3 - Understand cross modulation
A simple modulation is osc 1 which modulates osc 2 at the output :
A cross modulation is a loop : osc 1 which modulates osc 2 which modulates osc 1 which modulates osc 2 … we understand why the sound quickly becomes noise if the feedback level in the loop is high.
I tried to summarize the modulation setting on a graph :
I will put examples of sounds later.