README from GitHub, MIT
Fizzik
Polyphonic simplex physical-modeling synth for Ableton Move, built on the Schwung framework.
Fizzik makes sound the way physical objects do: a short excitation (a strike, a pluck, a breath of noise) is injected into two simulated resonators — strings, beams, plates, membranes — and what you hear is the object ringing. A single Couple knob cross-feeds the two resonators into each other, so complex, emergent timbres arise from the interaction of two simple structures. That's the simplex idea: richness from simplicity.
Distilled from MechanOdd by odoare (FX-Mechanics); all DSP reimplemented independently in C for the Move.
Quick start
- Install via the Schwung Module Store (or
MOVE_HOST=move.local ./scripts/install.sh), power-cycle the Move, and add Fizzik as a sound generator. - You land on the Patch page: browse Preset (knob 1), or roll the dice — Rnd Patch (k2) for a new instrument.
- Play the pads. Press into a held pad — polyphonic aftertouch makes notes bloom, swell, and sing (pick a feel with AT Preset on the Aftertouch page).
- Sculpt live with the global filter (Patch knobs 5–8) — 12 analog voicings.
- Got an MPE controller? Set the slot to Receive All, turn MPE On on the last page, and every finger gets its own pitch bend, pressure and timbre.
Architecture
┌──────────── Couple (cross-feedback) ────────────┐
▼ ▼
MIDI ─► EXCITER ──┬──► RESONATOR A ──┐
noise │ ├─► Balance ─► Amp Env ─► Pan ─┐
mallet └──► RESONATOR B ──┘ │ × 6 voices
crackle ▼
┌───────────────────────┘
▼
FILTER (12 voicings) ─► Drive ─► EQ ─► Chorus ─► Delay ─► Reverb
─► Width ─► Glue Comp ─► Soft-Clip ─► Lookahead Limiter ─► OUT
- 6-voice polyphony. Each voice: one exciter, two independent resonators, coupling, amp envelope, stereo spread. Voice stealing picks the quietest voice.
- Every coupled feedback node is guarded (DC-blocker + soft-limit) so coupling is self-limiting — it saturates like a real object instead of blowing up.
- All continuous knobs are smoothed (~20 ms, analog-style): no zipper, no clicks.
The resonator models
| Model | Physics | Character | Structure knob |
|---|---|---|---|
| String | Dispersive digital waveguide with tension modulation | Plucks, harps, basses, sitars | Dispersion (stiffness → inharmonic shimmer) |
| Beam | 1D modal morph f₀·n·√((1−b)+b·n²) | Kalimbas, xylophones, music boxes | String→beam morph (harmonic → n² partials) |
| Plate | Kirchhoff plate modes ∝ (m/a)²+(n/b)² | Bells, gongs, metallic shimmer | Aspect ratio (square → long) |
| Membrane | 2D wave modes ∝ √((m/a)²+(n/b)²) | Drums, toms, skins | Aspect ratio |
Tension (String & Beam): tension-modulation nonlinearity (Tolonen/Välimäki) — hard hits transiently raise the pitch, which settles as the note decays: the pitch-glide of a hard-plucked string.
Pages & parameters
Jog wheel navigates pages; knobs 1–8 edit the current page.
1 · Patch (home page)
| # | Param | What it does |
|---|---|---|
| 1 | Preset | 31 factory presets (click-free switching, even mid-note; last = Init blank patch) |
| 2 | Rnd Patch | Fire-button: new random instrument — exciter + both resonators + couple/balance |
| 3 | Rnd Exciter | Fire-button: randomize only the strike — audible on the next note |
| 4 | Rnd Reson | Fire-button: randomize only the two resonators (keeps your exciter) |
| 5 | Cutoff | Global filter cutoff (30 Hz – 18 kHz) |
| 6 | Resonance | Global filter resonance (ladder voicings self-oscillate at max) |
| 7 | Filter Type | LP / HP / BP / Notch |
| 8 | Voicing | 12 filter voicings |
The three randomizers are momentary buttons — click to fire. They're tuned to stay musical: darker-leaning, never above the played pitch, level-consistent, and applied through a fast fade so they never click.
