Sound Application XE-12S Power Conditioner

by Marc Mickelson
Editor-in-Chief, Soundstage

Power conditioners come in all shapes, sizes, technologies and prices, and few audiophiles, if any, eschew their use completely. In fact, we often mix and match depending on application and the perceived problems with the power that feeds our systems. Over the course of my time as a card-carrying audiophile, I’ve used and reviewed a number of power products, and while I can say that almost every one of them improved the sound of my system, I can’t say that all of them were worth the money they cost, especially when a speaker upgrade could effect a more noticeable improvement. No, power conditioners are for those who like what their systems do intrinsically; they are not Band-Aids for poor-sounding systems.

But one limitation of various power conditioners is the number of outlets they offer and thus the amount of equipment you can plug into them. There is no such problem with the Sound Application XE-12S, the latest iteration of Jim Weil’s carefully crafted conditioner. The XE-12S offers a half-dozen outlets for both analog (including amps and preamps) and digital components. A single XE-12S can thus accommodate most A/V systems with outlets to spare.

Each XE-12S is completely point-to-point wired and hand built, a process that reportedly takes 12 hours per unit. The chassis is made of hydraulically bent aluminum, which cuts the number of chassis pieces down to two and makes for a cabinet that Jim Weil claims sounds better than those of his earlier designs. Weil also says that smaller cabinets don’t sound as good, which is why the XE-12S has a dozen outlets: There’s room given the size of the cabinet. The XE-12S uses special 6N wire imported from South Africa to connect its various components, which include special Hubbell duplex outlets, custom Caddock Ultra Precision resistors, and a proprietary 11-stage surge-suppression circuit that Weil will say little about other than “it uses an RC network and varistors.” The bus bars used in the XE-12S are solid OFE copper that’s 99.99% pure — the same copper that NASA uses. Weil polishes each bar on a lathe and with three different compounds as such surfaces are reported to sound better. Only one connection in the XE-12S is soldered; the others are cold welded, which, once again, Weil says makes for better sound. When building each XE-12S, Weil works in an argon environment to eliminate all surface oxidation. “This really makes a difference,” he says.

The XE-12S requires a 20-amp power cord, but it is not shipped with one. Weil recommends any of those from Elrod Power Systems. The XE-12S measures 20″L x 6 1/4″W x 3″H and weighs roughly seven pounds. In addition to the dozen outlets and 20-amp IEC on top of the XE-12S, there is a Carling Switch magnetic circuit breaker that acts as an on/off switch for the entire unit.

How does the XE-12S do its work? First, its design and build are meant to provide the greatest transfer of power to your audio equipment. Weil has gone to great lengths to choose materials and construction techniques that optimize this. In addition, the XE-12S is said to provide “the greatest EMI and RFI filtration across the broadest frequency band, operating from audio frequencies to beyond 2 GigaHertz,” which allows “up to 60dB noise reduction across a massive bandwidth, from audio frequencies to radar frequencies.” Heady claims. So the XE-12S is meant to be not only a power-delivery device but also a power cleanser.

Weil noted that while the XE-12S is expensive, it’s meant to be competition for even pricier products from Goldmund and other makers. In fact, the XE-12S was designed for use with Goldmund’s top-of-the-line transport, DAC, and preamp, which cost a a lot more. Weil is rightfully proud of the fact that the XE-12S is used by Mobile Fidelity and in the Reference Listening Suite at CBS Studio Center. However, perhaps of greater relevance is that most of Weil’s customers own two or more Sound Application units.

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Sound Application sent me a pair of XE-12Ses to use even though one would easily accommodate my entire system. I thus swapped various pieces of digital gear, amps and preamps between the two, deciding that the configuration I liked best was one XE-12S for amps and preamp, the other for digital and subwoofer. Tagging along with the XE-12S was a pair of Elrod Power Systems EPS-3 power cords, which come shipped in long tubes because of their thickness. To determine what effect these cords had on the sound of the XE-12S, I purchased a pair of stock 20-amp power cords from Audio Research, as I had found these cords to be more than acceptable when I reviewed the ARC VT200 mono amps. My comments in this review refer to both a single and pair of XE-12Ses used with the Elrod power cords, which I talk about separately in a sidebar below.

I used the XE-12S with a vast array of gear: Tenor Audio 75Wi, Lamm ML2, and deHavilland Aries 845 mono amps; Lamm L2 Reference and Audio Research Reference Two Mk II preamps; Mark Levinson No.39 CD player used as a player and transport; Bel Canto DAC1.1 and DAC2 digital-to-analog converters; Wilson Audio WATT/Puppy 6 and WATT/Puppy 7 speakers; and a Wilson Audio WATCH Dog subwoofer. Interconnects and speaker cables were from Shunyata Research (Aries and Pegasus), Analysis Plus (Solo Crystal Oval and Solo Crystal Oval 8), Silversmith Audio (Silver), and Stereovox (SEI-600 and LSP-600). Power cords were from Shunyata Research (Taipan and Anaconda Vx) and TARA Labs (The One and RSC Air), along with the aforementioned Elrod and Audio Research cords.

