Earthquaker Aqueduct Vibrato PedalWhat really is 'Vibrato'? Contrary to whats written on the faceplate of certain famous deluxe amplifiers, Vibrato is a form of frequency (or wavelength) modulation which we hear as a variation in pitch. It is often confused with Tremolo, which among other things, is a type of amplitude modulation our ears hear as a change in volume. The Many modes of Aqueduct Aqueduct uses a short delay line with eight different modulation modes to deliver gentle