Shunyata Research Everest 8000 power conditioner

Shunyata Research is the brainchild of Caelin Gabriel, whose résumé includes stints at NSA, in military R&D, and in the computer industry, first digging weak signals out of noise then developing very high-speed network devices. He is also a lifelong audiophile.

Shunyata's roots are in the scientific understanding and engineering base Gabriel has developed during his career. I've long been impressed by those scientific underpinnings—which extend not only in audio but also to other fields including medical devices—and by how open the company is in talking about its technologies.

Just as I was starting to think about new power systems and cables, I got advice from a friend whose ears I trust and who knows my system and what's important to me. When I asked him to share his thoughts, he didn't hesitate: He told me to check out Shunyata. That seemed like a fine idea.

System and setup
The AC power serving my audio room is by all accounts quite good. AC is supplied to the room by a dedicated load center (breaker box) connected directly to a Pacific Gas and Electric input box. The load center feeds two dedicated 30A circuits; each connects to a quad box equipped with hospital-grade outlets.

After discussing my system with Shunyata's Grant Samuelson, he concluded that the best match would be an Everest 8000 Power Distributor ($8000), a Sigma v2 XC ($3250) power cord to connect it to the wall, and Alpha v2 NR power cords ($2000) between the Everest and my front-end components. My VTL amps would plug directly into the second circuit with Shunyata's Alpha v2 NR power cords.


The theory
Shunyata is known for having an extensive base of science and technology underpinning their products, including patents for some of their foundational technologies dating back to the 1990s. I'm the type of nerd who finds correcting textbooks entertaining: This was going to be fun.

Descriptions of Shunyata's technologies and their implementation are available on the company's website; instead of going through every aspect of those technologies, I'll refer the reader there (footnote 1) and mention only a couple of key ones here, which merit a few paragraphs because of their importance in Gabriel's design goals, and which describe areas where his approach may vary from conventional wisdom.

One of these is his assertion that the majority of the noise problem in AC circuits in audio systems is generated by the components themselves; only a small portion is a gift from the power company. "The difference is that people usually go along with the norm. In this case, that's viewing a component's power cord as the end of a long chain that delivers AC to the component. That's not right. It's a complete circuit. The component connects two legs of the AC, the hot and the neutral." Noise goes both ways: From the AC into the component and from the component into the AC. Both lines and the ground have to be addressed to eliminate component-generated noise.


The Everest addresses component-to-component interference—Shunyata has taken a trademark on the initialism, CCI—in a couple of ways. The first is to partition the outputs into isolation zones. The Everest has six: one each for four individual receptacles and one each for two duplex outlets. The next is to bleed off noise on the powerlines, which is done primarily by the "CCI Filter. "It's a potted module, so I couldn't take it apart, but it's described by Shunyata as "filter modules that consist of proprietary multi-stage filters that reduce power-supply–generated noise without the use of heavy transformers, coils, or large capacitors."

The other area where Shunyata follows a path less traveled arises from Gabriel's belief that one of the major factors limiting an audio system's performance, if not the major factor, is whether a component's power supply can draw enough instantaneous current from the incoming AC to keep up with the component's needs during musical transients (especially in power amplifiers, the more powerful, the worse). In Shunyata lingo, this is called Dynamic Transient Current Delivery, or DTCD. Shunyata worked with a recently retired Tektronix engineer to develop a test system that measures DTCD; their results appear to show clear differences among power cords, AC plugs, and receptacles.


But how much does it matter?
I'm convinced that the science is real enough, and the engineering makes sense. But how significant is it in the real world? Do those technologies add up to real, tangible improvements in a high-quality audio system? The rubber hits the road when the derriere hits the listening seat.

After installing the Everest and the Shunyata cords, I started by casually listening to a batch of randomly selected albums, just to get a feel for how the performance of my system had changed. Casual listening was more than enough to hear the difference: My system sounded significantly better.

Shunyata Research
26273 Twelve Trees Ln.
Poulsbo, WA 98370
(360) 598-9935

NeilS's picture

If a power conditioner can have such an effect, imagine the effect of a combined power shampoo and conditioner.

davemill8's picture

Shunyata refers to these products as power distributors not conditioners.

teched58's picture

Dwight Yoakam sounding better isn't worth $8,000 to me. Are measurements from John forthcoming?

John Atkinson's picture
Sorry, no.

John Atkinson
Technical Editor, Stereophile

cgh's picture

Do you have any thoughts on the measurements in the footnote (

5ms/div is certainly sub-integration for human hearing by a factor of 20. 50V seems large? What would be the effects? X modulation?

MhtLion's picture

See if it can improve Michael Fremer's place. And, see if it can replace PS Audio Power Plant at his place. If it cannot - it's definitely not worth $8,000.

davemill8's picture

Because your place has the same issue as Michael's? If not, your logic of it not being worth it doesn't make sense and that is putting it nicely.

I own the Denali 6000/S v2 which is currently Shunyata's second best power distributor after the Everest. I am also using the same power cables from the wall, to my amplifier, and DAC as Brian. Also using Alpha v2 XLR and speaker cables. In addition to what many other owners of the Denali and Everest have mentioned online, I have found that while the addition of these products improved the sound of a system right out of the box it significantly improved the sound after about 100 or so hours of use. To all of the naysayers who don't believe it, listening is believing. I also posted a reply to Michael's article saying that my money would be on Shunyata over PS Audio. I think PS Audio and Audioquest power conditioning products are long in the tooth. A faceoff between these products would be great but we know why Stereophile won't do one. We can hear what is measured but not everything that can be heard can be measured. My experience with all of Shunyata products I own is they are worth every penny. That's over $20K which is approximately half of the my system's total cost.

MhtLion's picture

Oh, believe me. I trust in the power product. But, I do not agree with their high prices all the time. For me, an $8000 product should fix the power issue such as Michale Fremar was having. But, that's just my opinion. Also, personally think the way you allocated the budget - 50% into the power accessories - is not optimal. But, that's just my opinion too.

mns3dhm's picture

Will you see a $2495 amplifier review followed by a $8000 power conditioner review. This brings me to the question as to how does Stereophile go about deciding which products to write up. I think you've covered this before but I am curious how the editor and or staff decide upon the components. Is there a reference article on this subject?

davemill8's picture

People have different budgets. Nobody expects the same person to buy a Brooklyn amplifier and use an Everest power distributor with it. That would be overkill. American is still a capitalist country.

cgh's picture

I hate to devolve into a conversation about price... caveat, I like what Caelin Gabriel does. I've heard their products. I am a fan. That being said...

