[upstateguy]

I was rereading an old post called: It's Done! Power Cord Shoot-Out-- 22 Power Cords Reviewed!   (here)
 
In the spirit of the Don't get why "Audiophile" USB Cable would improve sound quality thread I was wondering how power cords can improve sound quality.
 
My experience is that I when I joined HeadFi in 2004 the power cord to get was the Volex, so I bought a box of them and have been using Volex power cords on everything ever since, except on my GS-1, which came with it's own heavy duty power cord.
 

 
 

 

[DemonicLemming]

As long as the power cord isn't oversized or undersized for the application, I've yet to find an EMC or radio engineer who thinks it would make any difference at all.  Power is power, as long as you're sending a clean signal with no DC at the nominal voltage with minimal fluctuation that whatever you're powering needs. 
 
Power cables don't make o-scopes, sig gens, or spec analyzers in the lab measure or output any differently; how they'd have any effect whatsoever on a music signal borders on outright black magic.

 

[zoso947]

 
Quote:

As long as the power cord isn't oversized or undersized for the application, I've yet to find an EMC or radio engineer who thinks it would make any difference at all.  Power is power, as long as you're sending a clean signal with no DC at the nominal voltage with minimal fluctuation that whatever you're powering needs. 
 
Power cables don't make o-scopes, sig gens, or spec analyzers in the lab measure or output any differently; how they'd have any effect whatsoever on a music signal borders on outright black magic.

 
Here, you just found one:
 
 
Quote:

I was once asked a similar question about the cables I used to carry to a studio I used to use for my mastering work: If the recordings were made with "inferior" cables, what difference could a few feet of "good" cable make in the mastering?

It just took a short demo (of a single set of patch cords) for that studio owner to write a check for new studio wiring.

Granted, any damage done prior to the last few feet of cabling is already done. The question becomes, should that last few feed add to the damage?

The question each of us must answer for ourselves is: In the pursuit of the best sound we can get, if that last few feet does indeed make an audible difference, should it be ignored?

 
 
 
http://www.stevehoffman.tv/forums/showpost.php?p=6584426&postcount=113
 
 

 

[DemonicLemming]

Engineers are expected to answer things with facts, not personal anecdotes, especially when that personal anecdote deals with a single person, and doesn't go into any specifics of the previous state of the wiring - was it undersized, over-length, poorly shielded, piled in great heaps on the ground...way too many variables for that quote to even stand as a starting point for reasoning of why power cords make a difference. 
 
Also, and I can't tell by the post cited, but is he referring to actual source wiring, or raw power wiring?  I won't argue that there aren't technical merits as to why better-designed source cables could play a small difference in the end result, but the topic at hand here is power cords, specifically.  There is not, as far as I know, any technical argument to be made that how mains AC power is transferred via the wall to the component - when it has absolutely nothing to do with signal propagation or the like, nor does it make a difference in "power conditioning" insofar as proper waveform, good voltage regulation, and the like - will make any difference on the final result. 
 
If I have no DC on the line, proper voltage regulation, and good cable routing, what technical merit of an $8000 power cord is going to make a difference compared to a properly-sized bog-standard power cord?  Likewise, if power cords do make some sort of measurable difference, why would it not show up when using lab equipment?  There's nothing magical about audio gear; if a boutique power cord makes a difference on a headphone amp, wouldn't it likewise make some sort of measurable difference on an o-scope or signal generator?
 
I'd also ask: if the last few feet make such an audible difference, then wouldn't using said "uber-cable" for the entire run result in much better sonic performance?
 
Quote:

Here, you just found one:
 
http://www.stevehoffman.tv/forums/showpost.php?p=6584426&postcount=113

 

 

[zoso947]

I wasn't making any comment for or against custom power cords, only giving an example of someone who makes their living in the recording industry who thinks they do make a difference.  I'm not exactly sure how one would translate this personal experience into a handy pie chart with soothing "hard data", but I'm not going tell someone with this much experience that he can't possibly be hearing what he thinks he is hearing.
 
FWIW, I have not found changing power cords to do much in my system.  Also FWIW, I live less than 1/4 mile away from the power substation and have very clean AC.
 
