It’s the time of year for saving money!
Cable discussions can turn normally rational audiophiles into nut-cases. I know. I’ve been reading and watching the discussions since I wired up my first stereo system.
Recently I decided to ask two industry participants their take on power cords. My question was, “How can a basic stock AC power cable negatively affect audio gear?”
Here are two divergent viewpoints…
From Tommy O’Brien, Digital Amplifier Company
“The most important feature of a power cord for amplifiers is simple resistance. Other factors such as capacitance, inductance, and shielding, are “in the noise” and not significant enough to affect the sound of even the most revealing audio systems.
For power amps as well as other equipment, the quality of the connectors is important, but the reasons are reliability and contact resistance. Good quality is a must for any decent system, with every part of the system. Decent quality doesn’t mean high price.
It’s important to mention that well designed equipment doesn’t need special power cords or even power conditioning. Well-designed equipment filters and regulates power internally so that, aside from brownouts or blackouts, the equipment runs flawlessly even on distorted and noisy AC power. Going “off the grid” is another unnecessary endeavor with good equipment, as far as sound quality is concerned.
Another fact regarding power cords is that, behind the wall, there are 10’s of feet (sometimes more) of household wiring to the breaker box. If people think beefing up the last 10% of 60 foot run is going to make a difference, they will be sadly mistaken. Therefore, spending more than $100 on a power cord is usually a waste of money.”
From David Salz, WireWorld Cable
“Generic power cords actually do cause audible problems and that’s why a thoroughly engineered cord can make great improvements in music reproduction. Of course, the reason we hear sonic changes from power cords is that component power supplies are imperfect and they allow power line noise to mix with the music, which masks detail, adds coloration and compresses the sound. Shielding a cord is helpful because it can eliminate external interference and increase capacitive filtering, but other audible problems remain. These problems include triboelectric noise, strand interaction and contact noise.
Triboelectric noise is a static charge/discharge effect that takes place where conductors touch insulation. This noise is commonly defined as a reaction to vibration, but we’ve found that it is also generated by the current passing through the cord. The magnitude and frequency distribution of this noise varies dramatically according to the insulation materials used in the cord. The standard PVC insulation used in generic cords is not quiet.
The conductors in generic power cords are bundles of bare strands, which cause the audible problem known as strand interaction. Simply stated, strand interaction is caused by the electromagnetic proximity effect, which forces some of the current to jump from strand to strand as it passes through the cord. Of course, the connections between strands are imperfect and often poor because the copper oxide on their surfaces is semi-conductive, so it also creates noise.
The plug contacts on generic power cords also create noise. In particular, the common nickel plated brass contacts are especially noisy because of their low conductivity, but bare brass can even be worse if it’s corroded. Improving these connections alone can make dramatic improvements in sound quality and silver contacts are measurably quieter than the alternative metals.”
So how do I, a reasonably intelligent audiophile, respond to these two divergent points of view?
My paraphrase Mr. O’Brien’s thoughts are “Well-designed gear doesn’t need a premium power cord priced over $100 because it has circuitry inside that can reject AC power noise.”
My paraphrase of Mr. Salz is, “There are three primary sources or AC noise and inexpensive and “standard” power cords do not address any of these noise issues.”
So, what can an audiophile do after reading such differing opinions on a similar subject? For me the answer has always been “try listening yourself.” If I hear a consistent improvement by inserting (or removing) something from the signal chain, I can only conclude that there is a reason for using something different from a stock AC power cord. All you need for a test like this is two consenting audiophiles – one to listen and the other to do the switching…
Let me know how your tests work out…
“So how do I, a reasonably intelligent audiophile, respond to these two divergent points of view?”
The appropriate way to do that is to conduct an experiment. Doing it properly, however, requires a bit of time and resources. I’m hoping that one day a major audio-interest online magazine would do a proper “laboratory” experiment and post the results.
A “proper” test isn’t that hard you really only need two humans and two power cords to do either blind or sighted tests…
Well, that may often be the best we can do, but a “proper” ABX-based experiment is going to require an adequate sample size, at least in the form of individually repeated trials, but more ideally both individually repeated trials and trials repeated with a sample of subjects. We should be able to calculate statistics. Double-blind would also be preferred to single-blind. Obviously most of us can’t do this, but it may be worth it for a magazine.
