Kramer Electronics 903 903 is a high performance integrated personal stereo amplifier for unbalanced stereo signals. It allows selection between four inputs and delivers a speaker output of 10 watts RMS power per channel into a 4 ohm load. S/N Ratio - 68dB (unweighted). Highly Efficient - Class D Operation. Inputs - 3 stereo on RCA connectors and a single 3.5mm stereo mini-plug. Outputs - 1?4inch Headphone jack and terminal block for speakers. Control - Volume, bass, mid, treble, balance, and loudness. Compact Kramer TOOLS - 3 units can be rack mounted side-by-side in a 1U rack space with the optional RK-3T rack.