Here's one for the electric wizards to kick around. Whilst attending Axpona this weekend I was doing some power cord shopping. At one particular display I was being told by a very well known cable company representative, I'll not mention the name so it doesn't influence any responses, that the rule of thumb is that in order for the pwr cord to be effective it needs to be at least five feet long. This allows the current to be in the cord long enough for it to be effective. Ok, I'm really dumb when it comes to this sort of thing so maybe I said that in the most simpliest of words but that's pretty much how it was explained. Anyone care to elaborate on this good or bad?
20m or 2m no difference. length of powerline is much longer could be 2km The efficiency of current has nothing to do with length of power cord. Longer ones are usually more convenient to reach to power outlet from the placement position. I've seen those super fat ones that you can hardly bend, but "sounding super good" LOL! If you can't even bend them steep enough to reach the outlet, what's the use? The rule of thumb is super-simple, if you still unsure how aftermarket power cord works or how will one work in your set up, there's no need to bother and use stock one and save $$$. I still don't know why I should change my power cords unless they break and live with that with no regrets whatsoever. Many high-end components might not have sufficient "defense" from EMI of powerlines and may require to use SHIELDED powercord in case if such problem NOTED. See? I'm not completely against aftermarket powercords after all, but highly prefer well-engineered components that aren't susceptible to EMI, RFI or other electrical nature disturbances. A representative will always tell you to purchase because it will improve sound, but in fact not always true and most-likely not true.
Have never heard that the length on a power cable is critical. Their is a lot of discussion on the proper length of digital cables though. Perhaps the Mfg was referring to some harmonic resonance frequency of the 60hz power wave? I have heard a definite difference in the sound with some power cables and virtually no change with others. An audition in your system is a must. Many mfg's have a trial period and the Cable Co has their Library program. Good luck, enjoy the journey and trust your ears.
Maybe because at the factory where they're made, the workstations are five feet apart and one worker does the input side while the other does the output side. They call that their "current" configuration: the current workstations can be no closer than five feet apart. Ergo, the current has to be five feet, minimum.
dbtom2- not bad... Hopefully, almarg will post on this. He usually has the ability to answer these questions with scientific acumen. In my humble opinion, I would use a power cord that is long enough to reach the outlet and component, yet provide enough movement so that adjustments to interconnects can be done with ease. I went from PS Audio PC's to Zu. The PS were a P in the A, due to their thickness and inflexibility. The Zu's are more flexible, but only come in 1+ meter lengths-shorter lengths are priced at the 1 meter price-so I now have an extra half meter for some of my power cables. As far as sound goes, the PS cables sounded better than a stock cable, but the Zu's didn't seem to add or detract from the overall sound. So, I guess there is a point of diminishing returns with power cables. YMMV Bob
I believe I recognize which manufacturer is being referred to in the OP. Since the OP chose not to mention the name, I won’t either, although if I’m right it is certainly among the more respected manufacturers of audiophile-oriented power cords. I’ll say also that I would certainly consider it to be coincidental that its name begins with the same letter as the first name of the fellow who will soon be named NBA MVP for the second consecutive year :-)
That manufacturer recommends against particularly short lengths based largely on the rationale that more length rather than less will enhance the degree to which the designs of their particular power cords are claimed to be able to reduce high frequency noise that might otherwise couple from the component being powered into other components in the system, or even reflect back into the component which is producing it.
I suspect, though, that in most cases what Czarivey said is applicable, and a particularly short length won’t produce results that are any different than a more typical length of say 6 or 8 or 10 feet. However in cases where it **might** make a difference there are a number of tradeoffs that are involved, and how those tradeoffs will net out with respect to those length alternatives (i.e., whether a short length or one of those longer lengths would be preferable) figures to be dependent on the particular power cord, the particular component, the other components in the system, the voltage and noise levels of the AC at the particular location, and perhaps also on the room, listener, and even the recording.
