Fine Tunes #8

Bill Gates would have you believe we live in a plug'n'play world. Apple has proselytized same since day one. But I'm here to tell you it just isn't so for high-end audio. The orientation of a component's AC plug—even the quality of the wall receptacle itself—affects the sound! Oh no, Mr. Bill, not something else to futz with! Will it never end?

Alas, it will not. Understand that all the elements I've told you about so far—speaker placement and room modes, cable hygiene and dressing—have a cumulative effect that pays off big time when you plunk yourself down in the sweet spot and turn your attention to the music. This is as true for systems most modest as it is for monstrously expensive installations that ought to sound like a million bucks, but rarely do. Throwing money at them isn't the answer.

You can say that the higher a system's resolution, the more your attention to such matters pays off. But it's also true that modest systems can open up and deliver the musical goods in a very satisfying manner when put together with sensitivity and attention to detail.

Let's begin with the basics. Most audio components are equipped with a three-pronged AC plug. Holding the plug with the pins facing you and the rounded ground pin on the bottom, the blade on the upper left is hot, the one on the upper right is neutral. The ground pin connects the ground from the wall receptacle to the component's chassis. If AC voltage shunts to the unit's chassis because of an electrical fault, the chassis shorts that potential to ground and trips the breaker, in the process saving you from becoming like unto burnt toast. Hot and neutral are connected to the component's power transformer, which usually leaks some current to ground. The amount of leakage depends on the orientation of the plug: one way will produce less than the other and, in most cases, sound better. But nothing is absolute; as always, use your ears.

Before we delve into plug orientation (footnote 1), I suggest making sure your outlets are wired correctly. This can be checked with a $5 circuit tester found in most hardware stores. You plug its three prongs into the outlet, and a series of LEDs on its molded body tells the tale: open ground, hot/neutral reversed, and so on. Correct if necessary, if you know what you're doing. By that I mean: kill the juice at the breaker box, then test again to make sure the AC isn't still waiting to bite you. Don't take it for granted that the upper and lower sockets in a duplex receptacle are on the same circuit, especially in older buildings.

Take our loft, which started domestic life as Kathleen's live-in photography studio, and before that was a ribbon factory. She asked the guys doing the electrical work during the conversion for a good outlet for her strobes. That's what they gave her, all right: two separate lines from the breaker box, wired to the upper and lower outlets of a single duplex receptacle! "Of course I shut off the breaker, Kathleen. What do you take me for?" Zottt!

While you're at it, I also recommend the use of hospital-grade receptacles, for their higher-spec construction and tighter contacts. Screw-down connections are always better than spring clips, and hard-wired grounds will also provide superior performance. But don't fool around with it if you're not confident of what you're doing. If you have any doubts whatsoever, consult an experienced audiophile you trust, or arrange for an electrician.

That said, our own hospital-grade dual-quad receptacles were fitted by yrs trly and friends, K-10 dragging the two BX cables between ceiling and roof to the breaker box. What a babe; she came out looking like she'd been up a chimney.

Another way to quickly check your outlets is with a small penlike device that can also be found in most hardware stores. (My Pyramid VoltProbe VP-400 set me back around $12.) Basically, you touch the tip of the probe to the hot side of the AC plug in a wall receptacle, which should light up the tip of the probe. Touch it to the neutral side and nothing happens. Remember, facing the wall socket, hot should be on your right.

There's something else you should know. The AC supply to the home comes from a center-tapped transformer on the pole outside. Other than for clothes dryers and space heaters, the 220V balanced AC is split into two 110V unbalanced sources. Most audiophiles don't realize that there's usually more than one leg of positive AC phase in their homes. There are most often two, one from each side of the outside transformer, so your tester may indicate that you're wired up fine, but for really good sound you have to dig deeper.

Before we installed dedicated outlets, I mapped every socket in the area around our system. Why? For best results, your components should all be on the same leg of positive phase. Let's say that, depending on the design of the associated components—their power supplies and the way in which current flows through them—keeping everything on the same phase of positive can be less troublesome than not doing so. Your goal is to always keep the difference in voltage potential between chassis and ground to a minimum.

Testing for positive phase is simple and requires nothing more than a humble RatShack voltmeter. Set the meter to AC Volts, and drive the positive probe into the hot receptacle of one outlet and the other lead into the hot receptacle of another duplex outlet. (An extension cord to the remote socket makes measurement easy.) If both outlets are on the same leg of positive phase, you'll read 0V, or a value very near that. If they're not on the same phase of positive, you'll see 240V or thereabouts.

In the next several "Fine Tunes" I'll discuss grounding your system, techniques for finding the plug orientation with the lowest current leakage, and how to deal with ground-loop problems. I'll also cover prewar buildings equipped with only hot and neutral outlets, no ground. And further thoughts on running components—including amplifiers—on separate dedicated lines, or with everything on the same circuit. The whole shocking truth, Geraldo. Now it can be told.



Footnote 1: Detailed in the March 1999 "Fine Tunes."
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