It works fine with batteries, but the AC adapter has poor contact. It might be a problem with the adapter itself. I'm selling it at a low price. Multi-functional direct box with sound quality adjustment. - Brand: L.R. Baggs - Model Name: venue - Controls: bass, mid, high, notch, tune, volume - Input/Output Terminals: input, output, boost, mute-tune - Power: 9V DC 300mA Thank you for looking.