Power cords - do they really make a difference, other than potentially reduce noise?

es347 · May 21, 2016

..to answer OP's question...yes they do make a difference. My background in power distribution says they shouldn't for any number of reasons but darned if they don't. Do you have to spend thousands to benefit? Nope, not at all and I'll just leave it at that. In closing I must say...if you want to garner a litany of snarky comments just start a thread on power cables...sheesh

microstrip · May 21, 2016

Speedskater said:
Don's post is well worth reading as stand alone good engineering information.

Unfortunately good engineering can not currently give a good explanation why power (and signal) cables sound so different. The easy and apparently logical explanation seems that power cables become subjectively significant if some equipment in the system has technical design flaws and is not able to reject mains impurities or contaminates other equipment. However if we find that 99.99% of the high-end equipment falls in one of these categories we must look deeper in the problem.

Surely if one is a "non believer" and assumes that power cables have no effect in sound quality he can skip these posts ...

Speedskater · May 21, 2016

microstrip said:
Unfortunately good engineering can not currently give a good explanation why power (and signal) cables sound so different.
Surely if one is a "non believer" and assumes that power cables have no effect in sound quality he can skip these posts ...

Not at all true.
I have yet to see any repeatable, reproducible examples of cables sounding different that a skilled engineer with good equipment can't find the reason for the difference.
When audiophiles hear differences, it's situation specific and may have little to do with the cables.

DaveC · May 21, 2016

Speedskater said:
Not at all true.
I have yet to see any repeatable, reproducible examples of cables sounding different that a skilled engineer with good equipment can't find the reason for the difference.
When audiophiles hear differences, it's situation specific and may have little to do with the cables.

It's because most engineers think they know it all and offer oversimplified explanations for things they haven't actually studied in any depth, just like you're doing now.

FrantzM · May 21, 2016

DaveC said:
It's because most engineers think they know it all and offer oversimplified explanations for things they haven't actually studied in any depth, just like you're doing now.

And those who have studied it in depth, they're not engineers?

NorthStar · May 21, 2016

• http://hometheaterhifi.com/volume_11_4/feature-article-blind-test-power-cords-12-2004.html

• http://www.head-fi.org/t/486598/testing-audiophile-claims-and-myths

Mosin · May 21, 2016

There is something that may cause a powercord to affect the sound, and that is the amount of filtering the equipment has before it reaches the power transformer. A lot of equipment has none, but others have at least some amount. The Saskia turntable controller is bandwidth limited, so that the CPU remains free from any line influences, whether real, or imagined. The mains is heavily filtered before it reaches the power transformer. Earlier models were not bandwidth limited, so we did, of course, notice differences in incoming power. That's what started our discussion regarding cords. So, could a powercord actually be acting as a filter? If so, that explains why one might hear a difference with one piece of equipment, but not another. Maybe powercords act as a filter that takes off a bit of edge to musicr by killing high frequency noise in the mains power to some degree. Who knows?

Summary: Improvement, or lack thereof, may be dependent upon the equipment's power supply implementation.

microstrip · May 21, 2016

FrantzM said:
And those who have studied it in depth, they're not engineers?

Technical aspects have been studied in depth by engineers - what is missing is a firm correlation of the technical aspects with subjective sound quality.

I have hosted several brands of power cables, such as Shunyata, Nordost and Transparent Audio, most of them simultaneously. Although each of them impairs sound with some specific sonic attributes, it is when they are used with their matching signal and speaker cables that their signature shows more perceptibly. Considering that power cables work in a bandwidth completely different from the audio cables, I find astonishing that designers can "tune" their cables for some determined specific preferences. I have found that even digital cables have brand signatures, fairly related to to the generic sonic signature of the brand.

Some years ago we had great threads on cables WBF, with the active participation of Caelin Gabriel and Gary Koh, with plenty of technical details, interested people can always look in the forum archives.

Alrainbow · May 21, 2016

For me it's more about how does anyone know of no one can measure it right. Well that's not entirely true. We cannot measure with any accuracy how music will sound with speakers or headphones. Or even amps and tubes in some cases. But no one will say there is no sound difference. We hear Ina more complex way then we can measure or we do not know what too measure. I use ps audio Regens and as long as the power cords for amps is large enough I hear no change from a cheap cord to an expensive one. But every other cable type meaning interconnects and data does matter. So as I am an agnostic I still must have faith there can be in some situations

DaveC · May 21, 2016

FrantzM said:
And those who have studied it in depth, they're not engineers?

That's a ridiculous statement.

NorthStar · May 21, 2016

"Square waves and why we care about them

A square wave test is a very commonly used test for amplifiers. It indicates how fast an amplifier can respond to a change in the signal - sometimes referred to by the listener as transient speed. A square wave test is not a pass/fail test. One cannot simply say that component-X can pass a square wave. Component-X may be able to pass a 1Khz square wave with little visible distortion while at 10Khz the leading and falling edge of the square wave may be visibly rounded.

