Do powercords make a difference in sound?


Do they make a difference by upgrading stock power cords in amps, ect versus aftermarket power cords? If so, can anyone advise a good bang for the buck upgrade?
chad329
Dear Mr. Liguy: I would like to think a lot of things about myself (and a few of them may even be true!), but in the situation I had something of particular relevance to tell you, I'd go ahead and spell it out...
I am truly sorry but I simply do not subscribe to your accessment. I mean no offense. I am sticking to my guns that properly designed power supplies do not require fancy power cords. I do not disrespect your opinion, I simply do not hold the same opinion. I have designed power supplies for a living and fully believe that I, during my career, have designed more than a few that can allieviate the effects that would cause detriment to audio reproduction.
I mean no ill will, we simply disagree.
Liguy - Have you done any in depth listening/comparison with some good aftermarket power cords or is your "opinion" purely theory based?
Liguy: "power supplies do not require fancy power cords" Your statement maybe true for equipment to function however it does not eliminate the possibility of after market cords providing change in sound good our bad. Is this not what the original question refers to?
Liguy, I certainly can conceive of a power supply that show no response to what power cord is used to connect to the wall outlet, but I have not heard one apparently. I do have a question, however. How did you choose a power cord to use on these supplies? I mean that sincerely also. Did you just choose something from Radio Shack or did you make a power cord and use the same one on all the supplies you made?

I can certain conceive of a power cord that would have poor capability to pass the needed current. Equally I cannot imagine the design principles that would guarantee the very best power cord. I have made shotgunned multi-strand power cords that were more than 2 inches thick and too cumbersome to use easily and which didn't sound any better than those half as thick. I have also heard very expensive power cords that were not exceptional. And I remember once when a Radio Shack pc which I owned so embarrassed the manufacturer of a very expensive silver power cord that they bought several and reverse engineered it to make their "improved" power cord.
Liguy, I would like to know which audiophile components you have supplied designs for power supplies. I am assuming, of course, that you refer to designing power supplies for audiophile components. If not, then your entire discussion of the non-necessity of aftermarket cords or their ability to change the sound is invalid.

Now, if you are getting technical on us, and have run tests with various power supplies in said component and not been able to hear a difference, then you may have a point. I have not ripped out and replaced power supplies in components to judge whether solely a PS is effected by the various power cords. However, in absolutely EVERY component I have ever used, with power supplies which the manufacturers I'm sure feel are optimized to the components, the components have been altered sonically via power cords. Besides, it's not very easy to listen to a power supply sans the rest of the electronics; so in the narrow sense your argument is a moot point.

I have, however, conducted tests of actual audiophile power supplies (i.e. filters, power factor correction units, etc.) and found that EVERY single one of them is also influenced by power cords. So, I have serious reservations about your claim that a properly designed PS is not able to be influenced sonically by a variety of power cords.

It's not a matter of operation vs. inoperation, but more like mixed drinks. If I want a rum and coke, do I count the atoms to make sure the mix is ok? There are many "flavors" of Rum and coke. Simliarly, there are "flavors" of power cords, all of which are slightly different in their electrical properties. Sorry, your measurements will not show this. :( You'll just have to trust us on that. I know that can be difficult for a theoretical kind of guy. ;)

Unless, of course, you wish to conduct some simple, not too expensive informal testing, which I think would show you, in say about two to ten seconds, that I'm right. :)
Jeez, people the man has made it perfectly clear that he's stating his opinion, not discounting yours.
Firstly, I am not trying to start a war with anyone. This is my opinion and I hope you respect my opinion and I do respect yours.

My whole premise is that more effort could be put into audio equipment power supplies by the manufacturers to save a comsumer money in not having to spend megabucks on expensive aftermarket power cords.

I have no doubt at all that you all hear differences with different power cords. My thing is that if the power supplies were designed properly the need for fancy power cords would cease to exist provided the power cord could provide the proper current.

After a lot of practical experience, I have come to the conclusion that the effects of the following plague audio reproduction in the respect to the deliverence of AC power to audio equipment:

1.The rejection and reduction of internal radio frequency interference (RFI) and noise already present on the mains line.

2.Immunity to and rejection of additional external RFI, EMI (Electro-Magnetic Interference) and noise.

3.Low impedance and high current capacity, so as not to current limit any equipment.

Each of these problems could easily be addressed in the power supply of a piece of gear.

