Audio Power Cables / Cords - Do they really make a difference?

[admin]

We are sometimes asked our opinion of exotic power cords and cables and whether or not they are beneficial or worth the added cost over the stock power cords that come with A/V electronics.
With the help of Blue Jeans Cable, we explore the importance of properly designed power cords while simultaneously debunking the myths and bogus claims perpetuated by many exotic cable manufacturers and A/V review magazines.
Always remember the Audioholics.com mantra "only poorly designed cables can be sonically distinguishable" and you will never make a bad purchasing decision.
Once all of the nonsensical claims are peeled away, only three very basic and essential metrics are left to ensure quality power transfer from your wall outlet to your A/V gear which we discuss in detail...

Discuss "Audio Power Cables / Cords - Do they really make a difference?" here. Read the article.

 

[TLS Guy]

We are sometimes asked our opinion of exotic power cords and cables and whether or not they are beneficial or worth the added cost over the stock power cords that come with A/V electronics. With the help of Blue Jeans Cable, we explore the importance of properly designed power cords while simultaneously debunking the myths and bogus claims perpetuated by many exotic cable manufacturers and A/V review magazines. Always remember the Audioholics.com mantra "only poorly designed cables can be sonically distinguishable" and you will never make a bad purchasing decision. Once all of the nonsensical claims are peeled away, only three very basic and essential metrics are left to ensure quality power transfer from your wall outlet to you’re A/V gear which we discuss in detail herein.

Discuss "Audio Power Cables / Cords - Do they really make a difference?" here. Read the article.

I'm yet to see an under sized power cord come with a power amp. I suppose with this race to the bottom, especially from China, they are now out there. But a situation like that, if it exists, is totally ridiculous.

 

[KurtBJC]

But a situation like that, if it exists, is totally ridiculous.

Agreed. However, it's been known to happen. I gave a talk at our local AES chapter last month and spoke with one guy who had encountered just this situation--intermodulation distortion in the presence of heavy bass due to excess draw on the power supply--due to an undersized cord. The stars do need to be aligned just right, though; if the filter cap is generously sized, for example, it's not going to happen in any event.

 

[TLS Guy]

Agreed. However, it's been known to happen. I gave a talk at our local AES chapter last month and spoke with one guy who had encountered just this situation--intermodulation distortion in the presence of heavy bass due to excess draw on the power supply--due to an undersized cord. The stars do need to be aligned just right, though; if the filter cap is generously sized, for example, it's not going to happen in any event.

Yes, it takes junk from China to do this. Junk cable and a junk power supply to go with it. Amazing we have descended to the level we even have to discuss this. It's appalling, absolutely appalling.

 

[FirstReflection]

Another great contribution from Kurt Denke and the fine folks over at Blue Jeans Cable

Personally, I would love to see Blue Jeans Cable offer power cords for two simple reasons:

1) As Mr. Denke already mentioned, it would sometimes be really nice to have power cords of a length other than what was supplied with the device. Sometimes, you only need 3 feet of power cord, but the device came with 12. Other times, you need 10 feet, but the device only came with 6.

2) Stiff power cords are also common and can be a nuisance. So it would be great if Blue Jeans Cable could offer nice, thick gauge, but very flexible power cords that can be easily turned around corners and would stay in place.

I'd also love it if Blue Jeans Cable could offer little "pig-tail" power cords with standard-sized plugs so that I wouldn't have to deal with the major pain in the you-know-what that are the oh-so-common "wall wart" plugs". I HATE how I can have 12 perfectly useable outlets on the back of my UPS battery backup power filter, but those stupid,, huge wall wart plugs make it so that I can only plug in 6 devices!

So there's a market for power cords, IMO. And I'd love to be able to buy them from Blue Jeans Cable

 

[Warpdrv]

I was very surprised to see that a JL Audio F113 comes only with a

Our Fathom power cord is a 3-prong, 14 AWG and it's 6 ft. long.

I'm sure they tested it and thats how they ended up with their UL certification, but it would seem to me that one would want to use a larger gauge wire for an amp claiming the power they do...

 

[Nestor]

I was very surprised to see that a JL Audio F113 comes only with a



I'm sure they tested it and thats how they ended up with their UL certification, but it would seem to me that one would want to use a larger gauge wire for an amp claiming the power they do...

If your household wiring is 14ga from the receptacle all the way back to the panel, what difference will an extra few feet of a larger gauge make on your cord?

 

[Rickster71]

Next time you're in home depot etc., take a look at a receptacle.
There is a small brass jumper that connects the two outlets together,
That strip of metal is so thin and small, it's soon realized that most talk of oversight power cords is moot. I know that they've calculated it's surface area to handle the rated ampacity, it's just hard to believe when you see how small it is.

 

[Rickster71]

^ Edit meant to say "over sized power cords"

 

[highfigh]

Next time you're in home depot etc., take a look at a receptacle.
There is a small brass jumper that connects the two outlets together,
That strip of metal is so thin and small, it's soon realized that most talk of oversight power cords is moot. I know that they've calculated it's surface area to handle the rated ampacity, it's just hard to believe when you see how small it is.

But, doesn't the load carrying ability depend on the length and cross-sectional area? When I did 12V systems, we were always taught that the length of the conductor was as important as the gauge.

 

[kevon27]

My $5000 Kimber Kable power cords make all of my 64kbps mp3 sound better than best record bluray audio.
So I don't care what this article says.

