Fine Tunes #14

First, my thanks to HI-FI '99 attendee John Loveless (, who thrust a handwritten letter into my hands just after a particularly enjoyable "Grill the Editors" session:

"I enjoy 'Fine Tunes'!" it began, catching my attention immediately. "However, I do cringe a little at the suggestion of RadioShack power strips." He included a copy of an article from Canada's Ultra High Fidelity magazine, entitled "Down with Power Bars." It wasn't about snack food.

Loveless makes a good point. I've collected a number of the previous-generation, metal-bodied, Archer-branded power extenders, and they aren't really all that awful. But John is right, the newer RadioShack molded-plastic jobbies aren't much use in an audiophile system.

There are well-made, purpose-built power strips on the market, but they're not cheap. My paradoxical brief is to ferret out real audio improvements for zero or minimal cost; if you know what you're doing, then by all means roll your own. (Ever that proviso; Stereophile accepts no responsibility for injury or death from following the subsequent instructions.)

Putting a do-it-yourself power strip together is easy. All you need is a metal outlet box typical of those found set into your walls, or one made of thick, high-impact plastic. Then get a few Hubble, Bryant, or Eagle hospital-grade duplex outlets (about 15 bucks at The Cable Co.) to populate your box. Wire them up as explained in the April "Fine Tunes": screw down the connections, hard-wired ground, strain relief, etc. Slap on a cover plate and you're done.

You can build a few of them, as Kathleen and I did. The bare-metal box---especially with orange, hospital-grade receptacles---makes for a high-tech, loft-style, strewn-about-the-floor look that still offers tight, close-coupled connections. Good-quality 14-gauge three-conductor cable with industrial-chic connectors finishes up the Soho look. If you'd rather be shot dead than look Soho, there are plenty of acceptably domestic AC cable extenders from Cardas, Esoteric, JPS, and others.

Ideally, you want a star-wired power extender. That is, each duplex assembly carries all three connections back to the supply cord: hot, neutral, ground. But many of you might not want to get that elaborate. In that case, use good-quality jumper cables to daisy chain the outlets in each box, and remember to plug the component that draws the most current into the "front" outlet in the box nearest the cord for maximum power transfer. Apply felt or Teflon footers to the bottom of the box if you're fastidious or have nice floors to protect.

While I'm off on this little electrical shunt, I've got another good one for the nascent homebrewer in you --- but once again, only if you know what you're doing!

A pair of Jadis JA-200 monoblocks nested here for some time, with one of the chassis' AC supply wired electrically out of phase with the other. Now, the difference in sound between correct and incorrect electrical phase can be astonishing. In such a situation, you can, as I did, make your own electrical phase switcher(s) with a short run of good-quality 14-gauge copper three-wire and a pair of connectors, as above. Just reverse the electrical phase in one of the connectors and maintain the ground connections. This works a lot better than cheap cheater plugs, which cheat you of good sound while lifting the ground, perhaps inadvisably so.

Then again, if you just have to electrically float a component, using this switcher would be a convenient way of doing so while maintaining good-quality connections throughout. This time, leave the phase intact and lift the ground at the IEC end; whatever rogue currents are riding the ground plane should drain back into the receptacle and not into the component's chassis. Of course, defeating the ground can lead to some shocking problems, so watch what you're doing. Needless to say, I don't recommend it.

And speaking of ground, here's a "This Old System" tip for do-it-yourselfers accepting the Death and Destruction clause in these electrical meanderings. I've mentioned our hard-wired grounds on several occasions, but never drew you a map. As you may recall, we have two sets of quad hospital-grade outlets; eight at 20 amps for front-end components, and eight receptacles at 30 amps for the amplifiers. Each line gets its own run of BX cable back to the breaker-box, the bigger line on a heavier cable. As the lines run almost parallel, their ground potentials remain close, thus avoiding hum.

Here's what we do: Hard-wire thick, good-quality solid-core copper to the ground screws of each set of outlets, and "loom" them into a single line that runs back to a solid fitting on a cold-water pipe snaking through our walk-in closet. As our hundred-year-old loft building doesn't suffer a modern, plastic coupler to the city water supply, we wind up with a fairly good ground path.

That about taps me out on the raging electrical storm that powers your system. Next month we'll return to resonance control and its effect on your audiophile life.

Share | |
Site Map / Direct Links