COMPLEX OSCILLATOR
A complex oscillator differs slightly from a VCO in that it contains at least two oscillators, one of which is intended as a “wave-shaper” to the other.
There are a variety of configurations, brands and models, but in general a Dual Complex Oscillator will have 2 oscillators, some kind of bus to allow the cross modulation and some form of waveshaper on the output of one of the oscillators. 1V/Oct is standard voltage to pitch, though often in this type of oscillator (particularly Buchla and Serge) will be tuned at 1.2v/Oct. On the DPO (pictured) you also have voltage control over Linear and Exponential response, shape of the modulation wave, Follow (for hard sync,) and a separate FM bus leaving the modulation bus open for other wave shapes to “fold” the signal.