Vintage OG 1970's Maestro PS-1A Phase Shifter Guitar Pedal

Be the Maestro of your sounds with this incredible vintage 1970's Maestro PS-1A Phase Shifter! This is an absolute holy grail of vintage modulation, the very box that defined the lush, swirling phaser sounds of '70s rock, funk, and psychedelic pop. Designed by synthesizer pioneer Tom Oberheim, the PS-1A is widely considered the first commercially successful phaser unit, famously used by guitar icons like David Gilmour and John Frusciante.

Housed in its massive, heavy-duty wedge metal enclosure with attached AC power cord, this unit is built like an absolute tank and looks right at home sitting on a workbench or on top of a vintage tube head.

Unlike modern stompboxes with continuous sweep knobs, the PS-1A operates via three iconic color-coded rocker switches: Slow (Green), Medium (Yellow), and Fast (Red). Engaging these multi-stage filters creates a deep, warm 6-stage phasing sweep that sounds far more organic, woody, and three-dimensional than almost any modern digital recreation. The magic really happens when you switch between speeds mid-performance, the internal circuitry gradually ramps up or ramps down the LFO rate, beautifully mimicking the smooth acceleration and deceleration of a real Leslie rotary speaker cabinet.

So if you're looking for a pedal that has defined modulation this is it! It's in good condition especially for its age.  The Maestro PS-1A Phase Shifter is truly something special.

Serial Number: 06897