Richard Gray's Power Company 400S AC line conditioner:
Page 2 Gray's Anatomy
In the "Gray Paper," which "contains some technical Information, some not!," Richard Gray, "Partner and Inventor," describes how he "re-invented" power. Ahem. He points accusingly (and correctly) at the rumba line of modern devices hung on the AC line these days, to mix metaphors! The problem is the rabid, high-reactance load of modern electronics, which top up their capacitors at the top and bottom of the 120V, 60Hz AC sinewave, but only there (footnote 1). Like little starving piranha, the sudden multiple reactive loads create a sort of fizz at the top and bottom of the waveform, where the dinner bells rings. That's also where you'll find asymmetric notching due to uneven loads. And since you and everyone else on the party line insist on pulling maximum juice for all the contemporary electronics we take for granted, the waveform can wind up with a top as flat as the Intrepid's flight deck. Not to mention that capacitors then can't charge to peak voltage. The end result is some percent of harmonic distortion riding the line.

Devices such as the 400S, as well as others now on the market, attempt to "fill in" and smooth out the hashy distortion: power-factor adjustment, the buzzword of the day. Gumshoeing around for this review and "Fine Tunes," I've learned some amazing things. Did you know the public utilities use large capacitors to resonate the AC line to present a more "old-fashioned" and resistive load? Do single-ended guys know something we don't?

Mr. Gray further stipulates that resistance in the line robs the music of dynamics, and that any series devices—air-core chokes, isolation transformers, sinewave regenerators—just add resistance to the AC line.

So, all the rest of you power conditioners out there—forget it. You're not needed. Buh-bye.

But maybe not so fast...

Another flywheel!
So how does this thing work? As explained by Gray, "an inductor...resists changes in current flow in the circuit by storing energy in a magnetic field. When current flows through the inductor, a magnetic field builds up in the core and around the coil. When this current ceases, the magnetic field collapses and returns the stored energy to the circuit. Theoretically, the current in an inductive circuit lags behind the voltage by 90 degrees; realistically, the lag will always be a little less due to the small amount of resistance in the coil of [the 400S]. It is this lag that allows it to perform as a reservoir of current available to the circuit during the time period when the AC line is dropping."

Transients are said to be aided by this energy stored in its "proprietary" core. "Simply put, this effect is very much like that of a flywheel used in mechanical equipment. It extends the charge time during which the power supply in an electronic component can replenish its stored energy. What makes my RGPC unique is its ability to 'fill in' the AC line when demand momentarily overcomes supply and tends to 'even out' small line anomalies (footnote 2). This process suppresses or quenches the reflected back EMF or 'fingerprint' of the equipment connected to it. Although back EMF is usually small, it is nonetheless damaging to the quality of the reproduction and interaction of audio/video equipment."

As regards surge protection, Mr. Gray Provides. "We have one of the most effective surge-protection systems available, and [it] has proved to be completely invisible to eyes and ears. It is designed to blow its internal fuse whenever a surge greater than 280V hits your system."

Delores, tell everyone in the waiting room to go home. All positions are filled.

Methodology
I tried my four review samples of the 400S every which way but loose. On the amplifier side, I used them mostly on the Lamm ML1s (see review in the May 2000 issue) and the dual-mono Forsell Statement, an amp that has always been very sensitive to mains quality. I also tried them with the Linn Klimax, but the Linn's new-age switch-mode power supplies aren't affected by the quality of the incoming mains AC. I used one 400S in parallel with each channel of the amp(s), then added them, one by one, until I'd reached the maximum of four. I tried plugging the amps directly into one 400S, with a second one daisy-chained to it. I also used a high-quality Cardas power extender on the amps, and plugged in one, then two, then one paralleled pair, then two paralleled pairs, allowing for "quick switch" comparisons. (During play, I could plug one in, plug a second into it, add another to the extender, then plug another 400S into the second one. I even tried them all stacked up one into the other. My back, my back...)

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Footnote 1: And it's far from a perfect sinewave at that, as covered extensively in my "Fine Tunes" column, available in the "Archives" section of www.stereophile.com.

Footnote 2: Paul McGowan of PS Audio covered some of this ground in his interview in the May 2000 issue of Stereophile (pp.50-59). The question is: how much energy storage is necessary to restore the flat top of the AC waveform to its correct peak value?—John Atkinson