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After hearing positive testimonials, I ordered a couple of VH Audio power cords to see if there could be any sonic difference whatsoever. I went in completely skeptical, in fact wanting to disprove they could make any difference. Yet, they did. Snappier snare drums, a more spacial feel, more detail, pluckier guitars, etc.
I am in the same position as you. I can't bring myself to believe that any improvement in the last few feet of an AC supply is going to make a scap of difference. I still believe this, but have built VenHaus power cables "just in case"!
Quite frankly if good quality equipment manufactuers really believed that AC was a problem, they wouldn't use it. Apart from powerful (or valve / tube) power amps, AC is quite unnecessary. DC is a pure source of power and easily availably from batteries (recharged when equipment switched off) and CD players, tuners and preamps can be designed to run on DC. Moreover this solution is far cheaper than what many people spend on mains conditioners etc. I read on an AA posting a while back that someone had spent more on a conditioner than he had on the amplifier it was feeding! He surely needs his head felt. I think we all buy this stuff because we're told it improves things. It makes us happy to think we've done all we can to maximise performance. In medical terms it's the placebo effect. Having said that, I'm happy I'm using the VH cables. We all like to think a bit of DIY is a great investment.
"I think we all buy this stuff because we're told it improves things. It makes us happy to think we've done all we can to maximize performance."
True, we buy things because others recommend them, just as with any other product. The second sentence I very much agree with.
However, you also said:
"In medical terms it's the placebo effect.
How would this explain my wife hearing (sometimes large) differences between cables, when she doesn't even understand why I have two amps (i.e. pre and power)? She played the piano for 13 years, and while doesn't understand the word 'interconnect' she can tell if something sounds close to natural (regarding the piano at least). I never tell her before the 'listening test' what she should hear (if anything at all).
Of course she knows that I am trying two different cables, so she may be inclined to say that one sound different from the other (the placebo effect), but her observations about the sound are generally very close to mine, which cannot be explained by the placebo effect.
You also said:
"We all like to think a bit of DIY is a great investment."
I wish this was true. I have made several cables (ACs, ICs, spk cables) and some had terrible results. One of the most expensive DIY cables was an AC cord where I used 4N solid silver wire with teflon insulation, twisted and shielded and it sounds worse than the stock cord. Now I am wondering what to do with the silver wire, maybe some jewels....
A few months ago, someone brought up power cords on a forum I moderate elsewhere. The usual "snake oil" type posts came up and the thread died. Recently, there have been a couple of similar threads wherein people whose opinions I trust posted of their positive experiences with power cords. It piqued my interest, but, to be honest, I went in completely convinced that no positive change could result. As I said before, when I got my cords, the improvement was readily observable. I almost fought against hearing what I was hearing, but it was and is there. Next, an explanation and as I'm more of an audio enthusiast than an engineer, I came here, where I hoped to find an answer. I've taken back some of the information I've received from you gentlemen and added it to the thread (with due credit to the authors here). I will bookmark this thread for those times when I hear bashing on other boards, usually by people who've never used aftermarket cords. I just get tired of people knocking something they haven't even tried, as well as the pat responses you've all, I'm sure, heard such as "The electricity travels miles and miles before it reaches your house. A couple of feet aren't going to make any difference."
"The electricity travels miles and miles before it reaches your house. A couple of feet aren't going to make any difference." RFI is not a myth it is real just because you cannot see it. the proof is in the sound on the mains if you remove this you get better results and if you a better dielectric and metal etc.
Here is a bit from cable theory from AQ
We all like to describe how a good component improves the performance of our system, a perfectly legitimate comment. Unfortunately, buried in this statement is often the misunderstanding that the better component actually improved the signal in some way. There are certain areas of digital processing where this is possible, but in the analog world signals don't get better, they only get worse. The substitution of a superior component improves a system only because it causes less damage.
Cables, like all components, should be chosen because they do the least damage. This "damage" comes in two basic forms: a relatively benign loss of information, or a change to the character. A visual analogy might illustrate this distinction: consider "perfect" as a totally clear pane of glass. Since no component is perfect, the best we can strive for would be analogous to a pane of glass with a light gray tint. Lower quality components would have a darker gray tint. These various densities of gray tint would represent various amounts of lost information.
If the glass were tinted green or yellow or red, these colors would represent changes in character. We are far more likely to notice, and be bothered by, a light colored tint than a denser gray tint. It is this mechanism of character versus quantity that causes much of the confusion in the pursuit of higher performance.
