Level (Loud) controls the distortion output level of your guitar signal.
Low adjusts boost and cut of bass frequencies
High adjusts boost and cut of high frequencies.
Gain (Grunge) controls distortion gain from moderate to extreme.
Dual Outputs. The Amp output is for connecting directly to a guitar amplifier. The Mixer output’s Cabinet Emulation circuitry gives you an authentic miked guitar amp sound when plugged direct into a mixing board or recording device.