Firmware for the M-VAVE FM‑1 · open source · early
Veffbox is a resampling sound-design instrument for a 27-key pocket synth. Build one sound from a source, a strummed chord sequence, modulation and up to eight effects. Then RESAMPLE: the recording becomes the new source, and the recipe that made it is kept, so every sound can be rebuilt bit for bit.
Interactive · with sound
The emulator runs the Veffbox firmware itself in your browser: the same screen, the same engines, the same sound, and your bank is kept in this browser. Start tutorial lights up what to press next and says why, from the first sound to a resample, the tree and a chord sequence.
Eight steps on the FM‑1. You never lose anything: each roll can be undone, each resample is kept with the recipe that made it, and a sound can always be rebuilt from scratch.
EDIT opens the source page. Turn SELECT to choose the engine: OP4 (FM), ANLG (analog) or DRUM. The engine's name is the big title. Play the keys to hear it.
The four knobs under the screen edit the row shown by the dots. Press EDIT again for the next row. In DRUM, the key you press picks the voice the knobs shape. In OP4, the OP knob on the third row picks the operator, A to D.
On the source page, SEL is RANDOMIZE: new engine settings, and the sound plays once so you hear it. Tap again for another roll. CHAOS on GLO sets how far a roll goes, from a nudge to a whole new sound.
Hold SEL for 0.6 s to go back to the sound from before the first roll of the series.
ARP picks the mode: NOTE (the keys), SEQ (a 16-step line) or CHORD (up to 8 chords with exact notes, each with its own length, and a strum). SEQ edits the selected step: turn SELECT to move, press keys to enter notes. PLAY starts and stops.
Pick an LFO or envelope with SELECT, tap SEL, then turn any knob on any page: that parameter becomes one of its four destinations. A ~ next to a knob's name means something modulates it.
On the FX page, SEL is SCRAMBLE: a new chain of effects, with LFOs already routed into them. Tap a few times until something clicks, and hold SEL to go back. Or build the chain by hand: SELECT picks the slot, the knobs set TYPE, the amounts, MIX and the slot's position.
REC records the whole chain as a new generation: G1, G2… With AFTER on FLAT (HOME), the effects and modulation are cleared and the resample becomes the source, so you start fresh on the result.
HOME sets the resample: LEN (one note or 1, 2 or 4 bars), START on the grid, NORM, and how long the tail rings.
Now the resample is the sound. Play it as a sample (SAMP), scatter it into grains (GRAN) or cut it at its transients into slices on the keys (CHOP). Roll it with SEL, scramble new effects, then REC again. Every round adds a generation, a child of the one before.
SAVE shows the sound's generation tree. Pick a generation with SELECT, choose an action with the DO knob, and run it with SEL.
LOAD plays its resample again. EDIT brings back the recipe that made it, so the next resample grows a new branch and the old one stays. RBLD re-renders it from the first generation, bit for bit.
PRESETS picks which of the 64 bank sounds you are on, ALGORITHM which of the 4 tracks. Everything saves itself to the FM‑1's flash 2.5 s after you stop playing. To fill the bank, turn PRESETS to an empty sound and start again from step 1.
Why the tree can always be rebuilt: Veffbox uses integer math only, and every random roll comes from a seed stored in the recipe. A recipe is a few hundred bytes, so a sound keeps up to 12 generations in flash, while audio is kept only for the last resample. REBUILD renders the rest from their recipes and gets the same bits back.
Everything you do is a step on one road: a source, played, modulated, run through effects, resampled. The resample goes into the bank as a new generation and comes back as the source. Round you go.
Where the sound comes from: an FM, analog or drum engine, or the last resample played as a sample, as grains or as slices.
From the keys, as a 16-step line, or as an 8-step chord sequence with exact notes and a strum.
6 LFOs and 3 envelopes, each reaching 4 destinations anywhere on any page.
Up to 8 effects in a chain, in any order, the same type more than once if you like.
Records the whole chain. The resample is the next source; its recipe goes into the bank.
Start from a synth engine. After the first resample, the source can be the resample itself: played as a sample, scattered into grains, or cut into slices. The knobs come in rows of four; press the page button again for the next row. SELECT picks the engine.
