[jdandy]

bvlaw.......I think you would be safer in the long run to install the PS Audio P10 simply because of its higher current delivery capability. I believe the P5 will operate your sound system but there could be a possibility where some current limiting may come into play with the MC501's.

At one point after I first received my first PS Audio Power Plant Premier, the older brother of the P10, I powered my two MC501's with it along with the preamp and sources. The MC501's maximum current draw is 6.6 A at 120 volts, so the pair equals 13.2 A max current. The current draw for the remaining gear I owned at the time, a C1000C/P, MS750, MCD500, MR85, and Sonos ZP90 was 2 A. Powering everything, including the two MC501's would equal a maximum current draw of 15.2 amps, well within a 20 A dedicated circuit's ability to deliver current that the PPP was plugged into, although this equals 1824 watts which exceeds the PPP's 1200 watts maximum sustained output. Maximum load demand for this sound system was generally much less than that because the amplifiers were rarely pushed to anywhere near maximum current demand, and it certainly would not be sustained. I tested the MC501 using an amp meter and discovered that with audio peaks at 300 watts output the MC501's current demand was peaking at 3.5 A. Multiply that times two for both amplifiers and I had a 7 A current demand for both amplifiers peaking 300 watts. That is well above my typical listening level. So, take the 7 A current reading for the pair of MC501's, add the preamplifier and source loads of 2 A, and I only needed 9 A to satisfy the current demands of the entire system's components, including both amps. This 9 A current draw equals 1080 watts, which was well within the 1200 watts continuous output capability of the PS Audio Power Plant Premier. I kept the 501's on the single PPP until I decided to purchase a second PPP just for the amps. That way I was able to keep both amps on a separate dedicated 20 amp circuit and the preamplifier and source components on their 20 amp dedicated circuit. Both the PPP and the P10 have the same 1200 watt continuous load rating. The P5 has a 1000 watt maximum continuous load rating.

Judging from the gear you said will be powered by the newer PS Audio AC regenerator, I suspect the P5 can and will work, but I still recommend the P10. Power reserve is a good thing, even in an AC regenerator.