EQ UIPMENT R EPORTJASON VICTOR SERINUS

Nordost QKore and QKore WireSYSTEM GROUNDING ACCESSORIESA

s a longtime user of Nordost’s cable and AC-power
products, my ears opened
wide when they released
their three QKore Ground Units andQKore Wire at High End 2017, inMunich. While I’ve never questioned
the importance of proper electricalgrounding, to prevent problems withsafety and noise—the latter including measurable noise generated bytransformers, appliances, LED lighting,power supplies, and Bluetooth, WiFi,and cellular devices—I couldn’t fathom
what difference a passive grounding device might make in a high-end
system that, in my case, is fed by an
8-gauge dedicated line with its own
copper ground rod driven into theterra infirma of the fault-ridden PacificNorthwest.
From Nordost’s Michael Taylorand Michael Marko, I soon learned
that their three Ground Units—theQKore1, QKore3, and QKore6—wereintended for all systems, including thosewith dedicated lines and grounding
rods. While Nordost counsels againstremoving grounding rods, the efficacyof such rods seems to vary with season,temperature, and soil salinity. Whenthe soil dries out, you have to drivea grounding rod very deep to achieveeffective grounding.
“It has been said that keeping theground moist and salty enhances theelectrical connection to earth,” Marko
explained by phone. I envisioned myself, in bathrobe and pink fuzzy slippers, daily toting an iridescent green
watering can filled with salt water tothe exterior corner of our detachedmusic room to water my groundingrod. I also imagined the imminent
appearance of people in white coats,intent on grounding me permanently.
The QKore, which acts as a manufactured ground reference—a point ofzero potential—includes a “low voltage
attractor plate” (LVAP), made of a pro-prietary alloy, that avoids the variabilityof the organic materials that constitutesoil and that are affected by temperature and/or humidity. The QKores’
precise contents—and the names ofother companies involved in theirdevelopment, if any—are secrets kept
so close to the corporate chest thatI fully understand why anyone whohas neither attended one of Nordost’sdemonstrations nor tried a QKore athome would raise at least one eyebrow
at these things, if not reject them outof hand.

SPECIFICATIONSQKORE1, QKORE3,QKORE6 GROUND UNITS:
Passive grounding devices,connected to power conditioners and audio components with QKore Wires.
Dimensions (all three)10.6” (270mm) W by3.2” (80mm) H by 7.9”(200mm) D, or 8.9”(225mm) D with binding

posts. Weights: QKore1,13.25 lb (6kg); QKore3,13.55 lb (6.1kg); QKore6,17.2 lb (7.8kg).
Serial numbers of units
reviewed QKore1, 4157251;
QKore3, 4158509; QKore6,4158572.
Prices QKore1, $2499.99;
QKore3, $3499.99; QKore6,$4999.99.

Reprinted from Stereophile magazine

QKORE WIRE CONDUCTORS: 1x16 AWG,
solid-core, 99.9999%-pureoxygen-free copper (OFC),
silver-plated. Insulation:
fluorinated ethylene propylene (FEP). Terminations
available: banana, spade,RCA, male or female XLR,
BNC, RJ45, USB-A, USB-B.
Price $359.99/2m; add $150

per additional meter. USB,
RJ45 terminations, $399.99.
All Approximate number ofdealers: 95.
Manufacturer
Nordost,93 Bartzak Drive,Holliston, MA 01746.
Tel: (800) 836-2750‬.
Fax: (508) 893-0115.
Web: www.nordost.com.
www.stereophile.com

