A stage of OSC-1. It works the same on its own page as it does in the chain — same parameters, same paths.
Tremolo
Volume, going up and down on purpose.
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.
Tremolo
Amplitude modulation with rate, depth and a stereo phase offset. The oldest effect on the list and still the one that turns a held chord into a part.
Parameters
Tremolo
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 Tremolo, tapped after the output stage. It's a picture of what your speakers are getting.
About
Amplitude modulation with rate, depth and a stereo phase offset. The oldest effect on the list and still the one that turns a held chord into a part.
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 |
|---|---|---|---|---|---|
| Tremolo | |||||
Ratetremolo.frequency | 0.1 … 20 | 10 | Hz | Chops per second. Above about 15 Hz the ear stops hearing rhythm and starts hearing sidebands. | Yes |
Depthtremolo.depth | 0 … 1 | 0.5 | — | How far the level drops at the bottom of each cycle. At 1 it reaches silence. | Yes |
Spreadtremolo.spread | 0 … 180 | 180 | deg | Phase offset between left and right. At 180 degrees the channels are opposite and the tremolo becomes an auto-pan. | Yes |
Mixtremolo.wet | 0 … 1 | 1 | — | Blend against the unmodulated signal. Pull it back to keep some level through the troughs. | 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.
A sine LFO at Rate scales the signal level between 1 and 1 minus Depth. Spread offsets the right channel's LFO phase, so at 180 degrees the two channels trough alternately and the effect reads as movement across the stereo field rather than pumping.
Ported from the plugin's tremolo, including the pass-through-when-disabled behaviour: the LFO keeps running while the stage is bypassed, so re-enabling it does not restart the cycle from zero.
It's yours to read and to fork.
Research preview
npx codex clone tremolo
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.