Use in any application requiring mixing of two audio sources. A mic may be mixed with a line level music source. Two mics may be mixed to feed the mic or line level input of a power amplifier. A mic or professional +4dBu line level mono sum is possible. It may be used to convert mono line level signals from consumer to professional, or from professional to consumer format. It may also be used as a microphone preamplifier, or conversely to adapt unbalanced or balanced line level signals into the microphone input of other equipment. Unit requires a 24~33VDC, 60mA ground referenced power supply.