Power Cables. Are they overhyped?

[BE718]

To put it simply, if the product is useless the market for such a product fails quickly as anyone purchasing it soon realise it's a waste of money, .

This just isn't the case. People are marketed into believing things and hear what they want to hear and want to believe their purchase and judgement was valid and justified. Also there is a great propensity among the audiophile community to grossly exaggerate the differences that are real into a totally inappropriate level of significance.

 

[Jim Audiomisc]

The further problem is that what we 'measure' with our ears is the output from the speakers, not the output from the device, so measuring the signal from the amp (say) into a dummy load tells us comparatively little. We need to be able, at the least, to measure the signal delivered to the drivers.

I'm not sure about the confidence with which you assert "comparatively little" above.

Firstly, either attaching the speakers changes the behaviour in this respect, or not. If it *does* change the behaviour then that may imply any 'RFI' problem is via the speakers, not the mains. If it doesn't your assumption would be incorrect.

Secondly it is quite easy to measure the output *with* the amp connected to speakers just as with a load of some other kind. You can lsten and use a scope, etc, at the same time. Something I've done in the past for more hours/days than I could now enumerate! 8-]

However if the belief is that the problem *is* 'RFI' then what I said earlier will tend to be relevant. i.e. if you wind up the volume and don't hear the claimed 'noise variations' or obvious signs like crackles or someone ordering a takeaway, then there may be no RFI 'problem'. Yes, you can use your ears for this.

So far, though, I've only seen assertions that RFI is the root cause of what mains cables are used to 'cure'. That may be true in some cases, but is it the norm? If so, where is the evidence for it as the *cause*? And even then, why wouldn't a filter *designed* to block RFI fix it more reliably?

 

[adamdea]

I was hoping that this article titled 'Musical Electrons' would confirm what we all in fact know: that musical electrons are different from normal electrons. I was sadly disappointed.

Oh that looks interesting. Even allowing for google translate I'm still baffled though.

 

[BE718]

It hasn't been addressed upthread, and it is a crucial point, you're right.

The further problem is that what we 'measure' with our ears is the output from the speakers, not the output from the device, so measuring the signal from the amp (say) into a dummy load tells us comparatively little. We need to be able, at the least, to measure the signal delivered to the drivers.

My experience of mains cables is that where they have a beneficial effect, it is perceived as an improvement in dynamics; that is, micro-dynamic subtleties, dynamic range more broadly, and speed and impact. This all suggests that it is the system's ability to respond to the changing signal, into a reactive load which is being affected. Not sure anybody has measured that.

Remind me, don't you have mains blocks made of special plastic which allegedly improve the sound?

Really, are you sure its not all in your mind?

You have just told yourself a story to justify your beliefs. Why on earth do you think those performance parameters haven't ever been measured?????? Also why do think a mains cable affects that?

 

[Sue Pertwee-Tyr]

Remind me, don't you have mains blocks made of special plastic which allegedly improve the sound?

Really, are you sure its not all in your mind?

Alan, as a rule I've stopped responding to taunts disguised as responses, but just for the record, no, my mains block is made of aluminium.

 

[BE718]

Alan, as a rule I've stopped responding to taunts disguised as responses, but just for the record, no, my mains block is made of aluminium.

Sorry, must be confusing with someone else, but the example serves to make the point regardless.

It wasn't a taunt it was a valid point regarding the amazing ability (propensity) of audiophiles to hear things which when objectively assessed become inaudible.

 

[Sue Pertwee-Tyr]

It was a taunt. Dissemble all you like.

 

[whatsnext]

The part in bold you never read from a Mains Cable teller http://hifiwigwam.com/forum/topic/1...ables-sound-different/?page=2#comment-2159303

I invite anyone living close enough to come and listen for themselves.

 

[BE718]

It was a taunt. Dissemble all you like.

It wasn't. This is the one thing audiophiles refuse to accept, that their aural impressions are fallible, variable, influenced and biased.

 

[Sue Pertwee-Tyr]

It wasn't, its the one thing audiophiles refuse to accept, that their aural impressions are fallible, variable, influenced and biased.

Drivel. Sorry, but it is. It is true that aural impressions are all the things you suggest, but it is drivel to state that its the one thing audiophiles refuse to accept. I'm acutely aware of this, as are most of the people I know who share this interest.

I could say 'the one thing objectivists refuse to accept is that people who don't have their particular specialist knowledge may not actually be less intelligent, or less well-educated, than them'. It is true that in many cases objectivists do think like that, but as a generalisation, it is drivel.

 

[adamdea]

I did give ultrasound as a specific example of a portable scanner, upthread. As for the CAT scanners, in their various forms, it wouldn't surprise me to learn that they are hard wired, possibly the biggest directly to to 3-phase mains but equally likely, to some form of clean supply.

This is another valid point, of course. It is necessary to show that the medical/military/whatever device makes dynamic demands on its mains supply similar to audio devices, and isn't instead drawing a pretty steady operating current.

It's difficult to keep up with the non sequiturs, Sue. of course many CT scanners are hard wired, but how would that affect the portable ones? And anyway why would any of this matter if cables were the issue

And fancy foo mains cables are used for many audio devices not just power amps. How dynamic do you think the demands of a dac are? And what difference do the dynamic demands make anyway, especially bearing in mind how an AC/DC converter works? And what does "dynamic" even mean bearing in mind that we are talking about AC.
which put me in mind of an ealier thread on this topic
www.pinkfishmedia.net/forum/showpost.php?p=2814336&postcount=396

and this comment by Martin Clark

http://www.pinkfishmedia.net/forum/showpost.php?p=2814491&postcount=405

 

[Yomanze]

I think this sort of evangelising speaks volumes about your objectivity.