Chain Analogies, Synergy, Enhancement and Other Lies
We have all heard the truism that "a chain is only as strong as its weakest link. "Certainly this is true of a chain, but it becomes a misleading lie when applied to the world of audio and video. The quality of sound coming from your speakers and the quality of picture from your video monitor have both been compromised by some degree of distortion in every component, starting with the microphone or camera. No one actually believes that if you changed every piece of equipment except the proclaimed "weak link"-that there would not be any change in the sound or the picture. No matter how bad a CD player might be, no one would argue that you couldn't hear the difference if you changed speakers. It is worth noting that some components are more cost-effective to change than others, or that a particular complaint will not be eliminated until a specific component has been changed. These truths might seem like an approximation of the chain analogy but the chain story has so much strength because it is an absolute, and it absolutely doesn't apply.
The logic of a good system is very simple: Every component matters! The electronics, the speakers, the cables, even every solder joint, all cause damage. Each component is like one of the dirty panes of glass in this illustration. Each one blocks a bit of the view. The quality of the final performance, or the clarity of the view, is the original signal minus the damage done by all the pieces in-between. Improving any one of the components will improve the performance. Cleaning any one of the glass panes will allow a clearer view.
Recognizing that the challenge is to reduce negatives, to prevent distortion, makes it much easier to understand "unexplainable" improvements. If the panes of glass are not only dirty, but also have a red tint, then as each pane is cleaned and the tint is eliminated, the "view" of the music will improve as expected. However, the red, and the awareness of the red, will not be eliminated until the last pane has been de-tinted.
De-tinting this last pane will seem to make a bigger difference than de-tinting any of the previous panes. We are naturally more impressed by the elimination of the red tint than by the previous reduction in the tint's density. If you didn't want to hear traffic on the street, reducing the traffic from three cars per minute to none at all would be more impressive than reducing the flow from nine per minute to six. People are more sensitive to the presence of a phenomenon (the red or the cars) than to the quantity.
"But this is the plastic age,
the quiet rage
is damned and civilized."
I went to your site and saw that in the thread about this topic, posts from AA had been cut and pasted rather than linked to. Besides violating the copyright policy at AA, and failing to give adequate credit to the individuals who contributed the information, I think it does a disservice to the readership of HTGuide, who might potentially wander over here and find out a number of interesting things about audio reproduction that hadn't occurred to them before, then post their findings back to HTGuide, which sends more people over here, who tell more people at HTGuide, and so on. Cross-pollination, if you will. Personally, I found out about AA from a Jon Risch post at Audio Review, and I've benefitted greatly from it.
Just a thought.
"But this is the plastic age,
the quiet rage
is damned and civilized."
I'm fairly new to audio, and to this board, though I've been lurking for a while, and have posted from time to time. This discussion about power cords--a subject I've been interested in for a while--drew me out of my shell.
A while back I did some of the same analysis presented by audioengr, and convinced myself that voltage drop could, indeed, be significantly reduced with the use of low-impedence power cords. Then I read an article--and verified this for myself--that claimed that the biggest effect on sound is often with relatively low-power devices: dacs, cd players, etc. Sources. So what gives?
I've got a physics PhD, which gives me enough of a scientific background to at least know when I'm sure of something or merely speculating. Here, I'm just speculating. But it seems to me that power cords must affect sound in two distinct ways. One is the voltage drop effect, eloquently described by audioengr. But there's another, I think, and it's almost the opposite effect: digital devices create high-frequency noise, which is SUPPRESSED by inductance, not enhanced by it. Even with amplifiers, IMO, the biggest effect may well be (remember: I'm speculating) noise created by very fast, very intense current spikes (that "I" in audioengr analysis can get much larger than you might expect; that is, currents during that re-charging phase can far exceed rms values). These spikes cause voltage drops, surely, but they also radiate nastily. High inductance may cause voltage sag, but it suppresses these radiated nasties (and the digital ones, which ought to be less intense, but more numerous) which is a GOOD thing. If voltage sag were the only problem, some of the technologies used by amplifier designers to good effect--like baluns on the ac line (think PS Audio) don't make any sense. Those things make recharging those PS caps SLOWER, and INCREASE voltage sag. Yet they improve the sound. Why? Just speculating, but it's probably because they effectively reduce the bandwidth, attenuating some high-frequency noise?
Stands to reason, then, that there's an optimum inductance level--which isn't zero--for a power line--and that it's different for different components (CD players would require a different cord than an amplifier for optimum performance)...possibly even for different houses.
Now how do sources of noise that occur way, way above audible frequencies effect what we here? I've got some thoughts, but that's a subject for a different post.
