select_150w_tSometimes a company’s very name will tell what its driving philosophy is. This is the case with LessLoss, a Lithuanian manufacturer dedicated to the preservation of as much of the audio signal as possible -- the less lost, the better. I can’t think of a better starting point. And as audio company names go, it’s refreshingly honest. They could have called themselves NoLoss -- but that’s impossible. Instead, the name LessLoss states that, “Yes, there will be damage to the original signal, but by cracky, we’re doing everything we can to minimize its impact.” 

LessLoss FirewallLessLoss made its name in the product categories of power cables and digital-to-analog conversion. I first came to know of the company when its DAC 2004 was much praised in online message boards dedicated to audio. Later, I read many good things about LessLoss AC cords, in particular the Dynamic Filtering Power Cable Signature, or DFPC Signature ($1149 USD per 2m cord). The DFPC and the Firewall do their things by employing what LessLoss describes as its own “elegant solution” for utilizing the skin effect. In a nutshell, the skin effect is the natural tendency of the higher frequencies of an audio signal to migrate toward the outer surface of a conductor. LessLoss says that its method of passive filtering takes advantage of the certainties of physics -- i.e., knowing where the high-frequency grunge is hiding -- to go about removing line noise. 

But despite those positive impressions, I soon forgot all about LessLoss. Fast-forward a few years: I caught wind that LessLoss had an entirely new product to debut, its Firewall power filter ($4686 direct, including worldwide shipping). To say that LessLoss founder Louis Motek is proud of his new baby is an understatement. With the Firewall, LessLoss thinks they’ve really hit on something. 


The first thing that struck me about the LessLoss Firewall was that it seemed to be redundant. Why, I wondered, would a company that makes and markets filtering power cables decide to make a standalone power-line filter? The answer is simple: scale. In the filtering of power, some is always good, and a lot is often much better. But when a component’s filter is also its power cable, only so much filtering capacity can be included before the cable becomes unwieldy. LessLoss wanted to add a lot more filtering capacity -- so much that going the cable route would have made the cord thicker than a supertanker’s hawser. The Firewall is far more compact and elegant. 

The Firewall is made of a German-engineered material imposingly named Panzerholz (Tankwood, to the English-speaking world), a high-tech, dense, compressed-wood laminate. Using a combination of very high pressure and moisture, thin layers of birch are fused into a thick laminate twice as dense as natural birch. Tankwood has been used to damp vibrations in Formula 1 cars. According to LessLoss, canceling vibrations matters in the Firewall: it has a major effect “in terms of musicality, natural tone richness, and authenticity of timbral color.” The company has ensured that the Firewall cannot act as a microphone for vibration, and therefore will pass along no pesky resonances downstream to connected equipment. 

At either end of the Firewall’s 4"W x 4"H x 13.8"L case are endcaps of milled, black-anodized aluminum that look as thick and robust as the Tankwood. One end has a single IEC inlet set in carbon fiber, the other a similarly situated electrical outlet -- in the case of the review sample, one to North American spec. That’s right -- the Firewall comes with only a single outlet. That’s because it’s not intended to be used as a power-distribution hub, but as a so-called “whole-system” filter that cleans up the power for any and all downstream components. I’m sure that LessLoss would be more than happy to sell you a Firewall for each of your components, but they likely expect that a single Firewall will be placed upstream of existing power bars. That’s how I used it in my system. 

LessLoss Firewall


My own power conditioner is a Blue Circle Audio BC6000, with a second chassis that contains several extra outlets ($2325 for both). I removed the BC6000 from the circuit and connected the Firewall directly to the “dummy,” outlet-only chassis, at a single stroke using the Firewall to filter all those outlets and everything plugged into them. LessLoss also sent along four of their DFPC Signature power cords: one to connect the Firewall to my household plug, another to connect it to the Blue Circle outlet bank, and one each for my Simaudio Moon i5.3 integrated amplifier and Ayre Acoustics QB-9 USB DAC. I first listened to my system with the entire LessLoss system, then with just the DFPC Signature cords, and finally with the Firewall and other brands of AC cords. Because of the nature of power filters, I primarily reviewed the Firewall system by first getting used to its sound, then removing it from my system to hear what had changed. 


As I’ve heard with my Blue Circle BC6000 and similar products, any competently designed power filter will offer benefits in terms of noise reduction and the attendant retrieval of detail, size of the soundstage, and a generally more immersive listening experience. That wasn’t quite what I heard from the Firewall. 

During this review period I’ve been reading physicist Brian Greene’s The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos (Knopf, 2011), which discusses the theory that our universe may be only one of many. As Dr. Greene explains, there is an intriguing possibility that there is an infinite number of “multiverses,” each perhaps only very slightly different from the one we occupy, and each containing a slightly different copy of each of us. It’s all a bit Pink Floyd -- but the moment I removed the Firewall from my system, I was sure I’d entered one of those alternate realities: a joyless place where music was a lot less interesting and listenable. 

I didn’t like it when the Firewall was offline, and I got through that portion of my listening as quickly as I could. The problem I experienced sans Firewall goes back to what I said above about the scale of the filtering. With the Firewall sitting idle, the sound was smaller -- as if my speakers had shrunk by half, or my room had grown too big for them. It was also as if the music was surrounded by a sort of electrical haze, almost like the way the air is electrically charged just before a big thunderstorm. I can’t say I much liked what I heard. 

