Power cords: does length matter?

Hi Matthew- actually the theory is that power supplies are myopic - they really only react to what is closest to them.  That is why an upgraded power cord does result in upgraded performance even after hundreds of feet of romex in front of it.  Anyway - the optimal length for power cords is 5 ft - beyond that in length makes virtually no difference in the component's performance.  This is not only my experience, but also that of several well-regarded power cord designers.  Hope that helps you.  I know that this is going to draw out the nay-sayers, but happy to help a fellow enthusiast.

By that reasoning the best sound would be having the amp power supply right at the breaker box. Then two long pieces of wire to carry the + and -  DC of the rectified AC to the rest of the amp circuit. Absurd!

In the dark all power cords sound alike!

Matt, ime, keep power cables under 2 meters, if at all possible, and allow room for the bending and routing of them, keeping them as far away from the speaker and all interconnect cables, however possible with minimal parallel runs between them. My best, MrD.

"Keep power chords under 2 meters if possible"... LOL! Because we all know that electrical properties change drastically once power travels more than this. It just never ends what people still post on this site.

@jasonbourne71 another brilliant statement from you 🤣, and you have company, as it turns out. Using wire hanger material as you suggested sounds dull and lifeless in the higher frequencies, and over blown in the bass. I have experimented with it many years ago. My best, MrD.

 

jasonbourne71

831 posts

05-10-2024 at 04:06pm 

Two pieces of steel (carbon iron alloy) coat hanger wire fitted with AC plugs will sound indistinguishable from any boutique power cord.
 

I compared coat hanger wire to a boutique power cord. I disagree with the above statement. I like the coat hanger wire better. My shirts tend to get wrinkled hanging on a my Nordost power cords. But keep perfect on a coat hanger wire. 

The standard length of high- end power cords is usually 5 feet. If you need only 3 feet, then that's what I would buy. It will save you a few dollars and you won't have to loop or route the excess cord. Of course, if you want to use it somewhere else, in the future, it might be too short. Something to think about.

Wow, some surprising comments here. Enjoy !

+1 buy the length you need. To tell the difference between a 1m and a 2m power cord you will need an extremely resolving system and I am not sure that every power cord in these two lengths will sound any different. Keep it simple. 

Yes, the length does matter. I have directly compared a 1m and a 2m long Lessloss C-marc power cords, both previously burned in. The shorter cable had an audibly different tonal balance, more tilted towards treble. I also own 2 OCC copper power cables from Clearer Audio, a lesser known British boutique brand, a 1m long one and an otherwise identical 2.5m one. The sound is different in more than one way and there is no clear winner. In a third case, again with some Clearer Audio cords, a 2m power cord has stronger bass and treble than the 1m cord and seems preferable to me.

I've never heard two audio cables of any kind (interconnect, USB cable etc.) to sound the same regardless of their length. If I were buying a power cord and I had to chose a length without being able to audition first I'd probably go for 2 meters or so.

@donquichotte 

Sorry, I have to call BS on this! Yes, PCs of various manufacturers do sound different; however, in no way will an additional meter of the same brand change tonality so audibly. I think one of your cables was defective. It does appear that you are length envious, though!😁

Not unless they are so long that there is voltage drop. That would apply only to high-powered amplifiers and terrible cords.

"In the dark all power cords sound alike!" Yes JasonBourne, especially if they are switched off.

@jeffreyw  I totally agree with you. I am using 2 Audioquest Dragon HC PCs for my ARC Ref 750s. One is a 2 m and the other is a 1 m. They both sound exactly the same. 

Interconnects and speaker cables matter and the power conditioner matters a lot. The power cord just needs to be shielded properly, reject noise and not act as a noisy antenna, which can be achieved through a 100 dollar AliExpress purchase. Length doesn't matter.

That's what she says...

@jeffreyw : Of course, you are entitled to have your own opinion. I'm just reporting what I'm hearing. I also think my opinion makes more sense than your opinion - not that all the audio findings (mine and others') make a lot of logical sense. In this case, still, if you believe the power cord makes a difference then why wouldn't "more" (=longer) power cord make more of a difference? It's like saying that adding salt to your food makes it saltier, but the quantity of salt doesn't matter at all.

I've recently read an older article by Louis Motek, the founder of Lessloss, claiming that length does matter in power cords. On the other hand, he told me in an email talking about his C-marc power cords that the sound impact of 1m should be minimal, so there's that.

@jasonbourne71 

Love it!!

I forgot who made this claim before in this forum, but essentially, his theory is that a 2m PC works the best because it functions like a power conditioner. I don’t know whether it’s true or the rationale behind it. I have no clue why a 2m PC would function like a power conditioner while other lengths do not. I’m just mentioning it here for your information since nobody has brought it up yet.