NORDOST QKORE AND QKORE WIREThe QKore1 ($2499.99) includes one 2m-long bananato-banana QKore Wire and one QBase Ground gold-plated
binding post, and is designed to ground the primary power
distribution block/conditioner/regenerator/distributor. TheQKore3 ($3499.99), with one 2m RCA-to-banana QKore
Wire and three QBase Ground multi-use binding posts,
is intended to ground audio circuits on the secondary sideof the power supply. The QKore6 ($4999.99) combines aQKore1 and a QKore3 in a single box, and comes with 2mruns of banana-to-banana and RCA-to-banana QKore Wire,
as well as: three multi-use binding posts for audio circuits,
two posts for monoblock amplifiers or other components,
and a single QBase Ground post for the primary power
product.
QKore Ground Units are intended, ideally, to be connected to as many system components as possible via Nordost’s
patented QKore Wire ($359.99 each for a 2m length). This
comprises Nordost’s patented Mono-Filament technology
of a silver-plated copper conductor insulated with extruded
fluorinated ethylene propylene (FEP) insulation, aka Teflon.
The wire is solid, to better conduct resonance. Marko
explained:
Any wire that conducts AC physically vibrates. All of our
top [power cords] separate conductors from one another,and use mechanically tuned lengths to minimize resonance. Imagine a wind chime. When it normally hangs
in the wind, the chimes are separated, but when theytouch, they ring like bells. Now, imagine those chimes tied
together with a string. If you were to hit those, they would
not ring; they would thud. That’s a lot like what we do.
Instead of trying to damp resonance with filler and foam,
we get better results when we control resonances in a lessdamped fashion.
The QKores address two different aspects of ground noise
in audio systems. Pre-transformer ground noise (AC), whichcomes out the wall, is addressed when you attach a QKore1
to a power product’s ground post. Post-transformer groundnoise (DC), which lives in the audio circuits of the audio
components proper, is addressed when you attach a QKore3
to those components’ open jacks or ports: RCA, XLR, USB,BNC, Ethernet, etc.
Rather than analog, Taylor prefers open digital connections, when available, because digital tends to carry morenoise. As for RCA vs XLR, he said, “I tend to get the best
results when I connect QKores to single-ended (RCAor BNC) connections. However, it is very dependent
on how the manufacturer designs the circuitry. Whilein cases where the balanced circuitry has more noise init, balanced connectors should be used, I’ve found that ahigher percentage of components benefit most from pulling noise from the single-ended circuit.”
To further reduce noise caused by vibration, Nordost
advises keeping QKores off the floor. “The QKore is aresonant sink as well as an electrical-noise ground sink,”
Taylor said. “Putting it on three Nordost Sort
Kones creates a grounding path for resonance to travel out of the unit.” While
Marko prefers titanium Sort Kones($369.99 each), he acknowledges
that some audiophiles prefer bronze
Sort Kones ($149.99 each), or a combination of them. Those who lack space on their
Reprinted from Stereophile magazine

equipment racks can put QKores on the floor atop Sort
Kones. Each of the QKore’s removable rubber feet conceals
an indentation designed to accept a Sort Kone’s pointed top.
An ideal setup for an ultra-high-resolution system consistsof a single QKore1 for the power product, and a separate
QKore3 for each of three other components. While you cantheoretically double up connections by using two wires toground two components to each binding post, Taylor says
that, for maximum efficiency, each component should haveits own QKore binding post.
The most cost-effective Ground Unit, the QKore6, canaccommodate a power product and five audio components.
The two Michaels claim that, if budget and space permit,
going with a separate QKore1 and QKore3 instead of asingle QKore6, and connecting one component per binding
post, produces the greatest reduction in noise.
Setup and Choices
Nordost sent me single review samples of the QKore1,QKore3, and QKore6, along with sufficient QKore Wiresand Sort Kones to accommodate the three components I
was using while doing the listening for my review of CH
Precision’s I1 integrated amplifier (Look for it in the February 2019 Stereophile). Lacking was a QKore Wire with USBA termination to use on the MacBook Pro computer I’dinstalled for that review: I’d forgotten to ask for that Wire,and they take a while to build.
Setup decisions were simplified when Taylor explained
that, since the component LVAPs in the QKore3 and 6 are
identical, and the power-product LVAPs in the QKore1 and
6 are also identical, if I were to use the QKore6 to connect
only three components plus a power product, the soundwould be equivalent to connecting a separate QKore1 andQKore3. It got even easier when I discovered that the only
open digital connectors on my components were singleended BNC and RCA. This meant that I wouldn’t be able
to compare the sounds of the QKores’ grounding via singleended vs balanced connectors.
With no room on my rack, and little floor space behind asystem wired with 1,001 cables, I feared that more boxes andwires would consume all the remaining space behind therack. Happily, the QKores perched securely atop the diffusers that Bart Andeer of Resolution Acoustics had designed