 

[TLS Guy]

My $5000 Kimber Kable power cords make all of my 64kbps mp3 sound better than best record bluray audio.
So I don't care what this article says.

And you need to go on antipsychotics.

 

[Rickster71]

But, doesn't the load carrying ability depend on the length and cross-sectional area? When I did 12V systems, we were always taught that the length of the conductor was as important as the gauge.

Maybe I made it ambiguous by saying, "surface area" your "cross-sectional area" sounds better.
I was referring to a comparison between one of those wrist thick power cords and that little brass jumper between the top and bottom receptacle.
Visually, it doesn't appear to up to the job (though it obviously is) looks more like the element in a fuse than a substantial jumper.

 

[TLS Guy]

Maybe I made it ambiguous by saying, "surface area" your "cross-sectional area" sounds better.
I was referring to a comparison between one of those wrist thick power cords and that little brass jumper between the top and bottom receptacle.
Visually, it doesn't appear to up to the job (though it obviously is) looks more like the element in a fuse than a substantial jumper.

The reason it is not a problem Rick, is because it is so short. That will make its resistance insignificant.

 

[Rickster71]

The reason it is not a problem Rick, is because it is so short. That will make its resistance insignificant.

I absolutely agree!
It's just that when that little brass strip is visually compared to one of those 8-AWG power cords, the over kill of the cord becomes glaringly apparent.

 

[jeffca]

Finally...

This is great... a pro in the cable industry talks some sense on this subject.

While I agree whole-heartedly with your assessment, I think you missed a few things.

1) One of the most (if not the most) important things a power cable can do other than deliver the power signal unaltered from the wall to the equipment is keep any EMF pollution from the power cable to a minimum. Nobody ever seems to talk about that.

Keeping AC pollution from being induced in analog signal cables can be helped by properly looming the rats nest of cables behind most equipment racks, but any help from the shielding of the power cables is appreciated.

2) While you did a great job explaining the basic design and function of a power supply, I think you could have stressed that any power supply that requires a "special" power cord to perform at it's best is a flawed design from the outset.

A power supply should be able to perform in the real world as specified with a standard 3 ft. power cord. If it can't, it needs to be redesigned so that it can.

3) To test whether a power cable has any effect on any piece of equipment, a simple suite of automated tests could be run to see whether any changes in noise, distortion and deviations from linearity in phase and frequency response have occurred compared to using a standard 3 ft. IEC power cable.

If you run these on a few disc players, pre/pro's and power amps and find no measurable difference, the cable has no effect on the equipment's performance and none will be heard. If there is a change, you can now deduce whether the change is for the better or for the worse.

Of course, this requires some real work to be done and most reviewers are just lazy bastards who want a reason to slack off, listen to tunes and act like they're really doing something.

This brings me to one final thought: while the audible effects and the audibility itself of distortions and non-linearities are open for debate (because these are based upon perception), the fact that we have quantified and can measure all of these phenomena is not.

Our test equipment has long ago superseded the ability of the human ear/brain mechanism to detect distortions and non-linearities in audio equipment. To act like this hasn't occurred is to insist that the earth is flat and the center of the universe.

Cheers,
jeff

 

[KurtBJC]

1) One of the most (if not the most) important things a power cable can do other than deliver the power signal unaltered from the wall to the equipment is keep any EMF pollution from the power cable to a minimum. Nobody ever seems to talk about that.

Keeping AC pollution from being induced in analog signal cables can be helped by properly looming the rats nest of cables behind most equipment racks, but any help from the shielding of the power cables is appreciated.

Yes, that's a valid concern. The thing is, however, that shielding at 60 Hz against really high-energy fields like one sees in a power cord is very, very hard to do effectively--even steel sheathing isn't all that effective. The best thing one can do, most of the time, is simply to try to keep the cord at a decent distance from signal-carrying cables. In my case, I just try to route all of my power together at one side of the rack to the extent possible, and try to keep the low-energy cabling (line-level stuff) to the other side. They've got to meet one another occasionally, of course, but the less opportunity they have to interact, the better--the "square of the distance" rule is very much applicable here.

Kurt
BJC

 

[gene]

Yes, that's a valid concern. The thing is, however, that shielding at 60 Hz against really high-energy fields like one sees in a power cord is very, very hard to do effectively--even steel sheathing isn't all that effective. The best thing one can do, most of the time, is simply to try to keep the cord at a decent distance from signal-carrying cables. In my case, I just try to route all of my power together at one side of the rack to the extent possible, and try to keep the low-energy cabling (line-level stuff) to the other side. They've got to meet one another occasionally, of course, but the less opportunity they have to interact, the better--the "square of the distance" rule is very much applicable here.

Also routing power cables orthogonal to line level cables if you can't keep them spaced apart will eliminate any ill effects. Honestly I've never had a problem routing power and line level cables in close proximity if quality double shielded interconnects such as the 1694A COAX you guys sell is used.

 

[avliner]

Hats off to you Kurt, in this another very educational explanation!

What I can tell you so far, is that I 've never even considered the possibility of changing the original power cord of the many equipments I've owned in more than 35 years and for sure never will... Call me dumb, though

 

[bforsse]

Kurt,

Great article! I would be interested to hear your opinion on power conditioners and re-generators considering the perspectives in your article.

Are they something you consider un-necessary with money better spent on quality sources/amps with better designed power supplies? Are there any significant benefits to paying for that perfect 110 input sine wave?

Thanks,
-Brian