The Digital Signal Processing that PS Audio uses to generate a new AC sinewave in the Power Plant models has a 16-bit, rather than 8-bit, DAC. They have also improved the software-based phase locked loop (PLL) circuit to make the Power Plant more tolerant of phase issues. The new regenerator can also cope with a wider range of incoming voltages: it can deliver a steady 220 to 230 VAC, while the power coming from the wall can vary between 190 and 275 VAC. However, I doubt that most of us in the UK see even a ten per cent swing. While the technology behind the regeneration process is digital the output stage is essentially a Class A/B analogue power amplifier that, in the case of the P5, has a 1250 VA output.
The P5 is the middle model in the range and has four outputs for source and preamp type products, and a high current one for power amplifiers. I note that the US version of the P5 has eight outlets, on account of the smaller size of North American mains sockets. It always amuses me to see hawser size power cords struggling to stay connected to the tiny wall sockets at US shows. Also on the back panel are 12v trigger in/outputs, a reset button and a fuse.
I’m a reviewer and a man. That means manuals are for other people. Sometimes this laissez faire approach to technology can bite back. The Power Plants are very particular about the way they are used. You can’t switch it on and plug components in; rather you have to plug everything in with the power switches off and then switch on the P5, allowing it to boot up prior to switching on the system. Bad things happen if you do it the other way, as I discovered when I (eventually) read the manual.
I started off the assessment by hooking up the Akurate DSM streamer/preamplifier on the front of Linn’s Artikulat Aktiv loudspeakers. Having power amps in the speakers meant these could not be used with the P5’s single high-current outlet. The result was nonetheless quite obviously an improvement over standard mains. The sense of space and reverb on John Campbell’s Down in the Hole made for a larger image with excellent depth. The area where mains improving devices often fall down is timing, but this did not seem to suffer with the P5 inline. In fact, it was marginally improved. The extra openness clearly applies to elements other than image and the more I listened the clearer this became.