The Univibe (or UniVibe, or Uni-Vibe) is a footpedal-operated phaser or phase shifter for creating chorus and vibrato simulations for electric organ or guitar. It was introduced in the 1960s by Shin-Ei, and was intended to emulate the "Doppler sound" of a Leslie speaker. Though not a very successful Leslie-simulator, the Univibe has become an effect in its own right, putting its stamp on tracks like Robin Trower's "Bridge of Sighs", Jimi Hendrix's "Machine Gun" and Pink Floyd's "Breathe". The effect, though often associated with chorus, is in fact created through a staggered series of phasing filters, unlike the usually aligned filteres of a normal phasing effect. Unlike most other phaser pedals, this is achieved without the use of op-amps.