A line input Volume control allows level matching and mixing between the music source and the mic. Use it with MP3 players, computer audio outputs, DJ mixers, etc. in banquet halls, gymnasiums and party houses. Works with both dynamic and condenser microphones and passes phantom power from the sound system to the mic input. Line signals are input via a 3.5mm stereo or RCA jacks. The mic input is a balanced female XLR. A Ground Lift switch breaks the ground connection between the inputs and the transformer balanced output screw terminal.