Pulled from a doner Yamaha R1000. In my electronics lab, the amplifier module was repaired and tested using my R1000.  According the the Yamaha's specifications the output power on both channels is 100 watts with less than .01% distortion.  On my HP339A distortion analyzer, I meanured .0085% distortion at full volume (About 150 watts into an 8 ohm load).