I think the more interesting question is "why haven't prices come down in audio?" If price admits a decomposition roughly like price = parts + box + IP + conspicuous consumption factor... and, if parts are cheap relative to total price, box is expensive but still << total cost, and IP hasn't changed in years (cables and turntables and amps come to mind), or has been largely compensated away by early investors,..., and if prices pace or exceed inflation (which is non-existent), then it must be the luxury factor. Who knows? Maybe they could make up in volume if the prices were lower. I know Asian consumers of hifi have supplanted US demand in recent years maintaining and, in some cases, increasing prices. Small N on that last one but I have some datapoints that all point in the same direction.

davemill8's picture

There is a current shortage of integrated circuits limiting the production of automobiles right now. As for inflation, it will be coming if the Biden administration is able to pass all of its multi-trillion dollar bills. This doesn't answer your question though about why audio prices haven't come down and I can't answer it. My hope is that manufacturers use their profits towards developing new products. I am willing to pay more for a US designed and manufactured product like Shunyata produces. IMO and that of many others on online audio media boards, the Everest is the best power distributor on the market right now. It's price is more than fair to me.

cgh's picture

Maybe. Even more of a divergence... but we saw full employment and wage inflation and a subsequent breakdown (of the admittedly flawed) Phillip's curve (i.e., wage inflation leads to spending and increased core CPI). Now we can account for about 30%-40% of that due to other factors even less relevant here. Hopefully we see some inflation (we are seeing "breakeven inflation" in bonds now) but the mantra of late is "we haven't seen inflation in 40 years and it will not be like it was in 1980". Regardless, my generic point is that if you take a 10-12 swath of recent time we've seen prices of equipment increase despite the topologies - inductor and capacitor based - not change. I assume that most of the wires and caps and stuff have been "inventory" for a while now. If we are talking about SMIDcap companies they should be able to take profits and tax breaks and invest in R&D, which I believe hasn't really happened with power conditioners, cables, turntables, and class A amps in the past 10+ years, at least in any kind of fundamental way. I think my overall point is these are luxury items and scarcity protects their initial price point.

davemill8's picture

Unlike other brands, owners of Shunyata power distributors are upgrading to the new versions of products. That is development, thus my "long in tooth" comment.

shawnwes's picture

Are his multi trillion $ baleouts any worse than the Orange Faced Clown who got the boot and is the biggest crybaby in US political history?

That's all I got for ya. Back to audio.

Briandrumzilla's picture

Add in the price of the cords and you are at $13,250, assuming one $2,000 cord was used.

yourfriendfred's picture


davemill8's picture

Yes, the Sigma XC is actually the minimum power cord that is recommended for the Everest. After discussing this with Caelin on another audio social media site, it is the reason I purchased one for my Denali as I may upgrade it to the Everest in the future. Many Everest owners purchase the Omega XC power cord which is $7000. The other recommendation which I also did was to replace the duplex wall outlet with the Shunyata Copperconn duplex outlet which is $300.

BTW, I got called a shill and banned from the Revel Owners Forum thread on the AVS Forum website even though I own a pair of F228Be's which I only decided to keep after adding Shunyata's products. The F228Be's just didn't sound like $10K speakers until they have the right equipment supporting them thus the system.

allvinyl's picture

I used to have a A/V and all Alpha HC PCs, original version. I agree with Shunyata's recommendation of the Sigma XC for the Everest as I followed their advice some years ago on using a Alpha HC on my A/V. I have since sold the A/V and Alpha HC PCs. I am now trying to understand the new product line; differences between Denali v2 and Everest, which PCs to use, and do I still need the Typhon(which I still have)?

Glotz's picture

Yep. That too. If you spend enough on luxury, it requires the accessories to match it.

Otherwise one is using $100 tires on a $300,000 vehicle.

That doesn't sound right, does it? The same applies to audio. Michael has a over a million dollars invested in his system. He is also not a snob.

davemill8's picture

Actually, $3250 is a lot for a set of tires! Audio is getting high in price as a previous poster mentioned. I just bought a new set of race tires for my Porsche GT3 and they were about $1500 but they will wear out fast on the track!

Glotz's picture

But there are a lot of tires and/or wheels that justify $3k, especially with Ferrari and the performance level of several hundred thousand dollars. There are several other areas of spend in luxury cars that also raise eyebrows, as in audio. $200,000+ is a lot to spend on a track toy.

But your assertion only proves the fact 'cost of ownership' has a price requirements especially where high performance is concerned. You certainly wouldn't place $100 tires on your track car, despite the life of tire, wear and cost. The performance demands much more. Most normal people would scoff at $1500 per tire set like you scoff at $3250 for cables.

Either way, I know track guys can go through more than one set of tires in a day or a week, when compared to audio/power cables life spans. These cables would be a much lower cost to ownership ratio any way one would dissect it.

Audio and power cables have of lower priced alternatives. No expects the neophyte in audio like yourself to pay out $3k, $5k or $8k. Shunyata's Venom series is fantastic, as are lower priced offerings from AudioQuest or tons of other manufacturer's. They are also way affordable at a 1/10 of the cost here.

Despite being a cottage industry, these companies provide superlative performance. If one wants measurements to prove it, go to Shunyata's website.

High performance sports cars have also become exponentially expensive, very much in the way audio has. To imply anything else is BS.

davemill8's picture

You mentioned a Ferrari in title thus I introduced another superior car n my response. I own a Sigma XC and other Shunyata products that retail for over $20K! I own a full loom of Alpha v2 and you owe me an apology! Sorry, if reading comprehension isn't your thing!

Glotz's picture

Apparently your language is the issue here.

davemill8's picture

I was correct your reading comprehension is nil! Peace out ✌️

Glotz's picture

Uh huh. Right.

Jack L's picture


For cheapskate like your truly, $3,250 for power cables is worthy for me to scoff at.

Why would ever I spend such hard earned money to finance cables vendors when I can build my own, even BETTER, IMO.

Years back, I design/built my power cords for my tube power amp for much much much less cost. Conductors are 99.99% pure solid silver wire of German origin, air/Teflon dielectric as insulation, AIR tight to ensure pure silver free from oxidation. The total thickness of the power cord looks the same thickness of the $2,000 Shunyata power cable. 4-5xNines pure silvers are always expensive. Yet I got a bunch from a military surplus shop dirt cheap for all my interconnects & power cords. Were I smart or what ?

Please don't tell me silver does noy sound good before whoever ever auditions it as no such all silver audio cables available in the cable market yet, IMO. Might be way way too expensive to sell ???

Listening is believing

Jack L

PS: my cable know-how surely worths more more more than $3,200 !

Glotz's picture

Those are pretty audacious claims there.

I've made several Kimber Kable Silver Streak and KCAG variants with WBT connectors at a fraction of the cost of buying new. Real nice, depending on the application.

There are all-silver cables out there, available for 40 years or so. And embedded gold/silver cables and many other alloy-based ones as well. There are a lot of well-established, professional cable companies making cables at every conceivable price point and doing it competitively in a crowded marketplace.

Where do you think Shunyata needs to improve to get to your level?

I still think Audioquest and Shunyata Research are producing technologies that go above and beyond what single operators could possibly imagine, let alone create and mass produce.

Jack L's picture

Hi Glotz

I'll be more than happy to comment on any brand name cable designs as long as these designs are available to me. This won't happen as such designs are always deemed proprietary & kept from the public.

I can always start up my own manufacturing & vendering. But for what ? For making thousands more bucks? As I said before, I'm taking much easier monies in the money markets by simply hitting the keyboard ! Why bother ?

For own satisfaction in the PROCESS of DIYing & enjoying the accomplishment of it. Unlike most audio DIYers, I never want to crone whatever well-known brandnames. I want to design/build better than most, if not all, of them, backed up by my common sense logic & engineering background.

Like Leo Da Vinci who painted his masterpieces: "Mono Lisa" (1507) & Salvator Mundi (1490-1500). All these were his art brainchilds, not for wholesaling.

In fact, like most art lovers, I like genuine old paintings which all worth tons of money if still available today. In my family room, I framed up a few computerized replicas of the world's most expensive paintings: including "Mono Lisa" (priceless) & Salvator Mundi (USD 450 millions auctioned 2017).

Jack L

Glotz's picture

Isolation components are another great area to experiment.

Jack L's picture


Yes, components "isolation" is the right way to go: to reduce RGI/EMI pollution generated by individual components. to the sharing powerlines.

Many years back, I already discovered such issue & have an powerline line isolation system installed since then. It works like a chime.

The beautiful of it is no need of spending big big bucks to acquire whatever brandnamed power conditioner+isolators. Some such powerline gadgets might affect the sound - my main concern besides their cost.

Tomorrow, I will address this ISOLATION issue in detail in responding to J.A.'s post below.

