A stage of OSC-1. It works the same on its own page as it does in the chain — same parameters, same paths.
LFO
A slow wave pointed at something.
Audio and MIDI
Browser session
Audio is stopped.
Input · MIDI keyboard
Your keyboard is a keyboard. Middle row plays the white notes, top row the black ones. Z and X change octave. Keys are ignored while you are typing in a field.
LFO
A low-frequency oscillator with a rate, a depth, a shape and a destination. Point it at pitch for vibrato, at the filter for a sweep, at amplitude for tremolo.
Parameters
LFO
These knobs move the module's published schema, but the preview engine only renders OSC Mini, FX Mini and the OSC-1 chain — so they won't change what you hear yet.
Output · Audio signal
The signal leaving LFO, tapped after the output stage. It's a picture of what your speakers are getting.
About
A low-frequency oscillator with a rate, a depth, a shape and a destination. Point it at pitch for vibrato, at the filter for a sweep, at amplitude for tremolo.
Take it into your DAW.
Same DSP as this page. The plugin isn't a rebuild — it's the identical kernel from the identical TypeScript source, compiled native instead of to WASM.
Free forever, no account, and playing it in the browser will never ask you for one. VST3 and standalone today; AU and CLAP are on the roadmap.
Every knob, and what it actually does.
Generated from the module's parameter schema — the same source as the web UI, the worklet transport and the VST3 parameter table, so it cannot drift.
| Param | Range | Default | Units | What it does | Automatable |
|---|---|---|---|---|---|
| LFO | |||||
Ratelfo.frequency | 0.1 … 20 | 4 | Hz | Cycles per second. Under 1 Hz it is a slow drift; above about 8 Hz it stops being modulation and starts being timbre. | Yes |
Shapelfo.type | sine · square · sawtooth · triangle | sine | — | The modulation waveform. Square gives a two-state jump rather than a sweep, which is a trill rather than a vibrato. | Yes (stepped) |
Targetlfo.target | pitch · filter · amplitude | pitch | — | What the LFO moves. One destination at a time here - the full modulation matrix is a later stage of the port. | Yes (stepped) |
Depthlfo.depth | 0 … 1 | 0.5 | — | How far the target moves. Scaled per destination: at full depth pitch swings 100 cents, the filter 2 kHz, amplitude the whole way to silence. | Yes |
Parameter paths (filter.cutoff) are what you'll see in your DAW's automation list and in the SDK. Same names everywhere.
How it works.
One LFO running free (it does not retrigger per note) into a single destination, scaled by Depth against that destination's own range - cents for pitch, hertz for the filter, linear gain for amplitude. Those ranges are the ones the source schema declares.
One target rather than a routing matrix is a deliberate limit of this port, not a claim about the eventual engine. The source synth has a full routing list with per-route amounts; that arrives with the mod-matrix work, and this stage's param path stays valid when it does.
It's yours to read and to fork.
Research preview
npx codex clone lfo
npm run devThe codex CLI name is proposed, not shipped. That command gives you this module's DSP, schema, presets and UI as a local project — change a number, hear it immediately.