well, it's a mixer. so most of this is self-explanatory: just six audio channels with (from top to bottom) trebble, mids, bass, volume and mute. The big knob on the underside is probably master volume, the LED strips are gain, the LEDs with the headphone and the knob beneath them are probably for the headphone volume. seems pretty straightforward except for the FX part - if i had to guess, the blue I is "up", the orange II is "down" in the FX menu.

what worries me more is that this thing looks as frail and wobbly as i'd expect from Teenage Engineering, and that all these knobs are absolutely tiny.