Jack L

RH's picture

I know that Stereophile does not measure audio cables, power cables, power conditioners etc (and in my more cynical moods, I imagine why...)

But I don't see why the following wouldn't be a useful service to readers:

If a power cable, or in this case Shunyata Power Conditioner, produces an audible difference, unless we are talking about magic, it is therefore altering the audio signal. Whether it's an "improvement" in reducing distortion or whatever, the signal coming out of equipment, e.g. a DAC, the preamp, the amp, must be changed to some degree vs when the power conditioner is not in the chain.

Why can't this be measured? Analyze the output of the signal from the DAC, or the pre-amp, or wherever. You have the equipment.

I know working in Pro Tools myself that if I make ANY alteration to an audio file - volume, the tiniest move of eq, the least bit of compression, any bit of added reverb, literally any alteration of any sonic relevance, it shows up in the waveform. It will be different when compared to the original.

So why not do such comparisons of the music signal put out by, say, a DAC with and without a boutique AC cable, or power conditioner, to see if there's even a difference? I can't imagine there is no way to measure the alteration to the music signal, if the conditioner is able to alter the signal to the significant degree reported by the reviewer.

davemill8's picture

Via subjective hearing responses and provide statistically meaningful data. That is the challenge. Up for it?

For one, I am too impatient to wait. I just trust my ears.

RH's picture

"Via subjective hearing responses and provide statistically meaningful data. That is the challenge. Up for it?"

I'm first proposing something even more modest: that someone demonstrate the audio signal is measurably changing AT ALL.
At least that gets claims for the phenomena off the ground.
(Another way would be to demonstrate audible differences can be identified in blind testing, to a statistically reliable degree. That is truly "trusting one's ears." But since blind testing is a bogey-man in these discussions...we can leave that aside for a moment).

"For one, I am too impatient to wait. I just trust my ears."

Sure, I can appreciate that, if that suits your own personality and goals.

But when it comes to a product segment for which there are controversial claims, like AC cables and power conditioners, some prefer to see some reliable evidence, before they would bother putting money or time or effort in to acquiring the product.

Everyone has their own way of allotting their time, attention and money, in the way that makes them happy.


Archimago's picture

The job to start off with is not to prove that such a device can result in:

"Casual listening was more than enough to hear the difference: My system sounded significantly better."

As per Brian's claim in this article.

Show us that it actually changed the output of the Mytek Brooklyn DAC+ (low power) or VTL monoblock (high power) that was used in this review. Heck, even measure the room frequency response to show a difference if that might be helpful in identifying the "sounded significantly better" claim.

There is no other reasonable conclusion but to be very suspicious if after all these years, no such evidence exists when we can get down to measured resolution with noise floor down to better than -130dB, jitter of femtoseconds, precise frequency responses, easily repeatable power-distortion levels of amps, etc...

davemill8's picture

Your ears are oscilloscopes. I get it.

RH's picture

"Your ears are oscilloscopes. I get it.",

No, just the opposite. "Ears," being attached to our suggestible brains, can be fooled.

JHL's picture the objectivist challenge generally goes, we can't trust ears but we presume to measure everything, why do high end audio?

If not to beat it into submission to those equally faulty conditions.

It's widely known - in the places where it is and not in the places where it's not, that being how patterns of evidence go - that capacitors, for example, are quite audibly affected by the relatively subtle mechanical deformations they undergo from electrical signal and acoustical feedback. While Jung and Marsh wrote a seminal piece on capacitors - measurements included - way back in the eigthties, only fairly recently has this other phenomenon taken root in audio thinking.

So: How would you "measure" anything between the AC input to the power supply and the wall? Seriously; how would you? By your example adjusting an amplitude-domain factor adjusts the amplitude domain. How would you propose to measure what's apparently quite audible in passive power equipment and has no signature in output amplitude.

That's not a challenge. I'm genuinely curious.

Not long ago this publication reprinted an article on measuring cables. Measuring. When we throw around that word, are we certain it applies everywhere, every time, and with obvious pertinence?

Or may we just listen through our Easily Trickled Ears, listening being why we do this. I hear capacitors, for example, even though I've learned not to bother looking for their trace evidence in simple measurements. Until I decide to become a million dollar research lab - without a dime of grant money because there is none - that'll just have to do.

In my view objectivism needs to reexamine its subjective assumptions.

Archimago's picture

Long post but I don't see anything here of relevance.

Supposedly the sonic effect is rather obvious such that:
"Casual listening was more than enough to hear the difference: My system sounded significantly better."

Just show how this affects the sound system with something suggestive of this level of significance.

I have used my own ears at a number of cable, power conditioner, and related demos already. I cannot say I have heard the kinds of things people claim. I would happily pay money to own this stuff - in cash - if it made a difference.

JHL's picture

Relevance to the question of proofs in audio, either something can be measured and thereby assumed to constitute a sighted proof or it can be heard, which is to say there is a proof in the intended use. The latter cannot be passed around, however, at least not nearly as easily.

But it also relates to the first-order use, which in this case, is hearing it, which data cannot.

If it can be heard and not measured, which appears to be the case today - at least among us casual observers although likely not in the lab - you have a choice. Go with it or not.

If on the other hand, it can be merely visually represented by data, are you going to shell out to own the device? Presents an interesting question, wouldn't you say?

That's the abstract you may not have caught in my first remark. (Personally I'd never attend a commercial demo for the same reason I wouldn't fiddle with rigid AB testing: The experiment upsets the reason to do hifi and with it the result of great hifi: It corrupts the sensory and mental aspects and turns them into stressed, interrupted competitions. I don't enjoy music at home from a great system for stressed, interrupted competition.)

At any rate, the nature of science is that hypothesis follows pattern of evidence, and scientific finding follows them both. The phenomena is unmoved; it doesn't care if a thing is 'proved' by data or not. And there are plenty of patterns of evidence and even more delayed individual confirmations that go 'unproved' in a relatively narrow field like the audio high end.

Whether data ultimately arises in support is as unknown to much of it almost as often as it is, ironically, irrelevant.

Jack L's picture


Simple answer:

(1) train up yr ears in music listening. It takes times & patience.
No overnite business. Your ears are not critical enough to
appreciate the difference, subtle or obvious.

(2) have your ears checked up medically to make sure they still work
properly as you think they should.

Don't blame others' audition superiority because your's are inferior without knowing so yourself.

Don't waste money further in audios if your ears are not ready yet.

Listening is believing

Jack L

PS: I can hear the substantial difference between pure silver cables & non-silver cables, both I design/built to compare.

Jack L's picture


Yes, YOUR own ears can "fool" you too!

So why blame those sensitive ears instead of blaming your own ears being "fooled" by its insensitivity.

Listening is believing

Jack L

Jack L's picture such evidence exists when we can get down to measured resolution with noise floor down to better than -130dB, jitter of femtoseconds, precise frequency responses, easily repeatable power-distortion levels of amps, etc..." quoted Achimago

How do YOU know all these measurable data you stated got anything to do with what we HEAR ??

Please substantiate your own such ASSUMPTION scientically !!!

Let me give you the truth: whatever data obtained from the measurement methodology you stated are IRRELEVANT to what our ears/brain perceive.

The WRONG things have been measured regarding what we actually hear since day one decades back.

So please don't bark up the wrong tree !

Listening is believing

Jack L

davemill8's picture

You want to dismiss anything that you are not willing to work for.

Archimago's picture

By not working to demonstrate with any evidence that a product like this does anything of value, companies like these are selling to Flatearthers.

Science can prove that the Earth isn't flat, no matter what 10,000 witnesses subjectively sees with their our own eyes at ground level. And it would not take much to find another 10,000 who understand the difference between subjective opinions and the more complete truth.

