The Shin-ei Uni-Vibe, sold under the Univox name, is one of the earliest modulation effects, originally released in 19671. The Japanese company Shin-ei built it as a stand-alone effect with no footswitch, and conceived it in the 1960s as a portable emulator of a Leslie spinning speaker cabinet, the rotating speaker long associated with organs2. It was most famously used by Jimi Hendrix, and later by David Gilmour32.
What it does
The Uni-Vibe is a phase-based modulation effect similar to a chorus2. Its purpose was always Leslie imitation: Aion FX describes it as originally designed as a simulation of a Leslie spinning speaker cabinet3. The circuit gets there by unusual means. It is a four-stage optical phaser in which uneven capacitors in each stage cause a Doppler effect similar to a Leslie spinning speaker3. At its heart is an incandescent lamp-and-photocell arrangement working with phasing filters, a design Delicious Audio credits for the effect's character2.
Because the phase-shifted output can be used on its own or mixed with the dry signal, the same circuit covers both a vibrato-like motion and a chorus-like sound1. That in-between nature is why the Uni-Vibe is usually called a vibe rather than filed strictly as a chorus or a phaser, and why modern chorus pedals and vibrato pedals trace a line back to it.
History
Shin-ei introduced the Univox Uni-Vibe in 19671. It holds a genuine first: the Shin-ei/Univox Uni-Vibe preceded the Maestro PS-1, often discussed as the first phase shifter pedal, by four years, making the Uni-Vibe the first phase shifter on the market5.
Commercially, though, it started badly. Delicious Audio's Paolo De Gregorio writes that the product bombed rather badly among keyboard players, the audience its Leslie simulation was aimed at2. Its fortunes changed toward the end of the decade. As De Gregorio puts it:
"towards the end of the decade, some guy named Jimi Hendrix, and then some other guy named David Gilmour grew fond of it"
Hendrix used it live and on records, and it can be heard notably on "Machine Gun"2.
Finding one today
Vintage Uni-Vibe units are extremely rare. Delicious Audio's buying guide advises anyone after one to start looking around and to have $3k or so to burn2.
Shin-ei's later vibe designs carried the idea forward, including the Shin-Ei Vibe-Bro, the Shin-ei Vibe-2 and the Shin-Ei Vibe-Bro Vintage Chorus-Vibrato.
Videos
Science of Loud
Reverb
MusicStoreLive.com
Questions
What is the original Uni-Vibe?
The original Uni-Vibe is a stand-alone modulation effect manufactured by the Japanese company Shin-ei and released in 1967. It was conceived as a portable emulator of a Leslie spinning speaker cabinet, using a phase-based circuit similar to a chorus. It has no footswitch, and vintage units are extremely rare today, with prices around $3,000.
Did Jimi Hendrix use a Uni-Vibe?
Yes. According to Aion FX, the Uni-Vibe was most famously used by Jimi Hendrix, and Delicious Audio notes he used it live and on records toward the end of the 1960s. David Gilmour also grew fond of the effect in the same period.
What Hendrix song features the Uni-Vibe?
Delicious Audio points to Jimi Hendrix's "Machine Gun" as a recording where the Uni-Vibe can be heard. The effect's phase-shifted, Leslie-like movement is a large part of that performance's sound.
How much does a vintage Shin-ei Uni-Vibe cost?
Vintage Shin-ei Uni-Vibe units are extremely rare. Delicious Audio's buying guide puts the price at around $3,000, and suggests buyers will need to search to find one at all.
Does the original Uni-Vibe have a footswitch?
No. Shin-ei originally manufactured the Uni-Vibe as a stand-alone effect with no footswitch, according to Delicious Audio. Players who want to switch it remotely have to work around that in a rig.
Is the Uni-Vibe a chorus or a phaser?
It is best described as a phase-based modulation effect similar to a chorus. Its circuit is a four-stage optical phaser, and the phase-shifted output can be used on its own or mixed with the dry signal for a chorus-like sound. It sits between the two categories, which is why it is usually called a vibe.
Sources (5)
- Straylight Mini Chorus/Vibe, Aion FX, 2026-07-03
- The 9 Best Uni-Vibe Pedals In 2024: A Guide To UniVibe Clones, Delicious Audio (delicious-audio.com), 2024-02-16
- Straylight Chorus Vibe / Univox Uni-Vibe®, Aion FX, 2024-07-04
- Classic Gear: Boss CE-1 Chorus Ensemble, GuitarPlayer (www.guitarplayer.com), 2021-08-31
- How the Maestro PS-1 Phase Shifter changed popular music, Guitar World, 2026-07-03
