This is the master/slave setup used by Moog for their modular synthesizers (Moog called the Master Oscillator a Driver). The Idea is you have the one Master Oscillator, and you can sync the other three (Slave) Oscillators to the master. We can’t recreate this exactly, but can have a very close approximation to it.
The Master (Driver).
What we have in essence is the Master Oscillator (Shaded purple). Why the two oscillators running at the same pitch? One is the controller fixed to provide a pulse output, the second produces the audio (I found that changing the Audio waveform affected the sync operation), and the audio oscillator can have it’s output shape selected without affecting the sync.
Note: The Sync Oscillator should have its Pulse Width plug set to 0 for correct sync operation.
The Slaves.
These are set up just like normal VCOs’ would be, and the outputs of all four oscillators fed to the audio output. There’s no reason you couldn’t put switches into the Sync lines using a button and a Level Adj as a gate to allow you to sync/de-sync the slave oscillators.
There’s more you can do like using the PM Input, or PWM on the Pulse setting, but I have left these out to keep things simpler.
Note: If you select noise for a Slave oscillators’ waveform the sync won’t affect the noise at all. Why would it, after all noise is random anyway.
Note: Adding fine tune to each Slave will affect the Audio output, but all the time they are locked to the master you will not get a “detune chorus” effect. Once you “de-sync” an oscillator you’ll immediately hear things go out of tune.
This is my panel layout with controls added
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