... abit confused: how does a power cord affect the presentation of sound...

To add to discussion on power cables: no comments on audio quality - it is in the "ear of beholder," but just to point out how the cables heat up.  We burn in 100% of our AC EMI filters and we take FLIR images in near-infrared spectrum - if you are interested, here are couple of them that I put on our web site:  https://www.onfilter.com/cable-temperature  They get pretty toasty.  Whether this heating affects audio quality is a subject to a separate discussion.  The objective notes are that whenever you see higher-than-desirable temperature, there is an insertion resistance affecting output impedance of power line and, perhaps, some fluctuation of supply voltage with the load current on the receptacle.  The cables we use are industrial grade; if you are using thinner cables and/or consumer-grade plugs/outlets, the thermal effect is likely to be much higher.

If you are interested to repeat these experiments, we use FLIR'  One Pro (https://www.flir.com/products/flir-one-pro-lt?model=435-0013-03) - no endorsements, this is just what we use.  Fluke also offers similar products.

I have no idea who your friend is but where I live I don’t see line amplifiers on transmission lines every 50ft,  poles are more than 50 ft apart. That would be an amplifer on every pole??

The speaker causes the amplifier to work harder not the minimum resistance of a cable as long as it's rated for the job. Anything 12 awg or less should be fine up to 25 ft. Cars are DC which is why they typically use very large guages of wire. 

^But in your home you probably have 15’ to 40’ of 14 gauge from your electrical box to your outlet. 2’ of 2 gauge from the wall to your amp is doesn’t make up for that 14 ga run.  Its ridiculous actually.

Andy2, my deepest apologies, I got it wrong and I was in error, I feel bad! I now see that your not trolling any one, you never did!  You are one of the good guys and an asset to this community This is what I have to say:
djones51, it is you that is trolling!, there is nothing in my original post that suggest that I've deliberately provoked any one. but you have in your last post!

It seems crazy that after spending a few thousand on a component that comes with a stock power cord that spending another thousand on 5 or 6 feet of power cord can make the component that much better but it does.  Unfortunately my experience is that the more you spend on power cords the more you get back.  I have been using Wywires Platinum cords and am amazed at how much better the music sounds.  I have their digital cords for my DAC and Music Server and they make a difference over their regular power cords for those components.  They have 40 % off sales several times a year at CableCo or direct online.  
If you are going to start with one component start with a source or at least the pre-amp.  The amplifier can't sound any better than the signal it is getting.

Hello
i didn’t read everyone’s post but I would agree with starting with clean power : independent power aka home runs if possible with good quality wall outlets ( I use the porter ports )

CABLES make a difference BUT that doesn’t automatically mean that the sound will be better or and more importantly that you will enjoy the sound better.  Some experimentation is needed !
 I approach a cable from the perspective of not wanting it... So in it goes and then I’ll listen with music that I’m very familiar with and usually I can tell immediately if it’s something I might want.  I will give it a chance and let my ears adjust but again I hoping I won’t like and then won’t need to buy it...
If you are struggling to hear a difference then effectively there’s no difference. And sometimes a cable will effect the sound that makes somethings better and some things worse - like more detail at the expense of some musicality etc.  It always boils down to what YOU Like. 
BUT Then every once in a while you try something and your jaw drops...Those OMG Moments when the improvement is so significant that you won’t want to take the cable out.

Having said all that 

I wouldn’t expect cabling to be as significant as a component change.  You mentioned using a HT Receiver as a power amp with a separate pre
Receiver’s are amazing in all they accomplish in one box BUT there not really designed to be used that way.  And it’s very difficult to get a HT system to be as good as a separate 2 channel system for music.

But that is a different discussion...

Bottom line
Cables make a difference / Trust your ears and your taste !!  Don’t fall into the trap of using cables to correct a mismatch or something like that.  Experiment !! And hopefully get to a place where you won’t feel the need to experiment...............    at least for a while lol

Try to avoid products that are built by the cheapest bidder.  Good companies will not sacrifice a few dollars to mask the sound of a great design.  

The moment I see “I am an electrical engineer”, I stop reading right there 😂😂

I am electrical engineer . Auburn University (War Eagle). Can't really see advantage of "super" power cables. That being said, I did buybuy: https://www.pangeaaudio.com/Pangea-Audio-AC-14-Power-Cable
Because they look cool. That's it, the look cool.

