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Why Power Cables Affect Sound

I just bought a new CD player and was underwhelmed with it compared to my cheaper, lower quality CD player. That’s when it hit me that my cheaper CD player is using an upgraded power cable. When I put an upgraded power cable on my new CD player, the sound was instantly transformed: the treble was tamed, the music was more dynamic and lifelike, and overall more musical. 

This got me thinking as to how in the world a power cable can affect sound. I want to hear all of your ideas. Here’s one of my ideas:

I have heard from many sources that a good power cable is made of multiple gauge conductors from large gauge to small gauge. The electrons in a power cable are like a train with each electron acting as a train car. When a treble note is played, for example, the small gauge wires can react quickly because that “train” has much less mass than a large gauge conductor. If you only had one large gauge conductor, you would need to accelerate a very large train for a small, quick treble note, and this leads to poor dynamics. A similar analogy might be water in a pipe. A small pipe can react much quicker to higher frequencies than a large pipe due to the decreased mass/momentum of the water in the pipe. 

That’s one of my ideas. Now I want to hear your thoughts and have a general discussion of why power cables matter. 

If you don’t think power cables matter at all, please refrain from derailing the conversation with antagonism. There a time and place for that but not in this thread please. 
128x128mkgus
elizabeth
6,726 posts
 
Geoff. Can you point to a multi meter which can actually measure a tenth of an ohm or better, and you can see it doing so... and is ’cheap’? 
Not a criticism, just a real query.
jtucker
35 posts
 
We have test equipment that can measure small differences in impedance and no they are not inexpensive.  My inquiry is not so much about the impedance of PCs but rather is there measurable difference in the quality of the plus and minus dc power rails of the end equipment or a measurable difference in the ac line (EMI) due between stock and aftermarket PC cables (looking in or looking out relative to the end equipment).  At this point, I don't even want to say whether or not it makes an audible difference.  I just want to know if it makes a measurable difference.  If you can see that there is a measurable change in noise / ripple /  EMI ( or some other quality ) then it follows that you  (may or may not) be able to hear it.  I think it would be interesting to do a comparison between a stock cable and an aftermarket cable under controlled conditions.  I am an EE that has worked in power for many years (disclaimer, not ac but dc/dc converters).  If there is an audible difference, there should be a measurable difference ( and yes I agree that it may be possible that we don't know how to measure that difference yet ).  Anyway , it would be interesting to me at least to look at the obvious characteristics like conducted EMI and PSRR.  Those differences would be easily explainable.  If there is anyone in the DFW area that is interested in doing some real (and unbaised) testing let me know.
mkgus's avatar
mkgus OP
82 posts
 
@jtucker I like your idea. Let’s settle this thing once and for all and produce some measurements. It shouldn’t be hard to do given that the audibility is so apparent. I don’t know exactly what to measure but I would be inclined to look at transient behaviors instead of steady state properties. 
elizabeth
6,726 posts
 
I would repeat, the change in what a power cord does is not find-able with the current sort of measurements any folks are doing. The sad thing is, the measurement folks THINK they are making every measurement possible, or even imaginable. Like they have solved every mystery in the Universe already. When I make a comment about the speed of the wave, or the thickness or fuzziness  it is like I am speaking in Klingon. Right over the heads of the EE sorts, since no one has TOLD THEM such things might' exist??? SO I am again saying the things that matter, no one knows HOW to measure, nor thinks such measurements could even exist. Maybe some day some interested scientist will bother to study this, and find the way to measure it. Then suddenly all the folks who thought 'this cannot exist' will have their cake to eat. Until then, sorry you are blind. 
And yes I am sure this too is going to just be viewed as nonsense by the measure it or it does not exist types. No problem..
jtucker
35 posts
 
Elizabeth,Not necessarily disagreeing with you.  We might not be measuring the right characteristic that may or may not affect the perceived change in sound.  But why not measure the obvious things that most likely could affect sound?  If there was a measurable difference in ripple, noise, EMI or transient response, then that could put the naysayers to rest permanently.  If there is no measurable change, then you may be correct, we are just not looking in the right place.  If there is an audible difference, you should be able to measure some parameter, the trick may be in knowing what to look for.  Or maybe there is no difference...I'm not making any judgement on that one way or the other at this point.  I can't see why it would hurt to at least check some of the obvious characteristics.
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