Oberheim SEM 1977 via 360 System Spectre

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via this Reverb listing

Pics of the inside below.

"These used to be a somewhat well kept secret, obviously no more. But if you're not familiar with the 360 Systems Spectre, it was a pretty terrible GUITAR synth (slow & choppy tracking) that 360 Systems produced with Oberheim SEMs as the heart of these units.

Sometimes you'll see these listed as being "Converted to full-functioning SEM" but often there's a thing or two that were missed. You have to reconfigure a few jumpers, add a missing coupling capacitor to each envelope generator, add the missing Decay and Sustain controls to the EG on the Amp VCA, replace the input gain resistor for the external input, add shielded wire for the output, change the output impedance resistor and so on. Everything was done to this unit to make it true full-functioning SEM. An original SEM/CPS-1 power supply (recapped) was also installed inside.

I'm also including a 1977 CPS-1 chassis (complete with recapped PSU) with it so if you do find a faceplate, you'll have a complete SEM. My plan was to find or have someone make me an SEM faceplate in the rare black finish. I thought the gray knobs would look killer on the black panel. But tbh, I really liked the portability of the 360 case. Oh well, someone else can enjoy it now. I've used this in my studio for the last 5-6 years. I will miss it but I'm not doing much synth-based music.

-Synth was fully restored 5 years ago with some basic maintenance in the last 2 years

-All electrolytic and tantalum capacitors have been changed

-VCOs & VCF tuned/calibrated

-AC cord was removed from the front and an IEC was added to the rear of the case

-pots and switches were recently cleaned

-Sub OSC ckt. was added (non-invasive, made by Pete's Gear Garage in Sweden, uses 'Guitar' knob in mixer section)

-Each Jack on the bottom row has a function such as Hi & Low outputs, CV & Gate in, Ext. Input, LFO retrig, VCF in and out (for use with modular) and VCF CV.

-I still have the 360 Systems Control board. It was robbed of a few parts but the PSU and the Transpose rotary switch are still on it. If you want it, send me a msg and I'll include it with the sale."