Synthesist Enrique Martinez, aka Ricky Tinez, shared this video, explaining his approach to using a synthesizer’s mod matrix.
Martinez demonstrates mod matrix concepts using the Novation Peak synthesizer, but the ideas are applicable to other synths that feature a mod matrix section.
The concepts are also applicable to modular synthesizers, where you manually patch modulators to modulation inputs, and use attenutators to control how much modulation you apply.
Demodulate your mystery matrix synth.