For starters, noise reduction can trade off against bandwidth. More of one generally means less of the other, at least if everything else is equal or similar. And as Atmasphere has stated here in a number of past threads, power amplifiers in particular commonly require bandwidths on their incoming AC extending into the tens of kiloHertz, since they generally draw current in narrow spikes of very high amplitude, that occur during just a small fraction of each 60 Hz period. The manufacturer that I believe is being referred to, btw, emphasizes the extended bandwidth of their power cords, and even provides measurements to support that. So the noise reduction vs. bandwidth tradeoff might net out differently in the case of power cords from other manufacturers. And of course the importance of both of those factors is dependent on the design of the component being powered. And the importance of noise reduction that may be provided by the power cord, if any, will also be dependent on the designs of the other components in the system, into which noise generated by a specific component may be coupled.
Another tradeoff that is involved is voltage drop. The longer the power cord the more the voltage reaching the component will be reduced, although with a suitably heavy gauge cord that reduction will presumably be very small. But again, in the case of a power amplifier, especially class AB and class D designs, the wide fluctuations of their current draw that occur in response to the dynamics of the music, coupled with the fact that the draw occurs as spikes of very high amplitude within just a small fraction of each 60 Hz period, could make that a significant consideration in many cases. In fact in past threads Atmasphere has cited instances in which he has seen the voltage drop of a power cord reduce an amplifier’s power capability by amazingly large amounts. Although again there are application-specific dependencies, including the AC line voltage at the particular location, and whether that voltage happens to be higher or lower than whatever voltage the component was designed to sound best at (presumably 120V in most cases, for equipment sold in the USA and other 120V countries).
The bottom line, IMO: Within reasonable limits the length won’t make any difference in most cases. In cases where it does make a difference, that manufacturer’s length recommendation stands a greater chance of being applicable to their power cords than to other power cords, and the optimal length will also be dependent on many application-specific variables.
I will take a stab and say that it is Shunyata, as I believe I've read something previously quoted by Caelin Gabriel about this topic of power cord length.
I also seem to recall Purist Audio making similar claim years ago regarding speaker cables. If memory serves me right, I believe Jim Aud recommended using speaker cables no shorter than a 6 foot pair.
Whatever floats your boat. Just as the case involving other audio gear, if you support any manufacturer, you should at least try their recommendations. If you believe wire is simply wire, odds are you aren't buying Shunyata cords or Purist Audio cables anyway.
I'm sorry, but as far as I'm concerned, exotic AC power cords are pretty much a silly waste of time and money. As a simple general rule, the shorter the cord and the heavier the gauge the better. Both result in less resistance/better current flow and reduced potential for EMI and RFI effects. And if one is really plagued with RFI (I have 2 FM transmitters within 1 km of my studio), clamp a ferrite choke around the end of the cord where it plugs into your equipment. My studio system is dead silent and clean as can be.
That said, I never thought I'd be buying power cords. I have a bushel basket full of them. Nevertheless, a while back I bought a whole box full of 14 AWG 3 prong male NEMA 5-15P to 3 prong female IEC C13 cords in 1, 2 and 3 ft. lengths from our good friends at Monoprice. They are very well made, help clean up the mess of cables behind the equipment rack, and reduce the potential for problems. Prices start at $1.10 for a 1' cord and go up proportionately. Here: http://www.monoprice.com/category?c_id=102&cp_id=10228&cs_id=1022801
So save your money and spend it where you'll get far more benefit, on, say, more LPs or an early retirement or whatever.
Without getting into the debate of long or short cables and what sounds better or if aftermarket cables makes any difference...based on my experience with at least half a dozen high end cable manufacturers, they recommend to stick with standard lengths simply due to the best value, in-stock availability and future resale.
From what I have seen, the most common std. lengths being sold are 5' power cord and 6' or 2M speaker cables.
I have owned from 3', 5' , 6' and 10' power cords with absolute no audible degradation in any of those lengths.
It’s kind of a moot question since placing a Shun Mook Original Cable Jacket around whatever length cable improves the sound. Ditto the Highwire Power Cord Wrap. Plus you be got your wall outlet and wall outlet cover to worry about, and contact enhancers. Oh, my!
So what exactly does the DTCD Analyzer measure? As the name implies, it measures, in the context of a pulsed current draw, instantaneous current delivery in amperes and voltage drop across the device during the conduction period and the stored residual noise component rate of dissipation after the conduction period.
Food for though. For those that believe most of the EMI/RFI noise generated in the ac power feeding the power supplies of audio equipment is actually generated from the associated audio equipment of the audio system equipment consider this.
