Oscillators & timbre: cores, waveshapers, FM & additive

On a modular rig — and equally in a live-coded synth patch — the oscillator is where every sound begins, and the fastest way to sound generic is to treat its waveform switch as the whole story. This module builds toward a working sound-design vocabulary: taking one oscillator core and steering it toward radically different timbres on demand, the skill that lets you answer “make that lead more metallic” or “fatten that bass” mid-set instead of scrolling presets.

The arc starts supported. First, ground yourself in how an analog VCO core makes one native waveform and derives the rest through internal waveshapers, and why the sawtooth-vs-triangle core choice colours everything downstream — this explains what “a single oscillator core” in the capstone actually means. Then work each harmonic mechanism as a guided exercise: patch a rich wave through a filter (East Coast), pair two oscillators so one FM- or AM-modulates the other and use the C:M ratio and index to move between pitched and bell-like spectra, then drive a simple wave into a wavefolder and hear harmonics appear rather than disappear. The West Coast vs East Coast contrast atom gives you the map — adding versus subtracting spectral content — that turns three tricks into one coherent framework and supplies the explanatory language the capstone demands.

FM ratio/depth dialing and wavefolder drive are drilled repeatedly inside real patches because the capstone demands fluent, unhesitating control of both. The required atoms gate the capstone directly: without them you cannot build or explain the three timbres. Supporting atoms — additive-synthesis harmonic control, sub-octave outputs, binary-divider subharmonics, curvature-based waveshaping, digital base-width filtering, analog imperfection as character — widen the palette once the core mechanisms are secure.

Runnable examples

Generated from the context/ instrument corpus by concept (redistributable idioms only). Do not edit — regenerate with gen-module-examples.mjs.

fm-timbre

note("c3").s("sine").fm(4).fmh(2).fmi(3)

_{strudel-0204 · CC0}

osc (midicps 24 * (1 ~~ 4 $ osc 110)) >> audio

_{punctual-0006 · CC0-1.0}

additive-synthesis

{ Klang.ar(`[[100, 200, 300, 400], [0.4, 0.3, 0.2, 0.1]]) * 0.1 }.play

_{supercollider-0022 · CC0}