Core Power Technologies A/V Diamond Valiant, Defiant and Linx Cables | REVIEW

Who is Core Power Technologies (website), anyway? For that matter, who is Living Sounds Audio (LSA) and the LSA Group? A couple of years ago, I’d never heard of any of them. Now, I’m slowly noticing the surreptitious movements of this enigmatic collective as it moves to take over the industry, and mostly because of Part-Time Audiophile reviews I’ve already read..

In the last year or so, we’ve reviewed a handful of products from them: John Richardson reviewed the LSA 20 Statement loudspeakers back in June, and Brian Hunter also reviewed the LSA HP-2 Ultra headphones last November. Recently, I took on the LSA T3 turntable and unipivot arm combination because I recognized the original design from my good friends at Margules Audio in Mexico. Now, I have a box full of cables from Core Power Technologies. And I’m a little confused.

Who are these people? Where did they come from?

Here’s a name that’s very familiar to me: Underwood Hi-Fi. Just when I thought the LSA Empire was ready to seize control of the world, I got some of the back story and now I feel slightly less paranoid than usual. Underwood Hi-Fi is one of those high-end dealers who have been around for a long time. I remember them being somewhat famous for their modifications on a few amplifier brands—usually these mods involved upgrading some of the parts like caps and internal wiring. Underwood Hi-Fi didn’t charge an arm and a leg to do it, either.

For years, I wanted to check out one of their fully decked-out Unison Research Unico integrated amplifiers—it was within my budget, and I hear great things about it. This was many, many years before I became the US importer and distributor for Unison Research. And yes, I was told by the manufacturer that I could approach Underwood Hi-Fi to see if they could continue as a dealer and a modder. Unfortunately, I never put that deal together. That’s why I now review.

It turns out that Underwood Hi-Fi, the legendary shop owned by Walter Liederman (who everyone used to call “Underwood Wally”), has been steadily growing over the years. Wally built his business by finding close-outs, B-stock and discontinued items and using his skills as a one-time corporate buyer in the audio industry to pass all the savings onto his customers. In addition, he was able to perform extensive mods and restorations by partnering with Chris Johnson of Parts Connexion.

From there, Wally started expanding the reach of Underwood Hi-Fi. First, he bought Emerald Physics, known for their speakers. Then he bought Core Power Technologies A/V, known for their power conditioners, and LSA speakers. Then he expanded LSA’s line of products to include amplification, turntables, digital streamers and headphones.

The Diamond Series

Oh yes, I forgot to mention the cables. The story on the cables, straight from Wally himself, is consistent with the rest of the Underwood Hi-Fi tale. Wally found a source for high-end audio cables in the Asian markets. He can’t say who makes the cables—they’re a well-known OEM manufacturer—but before you start poo-pooing the effect of Chinese manufacturing in the world of high-end audio, you should probably know that the QC has improved to the point where most manufacturers are using at least some Chinese parts in just about anything. (Where do you think all those PC boards and power transformers come from?)

No, here’s what is different about the multiple lines of cables from Core Power Technologies A/V: they were selected because they sounded so darned good—to Wally, and quite a few others from what he tells me. (Hence, the secrecy about the source.) Wally knew that he had to make a move. And, in usual Underwood Hi-Fi fashion, he got a great deal and now he passes the savings to the consumer.

Each type of Core Power Technologies A/V cable has a name—the speaker cables are Defiant, the power cords are Valiant, the interconnects are Linx and the digital cables are Conduit. Each line comes in Silver, Gold and Diamond models. Walter Liederman sent me a full loom of the Diamond cables: the Defiant Diamond speaker cables (from $995/pair based on length and terminations), the Valiant Diamond power cords (from at $799 each based on length) and an assortment of Linx Diamond interconnects with both RCAs (from $799/pair) and XLRs (from $899/pair).

This is fairly expensive to the uninitiated consumer, but fairly affordable by high-end audio standards. But again, this is the top of the line—much of the Silver and Gold lines are very affordable. (A 2.5m pair of Silver Defiant speaker cables, for instance, are just $249.)

The Innards

Core Power Technologies A/V describes the guts of the Diamond series thusly:

Made up of multiple 8N ULTRA PURE OFC copper conductor stranding component with multiple minimum “tolerable” 16AWG finalized ”cores” that are covered in 85 microns of compressed silver. The Defiant Diamond uses 8 of these finalized cores per side (16 overall for the pair). Each conductor is wound with a helical “Dual Mono-Filament” of Fluorinated Ethylene Propylene (FEP) jacket as part of this esoteric manufacturing process. Precise double layer micro-space insulation is employed as well. TSC Shielding is also used to guarantee isolation and optimize that last nth degree of performance. Finally we sheath these 8 cores hand-knitted cores into a beautiful finished product that defies description

I was particularly impressed with the connectors used in the Diamond series—they’re from Furutech. Wally likes to say “no expense was spared here,” and this is the proof. Wally also likes to say they’re sonically comparable to cables five to ten times as costly, and that’s not so easily proven. That’s why I’m here.

The Expectation Effect

Before I launch into a bevy of creative adjectives to describe how the Core Power Technologies A/V Diamond series impacted my reference system in a positive way, I have to step back and discuss my expectations going in. Yup, I had ‘em.

