Powerline Accessory Reviews

P-300 with MultiWave part 3 My final test of the differences made by MultiWaves came about accidentally. I was playing with various settings, and turned off the system at the end of the day. A friend came by the next day to listen to the system and I fired it up. He was duly impressed, and the sound of the system was certainly very good in general terms, but I was a bit disappointed—the sound just didn't seem as open, as unrestrained dynamically as it had been in the past. I then thought of checking the P-300's display. (In my system, I have the display facing away from the listening area.) It turned out that I'd left the P-300 in the 60Hz sinewave position. I changed the setting back to SS5, and the open, dynamic quality was restored.

As Time Goes By
Regenerating AC makes a lot of sense, and it's hard to imagine any way that powering audio equipment from a low-distortion AC source could create problems for the equipment. However, some people have expressed concern about the use of AC frequencies higher than 60Hz, or any waveform other than a pure sinewave. The question is whether there are any long-term negative effects (eg, premature failure of components) due to the use of higher AC frequencies and/or MultiWave patterns.

By definition, the assessment of long-term effects requires data collected over a long time, and the P-300 simply hasn't been out there long enough. Transformers in equipment plugged into the P-300 do tend to make more mechanical noise when used with higher AC frequencies and MultiWaves, but this appears to be more a source of annoyance for the listener than an indication that transformers are being unduly stressed. The experts on transformer design whom I consulted (including a leading manufacturer of transformers) confirmed Paul McGowan's claim that transformers are not harmed, and may even function better, when fed higher AC frequencies or partial squarewaves. Of course, it's still possible that there are negative effects on other parts of the power supply (eg, diodes), but, again, the consensus among the electrical engineers I talked to was that this is unlikely.

I've had my P-300 (first with the power frequency set at 80Hz, later with various MultiWave settings) in my system for more than a year, with no problems with it or any associated equipment, and I'm not aware of significant problems reported by others. While it's impossible to say with absolute certainty that some problems will not emerge in time, the likelihood of such problems is sufficiently low that I, for one, am willing to take my chances. An ultra-cautious alternative would be to switch the P-300 to your favorite MultiWave pattern only when listening, then switch it back to the 60Hz sinewave position the rest of the time. Just remember to switch back to MultiWave when you're ready to listen!

Upgrade Time
A problem faced sooner or later by every serious audiophile is deciding what part of the system is most in need of upgrading and what kind of upgrade would represent a significant sonic improvement.

What if you have a system with no single weak link, no clearly identifiable sonic deficiency, but you'd still like the sound to be better, more like live music? Replacing components willy-nilly may result in a sound that's different but not necessarily better, and the process is likely to be quite costly. If you like the basic sound of your system but want to raise the level of realism a good notch or two, I can think of no better way of accomplishing this than by investing in a PS Audio P-300—or, if its 300W output is not enough and funds permit, a P-600 or (when it becomes available) P-1200. The basic P-300 is still available for $995, but MultiWave makes such a difference that I consider it a mandatory option well worth the extra $250.—Robert Deutsch