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. 
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If you purchase a power regenerator, I assume you do NOT need a better power cord for the regenerator itself. Yes? Because if takes power, confers to DC before producing ’clean’ AC again, I would guess the power coming in can be as dirty as you like. I don’t know, curious.

@dseltz
The problem with a regenerator will be its’ power capacity. It may work well for smaller loads like preamps but will likely suffer as many problems with larger loads. A regenerator needs to act as an ideal voltage source, meaning near zero output impedance, which means it would show no change in the voltage as currents are generated at its’ output. They are unlikely to be anywhere near as good as a decent AC line. This is why a good AC line conditioner may be more beneficial. Whatever is used should minimally restrict current delivery and should be effective at filtering/cleaning up noise on the AC line.

Given the differences are claimed to *audible*, I guess it’s reasonable to assume that sth like noise levels, sound distortions etc must show measureable differences after changing power cord. Curious whether anyone has done that.

@yang_hong
Transient signals are non-repetitive and difficult to measure without constructing sophisticated test signals. We can attempt to measure a broad spectrum of "noise" in a system which should be ideally silent. Even when visible, it may be difficult to correlate how the signal correlated noise will interact with the signal and manifest itself audibly.

I often hear the improvements as a broadening of the stereo presentation or as an increase in the harmonic richness such as is apparent in the sounding board of a piano.

In the end, if it doesn’t give you pleasure to strive for and realize these improvements then don’t worry about it. Competent interconnection is all that’s needed. As I mentioned in my original entry, some folks feel like they understand the world when they obtain a little knowledge and find it unsettling when others express ideas which suggest that their understanding may not be complete. This doesn’t mean that those who believe they hear differences aren’t themselves riddled with biases, usually of the sort that whatever they have is the best or all that is needed by anyone. This isn’t limited to audio. ;)

Thanks for the reply. I myself definitely not into AC cables, but I'm really curious what could be the reason, if there is any, that AC cables can make audible sonic differences. My highschool physics keeps telling me that's impossible, but again I welcome the opportunity to be educated on the science I don't know.
No EE here, but my trial-and-error experience has shown me that a large isolation transformer helps deliver a quality energy supply, and then differences in AC cords have been easily heard.  For a larger system, a 240V/120V transformer puts things in a different league.  I suspect many of you don't hear enough of a difference between cords because your noisy power supply cannot be improved enough with that last six feet of high-purity copper.  While an isolation transformer does have a common ground between the windings, I have never heard any switching noise or dropout in my house when major appliances come on---rock solid.  A big plus with the 240V/120V is it originates from both service bus bars and is always in phase compared to what may occur using multiple circuits. I've built two levels of AC cords, and I know the improvements.       
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