Monster Cable Sigma Retro Gold speaker cables & interconnects

I've been in a nostalgic funk of late. What started it was visiting Golden, Colorado, where I spent my graduate-school days, and seeing all of the changes, not to mention the lecture halls full of kids who couldn't be a day over 12. When I commented on how young the freshmen looked, our host—a colleague of mine from grad school, now a professor—responded, "Those are seniors, Brian." I felt a little old.

So when the Monster Cable Sigma Retro booklet began talking about "our Golden Age of Hi-Fi," and I assumed that they were talking about the early days of Monster Cable—my formative audio years—it was too much. I can handle the encroaching gray in my beard, and I can even accept the fact that my 1986 Ducati F1 is no longer a new bike—but don't call me an audio geezer!

Fortunately, when I read on a bit, I discovered that the Golden Age being recalled was the 1950s and '60s. "Whew!" I thought with relief. "Guess I'm not a geezer yet." See, I didn't really catch the audio bug until '79 or '80. And while the '50s and '60s were truly another age—just after the Jurassic, I think—1980 was only a few years ago.

My youthful self-image shaken but intact, I took a close look at the Sigma Retros, a special series of cables created by whiz designer Demian Martin, formerly of Spectral and Entec fame. According to Martin, the Sigmas were deliberately conceived as a "Retro" product targeted at the single-ended triode (SET) market. Although their architecture is based on up-to-date theories on wave propagation, they eschew such things as termination networks in favor of simplicity and an emphasis on very-high-purity materials. In this case, that means "six-nines" (99.9999% pure) copper and a polyethylene insulator called PEX2, specially modified to increase the cross-linking between polymer chains and thus reduce the amount of electromagnetic energy dissipated by molecular movement.

The resulting cables are expensive, though no more so than other super-premium cables. They're well-built and easy to use, flexible, with simple, solid terminations. They're also nice-looking and luxurious to the touch, with their smoothly rounded plugs—"a stylish termination that resembles a jet engine nacelle"—and soft fabric covering.

And "luxurious" doesn't even begin to describe their packaging. If you buy the full system kit—a pair of 8' speaker cables packaged with 6' and 3' interconnect pairs—it all comes in a brushed Halliburton-style aluminum briefcase, the cables themselves snuggled in soft, velvet bags.

Monster Sigma Retro Gold interconnect
The Sigma Retro Gold interconnects use three different gauges of six-nines copper conductors. They're drawn and annealed to Monster's spec, then wound with the company's patented Microwire thread. This serves three purposes: it creates a mostly air dielectric, correctly spaces the conductors, and prevents any noise generated by their rubbing together. The wrapped conductors are then wound in a variation of a Litz construction, with the smaller conductors more concentrated near the surface of the bundle and the larger ones near the center. The winding architecture is based on the principle of having each conductor spend an equal amount of time at the bundle's surface as at its center, but is modified based on the different conductors' ratios of "skin" to "core," to try to balance out their propagation speed across the frequency spectrum.

The bundles—two in the case of the interconnect—are each encapsulated in an extruded PEX-2 insulator dielectric. Next, they're wound using an architecture Monster calls Super Multi-Twist, designed to reject audio bandwidth distortion, and the twisted pair is encapsulated in another extruded PEX2 tube. The outer tube is surrounded by two shields, one foil and one braided, which are tied to one end of the cable and covered by the soft fabric I mentioned earlier.

My first impression of the Sigma Retros, after a couple of evenings of serious listening, was very positive. They struck me as very good-sounding cables that seemed to be doing everything pretty well, and that were free of any overt colorations. As I listened over the next few evenings, I made a quick run through the audio checklist: bottom-end definition and punch, high-frequency air and extension, nicely detailed midrange with rich tonal colors, expansive soundstage, solid three-dimensional images. The Sigmas earned an A+ in every subject. Everything that I knew my system could do was being done, with nothing added or removed.