Placebo, Ignorance, Stupidity, cables, the marriage magic of mythical manipulation with mechanical.

Cheers

Power cord length see here!

Mike

@ditusa Thanks for the link. Regarding length, I find that 5 ft is exactly 1.5 meters which some say is the optimum length for a power cable. I also find that 2 meters is 6.5 ft. I own two manufacturer-supplied cables which are very rugged and stiff [I’m assuming due to their shielding], they each measure 9 ft 10” (+/- 1.0”). I think they each came with used McIntosh equipment purchases. I find them a bit too long. They may be stiff because of the use of heavier gauge conductors.

I wish I could tell if a cable is shielded or not. I’m sure I’ve employed at least a few computer grade (16 AWG, unshielded) power cords in my system. I also wish I could tell what the conductor’s gauge is without opening it up to find out. I already make my own interconnects [Mogami fan here], now I guess I’ll have to add a new wing to make power cords —any length I want!

@immatthewj Good luck on your quest.

So, basically, dealer (Nordost) said "2m works the best for it to really filter." As much as I like the optimal design, I just think whoever states the "fact" he think it is also bears the burden of proof.

I really do not want to get into the "both cords must be same length for time alignment" statement he also made subsequently. Not even worth the time to comment.

Absolutely. Two meters is preferred. I experimented with an Audio Quest Hurricane one meter and two meter power cord on my Audio Research Reference 160s. The two meter power cord provided much better sound, doing more of what the one meter did. The rule of thumb is all cords should be two meter.

When I brought this observation up to my dealer, he said, “Yep, longer length, more power conditioning.”

@tattooedtrackman 

So, did you have two 1m and two 2m power cords and compare them? Because I can’t imagine anyone would be able to tell the difference between a blended soundstage and different length cords. But I have no doubt the difference would be very obvious on your system between two 1m Dragons and two 2m Dragons.

And people do not find the sound difference bet. 1m and 2m pc is simply because their system is not revealing enough, right?  Learn something new every day!

The proof I would like to see if how much difference in noise filtering capability can actually be measured due to that 1 m difference. 

Seems like just adjusting the tube bias based on whatever voltage you end up with is the easy answer. The line power goes through an input transformer and a rectifier before it’s actually used. I assume solid state amps do something analogous?

If you can discern a difference between a 6 foot and 12 foot power cord you are God's gift to humanity .

Although I think a case can be made for good shielding a power cord to reduce electronic interference along its journey from the outlet .

Also I would opt for 10 gauge all the time just to make sure there's plenty of pipe room in those moments where Power demand needed but no one is able to really know for sure.

Also as you may have guessed in this hobby you feel better when you spend more money otherwise you'll always wonder should I've spent more money on something maybe it would've sounded better and by spending more money you eliminate that thought. That's a really important consideration.

If everything else fails and you're still unhappy you can buy a puppy and if you get bitten there are those that believe it's OK to shoot it. 

@ghdprentice  Yes I did have 2 - 2 m HC Dragon and 2 - 1 m HC Dragon PCs. One of my dedicated outlets for my amp is about 1.5 m away and the other dedicated outlet is about 3/4 m  away from my other amp. At first I tried both 2 m HC Dragon PCs on both amps. Had them hooked up for about a month. Then I used a 1m for the one amp that was about 3/4 away from 1 amp and continued to use the 2 m for the other amp. Had them hooked up for about another month. Both sounded exactly the same as having both 2m. But we are also talking about the AC Dragons HC. The top of the lines from AQ. 

@emergingsoul 

++1

I’ve heard girth is more important 

*!*  Power cords?!  Is that still an iss...🤦‍♂️😬😣

...was hoping y'all'd drift into Power Chords, even better. 

Power Chorales :  Even Klingons get Sceerd....

...what snots me is the lengths.....

Too short too long too 'flexi' too big too stiff too light a gauge too hard to bend too flat too twisted too much a PIA x more of them than you......

...and we haven't even considered the hardwares at the ends....

BTW....If you've found Anything in the above 'exciting' is some *ah* unusual usual way.....
Something antidotal....subs to 11 if infinity n/a

Don't go quietly....toss the trump card...😏

Yes length matters you noobs. There is a reason why Shunyata won’t sell a powwr

cable under 1.75 M..!!!!

@pennfootball71 Shouldn’t generalize based on limited exposure. The standard length of SR cables is indeed 1.75 meters, but custom versions of certain models like the Venom HC v2 can be made in any desired length with various connectors. The "standard" length may indeed be set based on market demand rather than technical considerations discussed. I have not seen any technical white paper published by Shunyata Research to support such claims a 1.75m or length around it being an optimal design. Additionally, I have seen some audiophiles claim that power cables need capacitance, which is not accurate. In reality, high capacitance in high voltage applications can lead to power loss and inefficient operation of devices.