How to interpret a square wave test:
Look at the vertical rising and falling lines of the square wave. Are they 90 degrees to the horizontal portion of the waveform. Is there a slant so the vertical line. At the top and bottom of the waveform - look for a rounding of the vertical as it approaches the horizontal line. A rounded waveform on the rising vertical edge and the falling vertical edge indicate that high-frequency energy is either being rejected or absorbed by the component.

To properly interpret a square wave response you would want to know the frequency and the duty cycle of the test signal. You cannot compare a 1Khz square wave to a 10Khz square wave. You also need to know the settings of the oscilloscope when the test was taken. Changing the time-base of the scope will dramatically affect the appearance of the waveform. All the settings should be identical for a valid comparison.

I have seem some claims about cable square wave response where the diagram looks like it was drawn and there is no information given about signal specifications.

Why Shunyata Research uses a square wave test:
We use the square wave test to demonstrate the technical superiority of the ?TRON technology. We publish the screen captures from the oscilloscope and we have a video on our website that demonstrates the actual test. This test has also been demonstrated at several trade shows to live audiences where the members can come up and examine the cables and the test equipment.

This test demonstrates that ?TRON technology can actually improve bandwidth and square wave response compared to the exact same cable without the technology. This technology actually improves the response time to the signal by the wire itself. If you are interested in the technical aspects you can refer to the patent application:"

https://www.google.com/patents/US201...ed=0CEYQ6AEwBg

Caelin Gabriel
President
Shunyata Research

DonH50 · May 21, 2016

Good grief. Sorry I posted, had forgotten how abusive WBF is toward engineers, did not think I was saying anything that would cause such a mess.

Sorry Steve, I'm out - Don

fas42 · May 21, 2016

Don, what often happens is that people with strong technical backgrounds present an overview of how things work, and the subtle underlying message that people may pick up is that the particular explanation is the full story, everything else is not relevant. Since people may have much real world experience with systems not behaving themselves quite like the summary suggests, they become a bit twitchy in response ...

NorthStar · May 21, 2016

Just a small touch of 'grandeur' | Because life is fun living ...

Dan, Don and Frank; you all have valid points. :b
__________

• https://en.wikipedia.org/wiki/Submarine_power_cable

NorthStar · May 21, 2016

Right back on track:

? http://www.gcaudio.com/resources/howtos/powercords.html
? http://www.whatsbestforum.com/showt...ifference-other-than-potentially-reduce-noise

microstrip · May 21, 2016

Speedskater said:
Not at all true.
I have yet to see any repeatable, reproducible examples of cables sounding different that a skilled engineer with good equipment can't find the reason for the difference.
When audiophiles hear differences, it's situation specific and may have little to do with the cables.

Speedskater,

My original post was an invitation to extend the research in cables, "we must look deeper in the problem." Unfortunately your edition of it when quoting can give a wrong idea of it.

Can you explain what you mean your last sentence? What effects are you considering?

witchdoctor · May 21, 2016

DonH50 said:
Good grief. Sorry I posted, had forgotten how abusive WBF is toward engineers, did not think I was saying anything that would cause such a mess.

Sorry Steve, I'm out - Don

I don't think it is accurate to say the whole community is abusive to anyone. I think it would be more accurate to say you feel you were abused personally by a member(s) but the member may feel that post wasn't abusive, it's subjective.
Feel free to post anytime and in the future is you haven't read a thread you don't need to tell, there is no exam when you get to the end.

NorthStar · May 21, 2016

Very true doc; there is no way that all members have read all the threads of the internet. In my quick calculation it would take millions light years. ;-)
Dan was just a little precarious.

...We all are @ times, and we never mean any more than humor.

Just as an example:

DonH50 · May 21, 2016

fas42 said:
Don, what often happens is that people with strong technical backgrounds present an overview of how things work, and the subtle underlying message that people may pick up is that the particular explanation is the full story, everything else is not relevant. Since people may have much real world experience with systems not behaving themselves quite like the summary suggests, they become a bit twitchy in response ...

My main reason for posting was to bring up the bandwidth issue regarding current demands since it is not true that only 60 Hz gets passed by a power cable. The rest regarding potential benefits I just threw in to balance the discussion. Seems like nobody gives a damn even when the engineering might support their position.

I should have used the word "hostile" instead of "abusive" but I'm an engineer, audiophile, musician, father -- not an English expert.

NorthStar · May 21, 2016

Don, I found your previous post educative; thank you sir. Don't let anything distract you.

Power cords - do they really make a difference, other than potentially reduce noise?

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