 
Quote:

I'd also ask: if the last few feet make such an audible difference, then wouldn't using said "uber-cable" for the entire run result in much better sonic performance?

 
Well obviously, but I would think that ripping the cables out of walls that are probably acoustically treated is not practical.

 

[DemonicLemming]

Nor is paying $6000 for a power cable or $26,000 for a single RCA cable (prices I've actually seen) - but I would imagine with a budget sufficient to cover cable costs on par with a yearly house payment, "practicality" goes out the window, no?
 
I don't need hard data to "soothe" my conscience about anything, but without hard data, the debate as to whether power cables make a difference is cannot be won by either side.  Is it a truly psychosomatic placebo effect?  I'm as interested in the mental side of it as I am the hard specs side of it.
 
Quote:

Well obviously, but I would think that ripping the cables out of walls that are probably acoustically treated is not practical.

 

 

[zoso947]

Quote:

I don't need hard data to "soothe" my conscience about anything, but without hard data, the debate as to whether power cables make a difference is cannot be won by either side.  Is it a truly psychosomatic placebo effect?  I'm as interested in the mental side of it as I am the hard specs side of it.

 
And that is the reason why every one of these threads on every forum ever ends up in the same place.  We are dealing with things that at this point in time we have no way of proving.  How can one person "prove" to another what they hear?  Maybe it can be done, but not today.  I still "hear" artifacts from old recordings I had on cassette 25 years ago, even when listening to a modern pressing of the same recording.  They aren't there, but I "hear" them anyway.  Why?  How?  I have no clue.  Can I prove it?  Of course not.  It's some strange interaction of ears and sense memory, and I have no idea what it means(if anything).
 

 

[Currawong]

I have a couple of theories for this. The first has to do with the capacitance of the dielectric filtering noise. The second has to do with higher quality plugs and sockets providing better electrical connections and the third to do with dampening vibration. However, regardless of the merits of those things (if any at all) I feel that a good power filter or regenerator should come first, as there is no ambiguity with regards to the benefits.

 

[DemonicLemming]

Home vibration is a non-issue for solid state stuff.  Part of my job is directly involved with doing vibration testing, and the amount of vibration a home headphone setup sees would be so low as to be barely measurable, let alone cause any issues that the mass of a power cord would affect.  And even assuming there is a level of vibration that would cause any measurable effect, the mass of a power cord would do absolutely nothing to dampen resonance nodes and the like inside the amplifier case and among the components inside the case.  It's more arguable that an amplifier in a home theater setup - where it will see much, much more low-frequency noise and vibration - could have a slight chance of causing issues with a solid state amp, but with headphones, no.
 
As far as power connections (to be distinguished from source cable connections), it's either good or its not.  You're either transferring a stable waveform or you're not.  Modern transformers are capable of dealing with minute voltage differences quite capably with no untoward effects - hell, depending on the specification, to achieve a CE mark, a product must operate safely at +/-10% of its rated input power.  Unless you're seeing massive voltage swings - which a power cable would neither cause nor remedy - a connection that transfers AC is a connection that transfers AC.  It can be unobtanium-plated gold connectors, but a stable voltage is a stable voltage.  If there's a loose or bad connection, the issues will be on a much higher scale than, "I think this cable has a slightly reduced soundstage and a tiny bit of treble roll-off."  It would be easy to measure that sort of thing, too - run everything through a power meter, use Cable 1 and note the current draw, then use Cable 2 and note the current draw.  A bad connection would result in lower voltage, which would result in higher current draw, and once we establish a normalized delta for current draw variance using one power cable, it would be a simple exercise to compare a different cable.  Assuming audio amplifier boards have test points, one could also measure the voltage during operation with different power cords and note any changes there.
 
I think, if power cables make any difference at all, it's much more to do with real, measurable electrical phenomena - capacitance, inductance, and the like.  Undersize a power cord and you're create a low-voltage/high current situation that could potentially cause issues with components working.  Too large a power cord, and you can likewise run into problems.  But all of this would be measurable, and so far, I haven't seen anything even resembling actual measurements by power cable proponents.  (Yes, I know, sound science vs DBT free, so I'm not going to pursue that point of the discussion any further - simply pointing it out).
 