2 · Exciter — the strike
| # | Param | What it does |
|---|---|---|
| 1 | Exc Mix | Noise burst ↔ mallet (a single pitched sine cycle) |
| 2 | Crackle | Random impulse clicks mixed into the strike |
| 3 | Color | Resonant low-pass on the excitation — dark thud ↔ bright snap |
| 4 | Attack | Burst attack, 0.2–40 ms (slow = bowed/breathy onsets) |
| 5 | Decay | Burst length, 2–400 ms (long = scraped/bowed textures) |
| 6 | Exc Reso | Resonance of the Color filter (adds a formant-like peak) |
| 7 | Vel Level | How much velocity drives loudness |
| 8 | Vel Color | How much velocity drives brightness |
The exciter shapes the attack of the next note — it doesn't change ringing notes.
3 & 4 · Reson A / Reson B — the two objects
| # | Param | What it does |
|---|---|---|
| 1 | Model | String / Beam / Plate / Membrane |
| 2 | Structure | Model-specific (see table above) |
| 3 | Decay | Ring time, from dead thunk to near-endless |
| 4 | Damp | High-frequency damping — for modal models this is the brightness control |
| 5 | Position | Strike/pickup position — comb-like timbre changes (high = hollow) |
| 6 | Tone | String only: loop brightness filter |
| 7 | Tune | −24…+24 semitones relative to the played note |
| 8 | Tension | String/Beam: nonlinear pitch-glide on hard hits |
Detune A vs B a fifth or octave apart, then use Couple — that's where Fizzik sings.
5 · Voice
| # | Param | What it does |
|---|---|---|
| 1 | Couple | Cross-feedback A↔B. 0 = independent, up = interacting, emergent, alive |
| 2 | Balance | A ↔ B output mix |
| 3 | Glide | Portamento, up to 500 ms |
| 4 | Amp Atk | Amplitude attack, 0.5–200 ms |
| 5 | Amp Rel | Release, 20 ms–3 s (the resonators keep ringing inside it) |
| 6 | Spread | Per-note stereo panning width |
| 7 | Drive | Warm saturation (dry/wet blended — silent at 0) |
| 8 | Level | Patch level |
6 · FX
| # | Param | What it does |
|---|---|---|
| 1 | Reverb | Wet mix of the stereo Schroeder reverb |
| 2 | Rev Size | Tail length |
| 3 | Rev Damp | Tail darkness |
| 4 | Delay | Wet mix of the stereo ping-pong delay |
| 5 | Dly Time | 30–700 ms (tape-style pitch warp when turned) |
| 6 | Dly Fbk | Feedback (echoes cross L↔R) |
| 7 | Dly Tone | Echo brightness |
| 8 | Width | Stereo width (M/S), 50% = as-is |
7 · FX 2 (mastering)
| # | Param | What it does |
|---|---|---|
| 1 | Tone | Tilt EQ — dark ↔ bright around 500 Hz |
| 2 | Body | Low-end weight (~150 Hz shelf) |
| 3 | Chorus | Stereo chorus mix |
| 4 | Cho Rate | 0.05–6 Hz |
| 5 | Cho Depth | Modulation depth |
| 6 | Glue | Bus compressor — cohesion and sustain for chords |
| 7 | Lim Drive | Pushes into the limiter (maximizer loudness) |
| 8 | Lim Ceil | Brickwall ceiling. Defaults low (≈ −3.5 dB) for headphone safety |
The output chain ends in a warm soft-clip followed by a 2 ms lookahead brickwall limiter (design borrowed from MechanOdd's Limiter). Whatever you do with resonance, coupling, or the randomizers, the output cannot exceed the ceiling. Raise Lim Ceil if you want more level; it is intentionally never randomized.
8 · Mod — two LFOs
Each LFO: Rate (0.05–20 Hz) · Depth · Shape (Sine/Tri/Saw/Square/S&H) · Target (Off, Cutoff, Pitch, Couple, Balance, Tension, Tone, Reso).