"All I was saying is this is an opinion "we" don't know any thing of the kind. If this statement is true then the reason for it is measurable, the power cord has some anomaly"

dowjones,
As I've stated before, I suspect some day science will catch up to our little hobby & figure out what measurement accurately correlates to what we hear with the human ears/brain.

They haven't yet.    

Andy21 it is you that is trolling!, there is nothing in my original post that suggest that I've deliberately provoked anyone but you have in your last post. Get a life!!

Lols, I was referring to djones guy trolling and not you.

LOL!!! 😂 

The best power cord is NO power cord.  Why adulterate that painstakingly selected Romex 14-2 cable and the two Siemens circuit breakers that supply that pure pristine electrical power to your outlet? Just remove the outlet and continue with a short run of Home Depot Romex directly to the power switch of your components.  Or just buy the plug and IEC jacks and construct your own power cable out of that magical Romex cable?  Keep it pure fellas.

No one expects Audio Aristotle!

(with apologies to Monty Python and "No one expects the Spanish Inquisition.") 😄

All the best,
Nonoise

but what we do know is that power cords can and do have a big impact on sound whether it’s negative or positive

So , this a classic example of begging the question, I answered one with another.

We know nothing of the sort, he's assuming the truth of his conclusion. 

djones51

... If this statement is true then the reason for it is measurable, the power cord has some anomaly. 

Logical fallacy. This is a classic example of the measurementalist's use of circular reasoning, aka "begging the question."

phd,  You made a statement of fact,

what we do know is that power cords can and do have a big impact on sound

All I was saying is this is an opinion "we" don't know any thing of the kind.  If this statement is true then the reason for it is measurable, the power cord has some anomaly.  

djones51, I don't need to provide measurements or scientific data on how a power cord improves sound quality, after all we have you and others to cover that subject matter very nicely in the above posts, if people want to know more they can look it up on the internet.

Andy21 it is you that is trolling!, there is nothing in my original post that suggest that I've deliberately provoked anyone but you have in your last post. Get a life!!

and his posts make no sense.

Figured out how to do those measurements yet? 

djones51, please reread my post, I never said that power cords and the impact they have on our systems can not be measured. Rather I'm not concerned with measurements, only with the way they sound in my system.

To  phd,
Ignore him.  He's just trolling all the cable threads and his posts make no sense.  I think he got nothing better to do.

As an electronics guy here is my opinion
 Take it or leave it.  A power cords whole purpose in life is to supply power.  Many manufacturer's will do a great job in circuit design,  power supply design and for some reason overlook the amperage rating of the power cord to consistantly deliver the needed power without losing the power through resistance loss in heat.  I have seen power cords warm to the touch on high quality power amps.  If you feel any heat anywhere from the plug on down,  then the power cord is under rated. In this forum I would think it can happen often.  Appliance power cords are cheap and you can direct connect them the same depending if they were soldered or used connectors.  To hear the difference it would cost much.  I would be more concerned with conditioning the power having voltage regulation,  RF filtering. Under voltage, over voltage and spike arrestor before looking at the cord. 

I wonder if anyone ever attempted to make a power cord out of spark plug wire.

