Class D amplifiers like allot of on-demand current and they do not like voltage sags. The power supply consists of two high current parallel rectifiers. Together, they are rated for 50 amps. That's more current than will ever flow through them, but there's more to it: Diode junctions have resistance. At low voltages, there is a significant drop across these junctions. When in parallel, resistance is dropped in half. That means the amplifier gets a stable voltage and current source.
The power supply is point to point wired using short runs to further reduce resistance. Lines containing AC are on the opposite side of the chassis from the audio circuits and kept very short as well. The filtering section is just the right size, so that hey can keep up with the amp's power demands while not taking too long to recharge after transients. Filtering stages are not much use if they're too big or small. It's always better to err on the side of too big, but it is completely unnecessary. I like the power supply to be fast and well regulated.
