[sdiy] Yamaha CSY-2 solo synthesizer

[Colin f]

> The VCF board has four ICs on it, all by Rohm. Two BA626s and 
> two BA627s. I have been unable so far to identify what these 
> are but what is most peculiar about this is that the organ 
> features neither the older NE module based filters, nor the 
> IG chip based filters of the CS synthesizers

...unless those Rohm ICs are really transistor (or diode) arrays, and the
filters *are* essentially a re-hash of the contents of the NE modules.
Or even a discrete prototype of the topology used later in the IG chips.
There's a project for you ;-)

> VCA, FEG and AEG contain standard parts, CA3080 OTAs in metal 
> can packaging and so on.

The GX-1 uses CA3080 VCAs too.

Cheers,
Colin f