Be advised that this one was sold as a project in nonworking condition. Here is an edited version of what the seller had to say about the one pictured here:
It is reported that only 800 were sold and shipped including two bought by Robert Fripp.
“I bought this many years ago in nonworking condition and it sat for a while before I attempted a repair. The repair of this rare effect was further complicated by my inability to locate original schematics. Do they exist out there? I was however fortunate to have the loan of a working unit to assist in the repair process which ultimately did not fully succeed, hence this project sale.”
“As a result of my repair attempts the unit is about 85% working. All foot switches and pots function as they should. Cosmetically everything is original except for authentic repro knobs (original bottom plate, feet and screws are present).”
“Internally the power supply is working and it passes signal in bypass mode. Many of the 40 some odd chips have been replaced and socketed (a very complex circuit as far as vintage effects go) and the delay section is working.”
“The Harmony works from zero (same pitch as input signal), going up to about an octave and a half or so (the complete clock-wise motion of the pitch/range pot), however, when turned down counter-clock-wise going lower in pitch, the harmony just shuts off until the pitch/range pot is turned back to unity.”
“As it currently functions it sounds the same as the working unit I had for comparison, though a tad noisier (there is inherent noise in the design of the circuit and how it’s achieving polyphonic pitch synthesis) so that is normal and may be because the lower harmony currently isn’t functioning.”
“In the opinion of the technician attempting this repair the problem has more to do with how the digital side of the circuit operates with the
analog side regarding the polyphonic pitch shifting, meaning no signal is passing. Without the complete schematic or a technician with a more substantial background in synthesis this unit may be out-of-luck.”
So you might be better off trying one of these out for a lot less money and hassle.