Where's the proof that this device works? Why is Stereophile not working to measure the differences?

[Perhaps this is not the way you intended "Flatearther" to be read. But I have always correlated the pure subjective folks as the anti-science belief-based Flatearthers in this hobby.]

RH's picture

The flatearth diss is certainly ironic: it's the Flatearthers who tell everyone they are simply "trusting their senses" over all that scientific data and gobbledygook. "I mean, you can simply USE YOUR EYES to see the earth looks flat!"

ChrisS's picture

...If you can't hear a difference, then don't buy it.

If you can't afford it, don't buy it.

It's simple.

ok's picture

is perfectly ok for everyday use as also is the equally wrong newtonian physics which audio "scientists" like to demonstrate as a sign of superiority over casual empeiricists. Please don't tell me about satellites since cell phones rely on relativity principles for positioning accuracy.

RH's picture

Methinks you missed the point.

Jack L's picture

........Science can prove that the Earth isn't flat, no matter what 10,000 witnesses subjectively sees with their our own eyes at ground level. quoted Archimago.

Very true. Spherical Earth was first established by an ancient
Greek: Aristotle (384-322BC). Yet today, the International Flat Earth Society (founded 1956) is very active in selling the Flat Earth theory. It has taken some 2 & half thousand years since Aristotle & the Flat Earthers are still making loud noises today. So....

So you would expect objectivity vs subjectivity can be settled in a few decades??? Don't hold your breath so soon yet !

Listening is believing

Jack L

PeterG's picture

I'm the very satisfied owner of the similarly priced QKore/QBase system from Nordost, so I am not surprised at all with the reporting here. It matches my own experience, and if my stereo disappeared tomorrow, the only components I would replace without a second thought would be QKore/QBase.

But I do not understand why this stuff cannot be measured. I'm sure it's there.

John Atkinson's picture
RH wrote:
I know that Stereophile does not measure audio cables, power cables, power conditioners etc . . . But I don't see why the following wouldn't be a useful service to readers:

If a power cable, or in this case Shunyata Power Conditioner, produces an audible difference, unless we are talking about magic, it is therefore altering the audio signal. Whether it's an "improvement" in reducing distortion or whatever, the signal coming out of equipment, e.g. a DAC, the preamp, the amp, must be changed to some degree vs when the power conditioner is not in the chain.

Why can't this be measured? Analyze the output of the signal from the DAC, or the pre-amp, or wherever. You have the equipment.

I have been thinking about this a long time, since I experienced the improvement both a PS Audio PowerPlant (long since returned to the manufacturer) and an AudioQuest Niagara 5000 (on long-term loan) consistently made to the sound of my system.

I suspect there are two mechanisms at work here. First is the reduction of noise and distortion on the wall AC’s waveform. Second is the inverse, which is the reduction of noise generated by the power amplifier’s full-wave-rectified power supply being fed back into the AC supply for the source components. (The waveform of the current being supplied to the amplifier’s power supply is both discontinuous and dependent on the loudspeakers’ instantaneous demand for current.)

I am not sure what measurements of any one component would reveal the improvement in sound quality. Channel separation of the power amplifier at low frequencies might be improved. The noise floor of both the amplifier and the source components might be lower and with less AC supply components present.

But we don’t listen to these individual measured areas of performance. We listen to their effects, in combination with every other aspect of measured performance, on the quality of the perceptual models our brain creates in response to the two pressure waves, one from each loudspeaker, that reaches our ears. And this will be unique for every system/combination of products.

It will be very difficult, therefore, to determine which specific measurements should be performed to characterize what something like the Shunyata Everest does.

John Atkinson
Technical Editor, Stereophile

RH's picture

Thanks for the reply John!

Again, I wasn't necessarily talking about fully correlating the measurements to the purported sonic effects, but rather the more modest goal of simply "is it changing the musical signal AT ALL?"

Especially when it comes to the more controversial products, it makes sense to ask:

1. Is the product actually altering the signal in any measurable way at all?

If so:

2. Are the measured differences actually audible? (Given we can measure things we can not hear).

I was proposing to at least establish #1 to begin with. Simply show the musical signal has been altered in any measurable way.

"I am not sure what measurements of any one component would reveal the improvement in sound quality. Channel separation of the power amplifier at low frequencies might be improved. The noise floor of both the amplifier and the source components might be lower and with less AC supply components present. "

Sounds measurable. (?) Maybe null tests from the outputs?

Audiophiles and reviewers and cable manufacturers often speak of major sonic changes produced when replacing the AC cable on almost any device - amp, pre-amp, DAC etc.

If it's not an AC cable under review, but the Shunyata Everest, why not test the output signal from a DAC plugged in to the wall vs plugged in to the Everest? Even record the output. Compare for distortion. Compare the waveforms. Use a program that can find any difference in the file. etc. I know if I have two digital files that are measurably the same, they certainly sound the same. (And the waveforms are identical). Again, it seems to me if the audible claims are true the devices must be altering the music signal.

That would at least demonstrate something is changing in the signal, as a starting point.

It just seems rather odd that these companies purport to identify a technical problem that affects sound quality, purport to have devised a technical solution, but then the measurable evidence usually stops and we get marketing and testimonials. Or if any objective evidence is given it is indirect, showing how for instance noise on an AC line is reduced, which doesn't address the critics who point out well constructed equipment already filters such noise and so it's a solution in search of a problem. Of course the cable-makers claim otherwise. Which is why I think a demonstration that the output signal of a hi-fi system has been altered would make the most sense.

I'm certainly not saying I know the answers to any of this stuff. It's just the type of questions that seem to be raised by these types of products, and the reviews, for many people.

Thanks again!

Jack L's picture

....ONE from each oudspeaker.." quoted J.A.

Yes, you have hit the bulleye point-blank.

As you just said it, this is human nature to visual the 3-D spatial
perspectives from a pair of L & R channel loudspeakers. Closest to what we hear at a live music performance !!!

Obviously listening to headphones can't get such spatial effect like live performance.

That's the main reason why I woud not listen to any headphone music.

Listening is believing

Jack L

PS: that said, should I receive a quality headphone one day as a gift or lucky-draw prize, I would not mind build one simple tube OTL headphone amp for it. Circuit design crucially depends on the high or low impedance of the headphone !!!!!!!!!!

mns3dhm's picture

My original question above simply asked how Stereophile goes about selecting components for review. That does not seem like an unreasonable question so I ask it again: How does the team at Stereophile decide which components to evaluate and how are they grouped into an issue? It doesn't seem like this would be a trade secret so what's up with this?

Jack L's picture


First off, we got to qualify what are the "noises" in the powerline. Surprised this crucial info was not mentioned in the revew. What so 'mysterious'? Why Shunyata should hide it from us, the consumers ?

The noises are, IMO, RFI (radio frequency interferance) & EMI.

The main polluter is not the noises generated from any analogue equipment. It is the DIGITAL equipment that generate tons of RFI noise to the powerline shared with other digital & analogue equipment.

I noticed this problem many years back. So I tested the AC powerline noises with my digital wideband power line & EMI noise analyser. I plugged the tester in the outlet next to the CD player.

Whenever I switched the CD player on, the tester showed noise surged in the power line instantly. The noise surge was gone immediately when the CD player power was switched off. Noise surge of different amplitudes showed in the tester in different locations, ie: homes, offices & showrooms with different digital gears.

This shows digital equipment MUST be completely ISOLATED when sharing the same powerline.

I got to go now. Will carry on ASAP.

Jack L

Jack L's picture


The above Brian D requoted what C. Gabriel told him apparently.

