Nordost • Heimdall 2 Headphone Cable

by Dennis Davis | October 8, 2014


In the big picture, 35 years is an insignificant amount of time, but in terms of high-end audio, it’s an eternity. Give or take a year, it was three and a half decades ago that alternatives to lamp cord -- like Monster, Kimber, Polk Cobra and Fulton cables -- started stirring the flat-earthers into fits of disbelief at the idea that speaker cables could make any sonic difference -- or that anybody might think they could. Within a couple years, anyone seeking to improve his or her audio system without spending the mortgage payment had traded out the lamp cord for Monster Cable.

Who could have imagined back in 1980 the level of sophistication achieved in cable design over the next few decades? Esoteric interconnects and power cords were not all that far behind the speaker cables, but replacement cables for headphones were rare until the turn of the century, when mobile audio reinvigorated the headphone market. Even then, development of aftermarket headphone cables remained the specialty of garage-shop operations. Many of today’s most-sought-after headphone cables are made to order: You listen to them at a local headphone meet, are impressed by what you hear, contact the cable manufacturer, leave a credit-card payment, and wait weeks or months for your new cable to arrive. But the scale of the headphone market is hard to ignore, threatening to swamp sales of hi-fi separates altogether, so it’s no surprise that finally the specialist audio-cable manufacturers have sat up and taken notice.

Enter Nordost -- joining Cardas as one of the first full-line cable manufacturers with a dedicated headphone cable. Nordost introduced the Heimdall 2 at the High End Show in Munich in May. Although this isn’t the first red headphone cable on the market, its fetching color combined with its unique construction made it one of the most striking and interesting introductions at the show.

When advance word of the cable’s introduction first emerged, I initially wondered, why a Heimdall rather than a Valhalla or Odin headphone cable? Once I touched the new cable, plugged it into a set of Audeze headphones and tried the combination on for size, the answer became obvious. The Heimdall 2 is so light and flexible that you almost forget that your head is connected to a box of electronics by a length of wire. As you ascend the Nordost range, greater mass and weight deliver tangible rewards when it comes to speaker cables or interconnects, but such attributes would bring severe discomfort and a lack of flexibility (not to mention longevity) when attached to a set of headphones. And therein lies the solution to half the battle of designing a top-tier headphone cable: Comfort is king, or at least queen. Some of the best-sounding headphone cables on the market announce their presence every time you move your head, because you feel the drag of the cable. Mesh braids or the cloth sleeving used on many cables, no matter how fine the enclosed wire, create a drag on your head that intrudes on your listening and interferes with long-term comfort.

Nordost opts for the far more flexible FEP insulation developed by DuPont. Those without a chemistry degree can think of it as a softer, more flexile type of Teflon coating. To prevent this soft, flexible cable from ripping apart each time you move your head too fast or inadvertently step on the cable, Nordost integrated another extremely strong but light DuPont fiber into the cable. Aramid fibers are best known as Kevlar, used in body armor, helmets, tires and loudspeaker drive units. Woven into headphone cable, they prevent the more flexible insulation and wiring from stretching out of shape and suffering mechanical stress.

I once followed a Head-Fi thread where a blogger claimed to have modified Odin and Valhalla speaker cables to fit his headphones. It’s a mind-boggling notion, and I can’t help imagining his cans floating in space while he stoops and squirms to wedge his head between them without ripping them off the wiring. But whether real or a figment of the blogger’s imagination, the idea of mating Nordost cable to a set of headphones was not lost on the folks back in Massachusetts. Headphone cables are not like speaker cables, however, either from a flexibility or an electrical perspective. They carry a low-level signal and are more like a phono cable than any other type of wire. Comparing the construction of a Heimdall 2 tonearm cable with that of the headphone cable reflects exactly how Nordost addressed the latter’s unique requirements. Rather than the phono cable’s four strands of 24 AWG Micro Mono-filament silver-coated solid-core OFC wire, the headphone cable uses seven-strand Litz conductors equivalent to 32 AWG, also eschewing the silver coating of the OFC wire. That accounts for the flexibility, but just as important it makes the cable less prone to work-hardening (and eventual failure) of the conductors, a very real issue with any cable used in a mobile application.

