Prescription Electronics Vibe-Unit — Portland, Oregon. That big knob is for your foot.
*Photo: my dad, Dave Cowles*

Portland, Oregon, 1993. Jack Brossart start Prescription Electronics to build the late ’60s by hand — fuzz and vibe, that Hendrix and Peter Green corner, made right instead of guessed at. April ’96, Guitar Player run a Uni-Vibe shootout. The Vibe-Unit took it.

Brossart’s gone now and the company closed behind him. Brand came back in 2019 with reissues, but this one ain’t among ’em. Used only.

The Circuit

This here’s a real one. Not no LFO drawn up to look like a vibe — an actual lamp and four photocells, same way Shin-Ei did it when they built the original for Univox.

And here go why that matters. Current hit the lamp, filament take its time heating up to glow. Photocells read that light and drop resistance quick as it brighten — then climb back slow as it fade. That mismatch right there, fast down and lazy up, that’s the throb. Ain’t a waveform nobody drew. It’s a light bulb being slow, and every vibe that sound right sound right ’cause of it.

On the Bench

Speed, Intensity, Volume, plus a Chorus/Vibrato toggle. True bypass.
That Speed knob oversized on purpose — made to be swept with your foot mid-song, way you’d change a Leslie. That’s a decision, not decoration.
⚠ 12V, not 9V. Most boards can’t feed this thing without its own supply. Know that before it show up.
Discontinued. Used market only.

How It Plays

Vibes is just great, and this the one that explain why. In my hands it sound like David Gilmour playing terribly — highest compliment I got, ’cause the distance between us is all me and none of it the box.

Chorus side do exactly what it supposed to: lush, three-dimensional, the sound everybody mean when they say vibe. Then you flip to Vibrato and the wackiness start. Straight outer space. Stop flattering your playing and start arguing with it, best way possible.

Made me wanna keep playing. That’s the review right there.

Inside the Vibe-Unit — hand-populated board with the sealed opto can — Hand-populated, through-hole, not a surface-mount part anywhere. That sealed silver can is the whole trick — lamp and photocells shut in the dark together. Everything else on this board exists to serve it.
*Photo: my dad, Dave Cowles*

Bottom Line

The Vibe-Unit grades a 33 out of 36 — the red. Only the second box on this site to reach it, after the Space Station.

And it earn that for more than tone: a real Shin-Ei Uni-Vibe cost what a used car cost. This get you there without the ransom, on a true opto circuit, hand-built by somebody who cared enough to win a shootout with it. That ain’t a clone chasing a legend. That’s the legend, brought down where you can reach it.

Peak, without the budget.

Man built this by hand in Portland, won the shootout with it, then passed on and took the company with him. What’s left is a white box with a light bulb inside, still doing the thing nobody figured out how to fake. You can’t buy a new one. Somebody out there got one and don’t know what it is. Go find that person.

More info: this one turns up used, on Reverb — it’s the only way to get one.

Photos courtesy of my dad, Dave Cowles.

Built something too. Fretsmith — the reference I actually use on the bench: verified specs, string tension, setup calculators. No accounts, no subscriptions, one-time purchase. The pedals plug into a guitar. Somebody has to know what the guitar needs.

Prescription Electronics Vibe-Unit Review — Gilmour, If Gilmour Were Terrible

The Mixtape