I am an engineer by trade and I have designed and built quite a bit of audio equipment including their power supplies as a hobby. My power supplies are always designed to combat the above. I am also somewhat of a diciple of Nelson Pass and his SUSY or X designs and frequent his forum on DIYaudio.

I have listened to a number of high end power cords but have chosen to build my own. I am always a fan of using the best parts I could (wire, and connectors) to build a power cord just the same as using the best components I could when building an amp or premap or my turntable.

I hope I have answered everyones questions. I don't want to write a book here. Again, I do not dispute that people hear differences. I think those differences can be minimized by better power supply design.
Liguy, I sought no war either, and I totally agree that better power supplies can minimize differences, but that is not the real issue. Are there still differences? I hear them even with some very substantial power supplies.

My real question was how do you find a worthy power cord, given your beliefs. You answered that. Thank you.
Thank you for understanding my position. For a while it felt like I was under attack for having a different opinion when in fact I always maintained that power cords do make a difference in systems with poorly designed power supplies.

The sad part is that there are some high end companies that do not put very much thought in power supply design. I wonder how many companies actually use inductors in their power amplifier power supplies or how many use regulated supplies beyond a three terminal regulator in their preamps or build in EMI and RFI filters beyond a capacitor or leave out a filter to keep DC off the input of a power transformer to eliminate transformer hum? It is certainly food for thought on why power cords make a difference or sound different on different equipment.
hi liguy:

since you are an engineer, how would you test your hypoethsis that well-designed power cords are less sensitive to power cords ?

if you could devise a rigorous experimental design i might make tou a wager that the affect of differences in the sound of a stereo as power cords vary is independent of power supply.

keep in mind there are many variables which are involved in the fabrication of power cords. in your experienece, have you used gold, totanium, palladium, and other "exotic metals ? have you used a variety of iec connectors and plugs ?, have you used a variety of dielectric materials ?

all i am suggesting is the range of parts contained within a power cord could affect the sound of a stereo system , despite the best efforts of power supply design.

i will be convinced of your hypothesis when i hear the results.
oops, typo--i meant well designed power suuplies--my bad.

i meant to say how do you test the hypothesis that well designed power supplies are insensitive to power cords ?
Liguy, ok, very nice additional explanation; thank you!

So, your position is that any component which can be influenced sonically via power cords has a compromised power supply. Correct?

Which components/companies would you say have "done their homework" and have correct power supplies? You seem to be a fan of Pass amplifiers. Do you feel Pass has what you would consider a proper/good power supply? What other companies would you say have good power supplies?
Hi Liguy, never was any offense taken. I simply felt you should be more forthcoming rather than cryptic, and now you have been, so thank you. Yes, we'll agree to disagree -- I just find it impossible to believe that hundreds of high-end component manufacturers are all somehow derelict in the designs of their power supplies when, in your estimation, they could just as easily make them completely immune to whatever influences power cords have upon them.

Personally, I feel it's more likely the other was around: It's the ubiquitous generic stock power cords which were discovered to be suboptimally designed (as we might expect for something that's not even designed or made by the component manufacturers themselves and is treated as a giveaway 'freebie' and an afterthought).
I will try to answer you one at a time so please be patient.

Mrtennis: I am an engineer. In my career I have designed RF amplifiers and power supplies. I am an audio hobbiest and member of an audio club. It is my distraction and my method of escapism. My power cords are made of the 12 awg three conductor orange power cable (I wish they had it in black) you can buy at Home Depot. It is the same cable some people have used as speaker cable and claimed it is actually pretty good. I use Hospital grade connectors. I have not experimented with fancy materials or the like. I have made many power cables for members of my audio club and have listened to many of their high end cables during meet-ups at my home. I have yet to detect a sonic difference when used with my system. Being a hobbiest I don't have access to all the fancy materials you list. I like to keep it simple. When I design a supply I incorporate EMI and RFI filtration so I don't have to depend on the power cord to provide that level of assistance.

Douglas_schroeder: I am very much a Pass Labs fan. I may be overly harsh on the audio equipment manufacturers. I work in the defense sector. Our designs must pass rigorous specs for ripple, EMI and RFI specifications that commercial equipment does not. You can't afford to have a missile go off course because of excessive interference. Too often I have seen power resistors take the place of chokes and a single capacitor as an RFI filter instead of a common mode choke. Commercial products are just that, products made for the consumer. While they are designed not to emit EMI and RFI, I sometimes wonder how much thought was put into the succeptability to EMI and RFI. I guess that would put the conditioner manufacturers out of business. I don't want to single any one manufacturer out. That wouldn't be fair in my opinion. I can assure you I have seen some good ones and some bad ones.