IMO, it depends !! Only if the power transformer built inside the powerline conditioners or built inside the audio component got electrostatic shield sandwiched btween the primary & the second windings. Such shield will dramatically reduce noises coming from the power company distribution networks outside from getting into the conditioners or components thru capacitive coupling. The issue is not every such built-in power transformers get the electrostatic shields. Less costly standard gears normally don't.

Apparently C. Grabriel wanted to promote the 'specialty' feature: ISOLATION built inside his Everest model, downplaying the serious realworld situation of the dirty utility power inside our houses.

He either neglected or purposely disregarded the heavily RFI/EMI pollution of the powerlines installed inside our homes or offices.

The digital control boards built inside electric appliances, e.g. fridge, stove, washing machines,& electronic devices, like TVs, computers, SM chargers/wall warts for cellphones, laptops, cordless phones etc, ALL generate RFI/EMI noises which are dumped into the utility powerline loops installed behind the walls, underneath the floor & above the ceilings via the wall outlets.

Full-time WiFi will make things even worse by injecting more RFI/EMI (radiation noise) into the concealed powerline loops surrounding the premises.

This means the digital noises are already there in the powerlines, affecting our audio gears digitally & SONICALLY once our audio gears are plugged into the 'dirty' wall outlets = digital noise sewer manholes !!!!!

That's why I NEVER plug my audio gears directly into any wall outlets. Too digital noise polluted .

The best solution, IMO, is to obtain much much cleaner power for our audio electronics DIRECT from the mains breaker panel. So no direct connect with the household power sewers.

My solution for clean power supply is DEDICATED powerlines hooked up direct to my house main circuit breaker panel in metal grounded enclosure directly to my audio rig dedicated power strips.

With such much much cleaner power, no need expensive & complex conditioners which might affect the music sonic quality, my main concern besides the costly price.

For better sound, I installed simple LCR type RFI/EMI inline filters made in England (up to beyond 100MHz wth max insert loss of 32dB at 50MHz) for each of the 4 discrete powerlines for digital & analogue components.

Why 4 dedicated sub-powerlines so many?

For digital & analolgue components ISOLATION: 1 exclusively for digital gears: CD, Wi-Fi Blu-ray players, DAC, SM wall-warts etc.
1 for my tube preamps & tube power amps, 1 for my 3 active subwoofers. The 4th filtered subline is for my 240VAC TT.

So all my digital gears are totally ISOLATED from ALL my analgue gears. Clean power = clean musical sound.

This 4-sublined RFI/EMI conditioned dedicated power system works like a chime - installed some 8 years back for a very affordable cost. Play SMART clean power !!!

A test question: how to eliminate digtial contamination among the digital components sharing the same dedicated powerline like my case ??

Listening is believing

Jack L

tonykaz's picture

The PS Powerplants are the finest electrical engineering solution money can buy, it's measurable and verifiable. PS creates the ideal waveform.

These other outfits are offering filters.

Tony in Venice Florida

ps. Reviewing without having a PS Powerplant creates questionable conclusions, it's like evaluating a car by driving on a bumpy dirt road.

davemill8's picture

Right now, the majority of main stream audio sites are saying that the Everest rules! I would love to see an objective comparison.

Jack L's picture


Yes, PS powerplants generate pure sinewave AC power.

But do they also provide ISOLATION for individual components, particularly digital components which generate tons of RFI/EMI noises into the powrline shared by ALL other equipment ??

The AC powerline RFI/EMI noise situation is TWOfolded:
(1) pure AC power supply from the wall outs to the audio rig = purification.

(2) pure AC powerline SHARING with ALL auido compoenents which also
generate RFI/EMI noise into the shared powerline. = isolution

An ideal AC powerline conditioner must handle the above both issues effeciently.

From technical viewpoint, the Shunyata Everest seems capacable of tackling both above issues for a high price.

But my homebrew RFI/EMI powerline system can handle both the above situation: purification AND isolation, for a much much affordable cost.

Check out my post (2) on the same subject to J. A. later.

Jack L

tonykaz's picture

You seem to have matters well-in-hand and you don't seem confined to Audiophile Superstitions.

Well done.

Tony in Venice Florida

Jack L's picture


Thanks for yr compliments !

Yes, my electrical engineering background & experience defies

audio conventional wisdom or "audiophile superstitions".

Jack L

tonykaz's picture

Main stream audio reviewers work with 110v which uses price-point connectivity devices.

The published reviewers seem to be using Audioquest power filter devices ( probably on permanent loan ).

In the USA, All of the highest level of home audio seems to be running on half of a full 240V system when they could easily switch to a Full 240v configuration with properly designed devices. go figure! The rest of the civilised World runs 240V. ( except Japan which is way behind with their 100v )

We all have dirty Mains power with variations in voltage and cycles.

The PS Powerplant is an Audio Amplifier that outputs a user adjustable Output Voltage at it's Rated Wattage, it is not a Filter.

If you have clean power, you won't need filter devices!

By the way, anyone could build their own version of the PS device, it's just an Audio frequency Amplifier & oscillator. Today's Audio Amplification creates super pure outputs with super low distortions.

Tony in Venice Florida

JHL's picture

The first is power factor correction (PFC).

The second is in the article:

...the majority of the noise problem in AC circuits in audio systems is generated by the components themselves; only a small portion is a gift from the power company. "The difference is that people usually go along with the norm. In this case, that's viewing a component's power cord as the end of a long chain that delivers AC to the component. That's not right. It's a complete circuit. The component connects two legs of the AC, the hot and the neutral." Noise goes both ways: From the AC into the component and from the component into the AC. Both lines and the ground have to be addressed to eliminate component-generated noise.

tonykaz's picture

We create an abundance of noise from multiple sources including our LED bulbs, disposers, etc.
Even our neighbours running tools will cause havoc for our listening.

I think that you are suggesting some sort of noise trap between our gear and our power. I presume that you consider Audio gear to create it's own noise problems that the manufacturers neglected to address.

This entire field of Powerplants and noise filter systems is finally being considered by Audiophiles, while I've been working with it since the 1960s.

Rave reviews of filters suggests the reviewer lives in a horrendously noisy and unique environment that lacks sound engineering principals of design.

I support starting with a clean supply of 240v AC and then isolating problems for minimising.

Still, high performance-promising Audiophile gear tends to suffer from price point power supply issues.

Tony in Venice Florida

ps. Schiit seems willing to describe some of their design considerations when discussing power supplies, does anyone else ?

JHL's picture

...deviates from the salient point:

I think that you are suggesting some sort of noise trap between our gear and our power. I presume that you consider Audio gear to create it's own noise problems that the manufacturers neglected to address.

Kindly reread either the quote or the original article. It's as impossible to cure noise as it is to create zero output impedance or the perfect power supply. Noise can only be attenuated.

(Another term you could research is PSRR.)

Altogether and regardless of origin, noise on the power side is not infinitely attenuated. Likewise, amplifiers are imperfect.

The comprehensive question deals with all kinds of contaminates in all possible ways, a field unknown to the consumer. Casual assumptions about noise and power are likely to be flawed.

Jack L's picture


Both USA & it's neighbour country north of the border offer the same residential utility dual-voltage system: three wires = 2 live wires at same high voltage (120V USA, 125V Canada) & one neutral line.

For standard household appliances & electronics = 120V (1 live wire + neutral), & for high current appliances, e.g. kitchen stoves & clothes dryers: 2 live wires (120V+120V) = 240V bridged. The neutral wire unconnected.

For consumer safety, all household electrical appliances & electronics are design/built to operate at 120/125V60Hz AC ONLY.
No choice for consumers.

But if the audio equipment are built for 220VAC countries, most of them are dual voltage selectable.