IF you believe that two dedicated branch circuit is better than one to decouple the power supply’s of a CDP from an amplifier, there by preventing the digital hash from the CDP going back out on the power cord and then reentering the power cord of the amplifier, then why is it so hard to understand that a power cord couldn’t be designed to help do the same thing?
What IF you have a CDP and an integrated amplifier plugged into the same wall duplex receptacle using the OEM power cords that came with the equipment. Will the two power supplies of the CDP and amp be more likely coupled together than they would if they were fed from two dedicated branch circuits?
What IF a well designed power cord can reject the digital hash, (call it what you want, RFI, harmonics, high frequencies, what ever), from going back out on the CDP power cord to the duplex receptacle and then reentering the power cord of the amp’s power supply. Would that be a good thing?
So, IF you believe such a power cord can be designed and built which do you think could accomplish the task better, a power cord that is 2ft in length or one that is 5ft in length?
If the power cord performs some type of filtering than probably the longer the better. If the cord is to transfer current like for a Amplifier or a power conditioner than a heavier gauge shorter wire would be best.
But in reality, I have used quality power cords that are a few feet long and some that are 5 meters long. If they are properly designed for the task there should be no problem with sound quality.
Ok, so keeping with what usually happens here (which is what made me go away for so long) my simple question which was directed to those that actually knew something about electricity ended up being answered mostly by guesses, personal opinions, advice on how to buy cords and another debate as to wether aftermarket cords and cables are better then the stock cords. I don't remeber asking for any of that. I just thought somebody could explain why this company rep said what he said, other then to just make you spend more money on a longer cord. So you can all sleep easier tonight, the company was Nordost. Also, as long as it was started up again, anyone that doesn't believe that cords and cables don't make a difference, get a different hobby. For those of you that tried to give an answer with some merit, I thank you..
The minimum recommended lengths of Nordost cables are as follows: Power cables – 2 meters Analog interconnects – 1 meter Digital interconnects – 1.5 meters Tonearm cables – 1.25 meters Loudspeaker cables – 2 meters"
Ahem. "I just thought somebody could explain why this company rep said what he said, other then to just make you spend more money on a longer cord." I believe you answered your own question quite well enough. There is no reliable, double-blind, independent research *that I am aware of* that clearly shows any significant difference among reasonably well constructed power cords. What HAS been clearly and significantly demonstrated, repeatedly, over the years is the placebo effect. If you *think* it will sound better, it *will* sound better, at least to you, and for the ridiculous money it bloody well ought to! A little confirmation bias helps one along, too.
Well, good luck. For me, just spending money is NOT a hobby. I’ve rather better places for it.
Jim (Jea48), thanks for providing the Nordost quote and link. I’d have to say that those recommendations don’t say anything positive about their credibility as a cable manufacturer, as far as I am concerned. In addition to the lack of supporting rationale, the recommendations for analog interconnects, tonearm cables, and speaker cables are one size fits all recommendations that make no sense IMO.
The degree of virtually all explainable effects of line-level analog interconnects and speaker cables (including those whose audible significance is debatable or doubtful) is directly proportional to length. That would include the effects of resistance, inductance, capacitance, skin effect, proximity effect, dielectric absorption, and propagation delay, among several others that could be cited. Therefore if the goal is for those types of cables to behave in as neutral and uncolored a manner as possible, the shorter they are the better. In fact an advantage of monoblock power amps that is often cited is that they make the use of very short speaker cables practicable, thereby minimizing their effects.
The only effects of line-level analog interconnects and speaker cables I can think of that would not be directly proportional to length would be antenna effects, that could conceivably result under some circumstances in audibly significant pickup or radiation of RFI/EMI. But even in that case it would seem expectable that the shorter the cable is the better.
And when it comes to tonearm cables, their one size fits all recommendation ignores differences between moving magnet cartridges (for which the sum of cable capacitance, phono stage input capacitance, and tonearm wiring capacitance should conform to the recommendation of the manufacturer of the particular cartridge), and low output moving coil cartridges (for which minimization of capacitance is generally desirable, but the significance of which is highly dependent on the particular phono stage and the particular cartridge).
