Audio input on the Moog

I tired just now plugging in my Fender Jazz bass into the Moog Sub 37 but this did not result in much. I need to read the manual of the Sub 37 some more before getting this working. I think the audio in also just adds feedback or acts as a colour rather than a full control signal. I think full control would only come from a MIDI input. I know there are also Voltage Control Oscillators possible as inputs on the side panel of the Sub 37.