Since this is audio, not medicine, a two-person sample with a good system will be all most audiophiles need…
Proper ABX testing won’t be good for a magazine’s long term economic well-being for all they will end up reviewing are speakers.
Presuming it is compliant and built correctly (terminated properly, is of sufficient gauge size and doesn’t have extreme RF resonances), if said power cord truly does make a measurable difference then I would be concerned that something is seriously amiss with the power supply it’s attached too; either it’s malfunctioning and in need of repair or it’s egregiously designed and in need of replacement.
I believe every amp review I’ve read has covered the noise floor topic so it seems like all have “some” level of noise. If Mr. O’Brien is saying that his amps don’t produce enough noise to be detected, then that seems a bit optimistic.
Unfortunately, he didn’t cover the situation where a dedicated line has been run for the audio equipment.
I’m definitely in the “cables matter” camp. I’ve heard differences – both good and bad – from cables that I’ve used.
Audible levels of noise in SS amps is a rarity, at least at the level of equipment being talked about in the hi-end hobby. Tube amps are another matter obviously when it comes to noise
“in the noise” simply means not significant. It’s an engineering thing.
I didn’t say my amps don’t produce enough noise to be detected. Cherry Amps ARE very low noise, however. Most Cherry Amps have around 120dB SNR.
I’m generally in the camp where better cables (i.e. higher levels of manufacturing quality, not necessarily cost) sound “better” but that the point of vastly diminishing returns is reached very quickly.
On the power cable front, I’d suspect that if you have “clean” power, then indeed crappy power cables would not be a good thing. I doubt most audiophile equipment is outfitted with crappy power cables, but I might be off on that point. If the point of the premium power cable is to conduct the juice in the cleanest way possible, cool – at least you’ve eliminated that part of the power chain as a source of noise.
Lest I be accused of being a Luddite on this, I will admit that I have never heard a system with a premium power cable installed, so in fact it may turn out to be a revelation but for the moment I am quite skeptical on the value of super-premium power cables, at least for the systems that I can reasonably afford. If one has the pecuniary ability to spend $500k+ on a system, I would certainly not cheap-out on the AC cables, and holy smoke would I love to give that system a listen!
I must first question O’Brien first statement since power cord are transmitting AC impedance not resistance is the correct term. If it was DC the yes resistance . Being it is an AC transmission line inductance, capacitance are major factors. I have in the past postulated the audiophile power cords may cause an impedance mismatch for out of band noise and thus altering the AC signal . How easily that may be heard is to me the big variable . The third and larger question is value to the end user based on cost.
It’s NOT a transmission line for 60Hz you nudnick!! Stop using phrases and terms, that are irrelevant to Audio, form other factions of electronics,
Then what would you like to call it ? I was reffering the unwanted signal of noise not the 60hz . The 60hz is the part you want it the lf rf and such that is the problem. Common error made I see is to dismiss out of band noise to easily. The ampilifing device does not know audio from noise so it is relevant to it .
In the case of an amplifier, the AC mains input filter should be adequate for HF noise, and the power supply itself for LF noise. By the way, impedance becomes resistance when there’s no reactance.
Even if cheap cords had enough capacitance to affect the power coming in (5 feet of lamp cord at 60 hz has around 22 Megaohms of capacitive reactance, so it doesn’t matter), the power goes through a bridge rectifier (which switches 120 times per second), a bulk power capacitor, and then a linear or switching regulator that further filters the power. Cables make no difference whatsoever, unless you were using a 1000 foot roll of it wound on a spool.
P.S. 22 Megaohms of capacitive reactance is roughly equivalent to a 22 Megaohm resistor across the cable.
