Music in the Round #12

Ever since I installed dedicated power lines for my multichannel system, I've been wrestling with the issues of surge protection, power conditioning, and voltage regulation. I start with a bias based on decades of happy listening without being concerned about any of these problems, and my belief that competent electronic components must be, and are, designed to perform in the real world. After all, whether the device's AC power supply is a traditional transformer-bridge-reservoir or a switching supply, its output should be a DC source that is sufficient to let the active circuitry meet its specifications. Many manufacturers, such as Bryston, recommend bypassing any line conditioners and plugging their components directly into the AC outlet.

Despite the rarity of lightning strokes and catastrophic power surges in my neighborhood, my primary concern is protecting the money and passion I've invested in my system, which makes a lightning suppressor or Transient Voltage Surge Suppressor (TVSS) essential. A TVSS should be installed at the main circuit-breaker box, which should place it less than 10' from the main house ground and with almost direct access to the earth. This will minimize the chances of surges taking a destructive detour through your equipment, and the proximity to the main ground is what gives a TVSS the advantage over any plug-in or local device. If you live in an apartment complex, a TVSS should be provided at the main service entrance. If you live in your own home and you don't have a TVSS, call your electrician.

Good protection at the service entry and house ground is crucial and, in most cases, probably sufficient. However, according to power companies and manufacturers of power-protection gear, 1) the thresholds for a whole-house protectors are fairly high (500V or more), to prevent them from being triggered by minor power-line perturbations; 2) damaging surges can also enter via phone, cable, and satellite antennas; 3) surges and transients can be generated by appliances in the home; as a result, 4) local protection is needed to ensure the survival of valuable components.

Most surge protectors include other features, most commonly EMI- and RF-induced line-noise filtering and protection from brownouts due to low line voltage. My prejudice is that there's no need for a cure if there's no illness. I worry that adding superfluous devices might as likely worsen as improve the sound of my system.

First up in my survey of surge protectors was the BrickWall PW8R15AUD ($249), a small, solid black block with eight outlets (six switched) in four filtered banks, a circuit breaker, a power switch, and a captive 14-gauge AC cord (footnote 1). It's rated for 15A loads and is based on series-mode principles. A series-mode design (explained in detail at BrickWall's website) passes the AC through an inductance whose reactance inherently blocks transient surges. Supporting components serve to switch and dissipate the stored energy to the neutral line and to clamp the output within safe limits, nominally under 172VAC. Nothing is destroyed in the process, making the BrickWall quite durable. The AUD version differs from the standard PW8R15 ($219) in having isolation between the banks of outlets.

With my Bryston 9B amplifier connected directly to the 20-amp AC receptacle on the wall and everything else plugged into the PW8R15AUD, the system sounded the same as ever. I was concerned that the series mode might be a drag on dynamics, but that didn't happen. I added the power amp to the PW8R15AUD's load and was still fairly happy, though I suspected some dynamic compression at very high levels. Perhaps I imagined it, but I tended to not play things as loudly when the PW8R15AUD was running everything. What I got from the BrickWall was a complete sense of security that my equipment was safe from catastrophic insult. What I didn't get was any improvement in the system's performance, which was as good as ever. So: one upside (protection) and no real downsides with the PW8R15AUD, but consider one of their 20A units if your wall socket has the juice.

The next device is also series-mode, but designed with big A/V systems and audiophiles in mind. The Empower EM2100 ($1750) has a handsome, 19"-wide chassis with three isolated banks of four protected, switched outlets each, and two "always on" outlets on the rear panel. The 14 color-coded, hospital-grade receptacles can be sequenced for power up/down, and additional Empower units can be connected for coordinated operation. The rear panel also has a circuit breaker, a terminal block for hardwire control, indicator connections, and a tethered JPS Optimized Field Matrix power cable and plug. The milled aluminum faceplate has a power switch and LED, recessed programming controls, and a beautiful blue three-line LCD display. The EM2100 can be programmed from the display that normally reads the line voltage. Over all, this is an extremely sophisticated and flexible power control center for a very large and complex system.

Empower's description of the EM2100 emphasizes the parts selection, the soft turn-on to eliminate inrushing current overloads, and the device's adjustable out-of-range shut-down settings (90–110V for low cutout, 130–150V for high cutout). However, the main protection specs look similar to those of the commercial units from Empower's sister company, Surgex, as well as those quoted by BrickWall.

In operation, however, the EM2100 scored over the BrickWall in several ways. First, having four outlets in each isolated bank, meant that I was able to efficiently organize various components, separating digital from analog and video from audio. Second, the Empower could be programmed to power up different components in sequence to meet my specific needs—for the first time, I could say to my wife, "Just push that one button to turn the system on!" Third, I really liked the digital line-voltage monitor. Yeah, I could have used any AC voltmeter, but this one's easy to read and told me that my line voltage rose throughout the day, from 113V in the early morning to 121V in the late evening. The system always did sound better at night—and I thought it was the cognac! Finally, the Empower EM2100 lowered the quiescent system noise level just a little, probably due to the more coherent filtering arrangements between the various components. Did it sound better? Not really, but it sounded just fine—although, as above, I preferred to power the Bryston 9B independently.



Footnote 1: Because the cables on the BrickWall and Empower units are fixed, all units were auditioned with their stock power cables.
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