In this '70s multi-effects box, synth designer Tom Oberheim packed in virtually every effect he had created during his time at Maestro.
Back in the early days of that brand, Gibson utilized the Maestro name to acquire designs from other engineers. Tom Oberheim was already well on his way to success through the increasing popularity of his Music Modulator, the first ring modulator. He had licensed it to Chicago Musical Instrument Company (later Norlin Corporation), the parent firm of Gibson, which released it as the RM-1.
After that success, CMI worked with Tom a few more times, most notably for the PS-1A Phase Shifter—still one of the coolest vintage phasers you can find—and this week's Find of the Week, the USS-1 Universal Synthesizer System.
The USS-1 was Tom's final product for CMI, and has a bit of a misleading name. It's not a synth but an elaborate multi-effect device, including a phase shifter and other circuits found on modern synths: a sample-and-hold circuit, an envelope follower, a waveform generator, a filter, and a subharmonic frequency generator.
This particular USS-1 is being sold by Portland's Black Book Guitars. In the listing, they write that the unit is in excellent working order and includes the original footswitch and case. The USS-1 was designed particularly for guitar, but plugging a real synthesizer or any other instrument into it will produce interesting results.
Check out the full listing for more photos and info.