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Power Cables. Are they overhyped?

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The argument about sensitive medical equipment not using fancy mains cables is a bit spurious. Do you really think a CAT scanner plugs into a 3-pin mains socket? And mobile equipment, ultrasound scanners perhaps, just need to be good enough for the job at hand. I doubt it has occurred to anybody to blind test mains cables on ultrasound scanners and see if diagnostic rates improve.

FWIW 'CAT' scanners come in various types. PET, NMRI, etc. Their 'sensitive' bits will be well shielded, signal conditioned, and power filtered. They'll also probably eat more power that I'd recommend running through one domestic 13 amp mains socket! They will be designed or installed with subsidiary systems to cope with crappy mains, etc. They aren't typical of the bulk of instrumentation used in hospitals.

If you check out mains filters you should find they they do have some which are specifically 'medical' grade. This is because there are a number of quite specific safety requirements as well as sensitivity/signal ones for medical systems. Particularly for ones in any electrical contact with the patient. Mains filters are likely to be used to deal with RF in hospitals, not a choice of mains cable. How much sensitivity (to RF as well as the desired signal) varies with the type of device and function. Passive sensors used in contact may tend to be the most sensitive, not 'CAT scanners'.
 
I'm not.
I have a full understanding of the psychology of buying, it can be related to any purchase. Cars & shoes being the most prevalent, hifi comes a poor second to cars for men & shoes for women.
I don't see how this would affect a blind test.
 
FWIW I've seen the "RFI modulates the noise background" arguments before. Yes, that can and does happen in some cases/circumstances. However people can check this by winding up the volume when not playing something. Can you hear such patterned variations in the noise? If so, can you hear it even when the volume control is set at a level you'd use when listening to music?

If yes, fit a filter. If no, you don't have the RFI problems.

In my own experience things like 'crackles' from devices like fridges, central heating, etc, are more common. Particularly when listeing to VHF/FM. These are a dead giveway. Chances are a change of mains cable won't help. But again, a filter may - although for VHF FM you may have to play with the antenna and its downlead. That *may* mean a change of VHF coax. Although even here a clamp on ferrite may do the trick in some cases.
 
How many Night and Day experiences have our difference hearers and must tellers had?

Me I hear a slight difference I forget about after a while with line input, more so with phono and have heard vile noise others rave about with speaker cabling but not with mains cables or digital. Sorry I have tried, just doesn't happen.

A thought comes to mind are the difference hearers and must tellers romantic, artistic, imaginative souls who thrive on their creative efforts and cannot even change a fuse.
I do agree with some of this, night & day differences are mainly speaker related for obvious reasons, cabling comes in last with cd players & amps bringing up the rear.

I have never heard a night & day difference with any cable, I don't see how anyone could, subtle differences, sometimes, is all that is needed.
For example, I switched out my Castle speakers around an hour ago for my Neats, no cable, amp,cd player, speaker stand or support will change the sound to this degree.

Your post says more about you than any cable, it is based in non fact as I never read a cable has caused night & day differences here on pfm, I just wonder why you keep bringing this up here when it's clearly not the case.

Feels more like a troll post to me, "difference hearers & must tellers" for example. It's a little silly & immature.
 
Erm, you seem to be cherry picking some specific general classes of medical equipment here. In effect you can make a point by ignoring the rest.

'CAT' scanners come in various types. PET, NMRI, etc. Their 'sensitive' bits will be well shielded, signal conditioned, and power filtered. They'll also probably eat more power that I'd recommend running through one domestic 13 amp mains socket! They will be designed or installed with subsidiary systems to cope with crappy mains, etc. They aren't typical of the bulk of instrumentation used in hospitals.

If you check out mains filters you should find they they do have some which are specifically 'medical' grade. This is because there are a number of quite specific safety requirements as well as sensitivity/signal ones for medical systems. Particularly for ones in any electrical contact with the patient. Mains filters are likely to be used to deal with RF in hospitals, not a choice of mains cable. How much sensitivity (to RF as well as the desired signal) varies with the type of device and function. Passive sensors used in contact may tend to be the most sensitive, not 'CAT scanners'. So the entire area is rather more variable and complex than you portray.
AFAIK there do exist portable ultrasound and CT scanners. Would these not be connected by an ordinary mains plug? Not that it really matters since (whatever the connection) they would have to be connected via a cable.

Of course this whole topic is really only of interest if one accepts that audio signals conveyed by electricity and audio electronics devices are fundamentally the same as other electrical signals and electronic devices.
 
I just had an internal fuse blow on my power amp.
It was a silver one I put in a couple of years ago for the hell of it.
I replaced the blown one with a cheapo standard fuse.
My expectation was that it might sound worse, probably the same.
But, it sounded clearly better, much to my surprise.
I could see the blown silver fuse was slightly tarnished around the ends.
Make of it what you will, but my guess is that one explanation for differences in power cable sound is the cleanliness / quality / tightness / contact area on the pins (both ends).
 
