LessLoss Firewall module review

Sometimes, dealing with the noisiness of electricity feels rather like fixing a tourbillon wristwatch. For its complexity, there are so many hidden traps and ways one can go wrong. Of course, in engineering terms, much is known in theory about electricity, noise, and grounding, yet the available solutions based on established theories still seem to fall short when it comes to laying down an exact solution which satisfies all aspects of critical listening. Louis Motek of LessLoss Audio says that even the most advanced filters based on capacitors and coils reveal colorations in dynamic performance which ultimately disappoint. In fact, this is not the first time we hear such a statement. This undesired side-effect of power filtration has been known for several decades, and has been the reason that so many audiophiles either avoid filters altogether, or search for more exotic solutions.  

In recent years we’ve seen a proliferation of dedicated devices dealing with this phenomenon in different ways. Some are based only on typically known theoretical principles, some explore a more esoteric approach, and yet others offer a varying mix of the two. 

Presently, filtering solutions based only on theoretical calculations of lumped resistance, capacitance and induction (the famous “RCL”) seem to dominate the market, even the high-end market. Alternative solutions see little press and are harder to find. This may be because there is little left-brain consensus as to how they should work in the first place. Sadly, not only the consumer, but the media mogul usually just skips over any such iteration. Even well established high-end audio publications still examine these products with skepticism and reservation. The justification? Unfortunately, some manufacturers do tend to exploit the trusting nature of the mindless mob. Therefore, it is good to turn to the professional press for some level of protection. It is true that not all that shines bright is gold, but some of the gems are actual precious gemstones. To find them, dedicating attention, experience and time is necessary. 

This whole quest for audio gem products is not exactly commercially viable. Much time is lost in doing so. But the occasional reward that justifies our constant passion lets us again feel the thrill of progress in the field of advancing audiophile technology.

For many seasoned writers the absence of instant deliverance and cashing in is a complete turn off. I tend to believe that in our business of writing reviews of audio products, reader vigilance is required. We are all, writers and the reading public, enriched by the same excitement and willingness to explore. The day I’m out of passion and excitement, my job is finished. It’s a fact that I won’t get rich out of doing what I do. But I love it and continue because of that feeling. 

Enthusiasm is the very kerosine which constantly flares our creational drive's fire. The 21st century is all about the excitement of new technology. We’re finally getting to the stage where our beloved high-end industry is seeing a healthy revival. For a long time we were on the back track. Now, with the impact of globalization, new, dynamic, small companies are appearing, doing novel things that are finally advancing the art, and we can again talk about progress.

Imagine a person working in a larger audio company. He’s got his daily routine and dedicated work hours. Now peek into the smaller, boutique, almost underground, high-end audio brands. You see action almost 24/7. You don't hear “radio silence” after placing an inquiry. When calling, often times you don't get a secretary, you get the boss! This type of personal interaction cannot be matched nowadays by the giants. It’s not profitable and there is no money in the world which can pay for such personally driven passion. 

One such person is Louis Motek. I know him for four years now. He’s among a rare caste of people who seems to be in a constant, highly energized loop of deeply contemplating and exploring things beyond your typical modus operandi. In a short time, he brought LessLoss to an impressive plane, and looking back at his creations, one sees uniqueness and boldness. I’ve reviewed quite few products from LessLoss and they always represented not only high value for the money, but materialized ideas “out of the box” which make sense. With this new Firewall Module, he is again building upon this same heritage with an interesting new product. 


The LessLoss Firewall Module features the latest and most advanced LessLoss Skin-filtering technology, combined with a small footprint suitable for installation inside equipment. The Module claims to “block noise pollution to levels traditional capacitor and coil-based solutions can only hope to approach.” 

The Firewall Module was developed from the company’s critically acclaimed DFPC (Dynamic Filtering Power Cable). According to company literature, the LessLoss Firewall Module is supposed to “reveal hidden subtleties of the entire audio event as it eliminates the widespread negative effects of high frequency noise pollution.” 

From company description, the Firewall Module is “a unique no-capacitor, no-inductor solution for noise-laden mains. The solution’s efficient nature reveals itself immediately, as an obviously lowered noise floor, and then, over time, in an ever-growing and blooming naturalness of sound quality. Unlike transformers, the Firewall Module produces no voltage difference between input and output, and, also unlike transformers, does not buzz or hum, nor does it lose efficiency in the form of heat.” 


Louis Motek gives very strict instruction to be followed for installation. Without following the exact rules, the result supposedly comes as mediocre or even non-existing. Even though we are dealing with alternating current, which, supposedly, is non-directional, company literature defines the L and N line connections, and even their direction. It is known that mathematically there is no difference, and even he himself is first to make this point, yet Louis Motek still insists that directionality lies at the crux of his unique solution, and is fundamental to its effectiveness. 