Engines: make a sound from nothing
Four operators, A to D, in 11 algorithms that decide who modulates whom and which ones you hear. Integer ratios sound harmonic, odd ones metallic; a fixed-frequency operator makes drums and bells.
Two oscillators with detune, a sub one octave down, noise and sync, into a 24 dB ladder filter with drive and its own envelope.
Kick, snare, clap, hat, tom, rim, cowbell and cymbal, each with 8 shaping knobs: pitch sweep and its time, click, snap, metal, burst, choke. The keys play the voices.
Resample sources: play the last generation
Start and length, one-shot, forward or ping-pong loop, reverse, pitch, fade and gain.
Position, size, density and spray, random pitch and reverse grains, four window shapes, a freeze. Grain scatter comes from a seed, so a render repeats exactly.
Transient detection cuts the resample; SENS decides how many slices. Map them to the keys or to the steps, and play them in order, shuffled, stuttered or reversed.
Three play modes: NOTE from the keys, SEQ as a 16-step line with slides and probability, and CHORD: 8 steps, each holding up to 6 exact notes and its own length, from a sixteenth to four bars. Press a key to add or remove a note; the chord name is recognized for you.
| Step | Chord | Exact notes | LEN | Template |
|---|
Per step: ROOT moves the whole voicing, TYPE fills it from 11 templates (MAJ, MIN, 7, MAJ7, MIN7, SUS2, SUS4, ADD9, MIN9, DIM, 5), N1–N4 set single pitches, LEN runs 1/16, 1/8, 3/16, 1/4, 3/8, 1/2, 3/4, 1, 1½, 2, 3 or 4 bars, and GATE sets how long the notes ring inside the step.
TIME sets the gap between strummed notes (0–250 ms) and HUMAN adds timing and velocity drift. Each picture below is step 1, Cm7, as the screen draws it.
Nine modulation sources: 6 LFOs and 3 envelopes. Each one reaches up to four destinations, each with its own bipolar amount. A destination can be any knob on any page: an operator level, a drum's pitch sweep, a grain position, a delay time, even another LFO's rate.
Destinations are generated from every engine's and effect's parameters, so the list is long. LEARN skips it.
Signal runs from slot 1 to slot 8. Every slot has a type, four knobs, a wet mix, a bypass and MOVE, because order changes the sound. On the FX page, SEL = SCRAMBLE: a random, wild chain with LFOs patched into its knobs. Try it here.
| Type | Knobs | What for |
|---|---|---|
| DRIVE | DRV TONE BIAS OUT | Saturation, asymmetric with BIAS. |
| FOLD | AMT SYM PRE OUT | Wavefolding: bright, hollow, wild. |
| CRUNCH | AMT RATE HISS OUT | ADPCM-style grit and hiss. |
| BITS | BITS SR JIT OUT | Bit depth and sample-rate reduction with clock jitter. |
| FILTER | CUT RES TYPE DRV | A resonant filter in the chain, not only in the voice. |
| TAPE DLY | TIME FB HP LP | Delay with a tape's pitch bend when TIME moves. |
| REVERB | SIZE DEC DAMP GATE | Rooms to washes, gated if you like. |
| CHORUS | RATE DEP FB WIDE | Width and movement. |
| PHASER | RATE DEP CNTR FB | Sweeping notches. |
| RING | TUNE WAVE EXT KEY | Ring modulation, tuned or following the key. |
| RESON | TUNE DEC TONE CHRD | Resonators that turn noise into pitch, or a chord. |
| FREEZE | SIZE SPRY PTCH HOLD | Holds a moment and smears it. |
| SHIFT | PTCH FB WIN TONE | Pitch shifting, spiralling with feedback. |
One button acts on whatever page you are on. A tap rolls, another tap re-rolls, and holding it brings back the sound from before the first roll. You can explore without fear.
On the source page (EDIT): new engine settings. OP4 gets a new algorithm, ratios and envelopes with its carriers kept audible; DRUM reshapes the selected voice; GRAN rolls a new seed. At high CHAOS, OP4 and ANLG may even swap.
