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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Showing 10 responses by yang_hong

I’m new to this hobby, but seeing power cables priced to several thousand $ is just astonishing to me. As some users here have already said over and over: there is no way a power cable can affect your sound, unless it’s too thin, badly connected or you have a defective device.

Physics is just physics. I’d love to hear someone explain the physics how a power cable can improve sound quality. Haven’t seen any so far.
Ehh, English is not my native tongue, but hope mine is good enough to convey the message... 
But to be 100% honest, if any of you have, or can kindly point me to, good scientific explanations how an uber expensive powercord can improve the sound quality of a CD player or amplifier over a $10 powercord, I would love to be educated.

I’m a scientist (a biologist) and I do strive to be open-minded, as long as the science and logic we are talking are sound.
Prof, I really enjoy your sharp yet polite patient words. Couldn't said better by myself.
That’s a great list.

Let’s start with the first one: Purity of conductors.

Assuming we’re comparing a $10 Amazon powercord and a $1k pure sliver (the best conductor?) powercord, why the latter would make a CD player sound better?

To me, since either one of them would be a massive overkill for the meager power draw of a CD player as far as wire resistance is concerned, I’m lost how the silver powercord could make the CD player sound better.


One thing always pops up in this thread is that people often talk about AC cable as if it directly carries the audio signal.

Can we at least have a consensus that this simply cannot be true? Otherwise I see absolutely no point for any further discussions.
@sfischer1  I'm not EE but you said kind of make sense to me.

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


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.
@prof  I just love your posts. Everything I want to say you said it better. I hold exactly same position as yours. First, I don't believe an expensive AC cable makes a difference. Second, I welcome ideas that are scientifically sound explaining how AC cable can make an audible difference. Haven't seen anything solid on the latter.