The manufacturer states that the break-in time is about 30 minutes. I’ve found that after 20 minutes the effect is already evident, but 45-60 minutes in takes things to a different level altogether. For many, any high-end accessory falls instantly into the label of “esoteric” or even “snake oil.” I’ve been around long enough and have heard the effect of so many seemingly “irrational” things to remain openminded. One such thing is “burn-in.” Nobody knows what it is, but so many people have talked about it and relate to it, that it must exist. Other industries are researching deeply into the strangest of subject matters, yet our rather small high-end audio sector seems always to have the least resources and there is least interest from outside our circle to be able to move things forward with certitude. Louis Motek states that perhaps what remains to be found is a pragmatic application entirely outside the realm of audio, where the size of the market is much larger. In his opinion, it is not inconceivable to believe that areas of wider spread interest do indeed exist, but that until they are found and that gap bridged, we are destined as audiophiles to keep these little secrets (like “burn-in”) to ourselves. 

Louis Motek adds: “Stringed instrument makers have long known the effect of “play-in,” where freshly made, new instruments never sound as they will after a month of playing them in. The sound matures, the attack becomes more responsive, and the whole unit begins to sing as a whole rather than just a sum of mechanical parts. During no part of this process are there any measurable differences in the sound of the instrument, but all musicians recognize and use this aspect in their daily relationships to their instruments. Further examples, all without any cynical connotation, include cryogenically treated trombones, automobile enthusiasts “burning in” newly refurbished automobiles, and even tea connoisseurs claiming the repeated use of their utensils has an effect on the outcome of the tea. Cooks value and discern different aspects of heat coming from electrical, gas, or wood-burning ovens, though the temperature readings of all are identical. There is even strong evidence that lab rats inherit knowledge directly from the experience of earlier generations of rats, rather than only through DNA. And there are plants which grow to their recognizable forms and shapes without any DNA available whatsoever. See the work of Rupert Sheldrake for more on his controversial theory of Morphogenesis.”

My inquiring tendency keeps me up to date not only with the high end audio industry. Ever since the 80’s, I’ve been an avid follower of other branches of electronics as well. There is a progression happening across all of them. Without the same funding, not in such a grand way, with no mainstream press capturing red carpet moments, instead we take unseen baby-steps in high-end audio. Yet we're not in hiding, but somewhat rather more like an underground club of knowledgable insiders. It is within this club where developmental movement is ongoing and lively, and bit by bit, audiophiles and music lovers are being exposed to the more uncommon solutions in our niche industry.

Returning now to LessLoss and Louis Motek. Skin-filtering technology has already shown its potency in the form of the well established LessLoss DFPC power cable solution. As shown in my own and many other publications, the negative effect of high frequency noise pollution has become much, much less of a problem through the use of the LessLoss cables implementing this tech. In module form, it was highly interesting to see what effect this technology could have when not confined to the flexible form factor of a cable.  

But before we explore the Module’s audible results, here is a short summary of the theory about what’s going on under the hood…


At the heart of its functionality, the Firewall Module features LessLoss tried and tested Skin-filtering technology upon which their renowned power cables are based. Skin-filtering makes perfect use of the way that alternating electrical current naturally travels down a wire. Its functionality is based on the principle of attenuation over distance, and on the high-frequency skin effect first described mathematically in 1883. Users the world over attest to the supremacy of this technology while comparing to traditional power-filtration methods based on the resonance of capacitors and inductors.

Because nature determines that high frequencies reside at the skin of every conductor, it is easy to understand why LessLoss Skin-filtering can be the audiophile’s best and most efficient tool to condition the power before it enters his or her audio component. Treating the skin of the conductor attenuates HF noise, preventing it from entering your gear. Because this filtering solution is employed only at the skin of the conductor, the solution never restricts the low frequency power flow your gear relies on. This way you get enhanced HF attenuation without compromising dynamics or coloring the sound. 


The original Firewall was a rather large unit manufactured from highly expensive tankwood. The new Firewall module continues the performance heritage, but at much more down-to-earth pricing. The Firewall modules under test were designed to be inserted in the power line between one's power cable and the device to be conditioned, whether it be a power amplifier, preamplifier, a DAC or any source device. 

If one wants to go nuts, a chain of them can be connected in series. “Mad scientist” system owners can explore making the chain as long as they want it to be. Here only money is a holdback, but not dynamic impediment.