www.stereophile.com

NORDOST QKORE AND QKORE WIRE

for the front wall of my listening room. I could still tiptoe
through the cables.
I began by removing the QKores’ rubber feet and perchingeach Ground Unit atop one titanium and two bronze Sort
Kones. Later, well into my listening, I discovered that using
two titaniums and one bronze better illumined the sound.
I listened to three reference recordings: Lou Harrison’spercussion-rich Concerto for Violin with Percussion Orchestra, with soloist Tim Fain accompanied by Angel GilOrdóñez leading the PostClassical Ensemble (24-bit/48kHz
WAV, Naxos 8.559825); Andris Nelsons and the Boston
Symphony Orchestra’s knockout performance of Shostakovich’s Symphony 4 (24/96 WAV, Deutsche Grammophon
002859502); and Michael Tilson Thomas and the San
Francisco Symphony’s recording of Berg’s Three Pieces forOrchestra (24/192 WAV, SFS Media SFS0070). All threewallop the listener with copious bass, considerable highextension, dramatic outbursts, and a hell of a lot going on allat once.
Listening to the CH Precision I1, which includes a DAC,I heard a pervasive grayness that covered the music’s glory
like a light, transparent fog. I longed for richer colors in theBerg, more silence around climactic percussive strokes in theShostakovich. Then, when I connected the QKore1 to theTweek Geek Dark Matter Stealth power conditioner, I wasready to swear that the soundstage had widened and colors
were now a bit more distinct. Once I’d gotten past the shockof discovering how more transparent and vivid everythingsounded, I realized that while the soundstage had not widened, sounds now stood out more because much of the fog
had lifted. I especially loved how I could hear more subtle
bass differentiation in the Berg, and more vivid colors.
In connecting the CH Precision I1 to the QKore3, I now
had to make a choice between BNC and RCA inputs. Nocontest; using an open BNC clock input on the CH I1 delivered wetter, more transparent sound. With the Harrison
concerto, for example, images grew notably more three-dimensional and round. There was more air around the violin,
and the percussive explosions were now distinctly behind it.
I added the dCS Scarlatti clock to the signal chain, using
one of its open BNC outputs, listened, and noted: “Thesound is getting ghostly quiet. Everything I love about thismusic and these recordings is standing out more.”
For the CH Precision review, I’d intended to compare
the sound of the I1’s internal DAC to that of an externaldCS Rossini DAC, the latter’s analog outputs connected tothe I1’s preamp section. Connecting the QKore3 to both
the Rossini and the I1 further shifted the sound, from grayaround the edges to remarkably more vivid. As for which
open input sounded better, when I moved the QKore Wire
from the Rossini’s open RCA to its open BNC clock input,
BNC again delivered wetter, more transparent images.
Because I always listen to the Rossini DAC with the Scarlatti clock engaged, I next added the latter, but without theQKore3 attached. With the clock alone, the soundstage wasmore 3D, instruments moved farther back and seemed morenaturally differentiated from each other, and an appreciable
amount of additional air increased the distinction between
hi-fi and high-end.
Next, when I connected the external Scarlatti clock to
the QKore3, I heard the clearest, most color-differentiatedsound, and the most silence between sounds, that I’d yetheard from the combo of Rossini DAC and CH Precision I1. Harrison’s gamelan-like use of a wide variety ofReprinted from Stereophile magazine

A S S O C I AT E D E Q U I P M E N T
Digital Sources dCS Rossini DAC & Scarlatti clock; Apple
MacBook Pro computer with Intel i7, SSD, 8GB RAM; Intel
NUC7i7BNH with 8GB RAM, 128GB SSD running Roon;
Linksys routers with two sets TP-Link Gigabit Ethernet media converters, multimode duplex fiber-optic cables, Small
Green Computer linear power supply; external hard drives,
USB sticks, iPad Pro.
Integrated Amplifier CH Precision I1
Loudspeakers Wilson Audio Specialties Alexia 2.
Cables Digital: AudioQuest Diamond (Ethernet), Nordost
Odin 1 & Odin 2 & Valhalla 2 (USB), Wireworld PlatinumStarlight Cat8 (Ethernet). Interconnect, Speaker, AC:Nordost Odin 2.
Accessories Grand Prix Monaco rack & amp stands, 1.5”
Formula platform; Nordost QB8, QX4 (2), QK1, QV2
AC power accessories, Sort Kones, Sort Lifts; AudienceaR2p-TOSOX, Tweek Geek Dark Matter Stealth (with High
Fidelity & Furutech options) power conditioners; GreenWave AC filter; AudioQuest NRG Edison outlets; SteinMusic Super Naturals, Signature Harmonizers, Blue Suns/Diamonds, Quantum Organizer; Bybee Room Neutralizers;
Absolare Stabilians; Resolution Acoustics room treatment;
Stillpoints Aperture panels.
Listening Room 20' L by 16' W by 9' H. —Jason Victor Serinus

percussion—all manner of gongs, drums, bells, each with adifferent timbre and different length of decay—makes thisrecording a superb test for a sound system, as well as a thrilling musical ride.
Of the many improvements wrought by the Nordosts,
one that stood out was how much longer I could hear thesounds of bells and gongs decay, even as other instruments
began playing over those decays. That increased sense ofnatural decays in space—even with recordings, such as theHarrison, that lack a high sampling rate—validated all theenergy and money that we audiophiles devote to searchingout ways to increase our systems’ capacity to reproduce what
the finest recording and mastering engineers wish us to hear.
After listening some more, and having discovered mypreference for one bronze and two titanium Sort Kones
under each QKore Ground Unit, I found the music so convincing, colorful, and pleasing that I declared, “Enough snippets of orchestral tours de force!” Instead I revisited some ofthe recordings I love of sopranos and mezzos singing musicthat brings warmth to my heart and smiles to my face, as I
reveled in quieter backgrounds, more colorful accompaniment, and more thrilling overtones than I’d ever heard frommy system. It was good—very, very good.
Conclusions
I can’t imagine that anyone who’s invested considerable timeand energy and money in a high-end system would want tobe without the markedly “blacker” backgrounds, increasedtransparency and detail, more vivid colors, and greater overallveracity delivered by Nordost’s QKore Ground Units. Connecting just a single power distributor or conditioner to a
QKore1 or QKore6 brought marked improvements; adding
as many additional components as possible increased theeffect greatly. The law of diminishing returns does not apply;
the differences were cumulative, and anything but subtle. n
www.stereophile.com