Make of it what you will, but my guess is that one explanation for differences in power cable sound is the cleanliness / quality / tightness / contact area on the pins (both ends).

Yes, unplugging (and cleaning up) your plugs at least once a year is not a bad idea.
 
Of course this whole topic is really only of interest if one accepts that audio signals conveyed by electricity and audio electronics devices are fundamentally the same as other electrical signals and electronic devices.

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.
 
According to that logic, the luxury wrist watch market would have failed long ago.

Well, that assumes people buy luxury wristwatches in order to tell the time.

And before you say it, I don't think you can characterise mains cables as audio jewellery, for the simple reason that most of the time, they are not visible.
 
So do you have controlled, verified double blind listening results showing power cables make a difference?

And here we go again. I've said this already recently, but the cable sceptics always demand blind tests. Then when blind tests are done, they demand blind tests done to a more rigorous methodology, with statistically significant numbers of repetitions, and so-on. It's not hard to see why: the 'if you can't measure it, it didn't happen' position demands rigour and certainty.

But I, and many others, continue to contend that the sort of statistically significant repetitions required also risk inducing fatigue, which skews the results. If you're going to demand a particular methodology, it is up to you to show that the methodology is effective. So take two components known to be measurably and audibly different, subject them to your methodology and see what results you get. If the results bear out the known findings, and are statistically significant, then you have something. Until then, maybe ease up a bit on the intellectual superiority pedal, hey?
 
AFAIK there do exist portable ultrasound and CT scanners. Would these not be connected by an ordinary mains plug? Not that it really matters since (whatever the connection) they would have to be connected via a cable.

Of course this whole topic is really only of interest if one accepts that audio signals conveyed by electricity and audio electronics devices are fundamentally the same as other electrical signals and electronic devices.

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.
 
I don't know if this has been addressed up thread as I really haven't the will these days to wade through the shit, but any assessment of noise ingress via a mains cable should be made at the output of the audio equipment being powered. There are lots of fancy graphs and reports showing the ability of mains cables to reject noise, and invariably these measure at the cable under assessment. Utterly pointless excercise designed to mislead.

We don't listen to the mains cable, we listen to the unit being powered.
So the question must be, does a better mains cable improve the signal exiting the unit. That's after the power supply and any filtering has converted the ac to dc and it has powered the circuits.
 
I don't know if this has been addressed up thread as I really haven't the will these days to wade through the shit, but any assessment of noise ingress via a mains cable should be made at the output of the audio equipment being powered. There are lots of fancy graphs and reports showing the ability of mains cables to reject noise, and invariably these measure at the cable under assessment. Utterly pointless excercise designed to mislead.

We don't listen to the mains cable, we listen to the unit being powered.
So the question must be, does a better mains cable improve the signal exiting the unit. That's after the power supply and any filtering has converted the ac to dc and it has powered the circuits.

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.
 
I, and many others, continue to contend that the sort of statistically significant repetitions required also risk inducing fatigue, which skews the results.

Fatigue might skew the results, but totally erasing the results every time, no matter how long or short the test is? Unfortunately that becomes the analog of "I can bend spoons by mental energy, but not when there are sceptical people in the room who radiate negative energy".

If you're going to demand a particular methodology, it is up to you to show that the methodology is effective. So take two components known to be measurably and audibly different, subject them to your methodology and see what results you get. If the results bear out the known findings, and are statistically significant, then you have something.

I totally agree. That is why most proper tests include "calibration" points.
 
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.

So you agree that power cables have no effect on preamps and source devices?
 
Presumably, at some point in the past, some charlatan set to thinking about how to increase his income from hifi sales, and hit upon the idea of fancy supports and fancy cables. And, many bandwaggons later, we find ourselves where we are.

It is inconceivable that somebody happened to notice a change in sound when they moved to a different surface, or used a different connecting cable, and did a bit of empirical experimentation and now we find ourselves where we are.

Isn't it?

Thing is, if you accept the second scenario as realistic, then it kinda follows that the noticing of the effect preceded the development and marketing of the product. That the effect is not amenable to easy measurement doesn't mean the effect is not perceived, just that we don't yet have a simple explanation for it.

Well if for example, when some surface is sold as vibration isolating and there is nothing intrinsic to its design which would isolate vibration - all of which is eminently measureable and verifiable - then I know exactly where we are.

The problem is that when you do empirical testing on these items invariably people cant hear the difference and no difference can be measured.
 
It's OK, I don't really think Richard Bews could care less about a few pages on a HiFi forum slamming cable differences. He does make them though, as in from scratch custom made wire, ribbon and cable, especially interested in tonearm, RCA and speaker cable.

The proof is in the pudding, having owned and listened to a lot of LFD gear, settling on PA2M(SE) amps and the DLS pre it's clear the brand isn't interested in fancy names either. Put it up against the usual magazine fare and it'll make them sound like toys though.

Interestingly LFD doesn't make XLRs because they don't think they make any real difference, they only recently started making a power cable, because again not really much in it. RCAs and speaker cables are a different subject.

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.
 
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