Indeed, even 5′ of that cheap, toss-in, rubber power cord,will only have ~2.5uH of inductance or, @ 60 Hz, XL = 0.0009Ω
Have you looked at the effect of rf noise on the diode bridge of SS ampilifers coming from the ac primary ? It can be quite interesting .
why aren’t things like “strand interaction” known in industries other than audio? Due their complete non-existence. Triboelectric noise? Never an issue in applications like the power cord. The Wireworld guy has to make up all kinds on nonsense to support his product, I suppose, as he has no data. The one time I saw a measurement (was it Shunyata?) you have to wonder if the designer of the device that needed a shielded mains cord was call on the carpet in the engineering department of his company. Because it’s always “lower noise,” or “massive 3-D soundstage” it should be trivially measurable. In my own tests, both subjective and objective, if the card is reasonably spec’d, they are all fine.
I function in the RF world where noise and distortion truly matter and needs to be accounted for. If I brought power cord matters up to my fellow engineers, they’d laugh me out of the room and would likely never ask for my input again. Only in the <20kHz world can such nonsense actually be tolerated. Is it any wonder that most people shake their heads at such audiophiles?
I’ve never heard of “strand interaction” before, and I doubt it’s even a thing. On top of that, how is it even possible for a power cord to cause “compression”? Even with a non-regulated power supply(non-existent at this price point), a slightly lower system voltage would not cause anything more than a slightly earlier onset of clipping.
Best of all, it’s so easy to measure current starvation in a power amp from inadequate mains cord gauge that every cable designer would be publishing it in their ads. But, the cable that comes with the amp works fine, so that ones off the menu. The rest is all BS – especially the claims of different dielectrics, fancy windings, etc. I’m still looking for any engineering book that mentions the Golden Section in electronics. I think I’ve mentioned this for at least a decade now.
The answer is the most simple for the majority of issues like this : Try and you will hear. If you dont hear your equipment is either perfect ( pls tell me about it 🙂 ) , or so bad that you cant distinguish fine room information, your speakers have no bass , or you are really deaf ( < than 0,1% among listeners).
“Try and you will hear”… no difference between a lamp cord and any other wire you got conned into buying.
I forgot the last option sorry: The space between left and right ear is empty.
It’s a common tactic to say someone’s equipment “isn’t resolving enough”, or that they have “inadequate hearing” when trying to push the fancy cable agenda. There’s more psychology behind fancy cables than engineering.
I was recently given an AQ Thunder powercord by a friend to try out, so I called two of my fellow audio nerds over for a shoot out to see if we could hear a difference. Note the “if” in that last sentence; we are all skeptics. This was sighted and we didn’t feel level matching would be an issue, which it wasn’t, but I had my spl meter handy anyway. The AQ was inserted first into my Pass amp, then Furman Reference power conditioner, and finally Parasound phono amp . We chose a few tracks from two albums (Julie London and James Newton Howard & Friends) that we all knew intimately and took separate notes, only revealing our findings to each other at the end. Interestingly enough, we all noted the exact same changes in sound (although none was heard when inserted into the power conditioner, which we pretty much expected). The fact that the sound was worse through the not-inexpensive Thunder wasn’t the point, that was we all heard the same changes in sound was. So what’s the moral to this story? If you can hear a difference, you just opened a whole new can of worms. If you can’t, congratulations you just saved some money.
It’s also important to note that it is possible and permissible to detect a difference yet dismiss it as insignificant — although this possibility seems barely to exist in some high-end audio publications. How much difference do these changes really make in one’s appreciation of the music?
That can only be answered by the individual listener. As a drummer, I’m always attuned to what the kit and percussion sound like, sometimes to the detriment of enjoying the piece as a whole. 40+ years of playing does that to you. Jeff Porcaro is the drummer on the James Newton Howard & Friends album (along with the rest of Toto) and on this particular album, he is playing a Yamaha snare, likely a maple 14″ x 8″ based on the tone, with the top head cranked tighter than the bottom. I know this because I’ve listened to this album hundreds, if not thousands, of times. The AQ cable softened the leading edge and attack to a degree that it completely changed the sound of said snare and thereby altered the intended expression of Porcaro as an artist. For me, that’s completely unacceptable. However, I wouldn’t expect others to to regard the difference with such esteem and they may actually prefer the softened approach, to which I’d paraphrase the great Henry Rollins, “You can have an opinion…you’re just wrong.”