I’ve heard girth is more important 

@brian8383  , I believe that 10AWG has already been settled upon.

It sounds like the power supply in the components grab power about 2m away from the component. I don’t mean it is using the power 6.6’ away just that it is the length that matters to the sound. Nordost does recommend 2m. Is that to sell more cable or is that the minimum length they sell to keep things tight. I have not tested this but it’s so interesting. What I have tested is different power cords on the same pieces of equipment. That is awesome that power cords do not make a difference on some of your systems and you are happy with the sound. Seriously, you are lucky. That being said I did do a sound test using different power cords like Nordost Blue Heaven, Puritan Classic Plus and Ultra XX, Straightwire Pro Thunder and Black Thunder, and three different ESP power cords, even some Audio Quest NRG. They all sound different on every component I tried. I even bought an EIC to C7 (figure8) adapter to test on the Blue Sound NODE. Every power cord had a different sound in one way or another. Detail, Decay, Midrange, Bass, harshness. One thing I was surprised about how one power cable might not sound good with a different brand on a different component. In the end it all can make a difference. I have a killer Kubala Sosna Elation on my ARC Ref 5 SE preamp. I do not want to spend another $3k on every power cord so I am looking for a power cord for the amp and DAC to keep the killer sound. 

@immatthewj       The really short answer to why most stock power cords are similar is that the cord is seldom the reason for purchase.  Many customers don’t know enough to care, and the rest will buy what they want and don’t want to pay much for what gets tossed. 

@lanx0003    I believe you have arrived at the same conclusion as millions of marketing managers over the years – the optimum design (length, in this case) is the one that sells the best.  Is this purchasing preference based on what customers feel sounds the best (how many buy a handful of lengths of the same item so they can compare?)  vs how many buy what they think will be “about the right type and length” to get from wall socket to device?   We leave out for now the issue of price point, since every customer has a different idea of what is a “good value” for them at any particular moment.  

@tattooedtrackman
          It sounds like your experience when comparing two very similar cables seems reasonable.  There is minimal difference in the amount of shielding, conductor length and probably location of the power cable throughout its length in the room vs. other electrical devices, ground planes, adjacent or crossing cables (at right angles, of course…)  etc. that might have an impact on the electromagnetic environment the cable will be interacting with. 
Given the same brand and performance level of cables, the effects of differing or worn terminations can probably be excluded, and the comparative ages minimizes the impact of minor design changes, insulation degradation through aging of the plastic dielectric, or breaks in the shielding due to frequent flexing of the relatively fragile metal mesh usually used. Heck, given the subtlety of the effects being looked at here, even someone accosting a cable with the nose of a vacuum cleaner could cause an indentation in the shielding or insulation that would slightly change the impedance of the cable at that point, possibly causing an electromagnetic reflection up and down the cable forever after.  

@jlbkmb1958  re: “Seems like just adjusting the tube bias based on whatever voltage you end up with is the easy answer. The line power goes through an input transformer and a rectifier before it’s actually used. I assume solid state amps do something analogous?”  

Similar, but in opposite ways.  Tube units need to INcrease voltages for the tubes, and unless really well pre-filtered, thus INcrease the interference signal voltage.  Semiconductor devices work at low voltages, so their power supplies generally DEcrease the voltages sent to the circuit boards, thus DEcreasing the amplitude of the interference signals as well.  That does NOT mean they go away, and interference noise will be re-amplified in any gain stage in the device.  In either case, good designs work to isolate the power and signal sections of components and filter the dickens out of the PSU’s output. 

To these and others above, one consideration affecting power cables, at least in the USA, is that building codes commonly state that residential wall outlets cannot be more than 8’ apart, so a 2-meter cord can almost always reach to one, and most first-time cord buyers will be mad if the recommended cord does not conveniently reach the outlet. If I were buying a power cord and I had to choose a length without being able to audition it/them first I'd probably be far more concerned about the path it has to take to get to a dedicated outlet than the overall length. 2 meters MAY be an optimum length, but often for reasons other than actual length.

That said, when I am at the point where cable effects are my top concern, I would want to have evaluated ALL the potential interactions between the active devices in the system, including microphonics affecting the stylus and tube grids, radiated electromagnetic interference from devices locally and in adjoining rooms, be they laterally adjacent as well as above or below, and even the proximity of wireless IOT devices which can, through the interaction between their signal and that of other devices on the network, cause higher and lower harmonics that can couple to sub-optimally shielded points within ANY nearby cabling, and cause issues.  Effects can range from dropped packets in the data stream to your audio streamer (which SHOULD be auto-corrected) to just inducing something that sounds “a bit off”, and that is what we are at the level of here.  [As others noted, also try to keep IOT on 2.4 and audio on the 5gHz channels and suggest the same to your neighbors unless they are far enough away that their weaker 5gHz signals can’t reach to your place.]

