the review of the CS-80 -on behalf of a friend- is at a stop point.
There are 4 (!!!) dead Yamaha IG00153 VCO chips .. I don't know the history of this precise model, it arrived in conditions that are not exactly optimal, something will have caused the death of these chips .. I know they are nowhere to be found, but if for some reason someone you sell someone i'm here.
Too bad for the huge work done previously, including capacitors, op-amp, 4000 cmos series etc... You warned me that i would find some yamaha chips to replace, but the oscillators...what a pity!