Hemingway Audio Cable’s website bills the brand’s product as “The best audio cable ever created.” Reminiscent of slogans by companies like YG Acoustics (“The best speaker on earth”), ESS Laboratories (“Sound as clear as light”), and Kyron Audio (“The ultimate music experience”), this audacious assessment reminds us that the marketing claims of many audiophile companies aren’t exactly understated. Still, my friend Dave, an audiophile and cable aficionado, strongly advised me to audition Hemingway’s Z-core power cords.

Granted, Dave’s recommendation did come with a warning that the Z-core Ω (Omega), Σ (Sigma), and β (Beta) power cords, respectively priced at $18,000, $9500, and $4800 (all prices USD, per 2m length), aren’t exactly available at bargain basement prices. However, Dave suggested that going with the less expensive Z-core α (Alpha) cord ($2600) might offer me a taste of the more costly Z-core audio cord’s performance without having to resort to the sale of body parts or plots of land I don’t in fact own to fund the purchase.


Hemingway is a brand of Indratec Corporation, a South Korean telecommunications company located in Anyang, a satellite city of Seoul. Over time, I’ve noticed more and more high-end audio gear originating from that country, and without fail, every South Korean component I’ve auditioned has left me with a highly favorable impression.

Dave put me in touch with Hemingway’s North American distributor, Darrin O’Neill of Audio Limits, based in Laughlin, Nevada. Given my stereo system’s complexity, O’Neill sent me eight Z-core power cord samples—two Alphas, two Betas, and four Sigmas.

Easy to say, but difficult to do.
—Korean proverb

How did Hemingway Audio Cable set out to create what they claim is the best power cord ever made?

Indratec was founded in 1993 by Doyoung Chung, its lead engineer. The company designs and manufactures community antenna television (CATV) system components, including repeaters and radio-frequency (RF) power amplifiers. Cable TV providers use these systems to receive and distribute audio, video, and data signals. They’re also used by governments to manage automobile traffic and collect highway tolls.

The operation of many of Indratec’s products is adversely affected by radio-frequency and electromagnetic interference (RFI and EMI, respectively). Efforts to troubleshoot these issues, Chung recounts, led the company to develop a deep understanding of how to manage these performance-degrading electric fields.


In 2008, Indratec created the Hemingway brand. Today, it accounts for 30 percent of the company’s business and, at the time of writing, employs eight of its 64 employees. The brand consists of three lines of signal cables and power cords—the entry-level Indigo and two premium lines, Creation S and Z-core—all of which are manufactured in the company’s Anyang factory.

According to Chung, Indratec has invested in excess of $500,000 in R&D costs in the Hemingway brand and a substantial additional sum into developing the Z-core line. Chung states that the price of each Z-core cord is based on the complexity of its production rather than its performance level and that each cable takes a skilled worker two to three days to hand manufacture.

All of Hemingway’s signal cables and power cords employ a technology—patented in South Korea by Hemingway and developed over a 13-year period—called Frequency Modulation Cavity Fundamentals (FMCF), which is designed to convert RFI and EMI into magnetic energy. According to Chung, this conversion is accomplished via a spherical gold-plated network device that in the case of a power cord is placed over the conductors, about 7″ from the male connector. The company claims the conversion alters the conductors’ resistance, dramatically reducing noise and sonic artifacts.


As Chung explains, by varying several aspects of the geometry of the cord or cable—including the number of the conductors and their composition, gauge, and physical arrangement, along with the design, material composition, and placement of the dielectrics, shields, and other layers that surround the conductors—engineers can manipulate the magnetic energy created by FMCF. These choices can influence the sonic characteristics (e.g., pitch, soundstage size, resolution, and dynamics) of each cable or power cord model.

The first step in manufacturing each Z-core power cord is preparing its conductive core, which, depending on the cord model, consists of between 30 and 60 insulated copper conductors, some stranded and others solid-core. The conductors are part of what Chung refers to as a five-way system, meaning that they comprise five different gauges. Chung told me that the copper used in the conductors contains some oxygen since oxygen-free copper does not work well with the Hemingway technologies. Also, depending on the model, the insulating layers of the conductors are made of either Teflon, rubber, or nylon.

Once selected, the conductors are laid out and their ends twisted in opposing directions, with a different number of twists performed for each model. The resulting pattern is what gives the Z-core its name. According to Chung, Hemingway cords can be slightly stiff, a characteristic he says protects their structural integrity. If the cords are subject to excessive physical stress, he explains, their sonic performance can be compromised.


The next step is to place a model-specific arrangement of dielectrics, shields, and other layers over the twisted conductors. These arrangements—made of materials such as silicone, rubber, urethane, and Teflon—vary in thickness. Chung was hesitant to provide a lot of details about these layers. This, he says, is because some of them function to uniquely affect the cord’s magnetic energy—and thus its sonic character. Each cord’s internal geometry is then encased in a nylon mesh jacket.

