Designed as a table-top unit, the PS-1 is housed in a bent metal case with a heavy base that includes a mount to attach to a microphone stand. The unit is powered by 117-120 volt AC via a two-pronged plug, controlled by a power switch on top of the box. Three selector switches provide speed control, one also providing effect bypass. The PS-1 has a fuse and foot controller plug on the rear panel and 1/4-inch phone jacks for input and output on the front panel.
The PS-1 uses six field effect transistors (FETs) as filters modulated by a low-frequency oscillator (LFO) to control its effect. Unique to the PS-1 is a timer that changes between effects speeds gradually, mimicking the Leslie speaker that served as its inspiration. The PS-1 draws 2 watts of power.
Like many effects of the time, when the PS-1 phase effect is switched off, the guitar's signal still passes through the electronics of the unit. This has a pronounced effect on the high-frequency content of your guitar's sound, rolling it off substantially, while enhancing the midrange frequencies, producing what is described as a warmer or fatter sound. This can be worked around with modern true bypass-switching pedal boards.
The PS-1's circuit board has three trim pots that were set at the factory and will not likely need adjustment. However, these may have been adjusted by previous owners. If you have reason to suspect your unit is out of adjustment, there is a calibration procedure included with the schematic diagram link (see Resources). The trim pots are sensitive and delicate. Adjust them with care.