This is the last in a trio I started with the Syntom II and continued whith the Synbal. The Coron DS7 and DS8 were available commercially at some point, however I couldn’t find much information on the original unit. The Coron DS8 is identical to the DS7, with an addition of a noise source and a simple 2 state filter. I found the clone circuit on this excellent site. The only thing I changed was the controls labels to match the ones used in the previous modules.
I love this thing. It has the obvious tunable and sweepable VCO, but also adds two features that make it special: The VCO can be modulated via an LFO, and can also be controlled with a CV input.
It’s like this: