via this listing
"PPG Synthesizer 1002 for sale pro-serviced and comes with swan flightcase.Had this for almost 6 years and serviced recently by Stefan Hubner who has a deep understanding of PPG systems.
Some things to observe, one underside key broken but doesn't affect play..these are originals. Jacks for CV, Gate and filter modulation have been added and adjusted to 1V/oct. Jacks added in Service. 'The mains wiring has been re-done according to current safety expectations (not to say standards) including a 'pig tail' cable with an IEC male plug for easier connection. CV and Gate were never standard on the 1002 so the ones having it were all more or less hacks, especially when it comes to oscillator CV. One would expect 1V/octave with 0 volts at a defined note usually. For the 1002 without my modification this means you set the potentiometer on the back that usually came with CV in to track 1V per octave but then had to add an offset of something around 2 volts to reach the lowest C. My approach disconnects the keyboard instead of adding some external voltage somewhere and simulates exactly what the keyboard delivers starting at 0 volts for the lowest C. The connection is being made by a relay actuated by the contacts in the CV jack. By simulating the keyboard, all panel functions remain active on the external CV (glide, tune, modulation) Trigger/Gate is a voltage input (V-Trig) working from 5V up. The filter input only modulates the filter setting and is not intended to make the filter track, for this purpose you should rather use the panel knob that attaches the cutoff control to the keyboard CV.'"