Like my TT is 120V/240V switchable. I got it working on 250V60Hz AC as one powerline of my home dedicated powerline system is hooked up to 250V from the electrical breaker panel.

But do you think audio powered at 240VAC would sound better than working at 120VAC ??? That I am not so sure.

For sure, the sound of the same audio component will sound different subtlely on 120V vs 240VAC. Better or not, I am not so sure.

Jack L

Oilman's picture

Two of the Stereophile staff have experience with the PS Audio P20, and yet here is another wasted opportunity to COMPARE products. Have ~$10k to spend on power conditioning and need help deciding between leading choices in the category? You’ll get no help from Stereophile. Mustn’t compare the two and risk offending the “losing” advertiser.

Archimago's picture

And likely the comment about losing advertising probably is present at some level even if not overtly admitted to, right?

I'm still amazed by reviews of power products like this with page 2, the reviewer clearly states:
"The magnitude of noise reduction was startling.".

Jeez. How hard would it be to just plug in a DAC and look for any evidence of "noise"? Or plug in an amplifier and show that the noise floor improved? By all means, compare this and the PS Audio as well.

If that's not the kind of "noise" being spoken of in these kinds of subjective audio reviews, then perhaps another term should be invented to clarify what is meant!

[[This post has been edited to remove content that violates our posting standards.--Editor]]

RH's picture

3rd party testing validation would be intriguing.

Like you stated, I would certainly be likely in a product that can do what the reviewer claims! I'm just fairly cautious about what I am ready to believe when it comes to the more controversial realm of high end products.

The reviewer states "Shunyata is known for having an extensive base of science and technology underpinning their products,"

Where it would seem more fair to put it "Shunyata is known for CLAIMING to have an extensive base of science and technology underpinning their products,"

I mean, if a reviewer or company is going to invoke scientific credentials or methodology, then they are laying down the gauntlet of that high bar.

Peer review and/or testing by third parties is an important part of being scientific.

The problem is cable companies generally seem to all make their technical claims within their own bubble. They claim to have identified a technical problem (e.g. "noise" in AC power) and created the technical fix, but then the "evidence" is generally punted to marketing, anecdotal evidence and testimonials. In other words, dropping the scientific-type rigor just when it seems to count most!

Which, as you say, raises reasonable suspicions about the claims.
If any high end cable company could rise above this now-predictable pattern, for instance by actually having their technological claims objectively (or rigorously) verified by a competent third party, that would be unique as far as I'm aware.

(And, btw, I'm not talking about demonstrations with wall outlets or medical machines where one is supposed to infer that "therefore this will make your music sound better" but rather actual specific demonstrations that the product has a measurable/audible effect on the musical signal, which is after all the reason anyone buys the product).

Jack L's picture


No need to sound so helpless, pal.

As already posted here, I got 'evidence' of powerline noise: RFI in mV using my wideband powerline & EMI noise digital analyser many years back. This is powerline noise ABC to establish the need of powerline conditioning. NO sales pitch !

Whenever any digital device is switched on, it instantly injects RFI noise into the powerline via the AC outlet it is plugged in.

It proves we should NEVER get our analogue equipment sharing the same powerline with any digital equipment = isolation.

The issue is to fix this powerline noise problem effectively with wrecking the wallets of we consumers. Not many affordable willing consumers want to drop $8,000 for a power conditioner. Right ?

FYI, besides digital powerline noise: RFI, there is another more abstract noise passing through the air: EMI = radiated noise.

Jack L

303mikk's picture

Regardless of the effectiveness of power products, or their remarkable prices, or the lack of specifications provided, Stereophile is to be commended for continuing to make reviews like this available online for people to comment on.

Nice to keep a healthy debate going, but it would be even nicer to have someone with the knowledge and equipment to make meaningful measurements and comparisons, and testing to find under what real-world conditions power devices might assist with, and whether hifi power products actually need to be any different to common/cheap industrial power products.

Realistically though, the subject seems to be a minefield, and almost certainly not in the best interests of power product manufacturers, so would need someone independent to do so?

ChrisS's picture create a Consumers Report for "high end" HiFi.

Anyone interested?


Hmmm, we were getting this from CR-

and more recently

We just might be stuck with what we already have.

303mikk's picture

Not sure who'd be up for meaningful testing. If the power product manufacturers could do so, they would, in order to design/market their products and sell more. That means they either have done testing, but haven't been able to show many meaningful improvements, or they haven't done testing, in which case they're basically just making things up as they go, then trademarking a few meaningless acronyms to make things look legit.
It's not in hifi magazine/websites to carry out power product measurements, as poor measurements will lose them advertisers.
Reports by consumers are undoubtedly biased, as they've already spent money on a product they believe works, whether it does or not.
Are all hifi reviewers that give positive reports on power products not to be believed? Of course not, however even after the glowing reports (the more expensive the item, the more effective it is), we still have no idea if the item would do anything at all for our own hifi, and if it does, under what circumstances.
A minefield indeed!

ChrisS's picture buy it and try it.

JHL's picture

Readers who slog through the comments find reoccurring themes. We need a glossary.

The Measurements. There's an unfounded assumption that all phenomenon are testable. Obviously they are not (and if they are may be proprietary tech to the manufacturer of the DUT).

Testing. See The Measurements. Testing is presumed to produce meaningful Measurements that probably don't exist. Offering free subjective reviews online now carries with it a mandate to install a million dollar lab and staff it with a million in salaries.

Comparisons. Some readers, forgetting themselves (and the magazine) demand comparisons. After all, when you're not in the market for a device you've concluded does nothing you get to demand unavailable testing to produce measurements that may not exist to form something for you to second-guess.

The Editor. Bearing the brunt of all of these unexamined mandates is the Editor, who if he doesn't capitulate to producing things that don't exist for people who can't hear them in markets they have no interest in, must be some sort of operator, he and his editorial team of questionable reviewers.

I'm sure there's more but these are the high points.

It's the sheer presumption that gets me, that and the uncivil conclusions leapt to. Somehow, having done none of the critical thinking, it's acceptable to lodge any accusation at all, inferring it is itself critical thought.

ChrisS's picture

These are consumer products.

It's shopping.

And it's very simple- buy or don't buy.

Stereophile already does a great job telling you about these products.

303mikk's picture

Fair points, though isn't the purpose of a review to report how the item performs, verify manufacturers claims, compare similar products, and when the review appears from a publisher that views measurements as a critical part of their testing procedures, carry out measurements?
I thought comments along those lines were more than reasonable, and not a presumption or uncivil conclusion?

ChrisS's picture

...and procedures.

They may not do things the way you want them to.

JHL's picture

You may want to review this thread of comments to help answer your questions:


Isn't the purpose of a review to report how the item performs

It's in the text, no?


verify manufacturers claims

To the extent they can be.


compare similar products

Is it? I don't recall that being foundational or even frequent.


when the review appears from a publisher that views measurements as a critical part of their testing procedures, carry out measurements?

I'm not JA but didn't he just qualify what to expect for power products? It's a power product; specifically, what kind of measurements?


I thought comments along those lines were more than reasonable, and not a presumption or uncivil conclusion?

Along those lines, sure. What about when reckless accusations of fraud arise?

303mikk's picture

Perhaps it could be suggested that the high price point might warrant deeper investigations of manufacturer claims?

Does the item attenuate incoming high frequencies? Does it attenuate high frequencies between plugged in components? Does the output waveform shape differ from the input? Does it's output impedance differ from a wall outlet? (Edit- does output THD differ from the input? By what amount?)
These things are measurable, aren't they?