Fortunately, power cord inductance is not the only factor, you have the capacitance between the hot and neutral (more being good for suppressing digital noises) and the capacitance between the hot OR neutral and ground (less being better).
Also, see my post below for some of the other factors involved.
Yep it sucks that you need different power cords for different devices. Periodically I try out more cables and I have to try them out on my DAC, transport, processor, etc. independently. Unfortunately my amp has a 20 amp IEC connector so I have to get other cords to try on it.
Amplifiers demand current from the power-line when the capacitors in their power-supplies become momentarily discharged due to high-current transients in the music signal. This discharge condition must be quickly recharged from the power-line, through the power-supply transformer and rectifiers, or a voltage sag will occur. Such voltage sags can cause audible distortion at the loudspeakers. If the power-line has significant series inductance in the path from the power panel to the amplifier, this can prevent the capacitor bank from recharging in time to prevent a voltage sag from occurring at the amplifier output transistors. With a low-inductance cable, the voltage drop across the cable will be insignificant during high-current transients, minimizing the voltage sag. This allows all of the current needed by the output transistors to be supplied when they need it, resulting in fast, dynamic response to transient signals. This is why the sounds are "snappier".
Here are some actual measurements:
A typical 6-foot 14 AWG rubber cord and 25 feet of ROMEX has inductance of 7.2 uH and resistance of 235 mohms, ignoring the plug resistance effect. Therefore, the voltage drop at 20kHz will be I*(wL+R)= I*(.905+.235) = I*(1.14). With a 6-foot Low-inductance cord and 25 feet of ROMEX, the inductance is 5.9 uH and the total resistance is 147 mohms. This is an 18% reduction in inductance and a 37% reduction in resistance. The voltage drop for this combination will be I(wL+R) = I(.741+.147) = I(.888). So at a fixed dynamic current I, the voltage drop in the entire power feed at 20kHz is 22% smaller with a Low-inductance power cord. I would consider 22% to be significant. The reality is even more compelling. When you add in lower plug and receptacle resistance and the fact that the di/dt on the power cord will have spectra well above 20kHz with some amplifiers, the low-inductance cord makes an even bigger difference.
Following Vedric's questions and your, no doubt accurate mathematics, could you recalculate to take into account the resistance and capacitance of the COMPLETE cable system ie from the power station? I would anticipate that the "voltage drop in the entire power feed at 20kHz is 22% smaller" would drop to an unmeasurably minute figure.
In any event, do you not think that a decent amp designer would anticipate any minute voltage drops and provide capacitors capable of handling them? I would be unhappy if I thought that my equipment had inadaquate power supply caps, even if fed though the standard OEM cables supplied by the manufacturer.
Very nice post. I like how you included the 25ft of romex in each example. Complete and to the point. Thank you.
I have two questions. To get these distortions from voltage sag as you described, would the complete capacitor bank of the amplifier need to be discharged to a point that the next dynamic swing actually takes more energy than is available? If so, without getting into application variables, does this mean low inductance pc's will have zero-minimal effect on the performance of amplifiers with large ammounts of storage?
Unfortunately, I cannot answer your question. What I do know is yes they make a huge difference. I was like you, I even use to chuckle to myself when I see people paying a few hundred dollars for any cables, I thought they were being taken advantage of or were nuts. In the last six months I have grown to realize that IC, PC and speaker cables can dramatically improve your entire system, to the point that I now consider individual cabling as seperate components like an amp. Ever since I started researching the topic of cabling and tweaks I have spent thousands (DIY mostly too!) on cabling and tweaks and am glad I did! lol
If you liked the VH Audio PCs you just got, you probably will really like them when they break in. "Every" new PC, IC or speaker cable I get or try sound either unlistenable or like pure crap when I first try them in my system. I have learned that it takes at least 8 hours on my system before I get an idea of how a new cable sounds in it. Seems they keep sounding better as time goes by.
How AC cords can affect the sound:
(This is essentially the same as what I have at the web site, at:
Tests of a power cord on a digital recording system:
AC Power artifacts getting past a DVD power supply:
Now aside from all that I have posted/written already, I will address the other part of the issues with power cords, the "miles and miles" fallacy. Some folks contend that due to the miles and miles of power lines from the electrical utility generators to your home, tha the last few feet can not possibly amke any difference.
The very reason for the use of AC power, instead of DC power, lies in what is known as the "Eye-Squared-Are" (I2R) losses.
