This circuit is a 3-input MONO mixer with independent level control for every input. It also incorporates separate BASS and TREBLE controls. It can be used with SMART KITs 1023 and 1024 to make its inputs sensitive enough for MICROPHONE and P.U. Suitable power supply is the SMART KIT 1068. Operating voltage: 18VDC. Input sensitivity: 150mV. Max. current: 100mA.