Over the next several evenings, I listened more carefully, homing in on specific aspects of the Monsters' performance, and occasionally comparing them to one or more of my reference interconnects: Audience's Au24, Nirvana's SX-Ltd., and Nordost's Valhalla. All three are superb, but each has a slightly different personality. The Nirvana is smooth and natural-sounding, perhaps a touch warm, with blacker-than-black silences and the best ability to re-create a coherent acoustic picture I've heard. The Valhalla is ever so slightly cool, and the fastest, airiest, most precise cable I've ever had in my system. The Au24 sits midway between the other two, with a dead-neutral tonal balance and a pretty even mix of their strengths and weaknesses.

In terms of tonal balance, the Monsters matched the Au24's neutrality. There was no extra warmth—cellos sounded like cellos and violas like violas, and female vocals were intimate, but with the correct mix of delicacy and body, and none of the extra huskiness that some cables and components can add. Similarly, the Monsters weren't overly cool. There was no emphasis of a guitar's string sound over its body resonance, for example, and no extra steel in flutes, violins, and piccolos.

The Monsters were actually a bit better at the frequency extremes than the Au24s, and had slightly greater extension. They had more impact at the bottom end, but this was due to their improved precision and better pitch definition, not to an increased level. I really noticed the Monsters' great bottom end during Sam Jones' bass solos on "On Green Dolphin Street" and "I Ain't Got Nobody," from the Red Garland Trio's Bright and Breezy (LP, Riverside/Jazzland SMJ-6099, Japanese import). Things like the finger movements against the strings, the pitch changing as Jones bent the strings, or the snapping, changing vibration of the strings themselves, were more vivid and electric with the Monsters.

The Sigmas were similarly stellar in their speed, clarity, air, and extension at the top end. Charlie Persip's cymbals on Bright and Breezy had a marvelous ring, with just the right mix of bell-like tone and metallic edge, surrounded by wonderful cascading waves of outward-radiating shimmer. The way a piccolo could cut through the air above an orchestra was also spot on with the Monsters, perfectly balancing the instrument's cutting edge and sweet, hollow tone.

Edge definition and detail were superb. The Monsters' sonic picture was a little sharper and more obvious, in fact, than with either the Au24s or the Nirvanas—more akin to the Nordost Valhalla in this respect. The most obvious example of this I heard were the maracas on Jimmy Buffett's "Migration," from A-1-A (ABC DSD-50183). Through the Monsters, they had exactly the right hollow sound, and their movements in space were beautifully transcribed. I'd swear I could count the individual beans rattling and swirling around inside. In addition to the detail, the Monsters also had a sort of "crisp mountain air" clarity—the spaces between images seemed cleaner and more open, which made the images stand out even more sharply.

The Monsters were also excellent in their reproduction of dynamic transients, and in their re-creation of images and soundstages. In these areas they were somewhere between the smoother, more coherent Au24 and Nirvana and the explosive, wide-open Valhalla. They had a slightly more forward soundstage and more projection than the Nirvanas or Au24, and things like rim shots and sharp guitar chops were just a bit sharper and faster—though not up to the standard set by the Valhallas.

On the other hand, while the Monsters' images were dimensional and their soundstages large—particularly in width and height—they didn't have quite the image dimensionality or soundstage depth of the Nirvanas or Au24s. Both of those latter cables replaced my listening room with a stunningly natural, completely coherent reproduction of the original acoustic space, with a sort of walk-into-it depth and seamless ambience. The Monster interconnects were very good, but not quite as good. On the flip side, however, the Monsters—or the Valhallas—made things like miking patterns more obvious, and better distinguished between the specific environments around individual instruments in multimiked studio recordings.

Summing Up: The Monster Sigma Retro Gold interconnects were superb performers. They were on a par, overall, with my three reference interconnects—Nirvana SX-Ltd., Nordost Valhalla, Audience Au24—but with a slightly different set of strengths and weaknesses. The Monsters should sound great in any system, but whether or not they prove to be the single, absolute best match will depend on other factors, including associated equipment, source material, and listener preferences. The Sigma Retros and my reference cables all work beautifully in my current setup, and I could happily live with any of them. For now, I'm sticking with the Monsters.

Company Info
Monster Cable
455 Valley Drive
Brisbane, CA 94005
(415) 840-2000
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