Using a very simplified analysis, for any given run of power cable, the power losses in the line due to the resistance of the power line, will be proportional to the current squared. Voltage drop will equal the resistance times the current.
With DC, these losses just continue to go up the longer the power line run is, there is no way to string power to a whole line of houses, the guy at the end of a long parallel power line run would not get the full voltage, not by a long shot.
With AC, the voltage can be stepped up with transformers, and then stepped back down locally. For long distance transmission, the voltage is stepped up to thousands of volts, and then at sub-stations, stepped down to hundreds of volts, and then just outside your house, it is stepped down to a 240 V center tap, and you use one or the other of the sides of the 240 V center tap for your 120V wall power.
The (electric) water heater or furnace and/or dryer use the full 240 V, hence the special plugs and dedicated runs from the panel.
Stepping the voltage up reduces the current, and this is what keeps the power losses down, and is why electrical power is transmitted using a high voltage AC system.
So what matters from a local perspective, that is, what is relevant AT YOUR HOUSE, is that there is a step-down transformer outside your house that is the local low impedance source for the AC power, and it is this low impedance step-down transformer source that is actually the 'beginning' of the AC power chain AS FAR AS YOU IN YOUR HOUSE ARE CONCERNED.
The wires run from the house panel to the transformer on the pole are typically much larger than the house wiring, and are of a reasonably low inductance geometry considering that they have not been optimized for this.
So the limiting factor for power delivery to your audio system tends to begin right at the breaker panel and is primarily concerned with the length of romex that exists, and with how many wall outlet push-in connectors it has passed through on the way to your audio system wall outlet, with some slight extension of the limitations out to the local step-down transformer.
This of course, should illustrate why the myth of "miles and miles" of power lines is just that, a myth born out of ignorance of the actual situation, and the oft repeated mistatements of some who have a hard time actually thinking about AC power issues, and what is going on.
This latter info rounds out some of the many reasons that AC power cords can make an audible difference.
"So what matters from a local perspective, that is, what is relevant AT YOUR HOUSE, is that there is a step-down transformer outside your house that is the local low impedance source for the AC power, and it is this low impedance step-down transformer source that is actually the 'beginning' of the AC power chain AS FAR AS YOU IN YOUR HOUSE ARE CONCERNED"
This would indicate that the arguement for only concerning oneself about the last few feet of cable is valid only in US. In UK we have the full 240 volts from a substation several miles away where it is lowered from high voltage to 240. So, following you arguement, we have to upgrade the entire cabling from the substation to improve our supply. Sorry - wrong.
Your arguement against DC appears to be flawed also. No one is suggesting the DC should be used in place of AC for household supply - your point about the guy at the end of the street getting a lower voltage is correct, but irrelevent. DC can, and really should be used as a stand-alone source of power for hi-fi. Why use AC and convert it to DC inside the box if you could use DC to start with? It's the "convenience" of not having to deal with batteries that keeps AC king of the power supply.
If AC really was as bad as cable vendors claim, then equipment makers would simply use DC. Truth is that AC is not the devil you make it out to be. One of the best sounding rooms at the Heathrow Hi-Fi Show last weekend used no mains conditioners and OEM cables throughout. Now, cable vendors would have a field day in pointing out that the supply in an airport hotel full of hunderds of audio systems is poluted to the extent that results would be unlistenable to. Not so!
Your comments are helter skelter all over the place, but I will respond to this:
it is known that a 240 Volt system is less afected by the mains run AND the power cords.
The US 120V mains system in most locations is fraught with dirty corrupted interference ridden power, and as such, responds to efforts to clean it up abnd tighten it up.
You now argue that US mains is far worse than UK's. I wonder why this should be? We use similar power stations, use a similar high voltage grid and transform down to domestic voltage for use in homes in a similar way. The UK has a similar cross section of consumers - industrial, domestic, commercial, etc. What's the logic in your assertion? If it were true, then why do we have as many "tweekers" here in UK, and why are there so many "experts" wanting us to part with our cash to improve our AC supply? I think you may be making excuses for the arguement of yours that I challenged!
Here is the reply I sent to some other poor chap who found his outlay on mains improvement was not money well spent! Why don't we put more faith in the integrity and experience of Hi-Fi manufacturers. I don't know any who decry the state of the AC supply being fed to their equipment. Furthermore, as argued previously, if mains was considered such a problem by manufacturers, they (at least high-end ones) would surely stop using their present method of generating DC from AC and would use batteries with a re-charge circuit engaging when off or in standby?
