Nordost QKore system grounding accessories

As a longtime user of Nordost's cable and AC-power products, my ears opened wide when they released their three QKore Ground Units and QKore Wire at High End 2017, in Munich. While I've never questioned the importance of proper electrical grounding, to prevent problems with safety and noise—the latter including measurable noise generated by transformers, 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 the terra infirma of the fault-ridden Pacific Northwest.

From Nordost's Michael Taylor and Michael Marko, I soon learned that their three Ground Units—the QKore1, QKore3, and QKore6—were intended for all systems, including those with dedicated lines and grounding rods. While Nordost counsels against removing grounding rods, the efficacy of such rods seems to vary with season, temperature, and soil salinity. When the soil dries out, you have to drive a grounding rod very deep to achieve effective grounding.

"It has been said that keeping the ground moist and salty enhances the electrical 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 to the exterior corner of our detached music room to water my grounding rod. 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 of zero potential—includes a "low voltage attractor plate" (LVAP), made of a proprietary alloy, that avoids the variability of the organic materials that constitute soil and that are affected by temperature and/or humidity. The QKores' precise contents—and the names of other companies involved in their development, if any—are secrets kept so close to the corporate chest that I fully understand why anyone who has neither attended one of Nordost's demonstrations nor tried a QKore at home would raise at least one eyebrow at these things, if not reject them out of hand.

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The QKore1 ($2499.99) includes one 2m-long banana-to-banana QKore Wire and one QBase Ground gold-plated binding post, and is designed to ground the primary power distribution block/conditioner/regenerator/distributor. The QKore3 ($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 side of the power supply. The QKore6 ($4999.99) combines a QKore1 and a QKore3 in a single box, and comes with 2m runs 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.

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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 they touch, 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 less damped fashion."

The QKores address two different aspects of ground noise in audio systems. Pre-transformer ground noise (AC), which comes out the wall, is addressed when you attach a QKore1 to a power product's ground post. Post-transformer ground noise (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 more noise. As for RCA vs XLR, he said, "I tend to get the best results when I connect QKores to single-ended (RCA or BNC) connections. However, it is very dependent on how the manufacturer designs the circuitry. While in cases where the balanced circuitry has more noise in it, balanced connectors should be used, I've found that a higher 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 a resonant 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 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.

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An ideal setup for an ultra-high-resolution system consists of a single QKore1 for the power product, and a separate QKore3 for each of three other components. While you can theoretically double up connections by using two wires to ground two components to each binding post, Taylor says that, for maximum efficiency, each component should have its own QKore binding post.

The most cost-effective Ground Unit, the QKore6, can accommodate 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 a single 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 Wires and 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 USB-A termination to use on the MacBook Pro computer I'd installed for that review: I'd forgotten to ask for that Wire, and they take a while to build.

COMPANY INFO
Nordost
93 Bartzak Drive
Holliston, MA 01746
(800) 836-2750
ARTICLE CONTENTS

COMMENTS
Anton's picture

I like that you could hear a difference, but not sure what your reference was.

What grounding scheme were you using prior to the QKore, and, I guess, which other grounding products were you comparing it to?

If none, then I would be wary of the conclusion, because that would become a comparison of grounding vs. not grounding, which all audiophiles know is a crucial sound issue.

If you ended up sending the product back and not keeping it, I would recommend a Google search for "start grounding," as I have found that to be a superlative grounding approach.

I enjoyed the show report, I saw this product was in use in their display room, I wonder what their ultimate ground "anchor" was way up in that high rise!

Cheers, Jason!

Jason Victor Serinus's picture

First paragraph: ... 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 the terra infirma of the fault-ridden Pacific Northwest.

Jack L's picture

.... which all audiophiles know is a crucial sound issue." quoted Anton.

Hi

So you already stated above it is a "crucial sound issue" which means there is sound difference with & without proper grounding.

Whether one can hear the difference & how noticeable is the difference depends one's listening ability - which is again personal & subjective.

I would only comment on the lofty prices Nordost is charging its those grounding boxes. Way way out to lunch !

Yours truly, a die-hard DIYer, can easily build such grounding devices
dirt cheap !

FYI, my dedicated 120V/250V powerlines hooked up from my house electric panel direct to my dual-voltage rig with inline power conditioners, got its dedicated ground wires hooked up direct to the house main grounding enchor (at the incoming underground water main) at my house basement.

I believe my rig does not need expensive grounding boxes like Nordost.

Jack L.
Canada

spacehound's picture

"low voltage attractor plate etc. etc."

I sure would raise an eyebrow.
It's meaningless pseudo scientific gibberish from beginning to end.