I’ll give them some credit, though, for the 1.5 meter digital cable recommendation, which as you are aware has been well explained technically, and well documented anecdotally. Although even that recommendation will in many cases not be optimal (that possibility also having been well documented anecdotally). 1.5 meters should be thought of as having the best odds of being optimal (unless a very short length is practicable, such as 6 or 8 inches), but there will be a significant number of cases in which 1 meter or some other length will prove to be a better choice, as the optimal length depends on many unknown and unpredictable component and cable dependent variables. The risetimes and falltimes of the signal provided by the component which drives the cable being one very significant variable, that is almost always unspecified and unknown. Numerous other variables that affect what length will be optimal could also be cited.
" I’d have to say that those recommendations don’t say anything positive about their credibility as a cable manufacturer, as far as I am concerned. In addition to the lack of supporting rationale, the recommendations for analog interconnects, tonearm cables, and speaker cables are one size fits all recommendations that make no sense IMO."
I hate to judge too harshly but it would appear the high end audio community, I.e., the high end shows, the reviewers, the magazines that publish Class A components and the audiophiles themselves disagree with your assessment as Nordost has been at or near the top of the pecking order for quite some time. What is it, 25 years? You would be wise to audio Nordost Valhalla cables.
I hate to judge too harshly but it would appear the high end audio community, I.e., the high end shows, the reviewers, the magazines that publish Class A components and the audiophiles themselves disagree with your assessment as Nordost has been at or near the top of the pecking order for quite some time.
As a relative newcomer, I may be out of line, but I really hate it when the original question gets lost and rancor and animosity lead us down the slippery slope to nowhere. Either agree to disagree or just let it go.... Please.
For a second there I thought this was one of those April Fool's postings, but soon realized that it's already April 22nd. Seriously?? Power cord length??
Let's see: the power generating plant is probably hundreds if not thousands of miles from your amp, the local sub-station definitely a few tens of miles, the wiring from the transformer in your street to the outlet probably a few hundred feet ... and you are worried, and people are seriously discussing, power cord length? And after you connect the power cord, you still have to deal with all that pesky wire in the primary and secondary of the power transformer, which is just the size and length required by the amp.
So, the experienced and very knowledgeable electrical engineers at Krell build a $40,000 amp and it comes with a power cord that they tested and know it is absolutely perfect for the amp. Then some sales rep from an audiophile cable company tells you: they're idiots. Use my $10,000 power cord!! (which is mot likely worse than the one Krell sent you, and probably a fire hazard). I'm an electrical engineer and this whole discussion of cables and specially power cords and power connectors really insults my intelligence.
Let's say you're in a Supercar forum and just bought a Bugatti Veyron. There is a company, or someone in the forum, claiming that you should ditch the original fuel line from the gas tank to the engine and buy their improved super duper fuel line for just $60,000. They claim that will make the engine run smoother and you will feel the improvement in the horse power of the engine. Pretty ludicrous, isn't it?
So, the experienced and very knowledgeable electrical engineers at Krell build a $40,000 amp and it comes with a power cord that they tested and know it is absolutely perfect for the amp. Then some sales rep from an audiophile cable company tells you: they’re idiots. Use my $10,000 power cord!! (which is mot likely worse than the one Krell sent you, and probably a fire hazard). I’m an electrical engineer and this whole discussion of cables and specially power cords and power connectors really insults my intelligence.
I recently had the privilege to sit down with Todd Eichenbaum who has been with Krell for 20 years, and serves as Krell’s Director of Engineering where he’s led the design efforts for over 50 Krell products including every preamp, power amp and loudspeaker they’ve designed over the past 12 years.
Todd’s latest creation, the Vector HC Power Cord, is a departure for both Krell and Todd, however as I found out the leap from making amplifiers to power cables isn’t as great as one would think.
AR: Krell President, Bill McKiegan, said, "that with few exceptions most power cable manufacturers haven’t made a power amplifier so they don’t fully understand what is needed in a power cord." I thought that was an interesting comment and as I understand it the Vector HC is your baby, so how did it come about?