Like all Nordost cables, the Heimdall 2 is constructed in what the company terms "mechanically tuned" lengths, designed to reduce internal microphony and high-frequency impedance. The standard length approximates two meters and costs $799.99. That price allows you to specify one of seven of different headphone-end terminations, enough choices to match most ‘phones on the market, including Abyss, Audeze, AKG, Sennheiser, Ultrasone, MrSpeakers and HiFiMan. The source end of the cable is terminated with a four-pin balanced XLR male connector, compatible with the balanced output of most high-quality headphone amps. In addition, you also get a pair of short adapters that allow you to convert the cable for use with the 3.5mm stereo miniplug used on most portable devices, or the popular 1/4" stereo jack. Each adapter is built using the same wire as the main cable and again to specific, tuned lengths.

If the two-meter length is too short, Nordost offers two-meter extension cables at $599, which can be terminated with the same four-pin XLR (allowing daisy chaining), miniplug and 1/4" options. I did most of my listening using an extension cable, and I could detect no difference in the sound with or without that extension. I used the miniplug adapter extensively for headphone use with portable gear. Both full-size headphone amplifiers I used offer fully balanced four-pin outputs, in each case sounding superior to the 1/4" unbalanced output.

While I’ve already mentioned the striking appearance of this cable, my description really doesn’t do it justice. In the flesh it has an almost luminescent appearance. In the right light, the Heimdall 2 scatters light in a way that’s reminiscent of those classic, custom candy-apple auto paint jobs so popular in the 1960s. I satisfied myself with the cable’s appearance rather than its sound for a couple weeks as I let it burn in. Once done relishing the visual and tactile beauty while breaking in the Heimdall 2, it was time to finally wear this jewelry and find out what it could do. That involved listening to the cable in my own home and portable rigs, but I also sought out the Cavalli Audio table at a couple of headphone meets, taking the opportunity to listen to a wide variety of esoteric headphone cables and ‘phones through the same Cavalli Liquid Gold amplifier that I use at home. In my own system I started by running the Nordost cable between my Audeze LCD-3s and the Liquid Gold’s balanced output before moving on to the other options.

One of the CDs that seemed to keep cropping up throughout this long and varied process was of the Saint-SaŽns Symphony No.3 "Organ" [Ondine 1094-5]. This symphony is scored for a large orchestra backed up by the organ in two of its four movements. It’s a high-energy extravaganza, and the Ondine recording will let you know just how much (or little) air your transducers can move. The Allegro moderato really tempts you to keep turning up the volume -- the recording is so clean that it seems to have unlimited headroom. When the organ comes in on the opening of the Maestoso, it’s impossible to capture the full thunderous effect unless it's being played through genuinely full-range (for which read, "very large") speakers -- or through world-class headphones and an equally world-class amp. The Audeze/Nordost combination did not disappoint. I’ve not heard this CD sound better. The Organ Symphony is one of those house-rattling pieces that is probably responsible for breaking as many leases as marriages. Before portable audio brought headphones back to prominence, one of their major draws was to enjoy just this kind of music. The Heimdall 2/Audeze combination made me appreciate once again just how much fun headphone listening could be.

How did the Heimdall 2 experience compare to real-life music? Well of course that’s an unfair test, but for fun I did a "live versus recorded" test. In anticipation of hearing a performance of Ravel’s Piano Concerto with the San Francisco Symphony conducted by Michael Tilson Thomas and featuring Britain’s 22-year-old phenom pianist Benjamin Grosvenor, I listened to the spectacular 2007 CD of the same piece with the Berlin Philharmonic conducted by Seiji Ozawa and with 25-year-old pianist Yundi Li [Deutsche Grammophon B0010175-02]. Of course, this is just the kind of music that deters many audiophiles from headphone listening. You can forget that feeling of sitting ten rows back in the center stalls. Even with recordings that avoid over-miking the soloist, headphones have you feeling more like you’re sharing the piano stool, needing to scoot over a bit to avoid getting in the way. However, while the stage might not be your preferred listening spot, who would give up the chance to occasionally move in this close, the rare opportunity to enjoy a new and very different perspective? And while that perspective might not be considered correct, like many such things, it can certainly be a fun ride.

The Ozawa Ravel recording highlighted the differences between the stock Audeze cable and the new Nordost offering. The woodwinds sounded woodier, and it was obvious that there was wind flowing through them. With the Audeze cable, I knew that there were woodwinds involved. However, I could recognize the sound of woodwinds with a table radio. The Nordost brought me a lot closer to the woodwind experience than the stock cable. It let me see and feel the difference in character and texture between instruments, underlining just how different the clarinet and oboe sound. It took me back to my days sitting in the high school woodwind section, and the difference between that and listening to recordings a few years later in music-appreciation classes in college. The Heimdall 2 also brought more body to the piano sound while the strings' upper registers shimmered and vibrated in a way totally missing with the stock cable. The Audeze 'phones have garnered rave reviews throughout the audio industry with its stock cable, yet with the Heimdall 2 the LCD-3s were transformed into a much more sophisticated beast.