Guys - this is a complex issue, but broken down into its individual components it's relatively easy to understand.
I've attempted to over-simplify and explain this in the past and got all kinds of negative feedback - so I apologized for causing a controversy and stopped trying to explain the physics, magnetics and electro mechanics, dielectrics, metallurgy and engineering - of signal transmission.
teo_audio - what you stated is true, but you didn't explain the contexts nor did you explain the terms you use so "lay" people could understand them. Reminds me of some professors in grad school. Are you trying to make yourself appear intelligent? Are you trying to sell your cable products? Or are you trying to allow people to understand how things work? Maybe you are being sincere and that's the way you relate to people - if that's the case, my condolences. I would like to see the engineering of your cables.
Long story made short - power cords, interconnects and speaker wire most certainly play a part in system performance. I'm not trying to convince anyone, so please save the banter. 
A system has to be at a high enough fidelity level to reveal the performance difference of each component - not just with equipment, but with set up, room acoustics and source material. "The chain is only as strong as the weakest link" - most of the systems I've experienced were not set up to perform their best, including many high end dealer showroom systems for premier product introductions (some in NYC)! I've been involved in this commodity for more than 35 years (man, I'm old) and I've only experienced a handful of systems that were set up to perform to their best potential. A handful!
Anyone who believes differently is welcome to bring their own wires to my home and I'll blindly switch them into and out of our system. Only prerequisite is you have to agree to report the results here before you visit. I live in the central NJ area.
Every single person who heard our system easily noticed differences when something was changed - especially non-audiophiles. My wife notices and she doesn't pay nearly the attention I do.
Believe whatever you want - again, I'm not trying to persuade anyone. Those with an open mind and willing to learn can gain an understanding of why and how things work with relatively little research.
Many people enjoy their music and system with different objectives, I strive to assemble a system which reproduces the recorded event as it was performed. That is - to have the highest fidelity possible. It's far from perfect but for smaller acoustic venue performances, our system is very convincing. Stated another way - it sounds like the real thing, very close to the real thing - though it will never be mistaken for the real thing. Our son can play his sax in our music room and then we'll play some well recorded sax music and you can see / hear for yourself. To create a system that sounds like real music requires one to listen to live music - and not just on rare occasions. 
So many people state - this is better because it has more pronounced bass, or has a bigger image, or any one of a number of issues that demonstrate they're not using live music as a reference. Good luck with trying to put together a system that conveys the emotion of the music.
Last friend I had over to experience our system, upon first hearing it -  put his face in his hands and kept repeating "Oh My God" because he never heard a system sound like real music. He asked for my help and I told him I'd help him, and he then went out on his own and made expensive equipment purchases that won't allow his system to perform to it's potential. Go figure. I asked if he was happy with his system, he said he was and I sincerely wished him well.
I gave up trying to share and help people. Everyone has their own preconceived notions and is convinced of it. People even dispute each other here on Audiogon instead of having an open forum so concepts can be explained and shared. Sharing experiences and information shouldn't be so difficult, but unfortunately it is.
Best to everyone - I normally don't post such things but I guess the last experience with a fellow audiophile friend prompted this.

ghjuvanni -- Cool! You guys heard a difference and you didn’t like the more expensive, aftermarket power cord alternative. Ah, listening to your ears!

Think of your cables as antennas. 

Here's my $0.02...

I didn't believe PC could make any difference. (I studied electronics).
Borrowed a cable (Kimber) from a friendly Audio store (Q-Audio in Cambridge, MA). To my and my friend's utter amazement the cable DID make a pretty obvious difference in sound (context: MF M6si, KEF 104/2, AQ CV-8).
Punch line: neither of us preferred that (more veiled) sound. Both of us would characterize the sound as less in-your-face, more veiled, more suited to very long listening sessions w/o getting tired. But both of us preferred the sound with the stock cable. I would still use whatever came with the amp even if I could have the $300 PC for free. But the sound difference was undeniable and an eye-opener for us both.

djones51, please reread my post, I never said that power cords and the impact they have on our systems can not be measured. Rather I'm not concerned with measurements, only with the way they sound in my system.

I already stated the technical side.

1. voltage handling capability must be met
2.  Current carrying capability must be met
3.  Impedance (resistance, inductance, capacitance) changes over frequency.  this is the reason why cables that meet 1 & 2 but are different on number three show differences in sound.

These are measurable.  This is known science.  

Same with amps/pre-amps.  If you really want to see why certain pieces operate and hence sound different, even if they have the same WPC, gain, etc.   Look at the transfer function response of that piece over frequency.  That will tell you all you need to know.  

Then, take an amp that "sounds wonderful" vs an amp that is so-so with the same gain, WPC and look at the transfer function response and it is eye opening.

However, most don't design for transfer function response first.  That is what is measured after the prototype is designed or built.

For amps, it is:

1.  input impedance
2.  Output impedance
3.  Gain
4.  input signal level (min/max)
5.  Frequency response
6.  Power output
7.  phase response
8.  Noise level
9.  Distortion
10.  a few other things.

You decide on circuit design/layout and chose the components that suit your goals and go for it.

All of the above are equation based and can be calculated.

For cables, it is similar.  

1.  which material offers the least capacitance and inductance
2.  What is the impedance per foot of the material to be used.

