zp12	v2.1	2026-10-09	stable	sampler · drums	GPL-3.0	Sven Trogus (zvenson, DesignBurg)	sloopDX	E-mu SP-1200 (12-bit linear sampling at 26.04/27.5 kHz, no interpolation) · SP-1200’s 45→33 trick (×2 storage) +2 more
X0X	v0.10.3-beta	2026-10-08	beta	groovebox · drums	GPL-3.0	Charles Vestal	Felucca	ReBirth (the table’s format: 909 + 808 + 2×303 + breaks at once) · TR-909 (11 voices: modeled kick/snare/toms/rim/clap, sampled hats and cymbals) +3 more
FoMni	v0.3.2	2026-10-08	beta	chords	GPL-3.0	Charles Vestal	Felucca (via X0X)	Suzuki Omnichord (chord harp: strum on the white keys, chords on the black) · Omnichord harp voices (shimmering harp and plain harp) +1 more
Melodee	v0.13.1	2026-10-08	beta	synth · groovebox	GPL-3.0	Kerem Kiliç (keremimo, Ellic Studio)	Felucca	Sequential Prophet-5 Rev 4 (2 osc + hard sync, Poly-Mod, SSI Rev1/2 and Curtis Rev3 filters, .syx) · Yamaha DX7 (Dexed/msfa sample by sample, MARK I / MODERN / OPL modes) +2 more
Bubba	v2.0	2026-10-09	stable	synth · groovebox · sampler	GPL-3.0	Erbubar23	SLOOP	DX7 (FM6 with SysEx import; two simultaneous FM6 tracks) · 808/909 drum machines (32 synthesized kits, plus phonk/amapiano/UK garage) +1 more
Jangada	v0.8.2	2026-10-08	beta	synth · groovebox	GPL-3.0	zednaked	Felucca	Moog: 4-pole 24 dB/oct transistor ladder with saturated feedback (ANALOG engine) · DX7: FM6 on the Dexed/msfa core, 32 algorithms, two 32-voice banks in flash, live two-way editing with Dexed +2 more
GHOULBOX	v1.1	2026-10-07	stable	synth	GPL-3.0	Jason Persinger	Felucca 1.0.5.2	Hurdy-gurdy: GURDY engine — bowed melodic string, tuned drones, buzzing trompette bridge · Bagpipe: reed chanter over root and fifth drones +2 more
ChoralRoot	v0.13	2026-10-07	beta	chords	GPL-3.0	Quixotic7	Felucca (FM6/CZ-1 engines from Melodee)	Telepathic Instruments Orchid: roots on 18 keys (D4–G5) + a 2×4 chord block (DIM MIN MAJ SUS / 6 m7 M7 9 + LOCK) · DX7: Melodee’s FM6 rendered exactly like Dexed, .syx import, a 32-slot cartridge +2 more
FiMba-1	v0.6.0	2026-10-08	beta	synth	GPL-3.0	jadamsowers	Felucca (via X0X → FoMni)	Kalimba: modal physical modeling of tines in 6 materials (steel, brass, bronze, aluminum, bamboo, glass) · Mbira: bottle-cap buzzers and thumb patterns, with an approximate Shona Nyamaropa tuning +2 more
Hortator	v0.14.0	2026-10-08	beta	drums	GPL-3.0	DEADACTIVE	Felucca	TR-808 and TR-909: modeled kicks, snares, claps, hats, toms, cowbell, cymbal, rim, clave, and conga · Mutable Instruments Plaits: full ports of its percussion algorithms +3 more
Felucca [Salt]	v0.9-salt14	2026-10-05	beta	synth · groovebox	GPL-3.0	Chance Roth	Felucca 0.9	All 9 Felucca 0.9 engines, fully playable in the browser (FM6/Dexed included) · The web synth’s 54 factory presets and built-in samples, with chords and sustain +1 more
WaveLoop FM-1	v1.0.5.2-midi16	2026-10-09	stable	synth · groovebox	GPL-3.0	ELI7VH	Felucca 1.0.5.2	Re-voiced 808: longer, deeper kick, fuller snare and clap (original synthesis, no samples) · CR78: dry, short kick and snare, soft maracas, woody conga, rounded bell +1 more