Zaikesman: In retrospect, maybe I am overly harsh on the commercial HiFi manufacturers. They are not held to the same standards as those in the defense electronics arena. I sometimes that they also design to keep the costs down. I am not saying in defense electronics cost is not an object but the specifications are well laid out and they must be met and the designs reflect that. Our tax payers pay good money to protect our nation and expect our hardware to work and work well. In the power supplies I used to design we used RFI tight enclosures and some of the other features I already mentioned that are quite expensive to implement.

Again this is just my personal opinion. I guess in the end that power supply design in commercial HiFi equipment helps to sell power conditioners and power cords.

Thank you all for listening to me. I know these threads get a little crazy. Whether you agree with me or not is up to you. This is just one ex power supply designer's opinion. Thats what makes this hobby so much fun.

FYI...My DYI designed system is in our upstairs listening room. I enjoy what Nelson Pass has designed so much that I have an X350.5, X1 and Xono in my living room. If I could only be 1/100th as good an audio designer as Nelson that would be something.
Hi Liguy: It sounds like you've done due listening diligence in revealing systems, so if you've never heard a difference, no one can argue with that. Just count yourself lucky I guess, even if I don't quite see how power supplies for missle-guidance systems (of which I would wonder whether they need have their output modulated over as wide a frequency and dynamic spectrum as is present in music?) ought necessarily to correlate with listening impressions in high-end audio systems.

I heard an immediate difference the very first time I tried an aftermarket power cord with an amp around 12 years ago, and even though my gear is considerably better now than it was then, I continue to hear improvements, if not as drastic. (To me, power cords are more sonically consequential than interconnects, at least on a par with speaker cables. In fact, I recently ordered two more of my preferred power cord from my dealer, at a combined cost of about $1k. While hardly the most expensive model going, it still freaks me out a bit to think that I 'have' to spend even this much on power cords. But I'm just not as satisfied with the sound of my system if I don't, and since my investment in the gear they power is many times that amount, it seems justified if the ultimate goal is maximum enjoyment of recorded music.)

A couple things of note I find interesting:

It's easy to understand why an aftermarket cord might sound better than a stock cord, regardless of power supply considerations. What I've never had explained to me, and indeed suspect no one may be able to adequately explain or predict, is the fact that even among various aftermarket cords, all with better shielding and of heavier gauge than stock cords, there remain meaningful differences in sonic character. I don't think differences in resistance are significant enough to be the answer, but although I do feel that complex impedance must surely be a big part of it, I somehow doubt that is the entire story either.

Another thing is the fact that, even if we take the position that power supplies in components aren't as impervious as they perhaps could be, a thorough power conditioning regimen ought to help alleviate this factor. Yet even there, I have no trouble hearing meaningful differences when substituting power cords feeding the power conditioners themselves (in my system, of both the active waveform/voltage-correction and passive balanced/isolation-transformer types), as well as between the power conditioners and the components they feed.

But of course neither of those considerations can be cause for question if you don't hear differences among aftermarket power cords in the first place. So I also find it interesting that on this thread, the two posters who are career EEs both think and find this topic to be more spurious than legit. A small sample size, but it makes me wonder which group, audiophiles who aren't EEs or EEs who are also audiophiles, may bring the more prejudicial biases to their listening impressions.

PS - So what does Nelson Pass have to say about power cords?
why are so many concerned with the affect of a power cord on the sound of a stereo system ?

it can't be answered with knowledge. one can only say that there is some probability that power cords influence the sound of stereo systems. the value of the probability cannot be determined.

this whole topic is a philosophical discussion in that there is no definitive conclusion.
Mrtennis, is there a definitive conclusion to anything in music reproduction? I always think it is ironic that we only use our eyes rather than our ears in these groups. Certainly no one can demonstrate here the superiority of one brand of pcs, ics, ac filters, line stages, etc.
While hardly the most expensive model going, it still freaks me out a bit to think that I 'have' to spend even this much on power cords.


and since my investment in the gear they power is many times that amount

First let me say to Zaikesman I am only using your text as illustration for my question.

I am not singling him out, he just said it so well.

I am quite sure there are many people in the same boat.

Question:

For the amount of money many have spent on these components, doesn't it seem reasonable these components would come with the cord that allowed them to perform their best?

May be the wrong place to ask this but the opportunity presented itself with Zaikesman's statement.