A great place to source high-definition recordings for a review is a free sampler, HDtracks 96/24 Ultimate Download Experience (24/96 FLAC, Chesky/HDtracks), which features a variety of stunning recordings of classical, blues, and jazz music. A ton of information is stored in each of these files -- far more than just the notes printed on the sheet music -- and it soon became stunningly clear that, with my system, the Firewall was mandatory if I hoped to hear all of it. 

LessLoss Firewall

When the Firewall sat out Dance of the Tumblers, from Rimsky-Korsakov’s The Snow Maiden, so too did the superb clarity of the triangle, tambourine, and cymbals, which were submerged in the powerful brass and string sections surrounding them. Also lacking were the impact and control of the brass and timpani, which kicked with the precision of the Rockettes and punched like Mike Tyson when the Firewall was allowed to do its thing. With the Firewall, the music had so much more life, and such (here it is again) scale! Though my Definitive Technology Mythos ST speakers were placed only 9’ apart, the sound seemed to emanate from the full width of a concert hall -- and such a venue’s full height and depth, too. But even that statement is a little misleading; thanks to the Firewall, my speakers never sounded as if they had much to do with the music. I love it when a good speaker “disappears.” 

The layering of the electric guitar, glockenspiel, and cymbals in the opening of “Misery,” from Dave’s True Story’s Unauthorized (Chesky), was very transparent through the Firewall, with cymbals on top of the vertical soundstage, glock in the middle, and guitar on the bottom -- until just before the singing starts, when the guitar almost visually moves up to the top. Kelly Flint’s cooing, smooth as a particularly velvety chocolate mousse, stands out almost starkly in front of the band. With the Firewall in place it certainly sounded as if her vocal track had been recorded separately from the instruments, or at least that Flint was somehow isolated from her bandmates. Without the Firewall, that nuance wasn’t even audible. I suppose this could be construed as too much detail and clarity, but it didn’t detract from my enjoyment. In fact, it was kind of exciting to discover this sonic Easter egg. 


I made a point of trying out LessLoss’s DFPC Signature power cables without the Firewall, to find out what the cables themselves could do. It was that stark a difference with the Firewall. But don’t think that the DFPCs didn’t make a meaningful addition. When I used the Firewall with my reference Synergistic Research Tesla T2 ($550/5’) and T3 ($800/5’) power cords, the great majority of the LessLoss’s wondrous performance was still there, but the overall sound didn’t quite match the fluidity and ease of the all-LessLoss rig. This was even more true when I downgraded to the inexpensive Shunyata Research Diamondback AC cord, which sounded fine but wasn’t at the level of the Synergistics, which weren’t on a par with the LessLosses. Let’s say it was LessLoss 100, Synergistic 90, and Shunyata 80. 

Of course, this review is about the Firewall, so comparing it to the Blue Circle BC6000 ($1795 when available) was a must. As far as I could tell, the two filters work in different ways. The Blue Circle uses something near 160 small capacitors of different values to filter out line noise from 120Hz to 50GHz by effectively shunting the noise away into an electrical black hole. The LessLoss devices go a different route, using heavy-gauge wire coated with what amounts to a resistor to filter out high-frequency noise traveling along the skin of the conductor. The goal for each product is of course the same: to remove as much noise as possible without impeding the flow of clean electrical power to the components downstream. 

Whether it was the differing technologies at play or the sheer level of filtering capacity supplied by each component, I can’t say, but it was easy to tell the difference between them. The Firewall delivered better sound, with a clearer overall image, more detail, more energetic attacks, and longer decays of the sounds of such instruments as drums and cymbals. I also found voices more enjoyable -- they had a more natural air to them through the Firewall. Still, I can’t say that the LessLoss presented a quieter background -- quiet passages seemed to have equally “black” backdrops, no matter which filter was in use. It’s safe to say that the Firewall outperformed the BC6000 -- but it costs twice as much, and doesn’t have the Blue Circle’s 12 outlets. 


With its first attempt at a full-on power filter, LessLoss has delivered a triumph. The Firewall is an ultra-high-performance device that makes everything about my system sound substantially better and nothing worse. It’s not inexpensive, but it will surely find a home with those who are sure they’ve found the right amplification, source, speakers, and cables, but can’t help wondering if there isn’t something more to be had from them. It’s a pretty safe bet that the LessLoss Firewall will prove to them that there is something more -- and perhaps a lot more than they might think possible. 

. . . Colin Smith 

Associated Equipment 

  • Integrated amplifier -- Simaudio Moon i5.3
  • Sources -- Apple iMac running OS X Snow Leopard, Amarra 2.1 music player, Ayre Acoustics QB-9 USB DAC, Simaudio Moon CD3.3 CD player
  • Speakers -- Definitive Technology Mythos ST
  • Power conditioner -- Blue Circle Audio BC6000
  • Speaker cables -- Synergistic Research Galileo Universal Speaker Cells and Basik cables
  • Interconnects -- Analysis Plus Copper Oval-In
  • Digital cables -- Synergistic Research Tesla Tricon, Cardas Clear

LessLoss Firewall Power Conditioner
Price: $4686 USD.
LessLoss DFPC Signature Power Cable
Price: $1149 USD per 2m cord.
Warranty (both): Two years parts and labor. 

LessLoss Audio
P.D. 1231
46005 Kaunas
Phone: +370 698 48706 (worldwide), (310) 801-7089 (North America)