SLOOP Floyd FM	v2.4	2026-10-06	stable	synth · groovebox	GPL-3.0	René Bohne	SLOOP	Floyd Steinberg’s 4-OP FM concept: 4 sine operators (1 carrier + 3 modulators), independent ADSR per operator, 8 algorithms · Jonathan Zeppa’s FloydFM VST (MIT), as an open-source reference +1 more
SLOOP DX7 Banks	v2.4-b23-test	2026-10-08	test	synth · groovebox	GPL-3.0	majnikool	SLOOP 2.4	DX7: up to 12 voice banks imported as .syx cartridges, renamed and sorted from the web editor · Dexed-core FM6 with SysEx import, same as SLOOP +1 more
Groove OS	v1.1	2026-10-04	stable	synth · groovebox	commercial ($29)	Peter Gombos	—	Stock 6-operator FM (factory Dexed) intact, with its 128 presets · VA supersaw: up to 7 detuned copies, sub, noise, drift, and an LP24/LP12/BP/HP ladder filter with drive +1 more
fm1doom (FreeDM)	—	2026-10-07	experimental	games	GPL-2.0	Sven Trogus (zvenson)	sloopDX	Playable Doom on the FM-1's screen, installed from the browser, and your sloopDX projects survive.
fm1-doom (Keitark)	—	2026-10-04	experimental	games	GPL-2.0	Keitark	—	The other Doom: a Doomgeneric port whose current screenshots are desktop renders, unconfirmed on hardware.
FM1 Quest	—	2026-10-06	experimental	groovebox · games	GPL-3.0	hericdk	SLOOP	The SLOOP core dressed up as an RPG: your tracks are heroes and your loops are boss fights.
REDACTED (DJ Redacted)	—	2026-10-08	experimental	groovebox	GPL-3.0 (unverified)	—	Felucca	A 'dark fractured lo-fi' groovebox whose only public existence is an installer on chatgpt.site.
Lunar Modulator	—	2026-10-09	upcoming	synth · groovebox · upcoming	MIT (+GPL-3.0)	ip2k	independent (inspired by X0X/Felucca)	TB-303, TR-909, and TR-808 (ports of the X0X engines: Acid Bass, Comet Kit, Crater Kit) · DX7 (FM6 engine, Dexed/msfa core) +1 more
Optimist	—	2026-10-08	upcoming	synth · upcoming	GPL-3.0	w0ts	SLOOP/Felucca/Melodee/X0X	Compile-time à la carte engines: ANALOG 2, DIGITAL, PHASE, LOFI, SAMPLE, VOICE, TRIO, WHEEL, GRAIN, FM6 (Dexed), SLICE, PHYS, ACID · Drum kits, effects, and sequencer features: equally selectable
FM-1 Pocket Sampler	—	2026-10-02	upcoming	sampler · upcoming	no license	friendsmakenoise-prog	independent	Late-90s-style chop sampler — it won't be flashed until recovery is proven.
Sloop_ALG	—	2026-10-05	upcoming	synth · upcoming	no license	shaw-core	SLOOP	Karplus-Strong (modeled plucked string) · Approximate DX7 (2 voices per track) +1 more
fm1-polyseq	—	2026-09-04	upcoming	upcoming	no license	NOVALENTI	independent (no Felucca code)	Polyphonic sequencer in strict C99, no malloc — the no-Felucca route. Dormant since day 2.
Felucca S49 Edition	—	—	upcoming	synth · upcoming	no license	1bitfromdend	Felucca 1.0.2	Felucca 1.0.2 piloted from an NI Kontrol S49 MK3. No release: compile it yourself.
V15 patch (czietz)	—	2026-09-27	stable	patch	Unlicense (public domain)	Christian Zietz (czietz)	stock V15 (binary patch)	DX7 (detune corrected to match Dexed/Yamaha) · Aftertouch without vibrato (corrected behavior)

