A minimal MIDI synth: one oscillator shaped by an envelope, with four controls. It is a reference module for developers, showing how an instrument is assembled from Maru's built-in building blocks, and the starting point for new graph-based instrument projects.
What it does
Play it with MIDI notes. Each note runs an oscillator through an attack-decay-sustain-release envelope.
- Waveform chooses Sine, Saw, Square or Triangle.
- Attack (0 to 2 seconds) and Release (0 to 5 seconds) shape how notes start and end. Decay and sustain are fixed, so the envelope keeps a simple, predictable shape.
- Level sets the output.
The envelope drawing on the face is a picture of these settings, not a meter. There are no factory presets.
Building on it
The instrument is a short graph of existing nodes in src/index.ts: MIDI in, oscillator, envelope, gain, audio out. If the built-in nodes describe what you want, extend this graph. If they do not, its sibling SDK Processor Instrument shows the same kind of voice written as your own DSP code.