Kramer Electronics 900 900 is a high performance power amplifier for line level stereo audio signals. It accepts either unbalanced audio signals on RCA connectors or balanced audio signals on terminal blocks and delivers a speaker output of 9 watts RMS per channel into a 4 ohm load. S/N Ratio - 63db unweighted. Output – 4-pin terminal block. Control – Volume. Compact Kramer TOOLS - 3 units can be rack mounted side-by-side in a 1U rack space with the optional RK-3T rack.