I recently purchased a pre-amp and 2x 500W ncore monoblocks from a friend and asked him to bring some powerchords as well. After everything was installed, we listened carefully to the sound ans then switched to this AQ powerchord. In a split second after the switch, we both looked each other in the eye immediately and this confirmed that we both we shocked to hear the difference so clearly. I will be very interested to do a comparison in a blindtest, since this is the only way to test our hearing. I am also interested to know if there are examples of audible differences in a listening room which cannot be measured and verified by a microphone. As an example: vowelling in loudspeakers. Even minute changes are easily audible, but will a microphone measure this as well?
I’m a piano technician and have had a recording studio and also have worked at many many concerts . What you hear starts at the instrument .
The largest factor in audio is the recording, and in the case of a piano, the tining, voicing and regulation of that piano .
The audio system often fails at the instrument.
No recording studio buys in to the cable stories that audiophiles buy into . They use high quality durable cables in bulk as required .
If audio engineers and the technicians who work on the source materials don’t buy into this, then the whole audio chain doesn’t require this.
Face it, most generic power cords are just junk. They cost a few dollars, they have crappy ends, cheap copper, usually 18 or 16 guage, and basically have no thought put into their design. I am not advocating the use of expensive cords necessarily, but if I have any decent level of equipment, I am not going to use what comes with it.. Monoprice sells an inexpensive 14 gauge power cord in various lengths, same ‘ol crappy design, but at least it has some copper to it, and you can order them in proper lengths to suit your installation without having looped cable everywhere. Audio Advisor has some nicely designed power cables that aren’t crazy expensive in their Pangea line also.
Our auditory memory is short. Unless an A/B test is blinded and virtually instantaneous, and with precisely matched levels (max +/-0.05dB variation), the test is invalid. Some say they can differentiate subtle differences over long periods of time. Such claims are without merit (for subtle differences). This has all been shown repeatedly in objective lab tests, nothing new or ground-breaking.
Power cords aside, are there audible differences in analog cables (microphone, line, phono, etc.)? Sure, and sometimes not so subtle. As qualified by fast A-B blinded trials.
I beat problem #1 by having a 2nd separate AC line and Circuit Breakers installed in the Junction Box outside of my garage my listening “room”..
I run 4 Oyaide AC wall sockets with no crappy wire in-between..
I did this by hiring a very good Electrician..
My Electrician and my EE friend laugh when I tell them about the crazy Snake Oil products in the Audio hobby.
I got the best sound when I plugged my tube Preamp directly into the wall and out of the Furman 15i..
I have upgraded all the power cords but check out Waudio on Amazon as they have excellent AC Power Cords at 1/3 the price of Pangea..
In a home…where stereos are powered by a 15 or 20 amp breaker…you probably have about 50 feet or so of normal grade 14 or 12 ga wire. Its a snake oil sales pitch to say your last 5 feet of cabling matters….unless compared to inserting small ga that is not stock to your equipment say 22 ga
Interestingly enough, if you are 3 kilometers from the supply transformer for the entire street and you are the last on the line, there can be so much hash and DC on the mains to cause physical chattering of the linear power supply transformers. In this case an off the grid power supply or a dc blocker will make a huge audible difference to revealing audio systems. Much more so than any cable introduction to the system. Anyway, good review and read.
A number of years ago, I worked for a small engineering firm in the suburbs of Washington DC called “LectroMech” run by a man named Armin Bruning. By way of introduction, I’ll reference an anecdote:
In the early ’80’s, Mr Bruning had a small office and laboratory near Dulles Airport. He also had a laboratory in the basement of his home. During a major thunderstorm, lightning struck his neighbor’s house, causing major electrical damage and a small fire that, luckily, was quickly doused. Unfortunately, lightning travelled from his neighbor’s house, along the telephone and power lines into Mr Bruning’s home, as well, damaging several appliances, telephones and five computers in his basement laboratory.
