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Topic: audiophile power cords (Read 56830 times) previous topic - next topic
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audiophile power cords

Expensive "audiophile" ac power cords are esteemed to improve the performance of an audio system. Alledgedly, they stop interference from entering the syste, through cleaner contacts with the plug outlet and through stopping either induced electrical, magnetic or rf noise from entering the amplifier through the power supply. In theory, none of this sounds right. Suppose the power outlet is filtered by a good power conditioner and the power is "clean" ac for the power cord. A tube amplifier at each stage of amplification is greatly attenuated at radio frequencies. For instance, the Miller effect capacitance of a 6j5 preamplifier triode through a 100K volume control has a capacitive shorting that cuts the rf by more than 99% for 3 mHz and additional stages of amplification multiply this loss of rf amplification. We assume that rf gets into the system by capacitive path through the power transformer. If the filters capacitor in the power supply is wired with a smaller capacitor, such as 0.1 microfarad, that should short out mHz rf.
    Apparantly, these power cords are shielded to keep out rf and to stop electrical fields from entering the cable. Some have ferrite doughnuts which should stop much rf.
    I have the following questions:
    1. If imperfect contacts in the plug make noise, what about the screws that hold wires in the house wiring circuit breaker box and wire nuts and what about the electrical service and the hardware all the way back to tjhe telephone transformer? And besides, it is not practical to connect long grain copper or silver wire all the way back to the telephone pole transformer.
    2. If rf is a problem, would not the shielding merely make the power cord a transmission line conveying rf into the amplifier? Why can't a well designed power supply in the amplifier stop unwanted rf as well as a power conditioner?
    3. Is not the power cord a minuscule part of the long wiring that emulates an antenna to deliver rf into an amplifier?
    4. Some manufacturers apply the same sort of reasoning to power cords that apply to speaker cables and audio cables to the power cord. They use long grain or single grain copper wire or even silver wire, but what about the grains in the rest of the house wiring? They try to attenuate capacitive reactance and inductive reactance by the twist in the cable as though trying to impedence match the cable. Others use teflon insulator so that delays of dielectric reaction in the insulator will not distort the 60 Hz house current sinewave. But "cheap" insulation in the house wiring will provide this. Furthermore, if there is some sort of harmonic distortion in the shape of the 60 Hz sinewave from the wall socket, this consists of Fourier series harmonics that are higher in frequency and therefore more efficiently filtered out by the amplifier's power supply that the 60 Hz after rectification.
    5. If the power cord is an antenna, it is a minuscule fraction of the length of the wavelengths of rf in the 3 mHz range or longer wavelengths. At 3 mHz, the wavelength is 100 meters. For a 1 meter power cord, the amount of rf it picks, assuming that the power conditioner into which it is plugged stops rf, is 1/100 of a wavelength of a phase dirrerence of 360/100 degrees, the sine of which is about 0.06.
    I know these concerns seem simplistic and unsophisticated and inadiquate to decide whether or not to make a fine ans almost sexy looking power cord for an amplifier. Reality is not likely to be that simple. A home made transmitter made of a Colpitts oscillator, for instance, whether it in the single digit mHz or whether it is in the vhf frequency will make a stereo amplifier buzz loudly of the oscillator is powered by unfiltered half rectified ac. So perhaps there is some advantage to a shielded power cord for an amplifier. But you also posted an interesting article about double blind listening tests of some very expensive "audiophile" power cords that demonstrated that the music does not sound distinguishably different when expensive and cheap power cords are tested. The variable of outside rf interference might have been missing in these tests.
    Belden shielded power cord has a splendid ruby red transparent jacket over braided shielding akin to a candy apple paint job in an art show and would be a choice if there is any value to a good quality power cord for less than $30 for enough cord for the main amplifier and the phono amplifier in my sound system. But would this be purely a brimborian, something worthy of ridicule, in view of your double blind tests? So many audio pundits say to use a good shielded power cord,
    I cannot rule out the value of a shielded power cord.

audiophile power cords

Reply #1 –
That's rather restating the obvious, and the subject has been covered here ad nauseam, but OK.

audiophile power cords

Reply #2 –
In a word, "SNAKE-OIL". 

Paul

     
"Reality is merely an illusion, albeit a very persistent one." Albert Einstein

audiophile power cords

Reply #3 –
Quote
I cannot rule out the value of a shielded power cord.

Nothing wrong with shielding.

If you want to give it a try: http://products.lappgroup.com/index.php?id...2&rel=bymhb

But then you talk $

The problem with audiophile power cord is that you talk $$$$$$$$$

A well shielded industrial power cord won't break the bank and might give you piece of mind.