TE: My earliest inspiration was born of frustration. I’ll explain. About four years ago, not long after we launched the Evolution 900 monoblocks, one of our salespeople got a call from an irate customer. His 900s weren’t working properly; the microprocessors were indicating that one or more rail voltages were out of spec. Typically this is an indication that something is very wrong with an amplifier, but these were brand new, and furthermore, sometimes they worked OK. After many phone calls and much head scratching but very little success, we happened upon a juicy tidbit of information: the customer was using aftermarket power cables. When he removed them and reinstalled the very plain but quite functional cables that we supplied with his 900s, the amps worked perfectly. So, in fact, the customer’s ultra-expensive, super-exotic power cables were starving the 900s for current to such a degree that their power supplies were coming out of regulation.
Looking at this from my perspective, I found it infuriating that a company would design a power cable that was failing at its most basic purpose--to provide enough power to the component to which it was connected--and then to have the audacity to charge top dollar for it. A power cable is not a particularly complex piece of equipment; designing one properly simply involves knowing what it needs to do well, which is to provide a secure, reliable, safe, low resistance, and low inductance pathway from the wall outlet to the audio component.
At the end of the day, the Vector HC really was born from power amplifiers.
AR: You started with CAST and now you have the Vector HC power cord. Is Krell quietly trying to get into the cable business?
TE: We’re not making a conscious effort to expand into the cable business, quietly or otherwise. Rather, we’re filling what we see as gaps in current offerings. For example, the CAST concept started as a more accurate means of interconnecting audio components, not as a vehicle for selling cables. In fact, several other companies now offer CAST cables that, frankly, we prefer to our own CAST cables. With the Vector HC, we felt there was a need for a product specifically designed to work well with electronics that place heavy demands on the AC mains--in particular, our amplifiers.
AR: How is Krell differentiating themselves from other high-end cable manufacturers?
TE: By the design of the Vector HC cable itself, which has been optimized for what we, the designers of large amplifiers, know to be of greatest importance in providing AC power to such devices.
First, the cable had to offer low resistance. Of course, the larger the cross sectional area of the conductors, the lower the resistance; however, AC connectors do have a limit as to how large the conductors themselves and the finished cable can be. We determined that the largest conductor we could comfortably work with was #11 AWG. That’s twice as large as the #14 wire used in many premium cables, and still larger than the #12 wire used in many ultra-premium cables. We also specified oxygen-free copper for its improved conductivity, which further reduces the resistance of the conductors regardless of their size.
Second, because inductance, by definition, opposes rapid changes in the flow of current, and since we want the audio component connected to be able draw whatever current it needs instantaneously from the AC mains, the cable needed to have low inductance. We are able to accomplish that by twisting the two primary conductors together.
Third, we wanted to reduce the amount of high frequency electromagnetic noise that could enter or leave the cable. As luck would have it, twisting the conductors also increases their capacitance, and increasing the capacitance between the primary conductors helps filter high frequency noise. In this case the "capacitor" is formed by the two primary conductors behaving as its plates and the wire insulation as the dielectric between them. Since we want to maximize the capacitance over a wide frequency range (to minimize noise), we specified a Teflon derivative--the highest quality dielectric available--for the wire insulation. In addition, the two primary conductors are wrapped with a copper foil shield, also to reduce the noise entering or leaving the cable. We selected foil instead of braided wire because it works more effectively at the frequencies likely to be encountered by audio equipment in the home. The shield is connected to ground only at the wall plug, so any electromagnetic noise is shunted away from the audio component and into the earth ground. Since the shield is not connected to the component plug, however, no ground current can flow through the shield. Rather, a third conductor, located outside the shield, makes the ground connection between the component and the wall plug. Noise on the ground conductor cannot penetrate the foil shield.
The connectors we use are not unique to our cables, but they are unique. The mating surfaces are rhodium plated. Rhodium is a noble metal, very resistant to corrosion and extremely expensive, but much harder and more resistant to scraping than gold, which makes it especially well suited to connectors that might be inserted and removed many times over the life of the product. Internally, we terminate the conductors with gold plated spade lugs, which are then screwed into the connectors. Because the internal connections are not subject to repeated wear, we chose gold for its higher conductivity.
AR: A lot of people feel cables, especially power cables, have little to no effect on a system’s sound, what do you say to those people?