I think we'd all agree there's no place here for allegations of reckless fraud. We're all after the same end goal, and I think most of us are happy enough buying gear to enhance our enjoyment of music.
I would also suggest that many of us have bought items on the basis of manufacturer claims, that in hindsight have just come straight from the marketing department. I'm keen not to let that keep reoccurring, and would hope a thorough review process might assist with this.

ChrisS's picture

...Or just the comments?

Allen Fant's picture

Excellent review- BD

Anton's picture

I see this sort of debate as occurring at the point where curiosity and 'incuriosity' meet.

On the one hand, it is noted in the measurements if a speaker sensitivity measurement is 1 dB off the stated specifications, but we see no apparent interest in finding out how such "unsubtle" and "veil lifting" pieces of gear do what they do or how we could look at measurements.

Power conditioners and interconnects/cables seem to get a free pass regarding things measured.

I'm not saying differences don't exist, just that I have natural curiosity regarding how that happens and wonder why the idea of measuring these toys is anathema.

I think the anti-measurement crowd is as wrong as the members of the "blatant differences that can't be measured are real" club.

JHL's picture

1. Specifically, how would you measure a power device like this? Specifically.

2. 'Anti-measurement crowd' is a canard. A projection.

As long as we generalize and put things into artificial categories and camps disagreements will ensue. Meanwhile if it can't (yet) be measured, that's no harbinger of a conspiracy to not measure. It's just the current state of that science, such as it may be.

Anton's picture

Again, please hear anything you like. How do you suppose these are invented and manufactured, by using sheep entrails?
Of course there are things to measure.

Next up, the argument that this is "proprietary physics?" (If it can't be measured, how is it invented, tweaked, and how do they do any sort of quality control?)

If it is such an obvious difference, measure an amp (pre amp, digital toy, what not) with and without it and see. Does output change? Distortion or noise?

Measure by comparing with and without...not even a new test required in the initial investigation, right?

I know, who cares if you hear it, but why not care enough to wonder about what it's actually doing?

You are right about calling it "anti-measurement crowd," I would call them the 'Incurious' Bastards! (Tarantino joke, they are not really bastards, they just run out of interest at the point of looking a little further into it.)

Look at all the noise and distortion JA can measure, try it with and without these cables and conditioners!

Like I said, great toys, but why measure an amp and discuss the minutiae of it's measurements, but never one of these babies or cables?

Hell, make those room plots for speakers with and without tuning bowls and see what happens.

The review industrial complex can't even seem to be bothered to play with measuring 'break in?'

Look at the decades JA has put into measuring speakers data. I may be wrong, has he ever, once, compared 'pre' and 'post' break in?

All sorts of interesting things to learn, I would think. Why stop at the wall of "Thou shalt not measure this category of device?"

Beyond this line, thar be dragons?

JHL's picture

...the previous comments. I didn't say it couldn't be measured; I asked how *you* would measure it - measuring being a condition of showing its result - without a very specific lab and staff.

Is the manufacturer going to show their cards? Would you? You invent a new V12 engine for your hypercar. Do you publish the blueprints, metallurgy, and your proprietary controlling electronics down to the ten-thousandth or do you patent just the parts that are easy to copy and send a running sample to Clarkson for the butt-dyno?

You send a sample to Clarkson, of course. Who never dyno's it and who never ever publicly reverse-engineers the workings.

But again: Measure what? You assume the usual abstract elements are graphable here too. What do you base that on?

And break-in; are you certain that in a suite of data that subtly changes with each iteration, you can reliably derive meaningful differences? Is there no measurement error? How would you check amplitude at the amp's output to meaningfully assess the line cord end of its independent preamplifier? Does Clarkson run a tankful of ten gasolines through the engine and faithfully chart the results?

For all I know you *can* measure a device like this. I just don't demand the other guy do so, gratis, my not having $8000 to drop on it anyway, without knowing how. That would be an assumption followed by a presumption. None of us know how.

Glotz's picture

I truly believe in 20-40 years we will be able to measure more parameters. Perhaps these cable companies can and do measure it now, but how they do is IP?

Clearly, PS Audio, Shunyata Research and Audioquest have improved their lines' performance over the past 5 years.

If we can't or may not measure now, the experience still turns back on itself and to ask if it makes a positive, holistic improvement in one's system and if it's worth the cost.

This process also must be driven from one's own personal experience. Get a return policy, and it's at least possible and painless to experiment.

Perhaps its fallout from not having enough and more accessible brick and mortar stores to learn from, but trust in one's audio journey has eroded somewhere.

ok's picture

..would you take it had it been for (almost) free? I probably would. I'm pretty sure its creator has his own set of measurements, but the "scientists" here would always render them irrelevant as they also do with other people's subjective impressions. So many wasted words for simply telling "I can't afford to try!"

Glotz's picture

But the funny thing, I do see many open box returns on the Music Direct website for all types of gear, lines and price ranges.

If one has some credit, the chance to experiment and the protection to try for free is there!

ok's picture

what if they really like it after all? Sounds like a forbidden love scenario: "Me?? Never!!!"

AudioBang's picture

The Uptone Audio USB Regenerator is an example of no measurable difference yet reviewers and hundreds of end-users attest to its positive performance.

Uptone's EtherRegen product, which also has been positively reviewed in several audio publications and has a forum of hundreds of users recounting their positive experiences, was negatively reviewed and measured showing no before and after difference by an audiophile publication who's mission specializes in debunking snake oil products through measurements. From what I've observed at that site, very low-cost DACs purchased off the internet for hundreds of dollars that measure better than very expensive DACs are held in highest esteem.

Many esteemed audiophiles have testified their positive experiences with "quantum" products, some that don't even physically touch anything electrical, or cryo-treatments, both of which will understandably open yet another level of skepticism from one constrained to a Newtonian world-view.
Persistent intellectual curiosity and passion to experience oneness with the musical event [perhaps a new form of yoga?] to me is more important than time and energy spinning wheels around an intellectual argument aimed at gaining consensus from a fixed world view with heels dug in...

RH's picture

"Persistent intellectual curiosity"

Isn't it a sign of intellectual curiosity to want to know if something works, and how?

And if you truly want to get to the truth, wouldn't intellectual curiosity lead you to find ways to rule out variables in order to discern what's happening?

Are you intellectually curious?

Charles E Flynn's picture

At the Audio Science Review website, there is a 60 page thread about this topic. The current comment count is 1,191.

Anton's picture

Thank you for posting about it, do you have a link?

Charles E Flynn's picture

Anton's picture

I appreciate it!

JHL's picture

...around the foregone conclusion reached by The Measurements - where .001% absolutely surely sounds heaps better than .01% because that's how my rig displays and here's my handy chart to prove it - speaks to the state of current audio "reviewing" in some quarters, where half an hour with a single speaker of the pair confirms great insight.

I read Stereophile because it's not musically illiterate and because it doesn't subject itself to such a subjective belief system.

Anton's picture

What does this thing do?

How does it work?

You'd simply say, "Hell if I know, and I am not curious enough to be interested or care?"

You think JA1's measurements boil down to .001% vs. .01%?

That's kind of insulting to his attempts to correlate what we hear with measurements.

JHL's picture

I replied to Flynn, who replied to AudioBang. My context should have been clear too.

Jack L's picture


How are YOU so "absolutely surely" 0.001% sounds heaps better than 0.01% ???

You heard it with your own ears or simply your assumption or imagination or hearsay ???

I already posed many times in Stereophile forums re Cheever's audio engineering masters thesis.

In his thesis, he experimented with 2 power amps, one transistor & one tube. The transistor amp bench measured 0.05% THD vs the tube power amp of much much less output power, measured 5%.

Yet the audition result showed the tube amp sounded much better !!!

Our ears/brain work totally different way of bench measurement !

