This is an early model of a TRILOGIC-based preamp with multi-functional tone controls. Please check the photos for the condition. I am selling it to organize my equipment that has been stored in a closet. It powered on with batteries and produced sound. I believe the adapter was 18v, but I don't have one to test it. I can check it if needed. - Model Name: TRILOGIC - Country of Manufacture: USA - Controls: GAIN, VOLUME, LOW, MID, HIGH, LOW MID, HIGH MID - Connection Type: Passive/Active Switching - Input/Output Terminals: IN, OUT Thank you.