Powerline Accessory Reviews

The product responsible for the return of PS Audio to the audiophile market was the P300 Power Plant. Introduced in 1999, the Power Plant is essentially a power amplifier designed to serve as the AC power source for audio and video equipment, producing clean, low-distortion 115V/60Hz AC (or whatever voltage/frequency is standard in a particular country). While some people thought that this power-regeneration approach represented overkill and an inefficient way of dealing with noise and voltage variations in the AC power supply, the Power Plant was enormously successful (it was named "Accessory of the Year" in Stereophile's 2000 Product of the Year awards), and I think it's fair to say that it gave increased legitimacy to power-line conditioners as an audio/video product category.

Never a company to rest on its laurels—or to refrain from improving products that others think are fine as they are—PS Audio later came out with various other products to improve AC, including the Ultimate Outlet, a balun-transformer–based passive device, Power Port high-quality receptacles, and upgraded versions of the Power Plant with more power, alternative power-line frequency patterns, and other refinements.

The P500 ($2195) represents PS Audio's latest thinking on regenerator-type power supplies. It includes up to 500W of power delivery (vs the original P300's 300W), a choice between regenerated and filtered AC, isolated power zones for analog, digital, and high-current equipment, and front-panel display of a wide range of monitoring functions. Like the P300, the P500 allows control over output frequency, but whereas the P300's output was sinewave-only, the P500's includes a host of other waveforms, including MultiWave mixtures of specific waveforms, and AutoWave, which selects the waveform in response to the equipment's dynamic needs.

The current version of the P500 (and the P1000) includes MultiWave II+, which has two additional features: an ultraprecise turntable speed control and something called Clean Wave, the latter said to demagnetize or depolarize all equipment connected to it. Clean Wave consists of a special waveform with small "bubbles" in the amplitude of the waveform. Clean Wave is engaged by pressing the appropriate button on the front panel, and selecting the 60-second "cleaning" at the beginning of a serious listening session, or a five-second burst before listening to a CD or LP. (See PS Audio's website for a more extensive description of Clean Wave and what it does.)

My Linn LP12 has its own electronic speed control, so I was not able to use the MultiWave II+, but I did try the Clean Wave function, mostly in its more extended 60-second mode. (I couldn't be bothered using it before each CD/LP. This really needs a remote control to be convenient.) Based on comparisons of CDs played at the beginning of a listening session without having activated Clean Wave and the same CDs played again after Clean Wave, I'm convinced that Clean Wave works. Following Clean Wave activation, the sound was simply more open, with smoother, more liquid higher frequencies.

For owners of earlier versions of MultiWave, Clean Wave makes MultiWave II+ an essential upgrade (it's in the form of a chip that can be installed by the user), and it keeps PS Audio's latest Power Plant products at the forefront of power-line conditioning devices.—Robert Deutsch