Further evidence of how nuanced this cable really sounds can be found by listening to quieter and less densely arranged music. Mobile Fidelity’s new reissue of Miles Davis’s My Funny Valentine [Mobile Fidelity UDSACD 2141] is an excellent example. A live performance recorded at Philharmonic Hall in New York City’s Lincoln Center, the title track opens with audience applause, a short bit of noodling on the piano, and then as the applause dies away Herbie Hancock plays a quiet introduction to Miles’s entry on trumpet. Before Miles starts playing, you hear a little audience noise and a hint of Tony Williams warming up on the drum kit. Switching to the Nordost cable, I suddenly began to hear the hall, instead of just the audience noise, and felt like I knew where each rustling program and cough was located. Tony Williams began to inhabit a better-defined space. There was a sense of blackness around the quiet notes, as though I was holding my breath and absolute silence reigned until I exhaled. The Heimdall 2 gave me the feeling that I could reach out and touch Miles, a touch of magical presence and immediacy. The piano had more texture, Miles’s horn took on an extra dimension, and when the bass entered the game was up -- the Nordost was king in capturing the uncanny sound of the air being moved with each pluck of a string.

Before the arrival of the Heimdall 2, I’d been struggling with a comparison of two digital versions of Kind of Blue. Last year Sony released a version made in Japan using the proprietary K2HD mastering process developed by JVC [Sony 88697883272]. This year they released yet another version [Sony 88843026042], using Ultra HD 32-bit mastering (another JVC process) coupled with the "PureFlection" technology, a high-end CD replication process, developed by Winston Ma of FIM. I had compared the two versions a few times without getting too excited about the differences, and decided to give it another go with the Nordost cable. With the Heimdall 2 in play, all I needed to hear was the first 30 seconds of the two different CDs to realize that something had gone wrong with the FIM production. The tape noise inherent in the recording was missing, and along with it (in addition to a quiet cough in the background) the texture and ambience of the music had been sucked away. It sounded as if a noise-reduction system had been inflicted on the tape, but I doubt that this would have occurred at FIM. Perhaps FIM was supplied a doctored master tape for the project. Who knows? But given the outstanding quality of most of their reissues this result came as quite a surprise. Even so, working in the face of heavy expectation, the Heimdall 2 headphone cable clearly exposed this difference without ever sounding ruthless, overly etched or inarticulate.

For those whose portable audio world includes the use of full-size headphones, an ultra-flexible cable is a godsend. You’ll be the sharpest-looking nerd at the local Starbucks with this cherry-red Nordost cable running from your ears to your laptop. Just be ready for the cable to reveal shortcomings in even the best digital storage devices -- and high-resolution files.

The bottom line is that the Heimdall 2 is the headphone cable to beat. While it's not inexpensive, my comparative listening clearly demonstrated that you can spend a lot more on a custom headphone cable without getting better sound. In addition to that world-class performance, the cable packs in far more proprietary technology than most of the competition, and builds it into a truly sexy-looking length of wire. And unless you go with one of the silk-encased headphone cables, nothing comes close to the unobtrusive comfort of the Heimdall 2. It’s so good that the boost it gives to headphone performance may change your listening habits. Fewer leases will be broken and more marriages might endure -- although whether that will be down to lower noise levels or lower levels of interaction is anybody’s guess.

Install the Heimdall 2 and you should expect to get your groove on. Just don’t forget to check in with the outside world now and again.

Price: $799.99 per two-meter length.
Warranty: Limited lifetime.

Nordost Corporation
93 Bartzak Drive
Holliston, MA 01746
(508) 893-0100

Associated Equipment

Analog: Spiral Groove SG1.1 turntable with Centroid tonearm, Lyra Atlas stereo and Titan i mono cartridges, Nordost Valhalla 2 tonearm cable, Audio Research Reference Phono 2 SE phono stage.

Digital: Audio Research Reference CD7 CD player, Apple iPhone.

Headphone amplifiers: Ray Samuels Emmeline HR-2, Cavalli Liquid Gold, Cypher Labs Theorem 720.

Headphones: Audeze LCD-3.

Interconnects: Nordost Valhalla 2.