"Absolultely surely" YOU don't have a clue, right ?

Listening, not only measuring, is believing

Jack L

303mikk's picture

A quick re-read from an article from only 6 months ago-

Great example for the Uptone USB Regen.

Measurements that fail to show results are not failed measurements.

Power products are not built from magic and stardust, and viewing them as magic and inscrutable does a disservice to human curiosity, and basic science.

Anton's picture

Thank you!

sa122's picture

As Carl Sagan once said: "Extraordinary claims require extraordinary evidence". Manufacturers of 'extraordinary' mains products such as this don't supply any, and expect us to just fork out the 8k on faith, which just turns me right off. BTW, Is it coincidence the model number is the same as the price? I digress. As others have mentioned, we're dealing with mains noise here which is easily measured and verified. Could it be that they are relying on how easily human ears are fooled into thinking there are differences when there are none? I suppose though if you have a 200k system and a spending itch to scratch, then you'll not even blink when purchasing this. As long as you believe things are now better then that's all that matters, right?

JHL's picture a wealth of technical information and data at the two links in the footnote following the article above.

None of the detractors of power components in this long thread even mentioned it.

sa122's picture

Ah yes, articles that discuss cable burn-in and cryogenic treatment (pseudo-science). The power cord measurements are interesting. They seem delighted to report their cables can deliver hundreds of amps over very short durations. Most domestic sockets are only designed for around 13amps, and at those sort of currents you're in danger of melting your house wiring. Oh, and instantaneous releases of power come largely from the capacitors inside your amplifier.
Classic case of showing figures for a situation that either never occurs or is simply not audible, another tactic of manufacturers.

JHL's picture

...anyone wonders why nobody listens to "objectivists" anymore, the sheer obtuseness of your remark should well explain it.

sa122's picture

I think plenty of people are listening actually; those with a bit of common sense anyway. Oh, and yourself by the looks of it.
Obtuse? This explains pretty clearly what I'm talking about regarding capacitors in amplifier circuits:

Clearly you're the sort who likes to have the final say, so go ahead and have the last word.

I'll have the last laugh.

JHL's picture a term bandied about by self-styled skeptics of all sorts of sciences whose opinions have gotten the better of them.

Given the dearth of understanding some objectivists have of those sciences, it was appropriate to point them directly to just a sliver of pertinent real knowledge as it appears above. Which I did. Their beliefs then have to navigate those sciences and, we trust, come away reformed. Why? Because those sciences are real. It is the putative objectivist who, on the basis of his opinion about "science", is not.

When you call cryogenics a pseudoscience - and double-down with a 101-level clip on power supplies - who then would take your brief perspective on the subject of this review seriously? Cryogenics is so real it involves an entire industry ranging from aerospace to industrial power transmission and from top universities to the local specialty manufacturer.

You also have no evidence and certainly no rational premise to assume the manufacturer believes or would purport that a length of power cable passes many times the available wall current because of some mysterious phenomenon. Obviously the world knows that aspect of the cable product speaks to other factors, yet here it's become a canard because of the opinion of faulty skepticism.

It's not a last word problem, sa122, it's a problem with the sciences of the audio arts being expected to weather a constant din of ignorance by a society of armchair skeptics, even to the point it delves into direct denial of the basics of true science. True science is the ongoing and unbiased exploration of reality.

That doesn't advance the field, that dishonest skepticism. Rather, it serves a kind of pseudoscience itself. To borrow from another field where this false skepticism occurs:

Ethical skepticism supports bringing attention to this cognitive mistake on the part of mankind. However, rather than deem such mistakes an error of science, ethical skepticism instead identifies the problem as an imperious social agency which corrupts the common underlying philosophy in defense of science, skepticism. Social skepticism simply put, is the activist-minded exploitation and abuse of science by means of its vulnerable underlying philosophy, skepticism.

Note the distinction between ethical skepticism and false, armchair skepticism. There is indeed an 'imperious social agency which corrupts the common underlying philosophy in defense of science' running through supposed objectivist audio too. It is not that the science has failed; it is that the philosophy of truth has, and has become a social movement.

Failures with respect to science are the result of flawed or manipulated philosophy of science. When social control, close-hold embargo or conformance agents subject science to a state of being their lap-dog, serving specific agendas, such agents err in regard to the philosophical basis of science, skepticism. They are not bad scientists, rather bad philosophers, seeking a socialized goal. They are social skeptics.

Audio should be advanced, not retarded. Goal-seeking is not science and only harms the field and its pursuit.

sa122's picture

Well, after that rambling and incoherent outburst I'm now not sure whether you work for Shunyata or just need help.


barrows's picture

While I am well aware of the differences which well designed and implemented power conditioning can make in certain system environments, I really wish that Stereophile would commit to making measurements of these products. I understand that this would require the acquisition of a considerably expensive piece of equipment, but considering the asking price of many power conditioners, providing objective analysis would be worthwhile service to Stereophile readers. I would suggest the following measurement protocols:
Spectrum analysis of the output of the DUT, with various noise sources added to the input side of the power conditioner, such as a vacuum cleaner, an operating TV, and various other high load power devices, as well various operating audio components plugged into other zones from the zone under test. A test like this would easily, objectively, allow for evaluation of how much, and at what frequencies, noise reduction is being made. Then, in addition, a test of output impedance vs. the output impedance of the wall supply under high loads, and high transient current demands would be nice to know as well.

AudioBang's picture

Adding LED lighting to the noise source list would be appropriate in these times.
I think this level of testing would be distinguishing for Stereophile and educational for its readers.

AudioBang's picture

From Bill Whitlock's Grounding whitepaper -
I quote [Page 40] "In reality, many of the benefits often ascribed to “power treatment” schemes are simply due to plugging all system equipment into the same outlet strip or dedicated branch
circuit." I don't believe this is the whole story but certainly a valid statement. I was unable to find Whitlock's NEC reference to asserting that even grounds from different outlets on the same circuit can have a voltage difference [I recall him specifying up to .5V] - allowing a potential difference for capacitively coupled noise entering the system to flow.

I was fascinated by ADs cable review suggesting by the cable manufacturer how airborne noise capacitively couples from the shield and into the signal wires. There is supporting evidence to this from other cable solutions with ground absorption boxes. Again, that may be just part of the story.
In ADs review the manufacturer also asserts that the power cable at the end-most device - in ADs case, AC to his Quad ESLs, in most other user's systems, the power amp[s], makes the most difference.
In conjunction from insights reading the Grounding whitepaper and correlating how several cable manufacturers absorb noise from the shield, it got me wondering about how chokes in line to ground on some manufacturers power strips may eliminate or minimize high frequency parasitic noise traveling from component to component.
Was there a question pertaining to MY intellectual curiosity?

barrows's picture

Balanced signaling eliminates both of those problems.

Jack L's picture

........ voltage difference " quoted AudioBang

Nope! Whitlock stated in his paper there could be as much as 1-2V between the Earth holes of the outlets of 2 different powerline loops wired separately back to the mains breaker panel.

So the DC resistance between the Earth holes of 2 said wallouts is usually very low, in term of decimal ohm. So the up to 5A current will be passed from the audio component of higher earth voltage to the one with lower earth voltage through the SHIELD of the interconnect hooked up between the 2 components which HAPPENED to be plugged in 2 different wallouts of 2 different powerline loops!

Such large current passing through the shield of the interconnect between the 2 audio components in question is enough to cause very audible hum in the rig.

The issue is: how do we know how the utility guys installed the powerlines back to the mains switchboard ???

That's is another good reason I've installed DEDICATED powerlines directly hookup between the mains switchboard and my audio rig. No more risk of hum due to above.

Jack L