Some of my favorite repeated classical albums include the violin. These serve very well for when things go subtle. I dive into the deepest darkness of the audible ocean and explore the intricacies of the most minute details. In fact these make up the most important aspect of audio reproduction. Of course it's all about signal-to-noise, but I doubt that any of this is seriously expressible through measurement. In terms of influence, the Firewall module is doing things down deep. Way, way down deep.  

In choir music, pinpointing and following one singular voice might sound like a ridiculous enterprise. Yet, within a system of kaleidoscopic potency, such mental exercise is thoroughly possible, and quite enjoyable, for this is just how we listen in real life. In a way, the Firewall module re-injects a remnant of real life to the sound image. You begin to hear not only the musicians’ sound, but their effort as well. 

Take strings, for example. You have a group made up of individuals. They are playing in an attempt to mesh their instruments’ voices. Their success depends on how well they meld their voices through active musicianship. Electronic stereo equipment tends to mesh such organic ensembles in an artificial way. Its success depends on how well it can maintain separation of voices. This way, we can relate to the active musicianship of the individuals within the ensemble, and appreciate their effort. With the Firewall module, it becomes easier to comprehend the distinction of the individual within the section. You can literally hear their effort at maintaining the ensemble sound. Here the tonality is spot on and the Firewall Modules perform in this respect impressively.

Many of us share an affection for photography. There is quite a big difference when it come to lenses. This is how I would describe one of the Firewall Module effects. Imagine the clarity of Carl Zeiss optics being introduced while you’re slowly zooming in to the focus point. After 30+ minutes everything is resolving and slowly being revealed in just the exact same way. Unclear pieces of the musical signal start to gradually become more vivid and make sense. As with the LessLoss cables, a unique black canvas appears, one that projects a more clear interpretation of the music. But this time, as the focus continues to sharpen and become more revelatory and informative, it begins to seem like the canvas turns out not to be a black surface at all, but deep space. 

There is something about the unfettered resolution and timbral correctness that is revealed with the Firewall modules in action. This potency was acknowledged whether the modules were set before the DAC, the phono preamplifier, the power amps, or preamplifier. The amount of the change differed somewhat from device to device, but in a general sense, the positive effect was of the same type each time.

The tuttis in classical orchestra recordings usually challenge any component or system. Juxtaposition of voices and large orchestra is a real challenge for most electronics. The achievement of a great system would be when our left-brain analytical decoding vanishes. And this is exactly what happened with the insertion of the LessLoss Firewall module. With familiar classical material everything becomes more immediately evident, of much more notable transparency, and all becomes more detailed and revealing. It is easier to know what you are hearing, without having to constantly doubt or think about it. And it is definitely not an artificial etching or embossing effect.  

The Firewall Module provides a pleasing absence of coloration, where tonal color and timbre take on  much more believable manifestations. Tone, timbre and color are depicted in a much more realistic and coherent way. Their subtle yet distinctive nature is preserved, lending an overall authenticity which is undeniable. 

All in all, the low-level resolution and thoroughly maintained transient response creates a notable change that one usually relates only to upper echelon solutions. 

Louis Motek did indeed advance his art and created with the Firewall module a new horizon of attainable performance, the impact of which is impressive even to an experience reviewer such as myself.


There is no conjuring with the LessLoss Firewall Module. Although the provided devices are plug-and-play by nature, they do need some quality time with your system. 

Many audiophiles do not want to admit their system shortcomings and will stick only to old-school established solutions for upgrades. Those willing to go “out of bounds” to raise system performance will benefit. 

Louis Motek is restructuring LessLoss’s landscape to include new realms. He’s bringing his unique company tech down to the mortals. It is still thoroughly possible for those with more available funds to go nuts with any desired number of Firewall modules. Here only the sky is the limit. Or should I say, the blackness of deep space. Ok, and probably the WAF figures into the equation as well. But the new smaller form factor may indeed address that last point. 

The LessLoss Firewall module is this company’s most intriguing and resolving product so far. The business complexity of offering trickle-down technology into such an affordable product is no simple task. Louis Motek’s, shall we say, “half-altruistic” endeavor marks an interesting shift in this company’s vision. And given the new price/performance ratio, a very welcome one. 

Let me sum it up with an intentionally flawed syllogism, corrected only by this product's price/performance ratio:

The audiophile realm is not for everyone. The Firewall module is in the audiophile realm. Therefore, the Firewall module is definitely for everyone! For what it represents, and at what value, the LessLoss Firewall module clearly deserves Mono & Stereo's Highly Recommended Award!

Text and original photos: Matej Isak

Price: from 178$


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LessLoss Audio
P.D. 1231
Kaunas, LT 46005

TEL:+370 698 48706