- http://db.audioasylum.com/cgi/m.pl?forum=general&n=292125&highlight=cawson&r=&session= (Open in New Window)
Well Jon, you're at it again. Blinding us with Science, or is it Mumbo Jumbo? As my maths teacher at school used to remark to those who answered a simple question with a clever answer "True, but irrelevant". Your discussion of the virtues of AC over DC for supplying power to our houses is just wool over the eyes. You have a vested interest and make a good living from power cables. You have an answer for everyone who dares to suggest that mains is mains. As I said in an earlier posting in this thread, if high end manufacturers really thought AC was a problem, they simply wouldn't use it.
Sorry about my views, and glad to hear you're back in harness after your accident.
Where do people get the idea that Jon profits from making cables?
He doesn't sell cables. He does tell people how to make cables for themselves and charges nothing for the info.
He has a job unrelated to cables but still manages to spend a great deal of time trying to be helpful here. And posts like yours are the thanks he gets?
He tries to explain things to a mixed audience where some have very little background and others PhD's in the subject at hand.
Anyway, we all digress a little from the subject at hand at times, but often at least some people will learn something.
Some equipment uses battery power, but that has lots of obvious problems too, especially for those of us that keep our amps making sound 24/7 :)
OK, I take on board what you say about Jon's "proper" job, but he has set himself up as a cable guru and, as I see it, tends to blind his readers with probably true but irrelevant information about the virtues of the crazy sport of spending daft amounts of hard earned cash on the last few feet of our mains supply cabling. If he is such an expert, I wonder why he doesn't make a living from this expertise. I notice that you have $300-500 cables! I wonder what cable there is between the back of your IEC sockets and the transformers ie the last few inches of AC. Most equipment will use wire no better than what's in the derided OEM cable.
Batteries can, of course be recharged without turning off your 24/7 equipment. You are surely not listening 24/7, so recharge them when you're at work, maybe? My point is that if AC is the monstrous evil we are led to believe it is by the likes of Jon, don't use it - use pure and simple DC and no cable at all, neither OEM nor $1000.
Only my thoughts, of course. It's what we listen to that really counts.
Why do people spread such rumors about Jon (or others). I consider it irresponsible.
Jon doesn't sell cables, work for a company that sells cables or recommend expensive cables, read his posts and his site more carefully, he just recommends that people consider cables better than stock, gives some motivational arguments and makes some suggestions about how to build some.
I don't agree with all of his recommendations, but I don't agree with all of what any particular person says. I don't see him as setting himself up as a cable guru; I see him as sharing the experience he's gained in his life with others. Take it or leave it.
The cable that is inside the equipment is in a different environment that the cable that's outside. In so far as shielding is important in power cables this matters.
As to my cables, I know what cable is in my equipment do you? I also know what people think when they hear my system and I know that I enjoy it too. What do you care about how I spend my money? I don't tell you how to spend yours and neither does Jon.
Besides the links at the top of Jon's original post he was just pointing out that the 'miles and miles of wire vs. the last 6 ft.' is a fallacy. You are the one trying to read something else into it.
I was just pointing out that some of us (probably not most) don't have time for charging batteries. We could of course charge enough different sets of batteries while we are playing that when the ones we are using run low we have others to swap in, but I know that I'd pay more for than I pay for power cords to not have this inconvenience. I am home most all of the time and what work I do I do to music at home. I'm just pointing out that there isn't any down time in some people's system. I never claimed to be normal :) Yes there are some systems that are DC powered, but so far their prices are out of sight or have other inconveniences, etc.
Anyway your AC/DC arguments are red herrings, we all have equipment that requires good AC and whether it matters to you or not, it matters to some of us what power cords we use.
I would not presume to tell people what to spend their money on, but many seem to be carried away with the idea that mains is far worse than it is and that a "quick fix" of the last few feet will make a significant improvement.
If it was just screening that makes the difference then screened AC cable is a couple of dollars a meter. My point about what's inside the case is more than simply the screening aspect. The wire itself is nothing special, beacuase manufacturers know it's really not that critical.
Battery powered equipment (except hungry power amps) can be easily built without the need for spare batteries or effort in recharging. When not listening, they can be switched to "recharge" whether or not you turn off the supply to the equipment. Simple as a regular On/Off switch, but reading Charge/Run or something. The reason most equipment is AC powered is simply that AC is in fact, a perfectly acceptable form of power and manufactures are quite content for its use in their equipment.
Let's agree to differ on this - I would prefer spend the thousands that some spend on conditioning AC on better equipment where there is a genuine payback.