A suggestion: Connect your grounding rod via another 8 gauge wire to your main household water supply pipe with a metal strap. (It's standard practice here in the UK.) Then take your 'household ground' from one or the other, not both.

mrkaic's picture

Pseudo science is rather popular among audiophiles. Don’t you know?

spacehound's picture

But I'm not new. I have been interested in high fidelity music reproduction since the 1960's. Nowadays I see so many 'useful idiots' in the hifi magazines advocating such garbage (and many people falling for it) that it is beginning to put me off the entire hifi 'environment'.

mrkaic's picture

...you seem to be new on this site. I used to be bothered by audio flat-earthers when I started reading this magazine (and other audio related stuff). Now, I just laugh at all audio pseudo-science.

spacehound's picture

But only feel moved to comment when I see reports on nonsense such as this. (I'm a mathematician/physicist by trade, employed, but now semi-retired, in the 'big' computer industry in what you might call 'leading edge applied physics'.)

The pure unadulterated gibberish I see so often in the hifi industry and its dependents, such as the magazines, has, I feel, greatly damaged the credibility of the industry as a whole. EG: Where I live, Southampton UK, used to have about eight specialist hifi shops. Now it has only one, and that one is not doing well, despite that expensive hifi is not something people usually buy online.

Also of course the 'mass' manufacturers have come up so well that the tiny specialist manufacturers can offer very little in the way of better sound except possibly for speakers. It's not a matter of diminiahing returns, it's a matter of no returns at all from the high priced specialists, even more so when the price of all other electronic equipment is reducing while theirs goes up and up. It's not that people can't afford it, it's that they choose not to buy it.

Anton's picture

How can you deny what Jason heard?

_

Side note: I am fine with changing 'pseudo-science' to a term that doesn't associate itself with science at all. How about we switch to 'audio mythos' or 'audio superstition' and get well clear of besmirching science at all.

spacehound's picture

But what he (or anyone else, including myself) think we hear and what sound is actually emitted are not necessarily the same.

As for your other comment, "pseudo-science" is fine. It underlines the total falsity of many of these claims. Here in the UK we have an 'Advertising Standards Authority' and some cable companies have been prevented from making such false claims.

Jack L's picture

.. and some cable companies have been prevented from making such false claims." quoted spacehound.

Basing on what "authority" or jurisdiction the 'Advertising Standard Authority' can declare whatever advertised is "FALSE claims" ?

It is NOT as easy as one may assume to prove an advertisement or commercial a "false claim" for anything personal & subjective, e.g. food, wines, sound equipment. etc etc. Otherwise the authority will be challenged legally.

Jack L.

HammerSandwich's picture

Why, what could possibly go wrong with that?

The EU regulators who blocked amplifier outputs must have seen this insanity coming.

Bogolu Haranath's picture

"Terra Firma" ......... Todd Rundgren :-) ..........

NeilS's picture

"...Connecting just a single power distributor or conditioner to a QKore1 or QKore6 brought marked improvements; adding as many additional components as possible increased the effect greatly. The law of diminishing returns does not apply; the differences were cumulative, and anything but subtle..."

A sure shoo-in for the next Nobel Prize for Economics, just a matter of showing empirically these thingies do indeed invalidate a fundamental tenet of economic theory!

spacehound's picture

It's physics too. This nonsense box from Nordhost, the recently announced 24,000 dollar loudspeaker cables from Audioquest, etc, etc, etc.

And there is no known science behind any of it.

THEREFORE I will only consider purchasing any of such stuff when the manufacturers show me their Nobel Prizes for physics. Until they can it all remains snake oil.

Jack L's picture

"when the manufacturers show me their Nobel Prizes for physics. Until they can it all remains snake oil." quoted by spacehound.

Everything goes by the nature - physics.

So when Sir Isaac Newton discovered gravitation physics from the apple felt on his head, he did not awarded any Nobel Prizes or whatever equal qualification. So... ?

Jack L.

hb72's picture

you seem to have a very simplified idea of physics.

Physics is not (only) what is covered in a collage-level physics course textbook, but it is what governs processes in nature, some of which is known and can be explained with useful theories & models, some of it is only observed, measured if you want, but not yet well understood w.r.t. fundamental mechanisms. E.g. the concept of mass and mass-mass interaction is only recenetly started to be understood (beyond observational level, of course) and integrated into existing theories.

Rather than referring to all-too simple text book physics, physisists tend to rely on measurements when it comes to complex unpredictable systems (human perception of reproduced music on complex hifi kit IMO is complex).
I guess in musical reproduction this *could* be via "listening" as this, though subjective, is not only the ultimate but also the most accessible musical measurement process which involves the human processing of musical signals including the errors in reproduction.

Talking of measurements: grounding issues is an issue in experimental physics (the part that focusses on measurements and validation of theories, as opposed to theoretical physics): measuring tiny differences in electric potential (nV) is a problem common to some sub-disciplines in physics, and measurements are influenced by many disturbing effects (starting from contact resistance, noise of all sorts including thermal lattice vibrations,..). --> Having a useful reference for and not introducing error/noise to such voltage measurements is key.

Back to musical reproduction: firstly one never ceases to learn - the effect of grounding, even through slightly different ground levels on 2 RCA source inputs into a pre-amp, can be heard very easily (at least I can on my equipment, a NAIM NAIT XS).