Quote:

I have a couple of theories for this. The first has to do with the capacitance of the dielectric filtering noise. The second has to do with higher quality plugs and sockets providing better electrical connections and the third to do with dampening vibration. However, regardless of the merits of those things (if any at all) I feel that a good power filter or regenerator should come first, as there is no ambiguity with regards to the benefits.

 

 

[upstateguy]

Quote:

I have a couple of theories for this. The first has to do with the capacitance of the dielectric filtering noise. The second has to do with higher quality plugs and sockets providing better electrical connections and the third to do with dampening vibration. However, regardless of the merits of those things (if any at all) I feel that a good power filter or regenerator should come first, as there is no ambiguity with regards to the benefits.

Hi Curra
 
Are you sure about power conditioning? 

  I thought I read otherwise somewhere on the forum??? 

 
What I don't get is that the current comes from a certain sized wire in the wall, goes to a power strip, then to a big thick power cable and then goes to the little tiny wires inside you equipment. 
 
How does 2 or 3 ft of big thick cable do anything besides conduct electricity from the power strip to the gear?
 
The Volex power cables I'm using are thicker than the cable from my power strip to the wall. 
 
What happens if you have to use an extension cord from the wall to the power strip? 
 
My main rig uses 2 heavy duty 3 prong extension cords to connect 4 power strips to 4 computers and my audio gear.  What now? 
 
So what if everything has a thick Volex PC for the last few feet?
 
The other issue I have is with vibration.  If vibration was a problem you probably wouldn't see expensive powered sub woofers or powered speakers. No?
 
USG

 

[Uncle Erik]

Power supplies are engineered to deliver clean power. If they don't, the fault lies with your gear, not the power cable.

If you want to clean up your power, use an isolation transformer and a RFI/EMI filter. An isolation transformer costs around $50 and a RFI/EMI filter is maybe $5. These only help if your power is dirty in the first place. If not, then your power supply is fine for converting AC into clean DC. If you're having a problem with AC, then it's obvious. You'll hear - clearly - the electrical gremlims. If you're not getting buzzes and hash, whatever you're running is just fine.

 

[Currawong]

Quote:

Home vibration is a non-issue for solid state stuff.  Part of my job is directly involved with doing vibration testing, and the amount of vibration a home headphone setup sees would be so low as to be barely measurable, let alone cause any issues that the mass of a power cord would affect.  And even assuming there is a level of vibration that would cause any measurable effect, the mass of a power cord would do absolutely nothing to dampen resonance nodes and the like inside the amplifier case and among the components inside the case.  It's more arguable that an amplifier in a home theater setup - where it will see much, much more low-frequency noise and vibration - could have a slight chance of causing issues with a solid state amp, but with headphones, no.
 
As far as power connections (to be distinguished from source cable connections), it's either good or its not.  You're either transferring a stable waveform or you're not.  Modern transformers are capable of dealing with minute voltage differences quite capably with no untoward effects - hell, depending on the specification, to achieve a CE mark, a product must operate safely at +/-10% of its rated input power.  Unless you're seeing massive voltage swings - which a power cable would neither cause nor remedy - a connection that transfers AC is a connection that transfers AC.  It can be unobtanium-plated gold connectors, but a stable voltage is a stable voltage.  If there's a loose or bad connection, the issues will be on a much higher scale than, "I think this cable has a slightly reduced soundstage and a tiny bit of treble roll-off."  It would be easy to measure that sort of thing, too - run everything through a power meter, use Cable 1 and note the current draw, then use Cable 2 and note the current draw.  A bad connection would result in lower voltage, which would result in higher current draw, and once we establish a normalized delta for current draw variance using one power cable, it would be a simple exercise to compare a different cable.  Assuming audio amplifier boards have test points, one could also measure the voltage during operation with different power cords and note any changes there.
 