If you can make the cable impedance virtually zero over the frequency range, that is what you really want.  A straight wire with no impedance.  you are basically connecting the terminating equipment directly to the interconnection equipment.    This is Engineering 101.

But, as mentioned, if the interconnecting/terminating equipment is so sensitive in design that a slight change in cable impedance affects the sound, then that is a real problem.  some equipment is so well designed, that it is hard to hear differences in cables.  On others, you really can.

I imagine for some "high end" expensive cables, the impedance over frequency is extremely low.

for power cords, if it can't handle the voltage requirements it is not suitable. If it can't handle the current requirements, it is definitely not suitable.  Lastly, the impedance of this cable (transmission line) has to be really low over the frequency range.

enjoy

Why spend so much money on an expensive power cord?  Just make sure that the copper wire gauge is more than sufficient for the current draw of your equipment - particularly the power amplifier.  If in doubt, go with the next thickest (lowest number gauge) to minimize voltage drop.
The power supply of any quality audio component will absorb and properly filter any interference that might be picked up by an unshielded cord.  Use the money saved to upgrade the quality of those components instead.  Don't be fooled by the audio hype!  I have followed the power cord advice of legendary Marantz experts Sid Smith and Dick Sequerra for over 60 years with absolutely no regrets

There is only one explanation to be given until someone can figure out what is to be measured for...   They change the sound.  Depending on your system it will determine how much they can improve the sound.  Some systems - no difference.  Other systems - a great difference can be detected from cord to cord.

But this stands true.  They change the sound in any system with good transparency.

what we do know is that power cords can and do have a big impact on sound 

We know nothing of the sort. IF power cords affect sound then whatever causes this is measurable. There is no escaping this , this is actually something we do know. 

We can leave the scientific measurements to the experts but what we do know is that power cords can and do have a big impact on sound whether it's negative or positive Sometimes with power cord experimentation you can come up with a most positive outcome as if you went out and spent thousands of dollars upgrading your components. Other times certain power cords could possibly degrade the sound. I think it falls back on that cabling is system dependent.
Decibell your right, building your own power cords can be fun and save you money!

Substitute the word "more" with "less" and then it would make sense.
It's the audio equivalent of The Fox and the Sour Grapes.

All the best,
Nonoise

The more you spend on wires, the greater the placebo effect.

If you are somewhat handy I encourage you to experiment building your own power cable. Solid core dead soft silver wire (riogrande.com) placed in cotton tubing (ebay) with heat shrink tubing on outside for safe insulation. Ground can be solid copper but needs to be thicker gauge to achieve lower resistance compared to same length silver. Techflex on outside. Terminate with high quality pure silver plugs. Silver is the best conductor. Cotton minimizes power storage. I was not able to find a scientific explanation why power cords have an impact on sound. But all components in my system benefited from this power cord upgrade (even turntable!) - with most noticeable improvement on CD player and preamp.

Personally, I would keep a large pot of boiling snake oil on my component rack if it made things sound better.

Instead, I use nice power cables, interconnects, and speaker cables because they DO make things sound better.  Many compare stock to relatively inexpensive upgrades.  I tried this and noticed little improvement.  Tried Audience AU24SX and noticed nice improvement.
Not worth arguing why.  They just sound better to me and are thus worth it to me.  Ken.

This is my first time posting. I thought I join in the fun. I’m no electrical engineer but here are my thoughts:

1. The miles of cables before the wall outlets have no bearing on the quality of the sound just like the miles of dirty river water before our faucets. It’s the purity of the signal before entering the electronics that matters.

2. In audio, it’s all about vibration. It’s about the vibration of the electrons in the cable to the vibration of the particles in the air. If the electrons can vibrate in perfect sync, we get perfect sound. The quest of the cable makers is to reach this perfection. The differences in characteristics of the vibration of the electrons in the cable define the sound we hear.

My 2 cents.

Interesting point. Considering how all that current has to flow through a ’tiny’ fuse, yet a big honking power cord can still make a change to the overall sound still boggles my mind.

Richard Feynman once said if anyone thinks he understands quantum physics, he doesn’t know what he’s talking about.

How electrons and currents are not as intuitive as one thinks. There are still things that can’t be relied on "common sense".

