The modular system once developed by Robert "Bob" Moog went through a long production period between 1964 and 1981, including its development process. At that time, the new, electronic instrument was an avant-garde pioneering work that still had to be explained to the public, but ultimately found more and more interested parties.
The CP3A-O Oscillator Controller from Behringer does exactly what its name suggests: it controls oscillators. Ideally, this module is located between the keyboard or sequencer and the oscillators. The red switches determine whether the applied voltages are passed through to the outputs or not. This can be done in such a way that each input "fires" the output below it or all three outputs are supplied by input 1. An LFO is applied to the "Ext Input", which is metered with the knob and affects all active tone generators. So that the setting does not always have to be found again, it can be (de)activated with the blue switch.
Behringer CP3A-O Oscillator Controller