Mr Bruning put in a claim against his homeowners and business insurance (all with the same company), expecting prompt remuneration. It didn’t happen. Months went by with excuses from the insurance company. Finally, Mr Bruning got tired of waiting and threatened to sue. One of the senior people in the claims department contacted Mr Bruning and told him that, “the insurance company has contacted the IEEE and gotten the name of someone who is considered one of the nation’s foremost experts in damage within electrical systems, a Dr Armin Bruning, who just happens to live in the DC area … oh, oh, Mr Bruning, you’re … IEEE … Uh … Never mind, Dr Bruning, your check will be in the mail today.”
In the late ’80’s, Dr Bruning’s company was hired by a prominent manufacturer of high-end audio accessories to document the superiority of their products. These included power cords, line conditioners, speaker cables and analog audio interconnects. Dr Bruning’s conclusion was that their entire marketing campaign was basically junk science. His report to them was that there could easily be an argument for a decent line conditioner of which theirs was an inadequate example, and certainly, surge suppressors were a good idea for any sensitive electronic equipment, but their claim that their expensive power cables, speaker cables and audio interconnects were superior was pure bunk. Assuming that the power cables and speaker cables are capable of handling the appropriate current adequately, those available at any hardware store were equally as good. With audio interconnects, where very low signal levels might be encountered, insulation capacitance could easily cause problems; however, every one of the twenty samples of competitors’ products the company provided to be compared with its own passed complex audio signals at frequencies from 4Hz through 250KHz and voltages from 0.0001 to 2 volts, peak-to-peak equally well. The company was NOT pleased.
BTW, Dr Bruning was one of the experts the government contracted with to determine cause for the Challenger space shuttle and the TWA Flight 800 disasters. The cause of the Challenger disaster was O-ring seals, not electrical; however, the cause of the Flight 800 explosion turned out to be a defect in insulation in the electrical fuel monitoring system in the central fuel tank. Dr Bruning’s team found it.
Color me extremely skeptical of any claims of expensive wiring improving audio systems.
Why not discuss power amplifier Common Mode power supply issues and skip all this mumbo-jumbo?
Nope. They have no effect.
If we open a wall socket, and the amp. Bypass the socket-plug and amp connector altogether, by bridging it with 14/2 (or 12/2) romex (standard wall wiring) with standard twist connectors (also in standard wall wiring).
What this essentially does is uses the exact material and connectors being used to bring the power from the breaker panel to your wall socket, and extend it into your amp.
Does this whole power cable argument go away?
I personally feel using a 14/2 or 12/2 power wire and having clean contacts (no oxidation) in the plugs or sockets is pretty much all you need.
i just can’t resist commenting although I know I should not
I am a software architect with a BSE from Princeton University and have invented some pretty cool stuff over the last 25+ year in SV.
I picked up the audiophile bug in the early 2000s after having some fortune with some of my software inventions – and yes I’m betting you have used them and would know them.
I came from a background that “digital was perfect” of course, fewer things in the signal path were better, and there was no way in hell expensive speaker cables (much less power cables!) could make a difference. CDs should sound perfect. Solid state was, of course, superior to tubes. All of this was re-enforced with my first system in college after spending a summer as in intern at IBM.
Fast forward 20 years…after 5+ years of running double blind tests, testing solid state vs tube amps, being taught about the 25 years of absolute -stupidity- relative to CD players and digital music, and A/Bing many components/cables/music formats/and compression, I made some startling revelations.
Everything matters – damn it. For those of you who haven’t listened to these systems in a systematic way, you just don’t have a leg to stand on. Seriously. I can’t tell you how many “smart” people have told me they can’t possibly hear the difference in audio formats, DACs, Amps, Cables, Speakers…dozens of engineers in SV have told me that. however, -every one- of them is able to hear it when I do a blind test with them. Not that the differences are necessarily hugely “better” or, more likely, worth significant expense. But they have no trouble hearing significant differences when I setup controlled listening tests.