TE: Those people should listen to their systems with different power cables installed. If they still believe there to be no effect, or if the effect they hear is not enjoyable, or if it is enjoyable but not worth an additional $2000 or $4000 or whatever, then they should put their stock power cables back in their system and start listening to music again. Honestly, we at Krell heard differences we didn’t think we’d hear, so it’s likely that others will have that same experience.
The AC power that comes into your home travels great distances and there are hundreds if not thousands of feet in branch circuits throughout your home. Do you really think it matters if your power cord is 5 feet or 10 feet ? After 40 years in the power and electronic business I can tell you the only thing that actually matters is that the size of the cable be matched with the current consumption of the component and a power conditioner to remove motor induced frequencies.
And after all that, and the talk and concern about those poor electrons flowing like water molecules through a pipe, in reality, there is no net displacement of electrons, just alternating fields of sufficient magnitude.
The power cord effects how your equipment sounds. Easy to test by using the OEM for six months... Then switch and allow the audiophile power cord burn in. Someone I know designs audio equipment. He makes his own power cords (which I do not own). He explained something to me about how a good power cord acts like a reservoir for electrons... (or, something along those lines). That's why the length is important. I am not going to argue, I hear a difference when I switch power cords. They make a difference. If someone has a system that is not able to let you know the difference? I can not tell you why. All I can report on is what I have been hearing for the last few years. Even my PC sound improved with an audiophile power cord. I like the Pangea top of the line. Not as expensive as many others.
Mr Czaray to say stock power cords do as good of job,fine,sound the same,what ya smokin' son.Not only are you wrong,(new hearing aid batterys needed) but they can improve the sound of most every piece.cd likes small gauge,most others sound better with larger gauge.Silver coated helps most power cord wire sound better on every piece.Go buy a 2000.00 power cord,plug it in and rethink every theory you ever had.sorry to be so blunt. psst pass it over
Hi I have tried many cords and have only emperic knowledge regarding their influence on the sound. My experience is that the better your gear is, the greater the effect on different powercords ( or anything else ) is.I can easily hear the difference between a 2 mtr or a 4 mtr cord. ( Used fromt the wall to the powerconditioner )Why it is so, well i cannot tell and i really dont care as i dont have to design it. Trying to explain it with a theory or so called common sence, will only distrac me. I try things out. It takes time but its the only way to get the knowledge, as there always are so many factors you cannot predict.Happy lisining
I love how people who have never tried "fancy" AC Cords are so sure they cannot make an audible difference. I hate that they do indeed make quite a difference in most cases but they are terribly synergistic and it is difficult to recommend any one overall. Just the stiffness of the local electrical grid can be quite a factor as well as the associated equipment (and appliances) on the same lines. Damned if the ac outlets themselves seem to affect sound too. One poster is right on the money. They are indeed a parasitic element to the power supply. They can be designed as filters (or include filter networks), used for current or voltage storage and at least one claims negative impedance while others claim shielding makes the difference. Then there are those who claim they act as a transmission line so the geometry and dielectric matter there. Different metals, conductor shapes, and terminations also seem to have their own effect. Resonances (all finite length conductors have) based on length and propagation speed can be seen with an oscilloscope and frequency sweeps or a network analyzer. There are mechanical vibration and microphonics to deal with; even static charges are dealt with in some cases. Wire loss or DC resistance is a fact in any case and varies with frequency. Regardless of explanation or principals whether or not it is audible to you should be the criteria. We just do not know it all and our system of measurements are quite limited and lacking IMHO. Find a friend and try some blind testing if you can. Mixing and matching is part of the art. It must also be said that many designers are not going to give away their particular paradigm or trade secret while others do have white papers and measurements galore it is a complex issue. Ultimately it is your own listening judgement and I urge you to try experimenting. The relatively inexpensive DH Labs bulk DIY cable is a great place to start.
It must also be said that many designers are not going to give away
their particular paradigm or trade secret while others do have white
papers and measurements galore it is a complex issue. Ultimately it is
your own listening judgement and I urge you to try experimenting. The
relatively inexpensive DH Labs bulk DIY cable is a great place to start.
No, it's not a complex issue. A power cord is a very simple issue. Building an actual power amplifier IS a complex issue. Power cords, speaker cables, etc. are not complex at all.
What is really complex is our brains and the physiology of our acoustic system and perception. Every time I have a couple of beers my system sounds so much better.