Finally, the FMCF network device and the male and female connectors are fitted to the conductors. The connectors are manufactured by a third-party vendor and feature copper pins plated with chromium, platinum, and gold.

All Hemingway cables come with a five-year limited warranty against manufacturing defects.

A good-looking rice cake tastes good.
—Korean proverb

Each Z-core power cord arrived in an immaculately wrapped box, sheathed in bronze-colored eco-leather bearing the Hemingway logo and lined with black velvet. Inside each box, the cord was encased in a drawstring bag made of thick, brown cloth, also bearing the logo.


Once I had the Z-core cords in hand, I could see they were gorgeous. The fit and finish were impeccable. A Korean proverb observes that a good-looking rice cake will likely taste good because someone cared enough to put effort into its appearance.

My plan was to review the cords collectively as a set, though Darrin O’Neill told me that I would have to experiment a bit to discover where each of the Z-core cords worked best in my system. He recommended attaching the Alpha power cords to my system’s amplifier, the Sigma to the preamplifier, and either the Beta or the Sigma to the front-end components. He also cautioned that using too many Sigmas might be too much of a good thing.

What I found was that the more expensive Z-core models consistently outperformed the lower-cost ones regardless of the component. Another thing I noticed was that I never felt that I had too many Sigmas in my system. Curious about these findings, I contacted O’Neill, who remarked that since my system is highly resolving, he was not surprised by what I observed. With other systems, he suggested, the results could differ.


Ultimately, I placed one of the four Z-core Sigmas on an Esoteric Grandioso LPS1 power supply, which powers the “DACs and buffer amps” of an Esoteric Grandioso K1X CD/SACD player/DAC. One of the two Alphas went on the K1X itself to power its mechanical components and remaining digital circuits. The other three Sigmas went on my Esoteric Grandioso G1 master clock generator and C1 preamp, the latter of which uses two power cords. I connected one each of the two Betas to my amp and JL Audio C1 crossover. I put the remaining Alpha on the desktop computer I use to play music files and internet-based music streams, which has been modified with JCAT components.

Eyes are high.
—Korean proverb

When I talked to Dave about the Z-core power cords before I was even contemplating this review, he was uncharacteristically terse in his observations of their effect on the sound, reflecting only that they were difficult to describe but different from other cords. However, after receiving the Z-cores, I had high expectations. Another Korean proverb, “Eyes are high,” refers to the state of having lofty or even unrealistic standards. Naturally, as a result of the cords’ many tantalizing features—lofty pricing, high-end packaging, excellent build quality, and killer aesthetics—my eyes were pretty high.

After listening to my system with the Z-cores installed, it became obvious that these are some of the very best performing power cords I’ve tested. That’s saying something, as for decades I’ve been evaluating my own DIY cords and those made by professional manufacturers. Whatever’s going on with the Z-cores—and according to Chung, it’s in large part due to the FMCF technology—it’s very powerful.


While Dave was right that the Z-core sound is difficult to describe, I was able to discern three key attributes. First, the Z-cores imparted a unique type of drive, energy, and thrust on the music. They brought new sparkle and punch to “Brazil (2nd Edit),” from Deadmau5’s Random Album Title (16-bit/44.1kHz FLAC, Ultra Records, LLC/Qobuz). Pace, rhythm, and timing were spot on, and the track had remarkable momentum. With “Ha pìu forte sapore . . . Spoletta è giunto,” from the 1962 recording of Puccini’s Tosca with Herbert von Karajan leading the Vienna Philharmonic (24/96 FLAC, Decca/Qobuz), the aria’s climax—as performed by baritone Giuseppe Taddei—displayed not only uncommon liveliness, but also incredible force and impact.

That’s not to say that the Z-cores artificialize, hype up, or over-energize things. They didn’t. With Glen Gould’s fabled version of Bach: The Goldberg Variations (24/44.1 FLAC, Sony Classical/Qobuz), the controlled Andante sounded so soothingly gorgeous and serene I was practically in tears.


Second, the Z-cores created unusually dense aural images that were firmly planted in the soundfield. With “Pigs (Three Different Ones),” from Pink Floyd’s Animals (16/44.1 FLAC, Pink Floyd Records/Qobuz), the opening swine grunts, which appeared about a foot and a half to the left of the soundstage’s center, had world-class three-dimensionality—and massive heft. Speaking of heft, the Z-cores reminded me of some high-end power cords, including those from Shunyata Research, that deliver music with a fully developed harmonic structure.

Third, the Z-cores portrayed instrumental and vocal timbres in a stunningly accurate way. It seemed that no matter what I was listening to—whether it was the guitar strumming of “Crash Into Me” from Stevie Nicks’s The Soundstage Sessions (CD, Reprise 508028), Glen Gould’s piano notes from The Goldberg Variations (16/44.1 FLAC, CBS Masterworks/Qobuz), or vocals like Roger Daltrey in “Love Ain’t for Keeping” from the Who’s Who’s Next (24/96 FLAC, Geffen/Qobuz)—everything sounded gorgeously realistic and right in a way that I’ve never experienced before. Undoubtedly, the Z-cores parse timbre in ways other cords I’ve experienced don’t.


