[DCO-1] knob (OSC1 LEVEL) 
Adjusts the volume balance of OSC1.
[DCO-2] knob (OSC2 LEVEL) 
Adjusts the volume balance of OSC2.
ENV (MIXER ENV DEPTH) 
Adjusts the depth to which the envelope specied by 
MIXER ENV MODE controls the OSC2 level.
[DYNAMICS] button (MIXER DYNAMICS) 
Adjusts the sensitivity at which the velocity controls the 
depth of MIXER ENV.
[MODE] button (MIXER ENV MODE) 
Selects the envelope that is used as MIXER ENV.