JAM Pedals - RetroVibe mk.3 is a classic sounding, gypsy-defined, swirly vibe that sums up a guitar movement. 4 photo cells make this one of the most musical and faithful re-creations of the classic univibe sound. This new Mark 3 version is now compatible with standard expression pedals. Internally lifted voltage from 9 to 15, this pedal does the Leslie cab swirl sound all the way to more subtle modulation. After first strum, you will be charmed by the original psychedelic vibe. Jam Pedals are hand-painted and vary slightly in appearance.