PS Audio P300 Power Plant The PS Audio Lab Cable
The way Paul McGowan tells the story on PS Audio's website, the Lab Cable was developed because of a need to have a sonically neutral power cable in the reference system used for the final voicing of the Power Plant. They tried a number of power cables, from off-the-shelf shielded Belden to $2000/meter audiophile cables, but found each had distinctive sonic characteristics.
So they decided to build their own, based on two principles: minimum resistance/impedance and maximum shielding. They used 6-gauge, 1057-strand copper wire for each conductor, and triple shielding: aluminum foil around each jacketed conductor, copper braid over the foil, and a single braid over both shielded conductors. Then, to mechanically isolate the cable from vibrations, they wrapped the whole thing in Sonex. The result was exceptionally ugly, but had a lower sonic signature than anything else they'd auditioned.
The Lab Cable is a production version of that prototype, with the same electrical/mechanical characteristics but in a more attractive form. The cable is fairly stiff, but not unmanageably so. The male plug is hospital-grade, made by Marinco; the female is Kimber Kable's Wattgate brand IEC, designed by Kimber and made by Marinco.
The Lab Cable's most distinctive design aspect is the emphasis on shielding. McGowan argues that a power cable, like any piece of wire, has the potential to act as an antenna, both picking up RF and broadcasting it in close proximity to the audio system. He points out that all audio equipment, especially anything with a diode bridge/capacitor power supply, produces major bursts of radiated energy at the time of peak charging. The Lab Cable's triple shielding greatly reduces its tendencies to pick up and radiate RF. It's important to note that one end of the Lab's shield is connected to the AC socket ground; without this, the shield would become an antenna, making things worse.
The Lab also allows the electrical ground to be disconnected (a simple matter of pulling apart two wires linked with a connector) while maintaining grounding of the shield. Electrically, this is the equivalent of a "cheater" plug, used by many people to eliminate ground loops. While convenient, such cheaters are in violation of the electrical code in the US and Canada, and can result in death from electrical shock in the event of insulation failure in the equipment. A separate external ground, through a grounding post, is acceptable under some circumstances, but is not recommended. In my system, disconnecting the P-300's electrical ground yielded little sonic benefit; I played it safe and kept the ground connected.
Six feet of Lab Cable installed between my wall AC socket and the P-300's IEC socket did yield significant sonic benefits, especially when compared to the stock cable. (The TARA Labs Decade AC cable that I normally use was a closer sonic match.) The main difference was in noise level, which was noticeably lower with the Lab—music emerged from a background of greater silence. There was also an improvement in bass definition and overall transparency.
The improvements from use of the Lab were lower in magnitude than those from use of MultiWave or the Power Plant itself, but were definitely worthwhile. A 6' length of Lab Cable is $400, with other lengths available. Given the quality of materials and construction, the price is more than fair, and there are full return privileges. I'm told that a Mini Lab Cable will debut in November, with the same construction but using 10-gauge wire and fewer strands, and costing $150 for 6'.—Robert Deutsch