When I reviewed the very affordable Raven Audio Soniquil cables, I had no idea how much they cost. They couldn’t quite compete with some of my lofty cable looms in terms of ultimate sound quality, and I chalked some of that up to a new company venturing into the cable market for the first time and coming up with something still nice and competitive. Then I saw the bargain-basement prices for the Soniquils, and I almost had to re-write the entire review. (Spoiler alert: fantastic for the money.)

When I reviewed the Luminous Audio Technologies Prestige III loudspeakers a few weeks later, I checked out the MSRP before I wrote a single word. These were an astonishing $188 for an 8’ terminated pair. I continued with those expectations, that I was going to see if the Prestige IIIs performed well enough for systems that were either modest or secondary. (They did, by far.)

When I looked at the prices for the Core Power Technologies Diamond lines, however, I found them to be right in the middle—not budget, but not as expensive as some of the cables I use as a reference. (Which, in turn, are far, far less than some of the more exotic cables out there.) I started off writing about how we need more cable choices in the middle, for audiophiles who don’t want to skimp on cables but still don’t have the big guns when it comes to the componentry that will benefit from such connections. I finished off a big chunk of the review in advance, just talking about this nonsense. After spending time with these cables in the system and spending some time talking to Wally on the phone, I discovered that I had to delete every word and start over.


Why? Because I realized that Wally didn’t intend for these cables to offer mid-priced performance. He wanted the Core Power Technologies A/V Diamond Series to be considered purely as flagships, as Wally’s commitment to “unparalleled value at prices that bring sanity to the cable segment.” All of those expectations had to be scrubbed from my memory. This is the top of the line, treat it as such. Quit talking about the damn price tags.

I installed the cables into the reference system, let them burn in for some time, and then went about business as usual.

In the following months, many products took their turn in the review queue. We’re talking about extraordinary pieces of gear such as the Vimberg Amea, Marten Oscar Duo and Volti Audio Razz loudspeakers, the Jeff Rowland Design Group Continuum S2 and LFD NCSE Mk. 3 integrated amplifiers, and no less than four separate analog rigs—including the LSA T3 turntable, of course. In fact, I had so few reservations with the Core Power Technologies cabling in the system that I left them in most of the time. During this period, I had many memorable listening sessions with a killer high-end audio system and not once did I feel that I needed to swap in more expensive cables to really appreciate what I was hearing.

I would fail in my diligence, of course, if I didn’t make A/B comparisons with those other brands at least a few times. I have three, maybe four complete looms of quality cables in my inventory. I prize one brand for its sonic warmth, which is tailored closely to my personal tastes, I prize another for getting me as close to neutral as I wanna go without my head exploding. The other brand or two are chosen for flexibility—for serving as necessary odds and ends whenever required, and for not taking anything away from my enjoyment of the music.

Each cable loom presented its arguments as to why it was the best, and why I loved it. The Core Power Technologies A/V cables, however, refused to toot their own horns. They were simply neutral—not a little warm, not unusually incisive. Music flowed effortlessly through the holidays, and the Core Power cables never once suggested that something might be missing. Believe me, the Vimbergs will let you know if something is missing.

Defiant Diamond in the Spotlight

That title sounds kind of neat, like the name of a indie film, but it simply means that I was so intrigued with these Core Power Technologies Defiant Diamond speaker cables that I broke them out and continued to use them with other system combinations. I seriously considered reviewing them separately from the others in the Diamond series.

I could recycle some of my original thoughts on the Diamond Defiants, the ones I unceremoniously deleted after I smacked my own forehead three of four times, things like “$995 is a really interesting price point for a decent pair of speaker cables—many cable manufacturers seem to obsess about either entry-level cabling or the insane stuff that costs as much as a new BMW M8 Coupe Gran Coupe.” As a longtime audiophile, I’ve often felt that $1000 is a nice price to pay for decent speaker cables. Any less, and I feel like I can do better. Any more, and I feel dumb for spending that kind of money on wire.

Now, I feel like that doesn’t make any difference. The price of these speaker cables is irrelevant, as I implied, at least to a certain extent.

Whenever I used the Defiant Diamond speaker cables, I felt extremely good about the choice. They’re thin and flexible and easy to work into tight places without having to worry about bend radii. Since they were terminated with banana plugs instead of my usual spades, they were ideal for making quick comparisons in the system. Not once did I consider them as an obstacle, something that could lessen the sound quality. They did what I expected them to do.


If I noticed one quality that I could single out, other than “neutral,” I would like to nominate “open.” Whenever I used the Diamond series cables, I felt an open and airy quality that did seem to morph into something slightly different when other cables were substituted. I sensed a lightness to the sound, and not a lightness that sacrificed weight to sound untethered to the ground. Everything sounded clear, top to bottom.

But basically, the Core Power Technologies A/V Diamond series were neutral AF, and I didn’t have to think about them. Point A to point B every time.

In fact, I’d buy a pair of the Defiant Diamonds just to have something with banana plugs whenever I’m reviewing a compact integrated amp with a crowded back panel. I wouldn’t worry that I was making any sort of compromise. I’d be doing it because they’re that good, and Underwood Wally still knows what he’s doing after all these years.