Why an AC Power Cord cannot make a difference

[Beave]

I agree that a lot of power cords are not efficient because they do not work to cure the pb of EMI and RFI activated by the power cord itself. I work with many manufacturers of audio gears (very famous) that do not believe in power cords. I made some demonstrations with on of them, may be the most reluctant about PC action. After a long explication why PC could not work (He is Engineer in electronic and designer of probably the best amplifiers), I (engineer too but mainly in acoustic and mechanical vibrations, formerly professor in a University) made a test : blind listening with standard power cord of his famous amplifier and then with a highly regarded power cord that ASR say he could not work. All the people in the room said the second listening was vastly better! collective hallucination? electric compensation of ...? In fact I know why it's better and yes I agree 90% of PC change the sound but not improve it, but some do. I also made tests (blind) with audiophiles and same result. I conducted finally the same test with skilled musicians, same result. Some PC improve music playback and not only change it for a different taste.
The conclusion: as a scientist I always try to find why and how a phenomenon occurs.
This is the same subject that power conditioners. 95% do not work well because they wrongly "depurate" 230V. 230V should be perfect sine wave with no deviation with no harmonics... even if some electronic power supply make a very good job to filter AC at the input and they store energy. Only hearing transformers "singing" without music because there is some DC or too much pollution in AC that the power supply could not treat enough. This time too, proof is in the listening.
Scientist approach is mandatory but it should be well done and not conclude to wrong judgments due to inappropriate measurements (I spent 10 years making measurements).

Please tell us more about your comparison protocol, how blinding was done, how switching was done, etc.

 

[Beave]

As the saying goes, extraordinary claims require extraordinary evidence.

 

[PHP]

Please tell us more about your comparison protocol, how blinding was done, how switching was done, etc.

Blinding is simple, black room, no possibility to see which cable is on.
Switching is made simply by changing the power cable because the amplifier used has a very small time to be fully operational, on country to other gears that do no like at all to be deconnected (some preamps, many DACs and some of the best streamers).
Listening is done with very short selections of music that have their own qualities to check : transients, soundstage, first attack (quite revealing in streaming audio... most failed), dynamic headroom and tones "veracity" especially on piano and strings.
The best tests were done with "golden ears" persons that are persons that are real melomanes and go to concert nearly each week. Most of audiophiles are confused, the have poor music knowledge and listen only on audio systems. I also met some that were partially deaf not earring easy things. I also found that some audio manufacturers are extremely good engineers but are far from to have very good ears.

 

[PHP]

As the saying goes, extraordinary claims require extraordinary evidence.

of course, in both conclusions

 

[tw99]

I agree that a lot of power cords are not efficient because they do not work to cure the pb of EMI and RFI activated by the power cord itself. I work with many manufacturers of audio gears (very famous) that do not believe in power cords. I made some demonstrations with on of them, may be the most reluctant about PC action. After a long explication why PC could not work (He is Engineer in electronic and designer of probably the best amplifiers), I (engineer too but mainly in acoustic and mechanical vibrations, formerly professor in a University) made a test : blind listening with standard power cord of his famous amplifier and then with a highly regarded power cord that ASR say he could not work. All the people in the room said the second listening was vastly better! collective hallucination? electric compensation of ...? In fact I know why it's better and yes I agree 90% of PC change the sound but not improve it, but some do. I also made tests (blind) with audiophiles and same result. I conducted finally the same test with skilled musicians, same result. Some PC improve music playback and not only change it for a different taste.
The conclusion: as a scientist I always try to find why and how a phenomenon occurs.
This is the same subject that power conditioners. 95% do not work well because they wrongly "depurate" 230V. 230V should be perfect sine wave with no deviation with no harmonics... even if some electronic power supply make a very good job to filter AC at the input and they store energy. Only hearing transformers "singing" without music because there is some DC or too much pollution in AC that the power supply could not treat enough. This time too, proof is in the listening.
Scientist approach is mandatory but it should be well done and not conclude to wrong judgments due to inappropriate measurements (I spent 10 years making measurements).

There is just no way that a power cord can make equipment that you've described sound "vastly better". Surely your experience as a "scientist, engineer and academic" would lead you to search for a more realistic explanation... Frankly all your story needs is the partners of the people in the room to agree with the conclusion from the kitchen and we'd have got an audiophile full-house.

 

[PHP]

There is just no way that a power cord can make equipment that you've described sound "vastly better". Surely your experience as a "scientist, engineer and academic" would lead you to search for a more realistic explanation... Frankly all your story needs is the partners of the people in the room to agree with the conclusion from the kitchen and we'd have got an audiophile full-house.

more realistic explication may be also if I cannot proof why I cannot also like approach of not clever persons that always say that earth is flat. Nothing more to say.