I think, if power cables make any difference at all, it's much more to do with real, measurable electrical phenomena - capacitance, inductance, and the like.  Undersize a power cord and you're create a low-voltage/high current situation that could potentially cause issues with components working.  Too large a power cord, and you can likewise run into problems.  But all of this would be measurable, and so far, I haven't seen anything even resembling actual measurements by power cable proponents.  (Yes, I know, sound science vs DBT free, so I'm not going to pursue that point of the discussion any further - simply pointing it out).

Thanks for your comments. At least one person (an engineer) has privately commented that they are interested in testing my capacitance theory. It comes from having used two units which used noise filtering capacitors that I felt helped improve the sound with equipment that had only very basic power supply circuitry (and correspondingly I felt no audible effect on gear that had a very over-built power supply). Since all cabling has some capacitance, and a cable manufacturer suggested that power cables had to be at least 1.5m to have any useful effect, I thought it might be a possible explanation for any perceived difference.
 


Quote:

Hi Curra
 
Are you sure about power conditioning? 

  I thought I read otherwise somewhere on the forum??? 

I'd love to be sure about everything, but then I'd be God. Since that is out of the question, the best I can do is explore these matters for my own fun (especially if they improve my listening enjoyment) and suggest things from which we might, with some effort, learn something, as opposed to taking an attitude that one or other idea is absolutely right or wrong. 

 

[upstateguy]

Quote:

Thanks for your comments. At least one person (an engineer) has privately commented that they are interested in testing my capacitance theory. It comes from having used two units which used noise filtering capacitors that I felt helped improve the sound with equipment that had only very basic power supply circuitry (and correspondingly I felt no audible effect on gear that had a very over-built power supply). Since all cabling has some capacitance, and a cable manufacturer suggested that power cables had to be at least 1.5m to have any useful effect, I thought it might be a possible explanation for any perceived difference.
 

 
Hi A
 
How does your capacitance theory work?  I was under the impression that a capacitor stores a charge.  How does this apply to a wire?
 
E

 

[Steve Eddy]

Quote:

Originally Posted by upstateguy /img/forum/go_quote.gif
 
How does your capacitance theory work?  I was under the impression that a capacitor stores a charge.  How does this apply to a wire?
 

 
Reactance.
 
The reactance of a capacitor decreases as frequency increases. In other words, it acts as a low pass filter, shunting higher frequencies to ground.
 
se
 

 
 

 

[dymaxion]

I'm a pseudo audiophile in so far as I love listening to music and good quality music in particular.  I invested my first HiFi separates system in my first year at university and never looked back as the sound quality was amazing having gone from cheap all in one midi-systems.  I read BSc Physics at Imperial College and am also a trained classical violinist.
 
I'm constantly shocked how much money people spend on fancy speaker cables / interconnects / power cables etc.
I have a few sound engineer friends and they are equally shocked at the amount of mumbo jumbo black magic that is spouted to sell overpriced kit to people... there's a lot of good info out there but much of it is rubbish too.  These power cables surely fall into the nonsense category...?
 
Of course good quality interconnects and speaker cables make a difference but it's all about laws of diminishing returns, as long as your signal is clean and well shielded from interference and not subject to massive signal degradation within the tolerances of the appliances you are using then they are probably perfectly fine.
 
At Uni, we used pretty bog standard power cables for our oscilloscopes and all other fancy equipment.  They were sat on top of random worktops. Stacked, unstacked whatever.  Yes there were other signal cables that were shielded to connect up various bits of kit, which I'm sure were good, however they were definitely not ultra fancy. The scopes and other equipment were expensive and deservedly so, they are highly sensitive bits of kit.  My final year project involved building a custom electronics wired up to various scopes with sensors fully submerged in liquid nitrogen to study the quantum mechanics of SQUIDs  http://en.wikipedia.org/wiki/SQUID  Yes we encountered one or two dud connectors and cables which either worked or didn't.  However never would we scrutinise individual cables to the extent that audiophiles do.
 
When I hear of people spending a fortune on stands for their amps I kinda chuckle to myself.  Another friend was working on the CERN LHC and I visited him out there... audiophiles would be pretty shocked at what they saw in the labs there!
 
In summary...  power cables... meh...