User Manual:
Reset Proceedures: N/A
Operating System code: N/A
Patches or knob settings: N/A
Circuit Overview: below
Scematics/Service Manual: fdiskc archive
Common Service Issues/Tips: below
Parts Sources: Keys knobs semiconductors misc
Uncommon chips/modules used: 4034 filter sub-module, ROM chips
Modifications:
General Info Links: Vintage Synth Explorer
Circuit Overview:
The panel switches for patch selection create a static digital code on a group of wires that form an address buss for a set of ROM chips. These chips are programmed to give the proper high or low outputs on various lines that each alter the active components in the feedback loop of an op amp or the like. Thus changing for instance the filtering characteristics of a circuit. Tones generated can then be routed through the Moog filter copy 4034 module or not, also depending on the setting of a bit in a ROM chip for that particular patches address. Aftertouch can control all attributes but panel knobs only allow control of brilliance of the filter, AT amount, portamento amount, vibrato speed and volume. A reiterate switch is also present. The PRO/DGX model had improved switching, but lost the moog ripoff filter design. The rare 'Soloist' was the first product and I don't know much about it.
The only one I've worked on, mine, there were several issues. The most significant was that some of the sounds wouldn't work at all. Looking in the service manual at the functions which the ROM chips were activating for each of those, (very nice manual!) the common link was obvious. They all use the moog filter copy 4034 module. I found Parts
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