Fine Tunes #25
"Jonathan, grounding to a cold-water pipe is fine as long as that's the way the ground path does, in fact, terminate. If your building does not use a cold-water pipe for ground—that is, without a jumper at the meter—then ground floats around the building, so to speak. And that can be dangerous if you find a way, however unlikely, to touch both ground lines, as there may be a difference in potential just waiting to zap you!"
Good point. As it happens, in our old loft building there is a jumper from the service box to the ol' cold-water pipe. Steve also pointed out that if you install a "dedicated" ground rod for your audio system and you live in a house with a "main" grounding rod, there may exist the same difference in potential, thus creating the potential for an unwelcome shock.
"Yup," he continued, "that's because the grounded service conductor (neutral) will be connected to a grounding service conductor (ground), which will in turn connect to a grounded electrode (ground rod). It's true that, to reduce electrical noise, an isolated ground line can be run with the AC conductors through panel boards without being terminated. But according to code, it must be grounded at the main service entrance with the circuit ground conductors. And that would be via the same grounding electrode (or other means) as the rest of the building."
Steve freely admits to using the same "code violation" (250-74 Exception 4) in his own system. He's wired up separate "grounded electrodes" for digital components to avoid contaminating the neutral/ground of what he describes as "sensitive" preamps and power amps. As I've warned many times before in "Fine Tunes," and as Steve confirmed: If you don't know what you're doing, consult a professional electrician.
As long as, once again, I'm nattering on about electrical matters: A while back I received a fax from reader Glen Bartholomew, who thought my recommendation of Hubbell and Bryant duplex outlets was on the money, but might cost too much for budget-conscience audiophiles.
"Leviton devices seem to be often overlooked by the high-end community," he averred. "I have used Leviton hospital-grade outlets and plugs for a few years now and find them to be equal, if not superior, to Hubbell, Bryant, Eagle, etc., as well as being easier to find (at least in the New York area). Their outlets feature triple-wipe contacts and choice of side or back wire. The back-wire option is a hassle-free yet superior system that clamps the entire surface of the stripped end of the conductor like a vise when the side screws are tightened.
"I presently have Leviton hospital-grade receptacles installed on my 20A dedicated line and AC line conditioner. I have also terminated a couple of my component power cords with Leviton hospital-grade plug No.8215-C—the same device Synergistic Research uses on their AC Master Coupler power cord. With these excellent receptacles and plugs used together as a system, the mechanical connection is as solid as it gets. In Manhattan, you can get the full line of Leviton hospital-grade devices at Tudor Electric Supply, on East 48th Street between Second and Third Avenues."
Thank you, Glen, and sorry to have taken so long to acknowledge your informative fax!
Having presented these Final Thoughts on grounding, I'm going to change the channel and continue last month's discussion of do-it-yourself racks and shelves. While surfing Ye Olde Web the other day, I ran across a fascinating Italian site presented by Lucio Cadeddu. Hop on over and peruse the nicely illustrated construction plans for the TNT "FleXy Table," a DIY audiophile rack. Very enjoyably done, as only the Italians can manage, and quite informative. Mimmo Cacciapaglia, who wrote the rack article, suggests MDF shelving of at least 20mm thickness, but in my view you'd be better off with the multi-layer home-brew shelves I suggested in June.
However, Sr. Cacciapaglia also recommends a cracking good tweak that's well worth considering as a finish coat for your audiophile-approved shelving: Noise Killer, a damping compound distributed by Rockford Fosgate, who make in-car amplifiers, speakers, and accessories. Noise Killer is a spray-on material that, as its name implies, controls vibrations; it works very well on audio shelves, according to the good Mimmo. You can even squirt the stuff on audio components! Does that CD player of yours have a resonant case that yammers and rattles when tapped? Fwooosh, and it's All Quiet on the Western Front. (Just don't spray the drawer shut.) The material is nontoxic and, after drying, fire-, water-, and rustproof. Additionally, for all-thumbs DIYers like me, Noise Killer is water-soluble until dry. All you'll need is a damp cloth to remove any excess spray on the treated surface. Naturally, its effectiveness is dependent on the thickness applied; Mimmo suggests that a few millimeters' worth are all that's needed.
I couldn't find the retail price of the 24oz can of Noise Killer on Rockford Fosgate's website. (In an interesting analog to audio, they don't sell over the Net.) Their Dealer Locator for New York picked up The Wiz (a yank-yer-chain I personally find abhorrent) and Canal Audio: (212) 941-7301. I called Canal, and they now carry a different product, called Dynashield by Dynamat. It's essentially the same stuff, and a 20oz can goes out the door for $16.95. I also found Dynashield at audio-etcetera.com, "sale-priced" at $13.95 for a 10.5oz can; and at discountautosound.com, for $10.
Now get out there and start sprayin'!