Circuit Overview:
Duophonic 2VCO synth with fairly typical simple controls but interesting folding package. ua726 used 1/2 on each vco along w/ FET's and 741 op amps largely w/2 oct shifters +/- and 3 waveforms (saw, tri, PW), Ring mod, pink/white noise, two 4 waveform mod sources and 'pan' control for them as well as independent and combined rate controls, a simple A-R envelope/contour and moog ladder filter
Service Tips:
I imagine wires break from the folding/unfolding process over the years but no problem in 1st one I'm looking at in 2020. The power switch likely caused one ps rail to drop during evaluation. Clean that. Sh1000 has same design; switching + / - rails. A pot came apart inside from knob pulling too hard. 2.2 ohm resistor in V- reg. series was 50% over spec. and replacing reduced level of disturbance of x-y mod. on that rail causing vco mod. all the time; now more faintly.
Parts:
Have most of the parts here for them electronically.
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