**********REALITY CHECK***********
If you have a 20 amp dedicated line (and most homes have only a 15 amp line), the maximum power you can get from that line, assuming the amplifier is 100% efficient is 2,400 watts. Digital amps are usually 85-90% efficient assuming they use a switching power supply. Most audio class-D power amplifiers do NOT use a switching power supply for several reasons having to do with current capability and UL and European approvals, so the overall efficiency is more likely to be around 75-80%. This would yield a maximum power of around 1900 watts with a 20 amp circuit or around 1440 watts with a 15 amp circuit. In addition to that, there is significant power line sag on every circuit, especially in a home. That is why when during development of our power amplifiers, we use a very large variac which runs on 240VAC and has a current capability of something like 50 amps in order to keep the AC line at 120VAC even when the amplifier is running at full power.
The power capacity of home outlets is also a reason why the larger ATI amplifiers have two independent AC power inlets (usually 20 amp IEC), and two independent power transformers. These two inlets are intended to be run each on its own dedicated AC circuit, preferably on different phases of the incoming AC service.
Some of the really big amps with as many as 16 channels for cinema application which we make are designed to only be run on 240VAC, and these also have two independent AC inlets and power transformers.