That's hilarious. To be concerned about noise on mains cables but not the proven benefits of noise reduction on balanced signal cables beggars belief and further enforces my view on the companies technical acumen.

"Yeah, but that's just like, your opinion, man."

 

[BE718]

Drivel. Sorry, but it is. It is true that aural impressions are all the things you suggest, but it is drivel to state that its the one thing audiophiles refuse to accept. I'm acutely aware of this, as are most of the people I know who share this interest.

I could say 'the one thing objectivists refuse to accept is that people who don't have their particular specialist knowledge may not actually be less intelligent, or less well-educated, than them'. It is true that in many cases objectivists do think like that, but as a generalisation, it is drivel.

You are acutely aware but refuse the validity of blind/controlled testing. OK, its clearly not drivel.

 

[Sue Pertwee-Tyr]

It's difficult to keep up with the non sequiturs, Sue. of course many CT scanners are hard wired, but how would that affect the portable ones? And anyway why would any of this matter if cables were the issue

It's only a non sequitur if you divorce it from the point it was trying to address, namely that 'you don't see sensitive medical kit like scanners using foo mains cables'. I was merely pointing out that a) scanners may be hard-wired, which kinda limits the scope, and b) when they are portable, them simply need to do the job, and whether they would be better with a fancy mains cable is simply not tested. Amps all work (ie function) with any old lump of mains cable, as do portable scanners.

It was also pointed out that medical kit is often fed from 'clean' power sources anyway. Presumably, if that matters, then to use Keith's logic, the medical device is not properly designed?

 

[Sue Pertwee-Tyr]

You are acutely aware but refuse the validity of blind/controlled testing. OK, its clearly not drivel.

I don't refuse the validity. I simply don't accept the validity of a test whose sensitivity has not been demonstrated. See my exchange with Julf, a page or two back.

Anyway, two taunts and you're out, so no more from me,

 

[Whaleblue]

...
Sadly, if you have even the most basic understanding of electronics and an inquiring mind, it is patently obvious that at least some of what is written, reviewed and "generally known" in the industry (eg passing electricity through silver has an effect fundamentally different from passing it through copper) is simply nonsense. Once you grasp that, and apply some degree of independent thinking then the task becomes to work out what actually isn't nonsense. Frankly it's quite a tricky task.

Exactly.

...when trying to wring the best performance out of (eg) a scanning machine the radiologist will try out different sorts of mains cable.
...

[PEDANT MODE]Radiographer[/PEDANT MODE]

 

[BE718]

I did give ultrasound as a specific example of a portable scanner, upthread. As for the CAT scanners, in their various forms, it wouldn't surprise me to learn that they are hard wired, possibly the biggest directly to to 3-phase mains but equally likely, to some form of clean supply.

This is another valid point, of course. It is necessary to show that the medical/military/whatever device makes dynamic demands on its mains supply similar to audio devices, and isn't instead drawing a pretty steady operating current.

Do you have any idea what dynamic demands an audio product make on the mains supply?

If you did you wouldn't be making the inference that its is directly related to the audio signal, or that it is necessarily some kind of high/challenging load.

Here is the dynamic mains current draw of a Marantz AV amp running 5 channels at moderate volume.

It shows the reservoir caps charging. It does not show the audio signal. 1mV = 10 mA. Made this measurement a few weeks back with scope and current clamp on the mains live wire.

Something for you to ponder. Where does the power come from when the AC cycle is at zero volts?

 

[BE718]

I don't refuse the validity. I simply don't accept the validity of a test whose sensitivity has not been demonstrated. See my exchange with Julf, a page or two back.

Anyway, two taunts and you're out, so no more from me,

But accept your own judgement (which is your personal test) whose sensitivity is even less proven, has zero controls and is obviously subject to bias and other issues..

To say that controlled testing is not has no validity, but your opinion does is quite something.

You confuse valid questioning and challenge to your dogma with taunting. You are now at the stage of blind defence of your faith.

 

[adamdea]

It's only a non sequitur if you divorce it from the point it was trying to address, namely that 'you don't see sensitive medical kit like scanners using foo mains cables'. I was merely pointing out that a) scanners may be hard-wired, which kinda limits the scope, and b) when they are portable, them simply need to do the job, and whether they would be better with a fancy mains cable is simply not tested. Amps all work (ie function) with any old lump of mains cable, as do portable scanners.

It was also pointed out that medical kit is often fed from 'clean' power sources anyway. Presumably, if that matters, then to use Keith's logic, the medical device is not properly designed?

They really are all non sequiturs. Replacing them with a new set of non sequiturs does not help. The issue is whether in any context outside audio (perhaps occasionally consumer video) sensitive electronic devices require fancy cables to work properly and/or work better with fancy cables. (btw it was actually you who brought up CT scanners specifically: my point was always much broader).

Btw I think you have really raised the bar with the implicit idea that no one is interested in how well a scanning device works (including the manufacturers, the people who make the buying decision, the people who operate them) compared with the overwhelming importance of how a pre amp works.

 

[Julf]

Anyway, two taunts and you're out, so no more from me,

Unfortunately blocking people who you disagree with leads to living in a bubble.