PS I'm not suggesting that better cables make NO difference, but that a carefully designed screened cable of the type Chris Venhaus promotes (and Jon for that matter) will do all that's necessary. Spending more than the $50 or so (and that includes vast mark ups) is money not necessarily wisely spent. Those who believe the AC is so bad that several '000 are needed, should be looking to DC instead.
You are still presuming that some of us didn't do as you suggested and then found that even better cords made more difference.
I first got dedicated lines that made a heck of a difference. Then I tried more and more expensive power cords and stopped when I got to an optimum. In fact many of the cords that were even more expensive than the ones I have sounded worse. I even used single blind tests on my daughter at each upgrade.
You also didn't read my messages very well. I never have any down time for recharge.
Oh, well. As you suggest our time is better spent listening to music than arguing.
Putting on my Moderator hat: don't spread more rumors here.
What you say genuinely astonishes me. I can understand that unshielded AC cables in the usual tangle of wires at the back of ones rack is likely to upset signal cables, so I'm fully in favour of changing to screened cable. However, when you objectively consider what happens with the AC once inside the equipment, all this talk of megabucks cables makes no logical sense to me. Firstly as suggested before, the wiring between the socket and transformer is unlikely to be much better than what's in OEM cables. Then what happens? The AC goes into a transformer - hundreds of coils of copper wire doubled back on itself - the supply going in and out of the primary winding. This causes a fresh AC supply to be generated in the secondary coil, which has no physical or electrical contact with the primary. One wonders how imperfections in the AC cable can possibly adversely affect this new supply, now in the independent secondary winding. The rest of the equipment's power circuit rectifies, smooths and stores this secondary supply for use by transistors, valves, etc. In other words it tries to mimic a battery. Surely a well designed circuit can cope with an incoming supply deprived of a $1000 cable for the last few feet? As I say, it is astonishing to me that this should be the case and I would dearly like a logical explanation of physics I have may have missed.
I am happy though to believe that a decently designed amplifier is not adversely affected by a standard AC cable in the same way my washing machine washes just as well with an OEM cable as a $1000 one (OK I'm jesting, but you get the point!). Otherwise, as I have suggested earlier, manufacturers would not put up with grotty AC.
Incidentally even Maggie Thatcher, bless her heart (if she actually hadf one), admitted to spending 3 hours a night in bed. Plenty of time to recharge batteries!
I'm off to listen to music via my sub $50 AC cables - doesn't Eva Cassidy have an astonishing voice?
What you say about the internal transformer is only partial correct.
If it was a "perfect transformer" like those tault at college then you are correct. BUT in the REAL world with real components nothing is that simple. firstly there will be a coupling between the primary and seconday windings caused by the phyical spacing between them. ie they are capacitivly coupled, this will let through noise.
secondly the transformer core dependant on its material constuction, will also allow non 50/60Hz frequency coupling.
thirdly any RF on the line will travel on the outer surface of any metal, it can jump across the transformer and capactivly couple itself to the equipments DC line without too much problem.
Since most equipment manufacurer dont "design their" equipment to any great degree of noise immunity or rejection (those that do produce broadcast quality suff at a large price multiplier), we are left with a far less than perfect ("it will do @ that price") level of equipment.
Hence we are left to the snake oil saleman, and the genuine engineer/designer, and ferrite rings, JR & CVH and others to try and solve the problems. This is one of the reason that so much discussion goes on about mains, and cables in general. The others are lack of indepth knowledge, arrogance, ignorance, pride, prejudice, stupiity or any of the other deadly sins.
Incidently the platting of any wire is known to reduce the noise level of a signal on it. Kimber and others have made a lot of money out of this known fact. and not a serpent in sight.
Well, not everyone is like you. I need sound to sleep. Otherwise other distractions keep me awake.
I, Jon and others have answered, or at least tried to answer your other questions. I'm an EE and fully understand where you are coming from and used to be just as sure of myself and just as wrong. Listen for yourself, things make a difference and everyone has different systems, preferences and pocketbooks. You don't seem to understand that the components we use don't exactly match their mathematical models. A good engineer understands the limits of their models and keeps an open mind when things don't work like the math says it should. Better engineers figure out what's wrong with the models, refine them and build better products.
Is adding a $1000 power cord the most cost effective thing to do? It depends on your budget, how much your time is worth, how much custom engineering you are willing to do or pay for, etc. I never claimed it was the best for you. You also may note, that I don't use $1000 cords myself, but I have friends who do and I sure as heck can tell the difference in their systems when cheaper cords are used.