While the three attributes I’ve mentioned above are the Z-core’s calling cards, these cords do many other things, such as world-class detail retrieval and noise rejection. They also produce a large soundstage. Take, for example, detail retrieval. With the swine grunts in “Pigs (Three Different Ones),” I was awestruck by the amount of inner detail and reverberation that was reproduced. Although, perhaps due to the Z-cores’ unusually dense sonic character, they don’t have a particularly resonant sound. If the recording calls for reverberation, the Z-cores will produce it. They just won’t generally add an overall reverberant quality to the music as some cords do.

Also, bear in mind that comparing the Z-cores to other power cords can be misleading as in my experience, there’s nothing else quite like them. And while they may or may not be your cup of tea, there are quite a few high-end cable manufacturers that will be forced to up their power cord game once word of the Z-cores gets around.


One last thing. While I was initially switching the Z-cores around in my stereo system, I confirmed Dave’s theory that the $2600 Alpha power cord provides a taste of the more costly Beta and Sigma cords’ performance. The Alpha’s effects weren’t quite as strong as the Beta’s, and they were much weaker than the Sigma’s. However, the Alpha cords nonetheless displayed Z-core’s unique sonic signature and offered extraordinary performance for the price.

The best power cords ever created?

I can’t definitively pronounce that Hemingway Audio’s Z-core Alpha, Beta, and Sigma power cords are “the best audio cables ever created.” Though, with their lively, fulsome, and breathtaking timbrally accurate sound, I have no doubt that they’re among the best power cords that I’ve tried. Echoing my friend Dave’s sentiments, I’ll note that, as with many audiophile cords these days, the Z-cores can be ruinously expensive, particularly as you move up the model line. But for those who are still on board, all I can say is that they’ve earned my highest recommendation.

. . . Howard Kneller

Associated Equipment

  • Amplifier: Esoteric Grandioso S1.
  • Preamplifier: Esoteric Grandioso C1.
  • Sources: Microsoft desktop computer with JCAT components running foobar2000 music player; Esoteric Grandioso K1 SACD/CD player/DAC with Esoteric Grandioso LPS1 power supply and Esoteric Grandioso G1 master clock generator.
  • Other electronics: JL Audio CR1 active subwoofer crossover.
  • Speakers: YG Kipod II Signature.
  • Subwoofers: JL Audio f13 v2 Fathoms (2).
  • Interconnects: Synergistic Research Galileo SX.
  • Digital cables: Synergistic Research Galileo SX USB and BNC digital, Mad Scientist Audio Black Magic USB.
  • Speaker cables: Synergistic Research Galileo SX.
  • Power cords: Synergistic Research SR25 (power conditioner), Galileo SX.
  • Power conditioners and distribution: Synergistic Research PowerCell SX and QLS power strips.
  • Isolation devices: Symposium Acoustics Osiris Ultimate and Standard Racks, Symposium Acoustics Segue Platform, Synergistic Research Tranquility Bases, Synergistic Research MIG 2.0s, Symposium Acoustics RollerBlock Series 2+ Equipment Support System.
  • Room treatments: Synergistic Research Acoustic Art System, Atmosphere XL4, Black Boxes and HFT and FEQ devices, GIK 2A Alpha diffusor/absorber acoustic panels, WA-Quantum Quantum-Sound-Animator.
  • Misc.: Synergistic Research Active Grounding Block, Blue fuses, and Electronic Circuit Transducers (ECTs), Mad Scientist Black Discus Audio System Enhancers and Graphene Contact Enhancer, Hi Fidelity MC -0.5 Magnetic Wave Guides, Telos Quantum connector caps, f.oq damping tape.

Hemingway Audio Cable Z-core Alpha Power Cord
Price: $2600 per 2m cord.
Hemingway Audio Cable Z-core Beta Power Cord
Price: $4800 per 2m cord.
Hemingway Audio Cable Z-core Sigma Power Cord
Price: $9500 per 2m cord.
Warranty: Five-year limited warranty against manufacturing defects.

Hemingway Audio Cable (Sigma Wire Lab, Inc.)
18, Indeogwon-ro 30beon-gil
Dongan-gu, Anyang-si, Gyeonggi-do
Republic of Korea
Phone: +82 31 424 2646

Email: contact@hemingwayaudio.com
Website: www.hemingwayaudio.com/eng

North American distributor:
Audio Limits
3132 Acacia Ct.
Laughlin, NV 89029
Phone: (702) 299-0567

Email: audiolimits@fastmail.fm
Website: www.audiolimits.com