 

[SIY]

All the people in the room said the second listening was vastly better! collective hallucination?

That's not the word I'd pick but it's accurate.

 

[SIY]

The conclusion: as a scientist I always try to find why and how a phenomenon occurs.

Exactly what sort of scientist are you? And why would you not investigate the vastly probable explanation first? Like verifying that there actually is a change in sound before chasing explanations as to why?

 

[PHP]

Exactly what sort of scientist are you? And why would you not investigate the vastly probable explanation first? Like verifying that there actually is a change in sound before chasing explanations as to why?

I apprenait interesting comments even on contrary to what we clearly observed. An experimentation is done with exactly the same parameters is right, whatever is the finding, not the conclusion.
I had answered about my knowledge and my 30 years of science and engineering.

 

[pma]

Scientist for 30 years, you must have some publications, then.

 

[PHP]

That's not the word I'd pick but it's accurate.

It was a joke of course, trained musicians and concerts melomanes have really good ears, that was it was mandatory for the test. My goal was not to find how or why PC could be better (there are a lot of pseudo scientist and real scientist to explain as I'm not electrician nor specialist in magnetic fields), just if good ears will say : better, not better, not better just sound different. The result was clearly better.

 

[PHP]

Scientist for 30 years, you must have some publications, then.

Some of you are really stange people, I said I practice science for 30 years and in a university, but if you read carefully, I'm engineer not scientist with publications. Also yes I have a lot of patents in car industry.

 

[PHP]

To sumarize, I related a test I did to ... have a beginning of appreciation from trained music people not by audiophiles. If the goal of this forum is to shame people, I have nothing to do here.

 

[Old_School_Brad]

I apprenait interesting comments even on contrary to what we clearly observed. An experimentation is done with exactly the same parameters is right, whatever is the finding, not the conclusion.
I had answered about my knowledge and my 30 years of science and engineering.

In your description you wrote

"All the people in the room said the second listening was vastly better!"

Does that mean you kept "cable B" as second always in the test? -That you conducted listening tests in the following order; 1) stock cable, then 2) with new cable?

 

[PHP]

In your description you wrote

"All the people in the room said the second listening was vastly better!"

Does that mean you kept "cable B" as second always in the test? -That you conducted listening tests with 1) stock cable, then 2) with new cable?

A was a stock cable at 15 euros as you can find for every electric appliance. The second one (B) was a high-end cable that has very good reputation, and yes it cost much more than A. As the purpose is to relate an experience, I will not tell which brand is B.

 

[Old_School_Brad]

A was a stock cable at 15 euros as you can find for every electric appliance. The second one (B) was a high-end cable that has very good reputation, and yes it cost much more than A. As the purpose is to relate an experience, I will not tell which brand is B.

You misunderstand. I'm asking in which order you did the swap. was it:
1) A (stock)
2) B
Because of what you wrote here:

"All the people in the room said the second listening was vastly better!"

It seems that you kept the same order in your cable switch throughout the testing. -Which I can't imagine will bring much data of value in a blind test where you need to verify that the perceived difference "follows" the cable switch..

 

[PHP]

no. I do not use a sequence nor have all the listeners at the same time to be sure there was not influence by some words or....
Anyhow, my intervention is to give an experience not to speak endlessly on it.
The only thing I can say, it's that I prevent to test with "basic" audiophiles because they judge by assimilation to audio habits and not with unamplified music as reference.
This was also a statement for myself as I have audio manufacturers different voices on the sujet of PC.

 

[BDWoody]

To sumarize, I related a test I did to ... have a beginning of appreciation from trained music people not by audiophiles. If the goal of this forum is to shame people, I have nothing to do here.

We aren't here to shame anyone, but there are many well intentioned people who make extraordinary claims without anything meaningful to support those claims.

You might want to look more into controlled subjective testing, and rigorous use of appropriate controls.

 

[Old_School_Brad]

no. I do not use a sequence nor have all the listeners at the same time to be sure there was not influence by some words or....
Anyhow, my intervention is to give an experience not to speak endlessly on it.
The only thing I can say, it's that I prevent to test with "basic" audiophiles because they judge by assimilation to audio habits and not with unamplified music as reference.
This was also a statement for myself as I have audio manufacturers different voices on the sujet of PC.

Alright. If you didn't use a certain sequence then I don't understand this quote of yours: "All the people in the room said the second listening was vastly better!"

I don't understand exactly how your test was done. It's a key point to your argument so if you are sure of the data it provided maybe you should explain t so there's no doubt how it was carried out.

Or maybe I'm daft and it's clear to everyone but me.

 

[EJ3]

Amazon.com

These are nice; tested for EMI, RFI, Certified for use in surgical suites and catheterization labs under IEC 60601. $9

The LENGTH (10 feet) is very nice, too.