updated = release date of the version listed (last repo activity for unreleased ones) · hover a row's "emulates" cell for the full list · click a header to sort. Snapshot Oct 9, 2026.

vFM-1_096 stable

FM-1+VA (Baud Girl)

The FM-1's first custom firmware: patches the stock, fixes 4 factory bugs, adds a supersaw VA. Closed and free.

lic: closed (GPL promised)
type: synth · groovebox

by Madeline (Baud Girl)

v1.4.1 stable

Felucca

The base firmware: 13 engines, a deep sequencer, browser editor and emulator. Almost everything else forks this.

lic: GPL-3.0
type: synth · groovebox

by Leo Kuroshita (Hügelton Instruments)

v2.5 beta

SLOOP

The free-take groovebox: record without a click, close the loop on the '1', zero factory patterns.

lic: GPL-3.0
type: groovebox · sampler
fork: ↳ Felucca

by isod89

v3.4 beta

sloopDX

SLOOP with a DX7 inside: a Dexed engine verified sample by sample, and FM drums you program yourself.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ SLOOP

by Sven Trogus (zvenson, DesignBurg)

v2.1 stable

zp12

A pocket SP-1200: 12 bits at 26 kHz, zero interpolation. The aliasing is the sound.

lic: GPL-3.0
type: sampler · drums
fork: ↳ sloopDX

by Sven Trogus (zvenson, DesignBurg)

Screenshot of X0X running on the M-VAVE FM-1

v0.10.3-beta beta

X0X

A 909, an 808, two 303s and breaks, all at once in stereo: a pocket ReBirth with TB-3PO.

lic: GPL-3.0
type: groovebox · drums
fork: ↳ Felucca

by Charles Vestal

v0.3.2 beta

FoMni

The FM-1 as an Omnichord: strum plate, chord buttons, OM-84 rhythms with automatic bass.

lic: GPL-3.0
type: chords
fork: ↳ Felucca (via X0X)

by Charles Vestal

v0.13.1 beta

Melodee

Prophet-5 Rev 4, DX7 and Casio CZ-1 with real .syx, unquantized recording and 70 scales.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ Felucca

by Kerem Kiliç (keremimo, Ellic Studio)

v2.0 stable

Bubba

SLOOP stretched to 8 tracks: a looper per track, on-device slicer, chords named on screen.

lic: GPL-3.0
type: synth · groovebox · sampler
fork: ↳ SLOOP

by Erbubar23

v0.8.2 beta

Jangada

Felucca with a dark-industrial-Brazilian aesthetic: breathing drones, a Moog ladder, the MANGUE maracatu kit.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ Felucca

by zednaked

v1.1 stable

GHOULBOX

Dungeon synth on your FM-1: hurdy-gurdy, bagpipes, chanting monks and a 12-second cathedral of reverb.

lic: GPL-3.0
type: synth
fork: ↳ Felucca 1.0.5.2

by Jason Persinger

v0.13 beta

ChoralRoot

A pocket Orchid: roots in one hand, chords in the other, a semantic looper and three audio outputs.

lic: GPL-3.0
type: chords
fork: ↳ Felucca (FM6/CZ-1 engines from Melodee)

by Quixotic7

v0.6.0 beta

FiMba-1

The FM-1 as a physically modeled kalimba: six materials, gourd body, mbira buzzers, plate reverb.

lic: GPL-3.0
type: synth
fork: ↳ Felucca (via X0X → FoMni)

by jadamsowers

v0.14.0 beta

Hortator

An 8-track drum machine: modeled 808/909, Mutable Plaits/Grids/Streams, and a PERFORM mode.

