This uses the 74LS221 multivibrator design typical in Crumar 'dco' units it appears from tone gen photo. and the tone gen LSI used in Siel DK series. Reviewer notes that there appear to be five synth voice cards expandable to eight. Curtis VCF, EG, and VCA's. (Voice Board and motherboard) Nice Ensemble/pharser/chorus they also note. Very smooth editing. These sound like a GREAT project synth for someone who wants to redesign the VCO section really and run that part purely non-digital :-). Apparently the way they voice the oscillators make it sound really bad from what I can tell but perhaps just not hearing a great sample?
This appears to have the same mfg. as siel so watch for bad solder/oxidization on through holes etc. Regarding the photo of the motherboard for cards above, Simon Flinn who contributed photos notes:
In that picture, first card has cpu, rom and eeprom then a couple ls138's and some glue, 2nd card mainly 3631 divider, some cmos 4053 multiplexers, I've not figured where the triggers come from yet but I'll try to look. Third card has a small dac08 not much else, 4th is all the chorus tda1022 chips (3) and all voices get summed here before heading off to back panel. 5th card has a lot of 4051's and tl084's, looks very much like any other synths sample and hold stage.
Let me know if you need something specific.
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