A true pitch vibrato: the sound is bent up and down in pitch, not just pulsed in volume. Three knobs, Rate, Depth and Mix, cover everything from a singer's gentle waver to a seasick tape warble.
The idea
Vibrato runs the signal through a very short delay line and keeps changing its length. While the delay grows, the audio plays back slightly slower and the pitch drops; while it shrinks, the audio plays faster and the pitch rises. The delay rests at 2.5 milliseconds, far too short to hear as an echo, and swings evenly either side of that point.
Because the pitch change comes from how fast the delay is moving, Rate and Depth work together. Doubling the speed widens the wobble just as doubling the depth does. At the default settings the pitch swings by about 13 cents either way, five times a second.