Bottom LINE:  Power Cords, like everything else, exist in a complex environment.  The effect on each individuals' perception of the resultant sound will be impacted by both the design of the particular cord and the way it interacts with surrounding elements – electronic, magnetic, environmental and spatial.  Finding the optimal result is as much art as science.  Everyone’s mileage will vary, often from room to room in the same home and even the humidity that day. Enjoy the ride! 
-------------------------------------------  
Full disclosure- my background and signal interference in general:  My days of having the luxury of optimizing my space for my audio system are past.  Although an Electrical Engineer, I have also designed and built both residential and commercial buildings, including my own home.  I made sure that home had buried utilities, excellent service entrance grounding, whole house surge protection on both phases, 5 subpanels with oversized feeds from the main panel, and a separate transfer panel for the underground feed from the generator out back. When the Verizon guys I was training gave me a carton of 1000’ spools of coax to wire the place I came back for more.  When moving out of that 5000+ sf suburban home a few years back, we chose our new apartment based on the concrete and steel construction between each tenant and felt having a hardware cloth-like steel mesh that the 100+ year old ceiling plaster is embedded in was a big plus. I know this reduces some top or bottom interference, and foot-thick concrete walls all around certainly help, but I still get, as of this writing on a Sunday afternoon, 15 wireless networks from where I sit to type.  My network analyzer says I have good quality signals from the top 8 of them. The ceiling mesh is way too coarse to effectively block signals at cellphone or Wi-Fi frequencies.  Look at the size of the holes in your microwave oven door to see what is needed to block LOW-band cell signals and Wi-Fi.
Your personal situation may be less challenging, but I have visited and tested some locations where I see close to 40 viable sources of RF interference, all trying to share the same limited spectrum, and each one boosting their power to get their set of data packets through all that hash. OTOH, our ASUS Zen XT8 4-node mesh network throughput was cut from 1 GB/sec as transmitted to 10 MB/sec throughput between our apartment and our daughters’ unit, one floor above and about 20 feet away.  Only good for Minecraft despite focusing the antenna radiation pattern at both ends! Lesser units totally failed after 1 wall. 
 If I were to add in the kitchen appliances and potential interference from the surrounding spaces in a volume equivalent to the average private home, I’d have over 40 SETS of surge and RF sources including air conditioner compressors, refrigerators, microwave ovens, etc.  
At least even this is better than one place I lived (I think I mentioned this in an earlier post) where a local AM radio station was literally in my back yard, and I had to leave my system on all the time, because if the solid state amp was turned off, and even if it was unplugged from the wall and any input, would still play whatever was coming from that station.  The output transistors were acting as detector diodes, and the whole amp was effectively a very expensive crystal radio set. I pitied any cats whose whiskers touched unpainted metal.
 

Benjamin Franklin was once asked how long a man's legs should be. His answer was simple: "Long enough to do the job." Unsatisfied, the questioner continued, "And how long is that? Franklin replied, "Long enough to reach the ground." The questioner continued, "What then his manhood?" Not missing a beat, Franklin replied, "The same."

Similarly, I think that holds true for power cables. They should long enough to reach the outlet. And from there, the electrical wiring should be long enough to reach the power generators. As for how that cabling should be configured, I leave that to you and your power company to work out. 

So what beat did Franklin not miss!

He didn't miss any. He was Beatless.🙂

🙄...*sigh*   Th' guy jus' lacked tha' "natchurl rhytm".....

...couldn't resist, and seldom Dew... ; )

Thanx, @knittersspouse ...👍😎  I'll keep you in mind when I dive into a cable-lacing sess on a house.....always a + to ask of one who's been and done. 

immathewj

I have had two manufacturers tell me that minimum length should be 1.5 meters, but that keeping the correct length to not create a crossover with a signal component is more important. That is a 1 meter cable would be better if it would prevent a power cable from crossing over an RCA, XLR, or USB cable.

I will also say that I am unable to hear any difference in power cable lengths, but thought I'd follow what the designer preferred.

@tattooedtrackman …”Yes I did have 2 - 2 m HC Dragon and 2 - 1 m HC Dragon PCs.” 

That is a really interesting observation. It’s too bad we do not live near each other. It would be really interesting to visit each other’s systems. 
 

What kind of music do you listen to and how loud do you listen usually.

I listen to jazz, blurs, world mostly… with classical, electronic and occasionally other genre. Volume is typically 65db to 75bd… but if I feel like “rocking out”, 80db.