Sound Application also sent along a pair of its HC duplex outlets, which I swapped in partway into the review period.

I immediately preferred these to the hospital-grade outlets I was using because the sound had slightly greater liquidity.

The Sound of Power

Following Jim Weil’s suggestion, I first used the XE-12S on my TV as part of the break-in regime as well as a way to assess its value for video. I have a 35″ Mitsubishi direct-view set that draws a fair amount of power, so Weil’s suggestion seemed like a good one. I’m no home-theater expert, so I feel almost embarrassed to say that I saw improvements immediately with my TV XE-12Sed. Colors were noticeably more rich and saturated, which led to each looking more true. I left one of the XE-12Ses tethered to my TV for a few weeks so I could get used to the effect and test my perception by removing it. Sure enough, with the XE-12 out, the picture of the big Mitsubishi set was a little less vibrant. This made me anxious to get both XE-12Ses into my audio system.

I started with one unit and then added the other. I can’t say that two XE-12Ses were a dramatic improvement over one, but in my case, it’s hard for the subwoofer to reach whatever the amps and preamp are plugged into anyway, so a second unit was useful. The XE-12S’s sound (if it can be termed this given that it’s not in the signal path) was easily noticeable in my high-resolution system, even in comparison to the Shunyata Hydra, which I had been using for some time. Ease, liquidity, and background blackness were immediately discernible, the music taking on an elegance that quickly became addicting. One of my favorite recent CD releases is of an older recording: the soundtrack to the movie (not the Broadway musical) Ragtime [Elektra/Rhino 78245]. The music here was written and conducted by Randy Newman and precedes his wonderful score for The Natural. With the pair of XE-12Ses in my system, the strings on this recording were absolutely silky, and the entire soundstage unfolded in a naturally whole and continuous way — this is just the best way I can describe it. But perhaps it’s just that the music is simply gentle and flowing — organic. I used to own the LP of the Ragtime soundtrack, and I didn’t enjoy it nearly as much as this new CD.

But what about more raucous music? Does the XE-12S take away its edge? Not at all. The end product is rather like what I saw from my TV — colors being more dense and true to life. It’s still reproduction, but a higher, more refined grade of it. The K2 20-bit remaster of Creedence Clearwater Revival’s great Green River [Fantasy FCD-8393-2] is not just better than the original CD release, it’s a different listening experience. K2 is the remastering system JVC uses for its XRCDs, and while the remastered Green River is not an XRCD (and doesn’t display the utter ease of one), it does sound more contemporary — and far more detailed. With the XE-12S in my system, I enjoyed this 1969 recording very much. Guitars rang out with fierce edginess, and the entire presentation was complete, integrated. If there’s a band today anything like Creedence Clearwater Revival, I haven’t heard it. While musicians are able to steal licks and hooks from the Beatles, CCR remains unique.

There is also the sense with the XE-12S that the difference between the musical signal and underlying noise is greater. I can’t say this represents a lessening of the noise — I don’t necessarily hear that — but the perception is that there’s more music. At the beginning of “Graveyard Blues” from Clarence Brewer’s swampified King Clarentz [HMG HMG1007] there is a low-level buzz, presumably from the amplifier for Brewers’ electric guitar. With the XE-12S in and the lights out, that buzz becomes an important part of the presentation, like a lone cricket in a graveyard at night. It also reminds me that King Clarentz derives much of its considerable charm from the resounding tone of Brewer’s playing. King Clarentz sounds a little hot and splashy, but the music uses these maladies to its advantage, making for directness that many more gentle audiophile recordings can’t approach.

There were a number of things the XE-12S didn’t do. It didn’t color the sound or muddy it in any way. It didn’t emphasize any region or inject amusical artifacts of any kind. It didn’t reduce dynamics. It didn’t hum or give off any heat. With its dozen outlets, it wouldn’t leave you short of spots to plug in equipment, even if you have a complex A/V system. I wish it cost less, but this would apply for so many audio products I’ve enjoyed.


The Sound Application XE-12S is certainly a pricey piece of audio equipment, and even more so when you add an Elrod power cord. But it helped my very pricey system sound more natural and organic than it does sans XE-12S, and thus become even more enjoyable to listen to. You have to be prepared to pay dearly for equipment that inhabits the highest of the high end, and the XE-12S is just another example of this. But what you get for your money is a well-made and refined power product that will improve systems of all pedigrees