Here is an example of smart guy “group think” (I was one of those “smart guys”) – CD players have to be better than analog…
Except that audio engineers don’t understand software (sorry to all you folks who invented CD players, but oversampling is just plain stupid and someone should have taught you the concept of a software buffer back in 1980 when I was programming my atari 800). None of the electronics companies could make the USB Audio spec work from 97 to 2005 – which is a shame because USB (and now bluetooth) are perfect audio transports as they have built in error correction. CDs do sound different despite years of people (including myself) saying they shouldn’t sound different. Why? Jitter. Lack of buffering. Stupid 16X oversampling. 192k makes me laugh – the real difference, in my uninformed(sarcasm) opinion, with 192k bit rates is reduced error rates on resampling based on jittered clocks. Please, just get a USB dac (or soon bluetooth 24bit) with no re-sampling – playing back the original bits at 44093 hertz instead of 44100 is so much better than using giant compute to resample the original bits.
Solid State vs Tube amps. I hate that I have tube amps. I did not intend to get them. I hate that I have to spend $$$ every 4-6 years replacing 12 EL34 with tubes from 1935. I hate when a giant spark leaps out of one of my mono block amps and flames shoot out every 5-10 years. But, solid state amps that perform as well as my tube amps for what I like cost 3-5X more. You can accomplish similar things with solid state… but for me not for nearly the same price.
Cables – interconnects matter *the most* in my A/B testing (after my USB DAC with no upsampling/filtering). In fact, after several years of experiments, replacing decent normal interconnects (probably silly monster cable or something), with used Nirvana Audio interconnects based on Gordon Rankin’s suggestion (see wavelength audio and bare naked ladies amp maker) and leaving the room (not expecting a change), caused my brain to melt and me to turn around as Ella Fitzgerald was now in my living room singing through my old Energy 22 pro monitor speakers from college. Also, wow – bass like I had never heard before through those speakers – clear and unbelievably tight.
I then bought Nirvana Speaker Cables (used!) and guess what… -no- appreciable difference vs my $20 college bought 12 gauge junk speaker cable. FAIL.
OK, so obviously, low voltage extremely important… speaker cables who cares…
Therefore, power cables couldn’t possibly make a difference, right?
Fast forward to buying speakers after 5 years of doing this as a serious hobby. (Having spent 2 years trying to find amps that my wife I sounded half way decent and ending up buying used tube amps through audiogon after realizing that was the amp that had sounded best with my wife’s favorite speaker). Well guess what, tubes created a far superior sound stage and put me “in” the venue. Except, attacks were rolled off … A/Bs of Metallica, Pantera and others with my metal fiend friend were that ‘wow’ those amps make it sound like you are there… but that doesnt sound aggressive like Metallica.
Finally, with all other components in place, upgrade the speakers…new… and they are installed in my house..
Wow, they respond better to what the tubes are producing. All the musicality and realism but with less roll-off.
These cost enough that the local analog store owner spends hours installing and tuning them. At this time, I am debating a power conditioner… plug the amps into the power conditioner – loose the dynamics and air significantly. plug directly to the wall – the music comes alive more but sounds harsh and I cant listen for long (“glare” really is the word for what I experienced).
The owner laughs at my dilemma – “you need real power cords.” “No way, I have heavy duty computer power cable cords that came from the previous mono blocks owner … no way i believe that power cords will make a difference”
Laughter. “Let me check if I have some in the truck…here, keep these for a month… return them no problem if they dont make a difference…otherwise stop by in the next couple of months – they are $350″…
Damn him. A/B … no glare, all the dynamics … invite metal-fiend friend over without telling him what I was changing… “wow. that is so much better, metallica sounds like metallica again!”
Upgrade outlet with a medical grade outlet, run 12-2 circuits for each monoblock (I grew up as an electric contractor’s son) … wow… that made a difference.
So YMMV. California power sucks. I have lots of electronics in my house (then and now).
I am a hard core software engineer/architect/scientist. The above conclusions were generated begrudgingly with thought out experiments and plans and a significant budget (not relative to true ‘high end’ audiophiles though lol).
The experiments were done over 7 years with another hard core scientist from Stanford (metal fan) helping me with consistent blind experiments.
Oh, and please dont tell me music formats and compression don’t matter. Or that USB audio isnt far superior to a TOSLINK cable. They just don’t on equipment that isnt great or setup properly. I can tell you from working on flight simulators and real time graphics for the armed forces, Disney and others that anytime you resample an image (think 128×128 to 127×127 when talking jitter or bad jpeg images for photos), you completely destroy the image… it took a year of exhaustive A/B tests to convince my metal friend… guess what, no more compressed formats for him either.