Once again, the environment inside a unit isn't the same as outside, shielding is the most obvious difference. Also some of us have replaced internal point to point wiring with better quality wiring, others of us have bought components with high quality wiring already built in.
Ralph Vaughn Williams spinning here.
"This of course, should illustrate why the myth of "miles and miles" of power lines is just that, a myth born out of ignorance of the actual situation, and the oft repeated mistatements of some who have a hard time actually thinking about AC power issues, and what is going on."
Respectfully, it does not illustrate why one should spend hundreds orf dollars (or ebven over a thousand) on a power cable when one can simply install a good line (ie. 10 gauge) from the mains to a dedicated outlet --make it isolated ground. Total cost about $100 plus electrician. And it can feed your whole system
Even with four #10 gauge dedicated circuits for my system, power cords make non-trivial differences. Unfortunately each device likes different cords. The good news for me is that the most expensive (> $1000) cords that I have tried sound worse to me than the more moderate priced cords (say $300 - $600) in my current system.
Your response completely ignores the aspect of the power cord either radiating, or picking signals from other power cords or any of the other cables, including video or digigtal feeds.
This was touched upon in the referenced URL's. It might help to actually read them.
I am not ignoring that. You did yourself in your post. Read it again. You are arguing that the typical argument about long lines of cable before your expensive power cable is absurd, and then at no point do you say that the reason the expensive cable sounds better is because of RFI. Rather, you explain that there are losses between the mains and your outlet.
Perhaps a fair point if you have a poor installation. But an expensive power cable is an asburd solution.
OK, now you raise the issue of RFI. Frankly, I have yet to read a single white paper describing how a particular power cable filters RFI that makes sense to me (sorry, I had read yours, as well as Caelin's, etc.). My experience is that with an adequate installation all well designed (not too hard) power cables sound the same. Please respect that.
My previously posted and referenced URLs commented on a great deal, of which radiated noise, RFi, EMI, etc were covered. Only in the test of the last post, this one:
do I only talk about the line losses ONLY.
If the supplied post URLs do not make sense to you, then either I have failed at my laymen's explanations, or you are not geting it despite the layman's explanations.
I can respect someone's experiences, but that would have to include on your part having tried numerous power cords under varied conditions, etc., and having experienced a dedicated run on the same system, vs. the additional use of high perforance power cords, as well as having heard numerous power cords on other ssytems under diferent conditions.
Perhaps your mains are relatively clean, and you have really nice cable layout in back of your equipment. Regardless, your conclusions probably only hold for your system, and not necessarily for others.
I have done the above with all types of audio cables and with power cords. Each system reacts differently, and some equipment seems relatively immune to power cord/mains issues, and each component reacts differently to different cords.
As for an "adequate installation" of the mains, this is the exception rather than the rule, and basing your statements on some utopian ideal is not very realistic.
You're absolutely right. There's a load of garbage spoken about mains. See my reply to Jon a few inches up the screen!
I know I learned more about power transmission from your post than I ever knew before.
They all give me some fundamental understanding. I guess I was just like Ole Lund in that I didn't want to believe, but the improvement was so clear that I couldn't deny it was there. I went in a complete skeptic, but now I sit firmly in the other camp - power cords do have sonic significance. And thank goodness for a board like this, where I don't have to listen to a bunch of responses by people who've never even tried an aftermarket power cord and yet firmly deny they can affect such changes.
VH Audio VH-3 Power Cords. Their web address is http://www.venhaus1.com/VH_Audio_Test.html. A two foot PC was $60.99 and a four foot was $64.99.
I use these myself. Impressive cables that do all that other cables costing 10 times the price will do!
i found this site off ebay he does some good mains cable he advertises the basic stuff on ebay but he does do all wattgate connectors etc. i just emailed them they where helpful.
"Amplifiers demand current from the power-line when the capacitors in
their power-supplies become momentarily discharged due to high-current
transients in the music signal. This discharge condition must be quickly
recharged from the power-line, through the power-supply transformer,
during the short periods that the rectifiers are conducting, or a voltage
sag will occur. Such voltage sags can cause audible distortion at the
loudspeakers. If the power-line has significant series inductance in the
path from the power panel to the amplifier (such as a standard power cord),
this can prevent the capacitor bank from recharging in time to prevent a
voltage sag from occurring at the amplifier output transistors. Since
Empirical Audio power cords are low-inductance, the voltage drop across
the power cable will be insignificant during high-current transients,
minimizing the voltage sag. This allows all of the current needed by the
amplifier output transistors and pre-drivers to be supplied when they need it,
resulting in a fast, dynamic response to transient signals. The Grand Slam
provides a uniform low-impedance path for these transient currents, no
matter what spectral content the current has. This is what makes it so
E-Stat pointed to Ole Lund Christensen's explanation. It both sounds logical and an explanation for my experience, at least partially.
