Input Select - Used to assign the Mic/Line 3 channel to either the Mic input or the Line 3 input.

LINE 3 INPUT - This extra line level input can be selected with the Input Select switch and can be used as an extra line input or as a session input for team routines.

MICROPHONE INPUT - 1/4" connector

MIC / LINE 3 LEVEL CONTROL [on faceplate] - Controls the output level of the microphone/Line channel.
MIC / LINE 3 EQ - Individual controls for low and high frequency equalization with (+/-10 dB)