Circuit Overview:
I was mistaken re: this being a divide down machine. My apologies. The PE-1000 (which I finally got one in here..number 770098 which I guess is the 98th one made in '77, has 60 keys that each have their own oscillator. It's a rather different one using an scr device it appears and timing capacitor(s) so that it reaches a threshold then discharches the caps it appears to produce a sawtooth type waveform which is largely why these sounds so awesome it appears. Then there is a quad op amp that a section of is used to buffer this event for each of four notes. THe VCF's are a transistor/fet circuit that is not the Korg 35 module but has similarities it appears. I can get near self-oscillation on this one by adjusting the 10K pots on that board. There is a glide function that requires a switch and the native pedal has a toe switch it appears on the end of the CC pedal 10K resistor that subs in the for the panel's lpf control. Anyway it has the Reed, Pipes and Brass preset that can have the attack paraphonically (2 part... there is one trigger for the high and one for the low half of the keyboard. ) adjusted along with the manual button that goes all to knobs. Here you can select the wave type with square and two pulse widths, the native 'saw' and a chorused saw that interjects a 1 second ish lfo into the cards in some pattern of odd notes probabaly. I see the LFO but didn't check phases. Anyway quite a machine, along the lines of the RMI Electra-piano with a cool high/lowpass filter each with resonance and an over filter it appears that is simple to take the edge off as needed. The 'expand' I'm not quite sure what it does. It seems to envelope the highs out longer...?
Service Tips:
Use of a headphone amp recommended in tracking whether the oscillations are happening on each scr. Beware again that glide needs a pedal. Also note that on the one I worked on the increasing of the attack envelope with heavy lfo will cause the note to sound like it's coming in on a random pitch :-). Various oddities that might be confusing on this one. I had someone spill on the one I did and take out a transistor by rust and a couple diodes leaked causing extended play when keys aren't being hit. Get the diagrams and figure out where everything is first! Fortunately they at least NUMBER the connections on the boards and in the diagrams. I had to label some in the schematic to figure out where everything is by tracing with a continutity checker to make sure I had the right potentiometer etc.
Parts:
I probably have some parts for these. No clue who else would except probably vintageplanet.
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