GAIN AUX/FX [left] - Controls gain of AUX/FX inputs. While AUX/FX switch is placed in AUX, the gain control can be used to adjust the level of the incoming AUX input. While the AUX/FX switch is placed in FX, the gain control becomes a wet/dry control for the FX return.

GAIN PGM 1&2 [center, right] - Controls the gain level of each input channel.