lic: GPL-3.0
type: drums
fork: ↳ Felucca

by DEADACTIVE

v0.9-salt14 beta

Felucca [Salt]

Browser Studio for Felucca 0.9: play the full synth without owning an FM-1.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ Felucca 0.9

by Chance Roth

v1.0.5.2-midi16 stable

WaveLoop FM-1

Felucca 1.0.5.2 turned into a live rig with an Arturia MiniLab 3: 12-song setlist and autosave.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ Felucca 1.0.5.2

by ELI7VH

v2.4 stable

SLOOP Floyd FM

SLOOP with a visual 4-operator FM engine: the oscilloscope draws each operator's ADSR.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ SLOOP

by René Bohne

v2.4-b23-test test

SLOOP DX7 Banks

SLOOP 2.4 with up to 12 DX7 banks on board, managed from the web editor. Test builds.

lic: GPL-3.0
type: synth · groovebox
fork: ↳ SLOOP 2.4

by majnikool

v1.1 stable

Groove OS

The only paid firmware ($29 USD): a mod over stock V15, supersaw VA, and boots stock with OCT−+OCT+.

lic: commercial ($29)
type: synth · groovebox

by Peter Gombos

— experimental

fm1doom (FreeDM)

Playable Doom on the FM-1's screen, installed from the browser, and your sloopDX projects survive.

lic: GPL-2.0
type: games
fork: ↳ sloopDX

by Sven Trogus (zvenson)

— experimental

fm1-doom (Keitark)

The other Doom: a Doomgeneric port whose current screenshots are desktop renders, unconfirmed on hardware.

lic: GPL-2.0
type: games

by Keitark

— experimental

FM1 Quest

The SLOOP core dressed up as an RPG: your tracks are heroes and your loops are boss fights.

lic: GPL-3.0
type: groovebox · games
fork: ↳ SLOOP

by hericdk

— experimental

REDACTED (DJ Redacted)

A 'dark fractured lo-fi' groovebox whose only public existence is an installer on chatgpt.site.

lic: GPL-3.0 (unverified)
type: groovebox
fork: ↳ Felucca

— upcoming

Lunar Modulator

The most ambitious project in the scene — and it has never written a single byte to a real FM-1.

lic: MIT (+GPL-3.0)
type: synth · groovebox · upcoming
fork: ↳ independent (inspired by X0X/Felucca)

by ip2k

— upcoming

Optimist

Not a firmware: a factory. Compile your own, picking engines and FX to your flash budget.

lic: GPL-3.0
type: synth · upcoming
fork: ↳ SLOOP/Felucca/Melodee/X0X

by w0ts

— upcoming

FM-1 Pocket Sampler

Late-90s-style chop sampler — it won't be flashed until recovery is proven.

lic: no license
type: sampler · upcoming
fork: ↳ independent

by friendsmakenoise-prog

— upcoming

Sloop_ALG

Experimental SLOOP fork with 16 engines piled on — Karplus-Strong included — nothing verified on hardware.

lic: no license
type: synth · upcoming
fork: ↳ SLOOP

by shaw-core

— upcoming

fm1-polyseq

Polyphonic sequencer in strict C99, no malloc — the no-Felucca route. Dormant since day 2.

lic: no license
type: upcoming
fork: ↳ independent (no Felucca code)

by NOVALENTI

— upcoming

Felucca S49 Edition

Felucca 1.0.2 piloted from an NI Kontrol S49 MK3. No release: compile it yourself.

lic: no license
type: synth · upcoming
fork: ↳ Felucca 1.0.2

by 1bitfromdend

— stable

V15 patch (czietz)

The minimal mod: four bytes patched onto stock V15 — and in the public domain.

lic: Unlicense (public domain)
type: patch
fork: ↳ stock V15 (binary patch)

by Christian Zietz (czietz)