Try: LFO1→Couple (slow sine) for breathing interaction; LFO2→Pitch (S&H, low depth) for broken-machine detune; LFO→Cutoff (square) for rhythmic filter chops.
9 · Aftertouch — press into the sound
Move's pads send polyphonic aftertouch: each held note responds to its own finger.
| # | Param | What it does |
|---|---|---|
| 1 | AT Preset | 10 curated feels (sets all seven depths at once) |
| 2 | AT Bright | Pressure opens the pressed note's resonator brightness |
| 3 | AT Bow | Pressure re-excites the note — plucks bloom into bowed sustains |
| 4 | AT Cutoff | Peak pressure opens the global filter |
| 5 | AT Vib | Pressure vibrato (per note) |
| 6 | AT Bend | Pressure bends pitch up (string-tension feel) |
| 7 | AT Vib Rate | Vibrato speed, 3–9 Hz |
| 8 | AT Curve | Pressure response — soft (sensitive) ↔ hard (needs a push) |
AT Presets: Off · Gentle · Brighten · Bow · Swell · Vibrato · Expressive (default) · Cello · Wild · Sforzato.
Channel aftertouch (from external MIDI) is also supported.
10 · MPE — per-note expression from external controllers
Plug in an MPE controller (LinnStrument, Seaboard, Osmose, Erae, Push 3…) and every finger gets its own pitch bend, pressure and timbre. Fizzik's bowed/struck physical models are exactly what MPE was made for: slide between notes, bow one string of a chord, brighten a single voice.
Setup: set the Schwung slot's Receive channel to All and leave Forward on Auto or Thru (so the per-note channels reach the synth untouched — an explicit forward channel would flatten them), then turn MPE On here. Leave your controller on its default MPE layout (lower zone, 48-semitone bend) and it just works.
| # | Param | What it does |
|---|---|---|
| 1 | MPE | Off / On. Off = classic behaviour (channels ignored) |
| 2 | Zone | Lower (master ch 1, notes on 2–16) or Upper (master ch 16, notes on 1–15) |
| 3 | Bend Range | Per-note pitch-bend range in semitones (1–96, default 48 — match your controller) |
| 4 | Mstr Bend | Master-channel / global bend range (0–24, default 2) |
| 5 | Pressure | How much per-note pressure drives the Aftertouch engine |
| 6 | Timbre | Depth of the controller's Y axis (CC74) |
| 7 | Timbre Tgt | What Y does: Bright (resonator brightness, centred), Bow (continuous bowing), Vib (vibrato depth) or Cutoff (global filter) |
| 8 | Bend Glide | Pitch-bend smoothing, ~1–60 ms (low = precise slides, high = liquid) |
- Pressure goes through the Aftertouch page — so every AT Preset (Bow, Cello, Swell…) is instantly an MPE pressure preset, per finger.
- Pitch bend works without MPE too: with MPE Off, a normal bend wheel bends all notes by the Mstr Bend range.
- All MPE settings are part of the global performance layer: they survive preset changes and are saved with your track.
- The Move's own pads are not MPE (they send polyphonic aftertouch, handled by the Aftertouch page) — this page is for external controllers.
- Zone and bend range are set with the knobs; the controller's own MPE configuration messages are not read. If slides land flat or sharp, match Bend Range to your controller.
New in 0.2.0. MPE has been verified with generated MIDI streams (per-note bend, channel isolation, pressure, timbre), but not yet with every hardware controller. If yours behaves oddly, please open an issue with the controller model and settings.
Presets (31)
AlienChurch · BowedGlass · CaveStrings · CouncilsPiano · DistortedBass · FeedbackHarp · JudgementAwaits · OldResonances · PreparedPiano · RythmicBow · SensitiveSkin · Sharp · ShockingPluck · Slappy · SurroundedByBells · XyloStyle · GlassKalimba · IronLullaby · TidalGong · HollowReed · StarlightPad · BrokenMusicBox · DeepDiveBass · CopperTongue · GhostSitar · MarbleDrum · WhisperHarp · TitaniumBell · FrozenLake · PulseEngine · Init
Init (last in the list) is a blank neutral patch — twin plain strings, no coupling, no FX — made to be a clean starting point for your own sounds: dial it in, then save it as a user preset.
