Frequency Modulation Carrier (FM Carrier)

A compact mono oscillator built to be the voice at the heart of an FM patch. Pick one of four classic waveforms, tune it, and feed another oscillator into its FM input to grow timbres from clean tones to clangorous, bell-like, or buzzing. A lighter sibling of the Operator — no feedback or key-scaling, just a fast carrier ready to be driven.

How it works

Unlike phase-modulation FM, the FM input here bends the oscillator's running frequency: the incoming signal is scaled against the base pitch, so a modulator running at audio rate throws sidebands above and below the fundamental. Slow modulation reads as vibrato or pitch sweeps; fast modulation turns into harmonically rich, inharmonic tone. Heavier drive pushes further from the original pitch.

Controls

• Freq — base pitch of the oscillator, from sub-bass up to the top of the audible range.
• Wave — the waveform: Sin, Saw, Sqr, or Tri. Sine is the pure FM workhorse; the others add harmonics before modulation even begins.
• Level — output amplitude.

Inputs & outputs

• FM — patch an audio-rate oscillator here to frequency-modulate the carrier; this is where the FM timbres come from. Slow sources give vibrato.
• Freq — 1V/octave pitch CV; track it from a keyboard or sequencer to play the carrier in tune.
• Out — the oscillator signal.

Tips

• For tonal FM, keep the modulator's pitch in a simple ratio to the carrier (octaves, fifths) so the result stays musical; detune the ratio for metallic, percussive textures.
• Patch one carrier's Out into another's FM to build deeper FM chains.