There are people who think as long as the power cord is big enough, then that’s all you need. I actually have some power cords that are more than thick enough but they sound a bit "slow". How they are constructed also affects the sound.

My own experiments, not with cable tough, prove to my ears that all the electrical grid of the house is ONE entity in the perspective of an audio system...

Anything i put all along, modify the S.Q. i experimented with my own creation homemade device and various stones and minerals....

Then thinking that a power cord will affect the S.Q. is more than probable for me, never mind the equations that some will throw at my head to the contrary...

:)

I understand that many subjects have already been discussed many times over the years.  However, many times, it is difficult to surf through the years of posts to find adequate responses.  So, it really isn't a problem for a new audiophile to post a topic that has been discussed several times previously.

If you can lead the person to earlier posts, then fine.  If not, then it serves no real purpose rubbing it into their face that this has been discussed many times.  That person was not here then.

In any case, Power Cords are basic.  Then first must be able to handle with margins the voltage and current requirements.  That is mandatory.  In addition is the impedance of the cable.  This impedance varies over frequency.  This is the real problem.  If the interconnecting and terminating equipment isn't designed to handle this variation in cable impedance over frequency, then this is what really effects (afftects?) the signal and the sound.  And yes, this is indeed measurable.

Cable and transmission line science is known and has been around for many decades.

This is really why different cables may make the same system sound different.  Also, I can't recall if most cable manufacturers actually list the impedance of cables over frequency.  This, to me would be the most helpful of information.

This is also why some companies have "networks" attached to cables.  They are designed to minimize the impedance of the cables over the frequency range. Over certain frequencies, it provides for "resonance".  in other words, the impedance due to inductance of the cable negates the "impedance" due to the capacitance of the cable and you are left (hopefully) with an unchanging minimum resistance value.

So, yes, cable can and do make a significant difference in sound quality of the system.  However, It does also depend on how well designed or how poorly designed was the interconnecting equipment and whether they can handle the changes in cable impedance over frequency.

Another reason why some equipment manufacturers "recommend" certain cables.  They've tested their equipment with certain cables, so they know.

A quick bit of history and humor.  I purchased years ago a Mark Levinson 23.5 amp used.  It arrived with the incorrect power cord.  It sounded as if the singer was literally being strangled.  I contacted the seller and he realized that he shipped the wrong power cord with the amp.  He sent the correct cord and all was well.

I was in Stereo Design in San Diego years ago with friends listening to their top system.  It was great.  The representative quickly changed one set of interconnect cables for another and it was like he changed speakers.

I'm an Electrical/Electronics Engineer.  So was my friend.  This made no sense to us, until we thought it through.  So yes, cables do make a difference.

My view is that if I listened to a piece of equipment in the store with manufacturer supplied cable, then that's fine for me in my home system.  But, typically, the stores use much better or more expensive cabling in the top demonstration systems.  Which they should be telling us and at a minimum also demo the equipment with the cord that will be supplied with the equipment so we can make an educated and economic decision at that time.

just my thoughts.

enjoy

@andy2 .
Interesting point. Considering how all that current has to flow through a 'tiny' fuse, yet a big honking power cord can still make a change to the overall sound still boggles my mind.
B

You're asking why is a power supply different than a cable?  I didn't  notice anyone mention water but you. The power supply effectivly stops RF getting in and out with electrostatic screens between the primary and secondary in the transformer. As long as the power cord is of sufficient quality to provide the required current to the component that's all you need. 

Let think about it.  If you're saying the cable is the last 3ft, then why would a power supply be any different?  That is the power supply is the last one after many miles of cables, just like the power supply cord as the last 3ft, then why a power supply would make a difference at all?

People who are using water analogy and conclude that a power supply cable should not make any difference.  But electrons are not water.  Before you turn on the kitchen faucet, there is no water in the kitchen in the first place.  On the other hand, before you power up your equipment, the electrons ALREADY in the equipment.

Look at the tiny fuse in your equipment.  You intuitively think that it has to be the bottleneck but obviously that is not the case.  Now if you're using a power supply cable as tiny as the fuse, things won't be very good.  Your equipment may not work properly.  Why is it that a fuse can be tiny and slim, but not the power cable?  Because electrons are not as intuitive as you think.

Local market is over flooded again by pseudo scientists....musikologz