Guitar effect boxes appeared more and more in the 1960’s. One of the most remembered is the UniVibe; listen to David Gilmour’s guitar on Pink Floyd’s “Breathe.” or Jimi Hendrix playing through the effect on “Machine Gun” from Band of Gypsys.
The original Uni-Vibe pedal was created by the Japanese guitar effects company Shin-ei in the 1960s as an attempt to emulate the sound of a rotating Leslie speaker. Although you’re not likely to mistake the sound of a Uni-Vibe for a Leslie, it can produce some wonderful phase shifting effects.
So why is it so hard to pin down exactly what this effect is? The original pedal had a Chorus/Vibrato selector switch, and to this day you may see the pedal referred to as a chorus/vibrato pedal. However, it doesn’t really sound like a chorus pedal. Internally, a series of phasing filters were used, and in Chorus mode, the dry signal is mixed with the phase-shifted signal, producing the unique phase shifting sounds the pedal is most known for. In Vibrato mode, there is no dry signal present, resulting in a throbbing pitch bend (vibrato) effect.
Fumio Mieda is historically credited for the design which was developed back in the mid 1960's. The Uni-Vibe was originally intended as a rotating-speaker (ie; Leslie) simulator which was supposed to emulate the doppler effect of a moving sound transducer.
When marketed by Unicord/Univox it was re-branded as the Shiftee Uni-Vibe model U-915 and was slightly remodelled from the original Vibra Chorus format. The new unit had a 5-pin DIN socked added to the front panel to allow attachment of a "Foot Control" (speed pedal) and the "Repeat Time" (speed) knob was replaced by a Fuse holder. This is the configuration most of us know and a Uni-Vibe.
Eddie Muñoz most famously known as the flash guitarist from LA’s legendary Plimsouls, was the original owner of this effect pedal. Eddie has more recently been spotted in Magic Christian (alongside Flamin’ Groovies legend Cyril Jordan) and PA’s power pop stalwarts Parallax Project. Eddie’s “chaos theory” approach to rock and roll guitar is unique and immediately recognisable, yet squarely rooted in the timeless swagger of The Stones and The Yardbirds.
Eddie bought this pedal back in 1969.