FREI is a a condensed interpretation of the Uni-Vibe, stripped down, raw and unfiltered. It gets wild. Huge thump, deep throb, 3D swirl and when pushed hard by a fuzz, it’ll even go into a sort of through-zero uni-vibe thing, gating at the bottom of the LFO wave. I gave it two depth controls you can quickly switch between via foot switch and the big knob controlling the rate can be replace with a TRS cable to an expression pedal, the way the Uni-Vibe was always supposed to be controlled.
Only feed it 9VDC centre tip negative and expect it to draw about 250mA of current worst case scenario.