BTW: you cant ABX piece of mind
TheWellTemperedComputer.com

audiophile power cords

Reply #4 –
Power cords make no sense. What about the many yards of unshielded, possibly aluminum wire behind the wall?? What about the MILES of aluminum or steel-cored copper wire going to the power station??

audiophile power cords

Reply #5 –
How can audiophiles even enjoy listening to the music when all they do is worry about 1,2,3,4 & 5?

audiophile power cords

Reply #6 –
When you guys mention Audiophiles, power cords, insanely overpriced gear (feet to support equipment, tweaks in general), I can only think about this place:

audiophile power cords

Reply #7 –
This kinda stuff gets sold because people can be fooled into buying it. Dumb magazines do completely unscientific and biased 'listening tests' and try to convince their readers that theres a difference to be heard ['stoking the placebo fire']. ... Anyways... they probably take a cut.

What I wonder is if the employees at the companies that make these kinda things actually believe they improve the sound. Or if they are just laughing out loud as they update the product descriptions on their websites.

Coming soon: The Triple-Helix Ultra-Shielded Super-Stranded Silver Power Cable. Now featuring organic snake skin shielding providing the unparalleled level of isolation that only mother nature has mastered.

audiophile power cords

Reply #8 –
drbarney,

Your message is lucid and substantial, and in some parts infallible. 

I think what my fellow HydroForum members are saying is, "You're preaching to the choir!" 

With that said, re-post your message to as many 'audiophile' forums as you can!  Don't let your astute diatribe remain bottled-up in a forum of like-minded thinkers!

Thank you for your contribution!
-Elias

audiophile power cords

Reply #9 –
Quote from: Qest on
This kinda stuff gets sold because people can be fooled into buying it. Dumb magazines do completely unscientific and biased 'listening tests' and try to convince their readers that theres a difference to be heard ['stoking the placebo fire']. ... Anyways... they probably take a cut.

What I wonder is if the employees at the companies that make these kinda things actually believe they improve the sound. Or if they are just laughing out loud as they update the product descriptions on their websites.

The thing is that there's an easier way, if you don't go THAT loony in the the price department. See Monster cable for instance. Or google for Phiten, titanium necklaces moderately priced, and be amazed at what people use them. Then again, it's the same people that think keeping their beards or mullets intact will boost their batting average.

Or just open a psychic business in L.A. You don't need to even spend on employees! Jesus, you can even make an empire out of bending spoons.

audiophile power cords

Reply #10 –
The audiophile 'industry' is predicated on creating problems that don't exist and then solving them at great expense to the end user. The audiophile willingly buys into these problems because they genuinely know no better, the solutions to these non-problems pander to the audiophile's vanity on several levels and they satisfy the need some have for modern life not to be fully demystified.

In this respect, audiophile cables are no different to the beauty industry. And they both target a similar end user.

No 19 year old buys expensive skin-toning face cream. Their mothers buy the stuff. They buy it because they address problems that they didn't know existed ("aging skin is caused by micro-wrinkles being disenplumpenated over time. Our new Replumpenizing Complex with Polylipidinase helps reduce the signs of micro-wrinkles."). They buy this because they think the special magic ingredient is something more than face cream. These creams pander to their vanity because:

1. If it works, they look younger
2. If it doesn't work, they think they look younger
3. They want to be younger, or at least be told they look younger
4. They can show off to their friends about how discerning they are, with their expensive buying decision
5. They gain snob value among their peers in spending a lot of money on expensive creams
6. The magazines they read tell them how good they will look and how impressed their friends will be if they use the expensive stuff

Interestingly people still buy expensive skin creams even when the sham is exposed (never by the beauty magazines, usually by independent consumer groups). "What do they know?" comes the rationale, "They are only scientists, and probably jealous. I know it works because it works for me". If cornered and asked why it works, the response is "don't ask me, it's a mystery... but it works!"

Both cables and creams are seemingly sold on 'the science bit' (lab coats and long chemistry-sounding terms in beauty treatments, 'white papers' in cables), but why are beauty treatments sold on perfume and cosmetics counters in department stores? Why are audiophile cables are sold as male jewelry; an audiophile cable nerd could tell you the chemical composition and the rarity of every constituent part of an expensive cable, but never its measured resistance, capacitance and inductance (the only parameters that might conceivably cause a cable to sound different from another cable)?

We rip into the magazines for not exposing the lie of expensive cables, but would it really make any difference to the audiophile? They would just go elsewhere... as they did with more level-headed magazines like Audio and Stereo Review.

