I watched some more videos on the Rings and while it's not a VCO is is definitely capable as a sound source even without an oscillator fueling it. Still, another standalone VCO would probably be good to have. I'll keep researching these.
-- Mikecd
Rings is a resonator. Feed it with an audio signal and the built-in pluck sound will become madness. I have Rings and it's definitely a favorite but in a basic setup I would start with 2 analog VCO with FM and Sync Input and a wave folder as my main sound source.