I've been pondering this for quite some time. Looking forward to your responses.

Best,

Dave

Hi Corazon, I think audiophiles have already voted with their feet (and wallets) on this one -- we want the flexibility to play with different aftermarket cords on our own. It's like asking why most speakers don't come standard with 'matching' audiophile-approved speaker cables. Just give us an IEC inlet and a Belden cord we can stash in the closet, and don't charge us more for something we prefer to choose for ourselves.
I never asked Nelson about power cords although I believe he felt they would not make too much of a difference.

Nelson Pass on Power Supplies:

http://www.hometheaterhifi.com/volume_4_2/nelpass.html
I have stated my opinion but what I find interesting is how two different audiophiles can have differing opinions on how a specific combination of component and power cord sound.
Just for grins last night, I substituted a couple of older aftermarket cords on my CD transport which I'd never compared on that particular component before (and hadn't compared period in quite some time, predating my system's current configuration). The results surprised me by actually conforming to Byron's and Al's 'extrinsic-dominant' point of view, in that the sonic differences I expected, based on past experiences using these two cords on various amps (where their sonic characteristics had largely transferred with the cords), didn't at all translate in this application, for either cord. In fact my impressions, as well as preference, were just about exactly inverted from my expectations.
Liguy, with respect, the Home Depot cords are horrid. I happen to have made some for myself years ago when I was first experimenting with comparisons of power cords. I thought I was genius to get "top quality" sound on the cheap. But when I compared the Home Depot Home made to even approx. $100 power cords by the likes of Audioquest or Wireworld the H.D. cord sucked - that is sucked the life right out of the music. I couldn't stand to use them and got rid of them quickly. It was a waste of time and money, except for the fact that it reinforced the point that the cable manufacturers know what they're doing and the typical DIY guy does not.

Since I cannot prove otherwise, it may be that on your rig alone, given you have "hyper-power supplies" you designed, there may not be a difference in sound between power cords. OTOH, you suggest that some manufacturers of high end audio gear are getting it right. What if those amps also exhibited sonic differences with various power cords? Then where would you go in your argument?

I will say this, having worked with some of the finest audio equipment available, some with dedicated, optimized power supplies such as with the VAC Signature Preamplifier MkII (reviewed for Dagogo.com), not a one, not a single component I have ever come across has been impervious to power cord idiosyncrasies. I simply do not accept that when the dielectric, total gauge, conductor material etc. is changed on a cable the net result is nil sonically. I have used too many cables and too many components to concede that.

Liguy, you're a nice asset to this discussion and our little group here. I wish you could make a visit and we could test out some of our theories. I would find it fascinating to hear your rig and the power supplies you have made.

Dave (Corazon), the answer to your question is that manufacturers do not want to paint themselves into a corner with cables. If they don't believe in aftermarket power cords they're not going to promote them. If they do find them useful, they're not going to get in bed with one cord manufacturer or else they cut their fan base. Further, they may know that a particular cord renders a specific sound with their gear and it may not appeal to all listeners with all systems. Better to let the masses figure it out on their own.
there are many discussions on thie forum categorized by component type. people ask for advice.

however it has been shown in the psychology and sociology journals, that people vary in their suceptibility to be influenced by others.

riesmann coined the terms "inner directed" and "other directed".

i suspect that inner directed audiophiles will do what they want regardless of what others say, while other directed audiophiles arem more easily influenced by the comments they read and will buy based upon reccomendations.

some people ask a question for the sake of eliciting opinions and creating a discussion or debate, but have no intention of acting on any suggestions they read. what a waste of time to do that.

so, a question to ask is are you other directed or inner directed ? this question could be a theme and may be one soon.
Another thought strikes me; is it possible, Liguy, that you have been comparing/using power cords which are somewhat similar in characteristics? i.e. Aftermarket 14 total gauge with stranded conductors, vs. your 12 total Ga. with stranded conductors?

The reason I ask is that if the power cords you have been comparing have similar characteristics, then it is very likely that you would have a difficult time hearing differences between them. I can see a situation in which you replaced a stock power cord with a Home Depot DIY and found little difference. However, I would submit that this is not the best test of power cords, and that there are many more options available. i.e. A PC with 9 or 10 tot. Ga., or one with silver OFC conductors, etc. You would perhaps find it interesting to try a Wireworld lower end PC with silver coated prongs on the plug.