Bear all this in mind when buying last-minute Christmas gifts for your wives and mothers!

audiophile power cords

Reply #11 –
^^^ Great post. Don't forget diamond jewelry. That's the biggest scam ever, responsible for billions of wasted dollars. I once asked a jeweler if he could tell the difference between real diamond and zirconium. After squirming uncomfortably for a moment he said he thinks so if he looks with a loupe, but then admitted he can't explain what he'd be looking for to tell them apart. That was all I needed to hear.

--Ethan
I believe in Truth, Justice, and the Scientific Method

audiophile power cords

Reply #12 –
Ha ha diamonds and expensive metal and stone jewelry has to be the most irritating of all these scams. Somehow if you protest  against it (for instance, refuse to buy a month's salary's worth wedding ring) you are a cheap bastard. I'd rather buy a wedding 50-inch plasma thank you very much.

audiophile power cords

Reply #13 –
Quote from: Ethan Winer on
^^^ Great post. Don't forget diamond jewelry. That's the biggest scam ever, responsible for billions of wasted dollars. I once asked a jeweler if he could tell the difference between real diamond and zirconium. After squirming uncomfortably for a moment he said he thinks so if he looks with a loupe, but then admitted he can't explain what he'd be looking for to tell them apart. That was all I needed to hear.

--Ethan


an old prospector came into town during the gold rush. He had hit the mother load and went to cash his find. A few days later he was found on the streets broke. When asked what he spent all that money on he answered, "I spent one third on women, one third one wine and I wasted the last third." Value is in the eye of the beholder. Yes the diamond market is artificially inflated, but if one wants a diamond....

It's only a scam if you pay for a diamond and get something else. You do get a lot of false promises with many face creams. But there are products in the world of cosmetics that actually work as advertised.

Oh and Ethan, the jeweler you talked to may have just been a hack.

audiophile power cords

Reply #14 –
Let's not lump jewelry together with audio cables.  Jewelry is advertised as an investment in some countries and as serving a social function most everywhere.  Jewelry works as advertised for both of these.

Expensive cables are advertised as offering some technical merit over cheaper cables - yet nobody seems to be able to support such claims by measurement or in a controlled test.

However, cables do (unfortunately) serve a social function.  On many audiophile forums a reviewer will not be taken seriously if they don't have an expensive set of cables since they cannot fully defend the claim that they have thoroughly evaluated a piece of equipment.  This completely turns off some reviewers (like me) because any claims are endlessly derailed by comments like "Make sure you try it with this cable before you comment further..."

Beyond that, some cables are actually worse (in a practical sense) than stock or inexpensive cables.  Some of these "audiophile" cables can be heavy, difficult to manage, microphonic etc.  I've actually seen a cable pull a headphone amp off a table.  Imagine what a heavy and microphonic cable does to the feel of headphones on your head.

As for fake versus real diamonds - no direct comment...

audiophile power cords

Reply #15 –
Quote from: odigg on
Jewelry is advertised as an investment in some countries and as serving a social function most everywhere.  Jewelry works as advertised for both of these.

I agree that things are "worth" whatever people will pay for them. However, this is a matter for consumer education. A $5,000 used car can get you to work and to the supermarket. A $5,000 diamond has no intrinsic or practical value.

Quote
On many audiophile forums a reviewer will not be taken seriously if they don't have an expensive set of cables since they cannot fully defend the claim that they have thoroughly evaluated a piece of equipment.

Yes, when I bust myths in the pro audio forums, I'm a frequent target of that because I don't have a $5,000 A/D/A converter.

Quote
some cables are actually worse (in a practical sense) than stock or inexpensive cables.

Yes! Some of the most expensive audiophile products are truly lousy. Such as $5,000 toob amps with very high distortion. Or speaker cables with such high capacitance they send those same incompetent power amplifiers into self-oscillation.

--Ethan
I believe in Truth, Justice, and the Scientific Method

audiophile power cords

Reply #16 –
Quote from: Ethan Winer on
Quote
On many audiophile forums a reviewer will not be taken seriously if they don't have an expensive set of cables since they cannot fully defend the claim that they have thoroughly evaluated a piece of equipment.

Yes, when I bust myths in the pro audio forums, I'm a frequent target of that because I don't have a $5,000 A/D/A converter.


Well that and the lack of a Grammy! ;-)

It is amazing how working on a recording that wins a Grammy suddenly makes people infallible world authorities on all things audio.

audiophile power cords

Reply #17 –
Quote from: Arnold B. Krueger on
It is amazing how working on a recording that wins a Grammy suddenly makes people infallible world authorities on all things audio.

Yes, the ol' "argument from authority" we see all the time.

--Ethan
I believe in Truth, Justice, and the Scientific Method

audiophile power cords

Reply #18 –
Quote from: Roseval on
Quote
I cannot rule out the value of a shielded power cord.

Nothing wrong with shielding.

