Normally you'd use a sequencing module to send CV to the oscillator. I suspect that's where the orange patch cable is coming from. The rest of the modules do a

Normally you'd use a sequencing module to send CV to the oscillator. I suspect that's where the orange patch cable is coming from. The rest of the modules do a number of things. In the actual patch (so, in use) you can see a Quadrax working as an envelope generator, a VCA, a pan mixer, a filter (in this case Mutable Instruments' Blades). It'd be hard to explain modular in a HN comment, but if this interesting to you and you don't want to spend a lot of money (modular is expensive), give VCVrack a look.