The Matrixbrute doesn’t have built in AM (“ring mod”) per se, just FM, but you can make one in the Matrix with a couple moves. The basis is that LFO3 tracks VCO3, divided down several octaves to where goes at sub audio rates. To get it up to audio rates, set it to the highest subdivision, 16’ (in vco 3 area), crank up the vco3 coarse tune to +2 octaves, and jack up the keyboard octave +1 or +2 octaves. Then tune down VCO1 and 2 (or use the sub oscillator), to get back to a normal range. With the lfo3 going at audio rate, you can make AM by routing lfo3 to the VCA destination.
It also worked and sounded good just modulating the Steiner Volume or the Ladder Volume, if you make either of those a custom destination in the mod matrix, if you want to have one ring modded oscillator mixed with one clean oscillator.
Some great, classic Sci fi ring mods can be had, I liked modulating the LFO3>VCA amount, by assigning that matrix connection to one of the custom matrix destinations, so I could use ENV3 to change the amount of ring mod, fade it in, etc. I liked the sine and triangle wave for VCO3, for classic ring mod. Fun to have the mod wheel turn the pitch down on VCO3, to take the mod from ring mod slowed down sub sonic frequencies to a fast tremolo. Adding in the audio mod sections VCO3>VCO2 FM was good, and bedlam starts modulating that FM amount with an LFO.
