Arturia MatrixBrute User Manual page 14

Press PRESET, and the button will turn purple.
Push a button to load a Patch so you can play the instrument. Adjust the output
and/or headphone levels, and fine-tune the pitch.
( Be sure the Panel button mentioned above isn't lit, or you won't be listening to
the Preset .)
MatrixBrute stores 16 banks of 16 Presets (total 256). The banks are rows A - P
on the left, Presets within each bank are in columns 1-16. To select, say, patch B3,
go two rows down and three columns across; B 03 will appear in the numeric
display.
(The Matrix is also used for the 64-step pattern sequencer/arpeggiator, and when
you push MOD it becomes the electronic patchbay.)
8 Arturia - MatrixBrute Manual - Getting Started with MatrixBrute