If you want to give it a try: http://products.lappgroup.com/index.php?id...2&rel=bymhb

But then you talk $

The problem with audiophile power cord is that you talk $$$$$$$$$

A well shielded industrial power cord won't break the bank and might give you piece of mind.

BTW: you cant ABX piece of mind


Shielding is indeed useful in many aspects, but only  when it's use is applicable.
Shielded powercords are mainly used to shield off distortion/RF/etc from devices producing this, not to protect against it.
Grounding is obviously an important part of this, but it's easy to forget the noise and distortion it carries in larger facilities with many households.
There's often a very complex variety of distortions in these facilities that may cause all sorts of issues with electrical equipment, but most often they don't.
A shielded ölflex-cable or whatnot won't help you here.

As far as I know from studies, amp-technology has filtering of basic models at least (condenser-inducer parallels etc).

There should be a very limited case of scenarios where what you say applies.

audiophile power cords

Reply #19 –
You know, the job of a power supply is to convert the AC to DC, and filter out whatever kind of noise might be prone to occurring on any of its outputs, including ground.

If a power supply successfully does this, there is no need for any power cord beyond that which can convey enough power.

If a power cord TRULY DOES MAKE A DIFFERENCE, there's something wrong with the power supply its attached to.
-----
J. D. (jj) Johnston

audiophile power cords

Reply #20 –
Quote from: Woodinville on
You know, the job of a power supply is to convert the AC to DC, and filter out whatever kind of noise might be prone to occurring on any of its outputs, including ground.


..and doing this isn't rocket science.  One of the more powerful tools in the equipment designer's noise-rejection toolkit is the power transformer. First off, it inherently rejects all low frequency and DC common-mode noise. It may have excellent rejection of HF noise as well, because its windings tend to be inductive. Many power transformers are built so that there is very little capacitance between the primary and secondary as well. If you try to use a power transformer as an audio transformer, it will often have miserable response above a few 100 Hz.

Of course the filter caps are the second ring of protection. Not only do they smooth ripple, but they also deal with other sources of noise at all frequencies. Modern filter caps often have very low ESR and ESL so they are just wonderful at doing away with power line noise. The size to capacitance ratio of power supply caps has also been improving, so that packging relatively large filter caps is less of a problem.

The third ring of protection is power supply regulation. In many cases this is a series-pass high-powered specialized op amp. In switchmode power supplies regulation is part and parcel of the design, so regulation is even less likely to be skipped over.

Quote
If a power supply successfully does this, there is no need for any power cord beyond that which can convey enough power.


As several have pointed out, shielded power cords and line filters at the input of equipment power supplies are generally there to deal with keeping noise from entering the power line from the device, not vice-versa.

Quote
If a power cord TRULY DOES MAKE A DIFFERENCE, there's something wrong with the power supply its attached to.


For the sake of the audiophile, we hope that his bragging about good-sounding power cords is unhh perceptual in nature. Because, if it is for real, it means that his equipment is all POS's.

audiophile power cords

Reply #21 –
Quote from: Arnold B. Krueger on
As several have pointed out, shielded power cords and line filters at the input of equipment power supplies are generally there to deal with keeping noise from entering the power line from the device, not vice-versa.


Then it's a basic assumption that power supplies have bad line filtering? Oh well ...
-----
J. D. (jj) Johnston

audiophile power cords

Reply #22 –
Quote from: Woodinville on
Quote from: Arnold B. Krueger on
As several have pointed out, shielded power cords and line filters at the input of equipment power supplies are generally there to deal with keeping noise from entering the power line from the device, not vice-versa.


Then it's a basic assumption that power supplies have bad line filtering? Oh well ...


Some would call it ignorance

audiophile power cords

Reply #23 –
can we please not call these people audiophiles.

they are audiophools at best. or more likely, equipmentophiles.

i consider myself an audiophile but the most expensive bit of equipment for audio playback i have is my mp3 player(cowon s9). i can't tell the difference from that playing through my stereo speakers(generic no-brand bought in a car boot sale for a tenner) and the test models in bang and olufsen. i figure that means that if there is a technical difference then it isn't to big.

eitherway, when i listen to good music i enjoy myself.

then again, i also enjoy lo-fi as well as hi-fi. so maybe i'm predisposed to not minding some crap quality.

audiophile power cords

Reply #24 –
Quote from: Woodinville on
Quote from: Arnold B. Krueger on
As several have pointed out, shielded power cords and line filters at the input of equipment power supplies are generally there to deal with keeping noise from entering the power line from the device, not vice-versa.


Then it's a basic assumption that power supplies have bad line filtering? Oh well ...


It's a basic assumption of audiofoolia that everything is bad. That's why everything sounds different to them.