Maybe you have compared a wide variety of PCs but if not, then this is perhaps a legitimate reason why you are not hearing differences! I have conducted comparisons between PCs which sounded very similar and they were in fact similar in construction/design. That may be part of the answer to our disagreement. :)
From Wikipedia:
The high-end audio cable industry markets oxygen-free copper as having enhanced conductivity or other electrical properties that are significantly advantageous to audio signal transmission. However, conductivity specifications for common C11000 Electrolytic-Tough-Pitch (ETP) and higher-cost C10200 Oxygen-Free (OF) coppers are identical.[8] Much more expensive C10100, a highly refined copper with silver impurities removed and oxygen reduced to 0.0005%, has only a one percent increase in conductivity rating, insignificant in audio applications.[8] OFC is nevertheless valued by audiophiles for both audio and video signals in audio playback systems and home cinema.
Doug: I can't help but notice you've name-dropped Wireworld cords a couple of times. One of the cords that I tried and got rid of the quickest was their Silver Electra III+ (or some such). Didn't dig it on anything, despite its maybe having been the most expensive cord to pass through here. OTOH, a local Agonner of my acquaintance once bought one of my preferred cords based on my liking it, but didn't feel the same and wound up selling it to me! So I think IMO & YMMV are clearly the watchwords here...
Douglas_schroeder stated:

Another thought strikes me; is it possible, Liguy, that you have been comparing/using power cords which are somewhat similar in characteristics? i.e. Aftermarket 14 total gauge with stranded conductors, vs. your 12 total Ga. with stranded conductors?

Doug,

That IS an interesting thought. I am an open minded guy. My next club meeting is near the end of the month so maybe I can borrow some different cords from some members and have a listen and report back.
Liguy, well, count me as one of the most interested in your findings! :) I always distinguish between noticeable differences and efficacious differences. It's one thing for an effect to be noticeable, but another to be efficacious, that is "worth it" in terms of meritorious for an upgrade. So, when you do your comparisons, for the argument underway I'm interested in noticeable differences, not whether you feel it's "worth it", which adds another layer of subjectivity.

I'm beginning to think I've hit upon the culprit in the great "Power Supply Mystery," as you seem to have heard various power cords make a difference in other systems. It's not a hearing acuity issue. Also, you have not heard a difference in your rig, but that would stand to reason if the power cords (perhaps only the stock cord and your Home Depot cord were used?) employed by you were largely the same.

Yes, I will be quite interested to hear about this. I love discussions like this, where there is mental "jousting" but without rancor and with an open mind, as you demonstrate.

Zaikesman, your thought allows me to address what might be considered name dropping. It was not my intent; I was referencing the cables I used in comparison. I could have done the same with Magnan Cables, Jenna Labs, Clarity Cables, or any number of cables I've used/reviewed (WARNING! Major Name Dropping! ;0 ) I have never done a formal review of Audioquest cables, but I have mentioned them several times in trials/comparisons I've held with them over the years because they happened to be used in significant trials/breakthroughs in my learning process.

I've conducted dozens upon dozens of listening comparisons, and when one example seems suitable for my argument I select it. I believe I could reference illustrations regarding different aspects of cable use from any of the brands I've used; i.e. conductor material, geometry, total gauge, dielectric, terminations, etc. I'm not trying to make any definitive statement about the merits of brands in this thread, merely illustrating my logic. Frankly, I'm trying not to push my preference in that regard. I don't know that it's possible to avoid the appearance of name dropping when using real examples, but the fact that I'm not making statements about the performance in relation to other cables should help in that regard. I've written enough about them that people should get the feel for my assessment of cables I've used.
In answer to your query Zaikeman Douglas_schroeder wrote:
However, I would submit that this is not the best test of power cords, and that there are many more options available. i.e. A PC with 9 or 10 tot. Ga., or one with silver OFC conductors, etc. You would perhaps find it interesting to try a Wireworld lower end PC with silver coated prongs on the plug.
Rwwear, my point wasn't the ofc (oxygen free copper) as the cable being silver coated copper. A silver conductor sounds quite a bit different than copper.
Clean power does, however best that is achieved.

Power cords alone may be hit or miss. Current delivery capability and a good ground are keys. This is not rocket science. Personally I believe a lot of power cords are overengineered for the task at hand or sometimes just overpriced and not a good value.
Funny? Hardly. Back to the Wireworld; I did direct comparison between two models of interconnects and speaker cables with only the conductor (copper vs. silver over copper) different. The change in sound was no laughing matter.