All presets are level-calibrated (peak and perceived loudness) so browsing never jumps out at you. Presets carry only the instrument — the global performance layer (filter, aftertouch, LFOs, FX 2 mastering) persists across preset changes and randomizes, so your live setup stays put.
The 12 filter voicings
Clean SVF · SEM · MS-20 · Steiner · Ladder 4P · Ladder 2P · Ladder 1P · Prophet · Oberheim · Diode · Sallen-Key · Vintage
Two engines under the hood (trapezoidal SVF + zero-delay-feedback transistor ladder, from the published VA-filter math), level-matched, all working in all four filter types. The ladder voicings self-oscillate at full resonance — bounded, never runaway. The filter is the main tool for taming a patch that's too bright.
Tips
- Bell into drum: Reson A = Plate (Tune +12), Reson B = Membrane, Balance center, Couple ~30% — struck metal over a resonant skin.
- Bowing without a bow: AT Preset = Bow or Cello, hold a pluck and press.
- MPE cello: MPE On, Timbre Tgt = Bow, AT Preset = Vibrato — slide Y to bow each string, press for vibrato, glide between notes with per-finger pitch bend.
- Dub station: Delay mix + feedback up, then ride Dly Time — tape-style warble.
- One-button mayhem, safely: park on Patch, hit Rnd Patch between phrases. The limiter ceiling guarantees it never gets dangerous.
Building from source
./scripts/build.sh # Docker ARM64 cross-compile
MOVE_HOST=move.local ./scripts/install.sh
Requires Docker (aarch64-linux-gnu-gcc). Single C file, no dependencies. Power-cycle
the Move after installing so it reloads the module metadata.
Offline tests
The DSP links natively, so behaviour is checked without a Move (any gcc; the repo uses a
fizzik-native Debian image):
gcc -O2 -ffast-math -o /tmp/t scripts/test_state.c src/dsp/fizzik.c -lm && /tmp/t
| Test | Checks |
|---|---|
test_state.c | Saved tracks/presets restore exactly (preset, level, every page incl. MPE) |
test_mpe.c | Per-note bend, channel isolation, bend seeding, channel-aware note-off, CC74 bow |
test_filter_stress.c | 12 voicings × 4 types at full resonance stay bounded; chords don't clip |
test_voicing_levels.c | All filter voicings level-matched to Clean SVF |
test_levels.c | Per-preset loudness calibration meter |
scripts/mpe_demo.py (Windows, experimental) plays an MPE test stream into the Move over
USB for trying MPE without a controller — run probe first to find the port that reaches
Fizzik. It depends on the PC's MIDI service opening the Move's ports, which is not
reliable on every machine.
Changelog
0.2.0
- MPE for external controllers: per-note pitch bend, pressure and timbre (CC74), on a new MPE page (zone, bend ranges, pressure/timbre depth, timbre target, bend glide).
- Pitch bend now works without MPE too (bend wheel → all notes, Mstr Bend range).
- On-device help rewritten to match the current pages.
0.1.1
- Fixed saved tracks reopening on a factory preset; presets/tracks now restore exactly.
- New Init preset (blank patch).
- Chords no longer distort: real polyphonic headroom; all 12 filter voicings level-matched.
- Main page reworked (full filter on knobs, randomizers are buttons, Rnd All removed); both LFOs draw the animated graphic.
0.1.0 — first release.
Credits
Inspired by MechanOdd by odoare (FX-Mechanics). All algorithms reimplemented from published references: J.O. Smith, Physical Audio Signal Processing (CCRMA); Tolonen/Välimäki/Karjalainen, tension-modulation nonlinearity; RBJ Audio-EQ Cookbook; Cytomic/Zavalishin VA-filter design. Built with Schwung by Charles Vestal.
By Filliformes.
License
MIT — see LICENSE.