The power output of the amplifier is rated at 120W RMS for the subwoofer and 40W RMS each for the two satellites but at a horrible-sounding 10% distortion. Nobody listens to music when the amplifier is clipping like mad and producing horrible 10% distortion. It begins to clip at a total of only about 160W. Don't forget that in addition to the 160W of output there is an additional amount of maybe 160W of heat. Then the transformer must be able to supply 320VA if the amplifier plays at full blast all the time.