I have made a pure silver (4N) power cord with teflon insulation, twisting the pairs and adding double shielding. It had a very characteristic sound, lots of highs (brightness?) and very poor bass. I used it between the wall socket and a power tap for a while.
Then I swapped it with the PC used for the CD player and all the characteristic features became much more pronounced; simply put it, the music became unlistenable. I didn't (don't) understand how changing the order of two cables leading to a CD player can result in a very different sound.
In the first case you'd expect to hear the DIY silver sound more clearly as it affects not only the CD player but the power amp and pre amp also plugged into the power tap. I heard exactly the opposite.
My conlclusion is, the closer the PC to the component, the more it matters. This explains why the long power lines from the power station and wall wiring matter less. It also means that the most important cables are probably inside your components.
I cannot provide a scientific explanation, but Ole Lund Christensen's explanation is logical. The only thing that it doesn't explain why CD players and DACs are most affected despite not having a rectifier...
CD players and DACs include DC supplies, so they contain rectifier diodes. While they do not draw as much current as power amps (and have as much opportunity to generate rectifier hash), they also contain high-frequency digital circuits. If any of the digital noise gets back through the power supplies and is radiated from the power cord, it will make the device sensitive to the type of power cord used within the context of the audio system. The device will also be sensitive to type of power cord if the internal power supplies do not completely block the RFI that comes in on the power cord.
In general, power cords are connection devices, filters, RFI radiators, and RFI receivers. Standard cords are designed to act as safe and reliable connection devices, with little or no design attention to the remaining three aspects of their behavior.
how can PC designers aim for the particular effects they achieve? Is it all just trial and error?
I particularly like Ole Lund Christensen's response. Here is the perspective from a skeptical engineer of exceptional audio components. His GamuT products are universally well regarded.
...what effect an AC cord can have on a Turntable's drive motor.
It's out of the signal loop, right? Yet VPI has introduced an aftermarket power cord for their products.
I was able to drop the noise floor on my 25 year old Ariston when I replaced the wimply lamp cord with a DIY 14 gauge one a couple of years back. Was it simply due to the fact that the new wire had clean contacts and a commercial grade plug? Was it better shielded than the other such that my low output Dynavector MC cartridge picked up less in the way of interference? Don't know, but I experienced an improvement and it didn't cost a lot.
I used to think this power cord/interconnect stuff was nutty until I bought a plasma HDTV. The picture was so bad I was ready to send it back. Thanks to suggestions here, I replaced the power cord with shielded, 12 gauge wire and industrial fittings. Amazing! An s-video cable from Better Cables improved the picture further.
At the point, I figured, what the heck, lets see what happens with the audio gear. I have a decidely inexpensive system, a Foreplay, Art/DIO tied into a PC audio server, a couple of GR-Research speakers in different rooms, and two cheapie Audiosource Amp IIs.
The Audiosource power cords were junk, as in zip cord. Replaced with 14/3 shielded Belden cable, floated the ground, got a couple of heavy duty plugs at Home Depot. Did the same favor for the PC. They had a nice 8-outlet/metal box/extension cord at HD, so I bought that too, on the assumption that everything I ran into it would have the same ground potential. Also replaced that cord with shielded Belden.
Well doggone, up until then I didn't know what they meant by a "black" background. Junk I didn't know I was hearing disappeared. The space between cd tracks sorta hits you on the head, and subtle content (yes, Dianna Krall licking the bassman's ear) became audible.
At less than $2 per foot, this is a hugely effective upgrade. You'd think that you need high end equipement to hear something as subtle as a power cord, but I have to wonder whether the counterintuitive is true, since the cords on cheap stuff are so inadequate.
Given that changing power cords on my transport makes a non-trivial difference and the transport is hooked up to the DAC with glass fiber, I agree, it's weird. Everything counts.
If you search here or on General or PropHeads you'll find a lot of speculation and argument about whether there is a difference and what it might be.
Some ideas that make sense to me:
Some PCs have better shielding from RFI, etc..
Some PCs have filtering of various sorts.
Some PCs have lower inductance so high current draw amps or switching supplies can get all the current they need when they want it.
Sometimes instead of asking how the cord helps the component it's hooked to it makes more sense to think of the cord as helping shield the rest of your system from the component it's hooked to.
Good luck and if you figure it out let us know :)
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