Whether and to what extent the effects of Kimber's grounding system can be heard I cannot say, but the obviously most useful working hypothesis might be "just about as JVS has described them for his system" until you or I have heard it with our own ears. Until then, keep calm and do not feel coerced to spend money on kit you haven't heard.

Bogolu Haranath's picture

Waiting for the review of that $24,000 speaker cable by JVS :-) ...........

Bogolu Haranath's picture

If the loudspeaker is Quad wirable, the total cost for the speaker cable would be $100,000 :-) ..........

That would be the 'law of increasing returns' :-) ............

May be DSD 1024 and PCM 32/768 are examples of 'law of increasing returns' :-) ............

mrkaic's picture

The stuff is actually too cheap. It would sound so much better if it cost twice as much.

spacehound's picture

As I have said before, here and elsewhere, when these manufacturers show me their Nobel Prizes for discovering previously unknown physics I will start to believe there may be some truth in what they claim.

But there is another problem. I have never seen any physics equations with 'price' as a factor and I doubt I ever will.

Anton's picture

Happy new year!

spacehound's picture

I have got fed up with all the nonsensical stuff reported on many Hi-Fi sites so mostly only comment when I feel really annoyed by all the garbage.

For what it's worth Stereophile is far better than most. There is one well-known site where the 'anti-science' (not just ignorance) has reached ludicrous levels and any semblance of objectivity appears to be actively discouraged by the site operator.

Happy new year to you.

Jack L's picture

... as a factor and I doubt I ever will." quoted spacehound.

Hi

Apparently you never own/run any business to make some profit. If you did, would you tell the world how much money you make in yr business, be it
audio equipment or cars, or whatever, in "any physics equations with price"?

Jack L.

Hobbyist's picture

After reading this JVS review with some interest and a great deal of skepticism for the “LVAP” device, checking some basic physics and electrical engineering topics, and downloading some excellent AES articles/white papers on hum/noise problems by Bill Whitaker of Jensen plus a series of RaneNotes from Rane Commercial Audio Products, I then found these posts on the Stereophile website. I also studied all information available on the Nordost web site, including the product’s Instruction Manual.

It was gratifying to see from these posts that there are a number of electrically astute Stereophile readers.

I suspect that these magic QKore boxes and wires may actually do some good if your system has unequal chassis ground potentials that are causing chassis noise currents (as in AC, NOT DC, as Serinus mentioned on p. 114). If so, then the QKore devices may be working to establish a proper star grounding system, but at terrific cost. My estimate is $13,610 to ground six components and a power strip, using two platinum and one bronze “Kone” for each of three QKore boxes, which comprise the Nordost recommended setup.

As a simple “proof of concept” experiment, I constructed a star ground system, wiring together four components (all with 3-prong grounded AC) and a power strip via 16 AWG stranded/PTFE-insulated wires with spade lugs, connecting to a solid chassis ground point on each device. I did NOT use an RCA, XLR or other open jack, since jack wiring is variable. Having no idea what electrical principle gives the Nordost LVAP its low voltage attractive powers, a stack of scrubbed and sanded thin copper plates, mounted in an aluminum project box, was used to provide a low impedance sink.

Based on Coulomb’s Law and the definition of ampere (Halliday and Resnick, Physics 3rd Ed, Vol. II, p. 569, 1978), the charge carrying ability of copper is quite substantial. My stack of about 60 plates, each 0.005-inch thick and 4.5 by 0.75 inches, weighing 150 grams total, has enough copper atoms to accommodate a charge of some 6.5 x 106 Coulombs. It would take over 2,000 years to accumulate this charge at a rate of 0.1 mA. This is a typical chassis current for a medium power (20-100 Watt) audio component with a 115V mains transformer, according to Bill Whitlock of Jensen Transformers (AN-004, “Hum and Buzz in Unbalanced Interconnect Systems”).

Results: There MAY be a slight improvement in background “blackness”, but since I could not initially measure any inter-chassis currents or chassis potential differences (all zero), and had a low 1 ohm Neutral to Earth ground DC resistance in the dedicated 20 amp circuit used for the audio system BEFORE the star grounding box was added. There were no audible noise problems to begin with, so it is impossible to say if there was any real improvement, or merely a placebo effect. No harm was done, it was fun, and I saved about $13,600. (It IS a hobby, Jason!)

Bottom line – Even 150 grams of copper apparently has enough charge carriers to function as a sink for the tiny alternating currents which are the primary cause of audible and inaudible system noise.
Star grounding – good.
LVAP – audio mythology and a sales pitch. Ditto for the vibration-dampening “Kones”.

Jack L's picture

"t would take over 2,000 years to accumulate this charge at a rate of 0.1 mA." quoted Hobbyist.

So who needs the thick $356 charge drain cable built with silver-plated copper & Teflon insulation etc etc. Well, money talks !?

I can build a much much thinner cable (just to drain out 0.1mA) built with silver-plated oxygen-free pure solid copper wire in Teflon tube jacket, costing me like peanut !

My question: so we NEED to have such exotic drain cable to drain off
micro currents?

Knowledge is the power to save money !

Jack L.

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