I didnt even mention the whole pre-amp dilemma just as a volume control…my active tube pre-amp is better and worse.
OK, end rant.
Everything matters – each time the signal passed things are emphasized/deemphasized and changed slightly. These changes are then re-interpreted by the next component. In the end, fewer components arent necessarily better. Your speakers are gonna end up mechanically reproducing based on what signals are handed to them. You need a signal that is gonna allow those particular mechanics to produce the sound that is most convincing and musical for you.
Please, just don’t be another who slams something without actually running the experiments. I was… no more.
Thank you for your thoughtful post.
great post. So, if Marantz includes their standard power cable with their $7995 PM10S1, do they believe their power cable is crap? That it would negate the sound from an $8000 integrated? Does Marantz expect that audiophiles WILL replace the stock cable? If so, why include one at all.
I wonder how many people who pay hundreds of $$$ for power cables have actually ever wired a house. There is nothing fancy or special about 14 gauge home wiring, I can assure you. Let me tell you what the biggest benefit of expensive power cables is….they look cool.
This question has been on my mind recently. I recently purchased an all tube integrated amp (Prima Luna Prologue Premium) to replace my Krell s300i. I much prefer the sound produced by the PLPP. When I bought the Krell I also purchased an AQ power cord. For months, I was very disappointed by the sound produced by the Krell. Once I realized it had in fact been broken-in, I called Krell. Friendly folks! They asked me a few questions about my house (it’s small, built in the 1930’s, plaster walls, no complicated electronics, etc), and suggested I use the power cable that came with the s300i. Quick switch – immediate results! I could not believe how much better the sound was with the cord that came with the amp (a basic power cord – not a custom Krell cord). I’m thrilled with the sound of the PLPP, but nonetheless, to test, I dusted off the AQ cord and used it instead of the cord provided with the PLPP. No difference, so I put the provided cord back. The real question for me is how do I know if I need an upgraded power cord? Speaker cables make a clear difference in my system. I replaced the Cardas cables I used with the s300i with a pair of Analysis Plus cables, and the sound went from great to fantastic. Perhaps the answer to my question is just to trust my ears and enjoy the music!
In a digital system, it all comes down to a DAC for sound. The final D/A stage within a DAC relies on two things: 1) stable clock reference and 2) stable reference and ground voltage levels. That’s it.
In my company, Audiowise Inc., I followed the evidence toward a final cause for why a power cord (or interconnect) matters. I performed experiments based purely on RF isolating a DAC …the argument is that changing an amplifier power cord does nothing to make the power ‘better’. I find it incredulous that industry experts make the claims they do.
Fact: power cords just act as antenna to radiate RF noise from the amplifier back to the DAC. What is the source of RF noise? Why, its the out-of-band noise generated by the DAC itself. The interconnects transmit the entirety of the DAC output (in-band and out-of-band) to the amplifier where everything gets amplified. The metal tentacles of the amplifier radiate this energy back into the environment.
I have 100% proven this is the case: a 90dB RFi/EMi isolating sleeve placed over any power cord stops RF emissions and turns a system into the best its ever sounded. The DAC has no (less) impinging RF noise and thus less disturbance to the clocking/reference voltages. Less RF noise = more perfect sound.
I know i am claiming that the earth revolves around the sun …but this it the reality of the situation.
I use tube amplifiers, with separate pre- power amps. For years, I’ve been annoyed by an audible hum from my speakers, Always thought it was because I bought the set second hand and it’s been with my for almost 20 years so it’s “to be expected”. My power cords are the two pin versions that came with the power amps. Left power amp was connected to the power socket using a travel adapter. The right was pushed into the socket without an adapter.
Last night, came across the article below. Today, I went to dig up a 3 pin power cord and swapped out the power cord for the left power amp. The hum from both speakers, which used to be audible from 2 meters away have all but disappeared! There’s now only a soft hum from the right speaker (audible only if you’re next to the speaker.
Guess mine is an extreme case but I’m now convinced that at the very least, we should not use power cords with travel adapters !