LFOs
An LFO is an oscillator too slow to hear as a note. It repeats a movement in pitch, level, pan, or a filter. Rate is the speed. Depth is how far.
An LFO (low-frequency oscillator) runs too slowly to hear as a note. You hear the parameter it moves.
| It moves | You hear |
|---|---|
| Pitch | Vibrato |
| Level | Tremolo |
| Filter cutoff | A repeating wah |
Rate is the speed of the cycle. Depth is how far the target moves. At depth zero the LFO still runs, and nothing in the sound shows it. Sine is a smooth cycle. Square jumps between two values. Saw ramps and resets. Sync locks the rate to the project tempo, so the cycle lands on beats. With sync off, the rate is in Hertz and drifts against the grid if the tempo changes.
An envelope runs once when a note starts, then waits. An LFO keeps cycling for as long as it is routed. Both are sources in a modulation setup.