But remember, one has to have a good system, a good room and good hearing or else the distinction will be moderated.
Mapman, you say much, such as pcs being overengineered, just overpriced, and not a good value. I am quite comfortable with you holding those as your personal opinions but they have no credence as to being true. I have no idea why you might argue they are over-engineered or how that would be evidenced.

At least you don't resort to Rwwear's nonsense.
Ha Ha. I tried being serious but nothing works when your dealing with a fanatic.
TBG,

I said some PCs are overengineered and overpriced and not a good value, not all.

I'll stand by that assertion with no problem whatsoever.

ALso that making a good power cord is not rocket science.

GEtting lots of clean power when needed in general can be an issue in many but not all cases. A power cord alone cannot solve that problem when present.
Mapman, I'm sorry, but as I said that doesn't make your case. I doubt seriously given my experiences that many pcs are well engineered or as I would prefer, designed. As we know from NASA, neither are rockets perfectly designed and trajectories perfect, or we would not need midcourse corrections.

I don't expect to alter your opinion, and you should not expect to alter mine. I would never argue that a power cord can solve all the problems with unclean power. Maybe Enid Lumley was right a long time ago, when she said we all need to generate our own power off grid.

All I can really say is that I have heard changes on the same component of many different power cords. Their impacts varied greatly. I certainly don't have cheap power cords, but I have seldom heard benefits provided by very expensive power cords to justify their prices.
Tbg,

Sounds like we agree on more than disagree.

I wouldn't compare the technical complexity of building a good PC or launching a successful space mission to that required of a power cord though. Very poor analogies!

Plus the space program is government funded therefore I would look there for innovation perhaps but not value.

Succesful commercial computer technologies tend to deliver both or do not survive.

High end wires are a boutique market with limited market. By their nature, they have to be expensive in order to survive. Only a select few will see value for whatever reason.

I might like to buy NASA mission grade surplus power cords if available for market value. Anybody know of such a thing? I think I have seen some power receptacles around this site that are of similar lineage.
Rwwear, I'll take that title "fanatic" as a complement. :)
If using several sets of cables in comparison is fanatical, then it applies. If facilitating dozens upon dozens of real world comparisons on the effects of cables (including comparison of silver vs. copper conductors) is fanatical, then it applies. :)

You may take it as you may. If you have compared dozens upon dozens of cables I submit your judgement will become convoluted very easily after just a few. Unless you have a number of folks doing blind listening without outside influence and being sure to take notes, it would be in the least very difficult to believe your claims by me. I'm not insulting your methods, they are just hearsay if using a scientific approach. I have heard so many claims that just don't hold up under scrutiny that I have to have irrefutable evidence before I will begin to believe unlikely statements such as being able to hear the difference between copper and silver power cables. I am not saying you can't. I am just very skeptical.
we live in a stochastic world. there is a probability that power cords make a difference.

in the broader scheme of things it doesn't matter if there is a disagreement on this subject. if a consumer believes and hears a difference, that is all that matters.oo
Rwwear, skepticism is allowed.

Does a conductor's judgment become convoluted by hearing dozens of symphonies?

Does a circuit designer's judgment become convoluted by designing dozens of circuits?

Your argument that the more experience I have makes me less of a good judge of a phenomenon is weak.

I used to be every bit as skeptical, until I got over it (i.e. put my pride aside and actually compared).

BTW, I don't disagree that humans are horrible at double blind listening tests. However, I also insist that humans have phenomenal capacity to hear distinctions in sound/music. The rub is that I believe we have poor acoustic memory, which makes us poor at the testing. So, both are true; there are differences in sound which are easily heard, but we are poor at matching/identifying precisely sound snippets under tightly controlled conditions.

Based on studies about recall and the human mind (i.e. how poor people are at describing/recalling details to police what they saw as an eyewitness) I think I have pretty good ground to stand on for my position. :)
Mapman, I only alluded to NASA because of this trite phrase, not rocket science. I do know a guy that used to be in NASA who got surplus electrical wire, he prefers newer stuff. He assured me that current capacity was not their only concern.
Rwwear, yours is just one side of the constant argument about hearing differences. I just compared two identical cables other than one using long linear crystal copper and the other silver, anyone who could not hear the improvement of the silver should invest very little into reproducing music. But my only dispute with those holding your position is why you care that I don't hold with your position. You cannot provide proof that there are no better or worse pcs. Please don't tell me of the same/different 30 sec. comparisons, they are invalid measures of what people hear.