How far RANDOMIZE and SCRAMBLE go. Every value moves toward a random target by the CHAOS amount, so low settings nudge your sound and high ones replace it.
Holding SEL for 0.6 s undoes the whole run of rolls, not just the last one. It works for RANDOMIZE and SCRAMBLE alike. And since every roll comes from a seed, whatever you resample is in the recipe.
REC resamples from any page. The output of the whole chain is recorded as a new generation, a child of the one you started from. With AFTER = FLAT, effects and modulation are cleared and the resample is loaded as the source, ready to be bent again.
On SAVE, pick a generation with SELECT and run an action with SEL.
Why bit-exact matters: the FM‑1 has room for the recipes of every generation (stored as small deltas against the parent) but for the audio of only a few. Everything is integer math, all randomness comes from seeds in the recipe, and a shipped engine never changes how it sounds; a fix is a new engine version. So REBUILD gives back the same bits, and you never notice the audio was not kept.
The bank holds 64 sounds, each with its own generation tree. Four tracks each play one bank sound. You edit one at a time, full screen, while the others keep playing as context.
ALGORITHM picks the track you edit. PRESETS picks which of the 64 sounds sits on it. Recipes live in flash as deltas against their parent, so 64 sounds with many generations each fit in the FM‑1's own memory.
The FM‑1's labels stay; Veffbox gives them these meanings. The four knobs under the screen always edit the lit row of the current page.
| FM‑1 control | Veffbox | Details |
|---|---|---|
| EDIT | SRC: the source | SELECT picks the engine or resample source; the keys pick the DRUM voice. SEL = RANDOMIZE. |
| ARPSEQ | PLAY | ARP: mode and strum row. SEQ: the step row (chord or note of the selected step). |
| LFOENV | MOD | 6 LFOs, 3 envelopes, 4 destinations each. SEL = LEARN. |
| FX | FX chain | 8 slots, 13 types. SEL = SCRAMBLE. |
| HOME | Resample settings | LEN, START, NORM, AFTER, TAIL. |
| REC | Resample | From any page. |
| SAVE | Bank | The generation tree: LOAD, EDIT, REBUILD. |
| GLO | Global + CHAOS | BPM, and how far the random rolls go. |
| PLAY | Transport | Start and stop. Flash is only written while stopped. |
| SEL | Act on the page | RANDOMIZE on SRC, SCRAMBLE on FX, LEARN on MOD, resample on HOME, run the action on SAVE. |
| hold SEL | Undo | Takes back the whole run of random rolls. |
| SELECT | Engine, or the item on the page | The engine on SRC; the step, LFO, FX slot or generation elsewhere. |
| ALGORITHM | Track | Which of the 4 tracks you edit. |
| PRESETS | Sound | Which of the 64 bank sounds sits on the track. |
| KNOB 1–4 | The lit row | Press the page button again for the next row. |
| OCT−OCT+ | Octave | Shift the keys by an octave. |
| OCT−+OCT+ 5 s | UBOOT recovery | The way back if anything goes wrong. |
The emulator above is the firmware itself, compiled for the browser. It is portable integer C, tested on a computer before it reaches the hardware, and installed on an FM‑1 from the page below.
Measured on a real FM‑1: a strummed OP4 chord sequence through a scrambled FX chain peaks at 45% CPU, with no late audio buffers.
Over the FM‑1's own USB cable. The update path is the same as MNM-1's, so a Veffbox image can always be replaced with the normal installer.
One button, in Chrome or Edge on a computer. Connect the FM‑1 with a USB data cable and keep the page open until it says Done.
M-VAVE's own updater puts the official FM‑1 firmware back.
Hold OCT− and OCT+ together for 5 seconds: the FM‑1 goes into UBOOT, its recovery mode, and takes a new image from there. A build that keeps crashing in its first 30 seconds drops into UBOOT by itself.
With the install tool from an MNM-1 checkout:
$ python3 tools/fm1_install.py veffbox-X.Y.Z.fwsc --port FM‑1 --yesTest firmware, installed at your own risk: no warranty, and the author accepts no responsibility if your FM‑1 is damaged or misbehaves.