If you look at the specs of most stereo integrated amplifiers, the rated RMS power output is between 60 watts and 120 watts per channel. This is lower than the power output of outboard power amplifiers, which typically are about 125 watts to 300 watts per channel. Monoblocks go all the way up to 2,000 watts output. One of the main reasons for this is that in an integrated power amplifier, the preamplifier circuit is situated very close to the power amplifier. Keeping the high voltage, high current power amplifier signal from inducting noise into the preamplifier circuit is difficult. NAD apparently has solved this problem with the introduction of their M3 Integrated Amplifier, which has a rated output of 180 watts per channel, at 0.004% THD+N, and clipping (1% THD+N) at 220 watts.