40W stereo audio power amplifier with 2 unbalanced line level inputs on high-reliability gold plated phono (RCA) jacks. A front-panel recessed gain control trimmer permits setting the desired amplifier output level for each channel. The gain range accommodates the range of typical unbalanced audio signal levels. Each of the 2 outputs will drive a 4ohms or 8ohms speaker or multiple speakers connected to present a 4ohms or 8ohms load to the amplifier. The output impedance is switch-selectable on the front panel of the module.