| alvaius |
I am curious to see what other people think of these $200 - $300 power cords on the market and whether they improved the sound.
While I hate to think that properly designed equipment requires power cords that are as expensive as these, I have looked at enough poorly designed equipment [even some esoteric expensive stuff] to see how they can help. I also have to admit, I have noticed a difference, sometimes significant, when they are employed, so........
I was bored about a month ago and looking at my stereo. I proceeded to go out to my garage, grab my 4 guage booster cables, started cutting, and made several 4 foot lengths of 4 guage cable. To the ends of these cables, I attached eyelets. I removed a screw from all my audio equipments cases and attached the cables being careful to ensure I made a good electrical connection to the case. I took the other ends, soldered them together. I butchered a plug and soldered this mass to the ground plug. I plugged the whole thing into the remaining outlet on the power bar for my stereo. Low and behold, it made a difference. The power cords on most of my equipment are 14 guage shielded cords I picked up for about $3-$5, hence the rest of the equipment was not that esoteric. I think the booster cables were around $15 and well that plug had to be at least $3!
I proceeded to call my friend who runs a local high end audio store and told him about my test and told him I would like to try it out with some other "gear". After promising many times to pay for anything I destroyed, he agreed.
So, my Audio Octopus (don't even think of stealing that name!), and $15,000 of Arcam, Classe and Musical Fidelity later, we had a test on our hands.
We initially ran with his expensive power cords and got a feel for the sound. Then we put on my $5 power cords. There was a noticable difference in the sound. Female vocals were just not as crisp and sound-stage did not seem as "open". We did the old A/B thing with one of us switching the cords and the other guessing which was which. I was amazed that we could reliably tell the difference. Not in the first 30 seconds of listening, but after about 5 minutes things just did not seem right with the cheap cords.
We then installed (I did actually), the Audio Octopus (TM - well maybe one day!) and started swapping in and out the cheap and expensive power cords. After about an hour of this, it was obvious that if the expensive power cords were having any effect, it was minimal.
I should not that in all cases, I was careful to ensure that power cords did not run parallel to interconnects for any length.
I am curious if anyone else has tried this?? I think you still need okay quality power cords and shielded is definately a good thing. I hope that other people try this and tell me how it goes.
From simple minds come great products........ |
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| sam9 |
Ok, here's my take. If someone is willing (and able) to spend $300 on a power cord they are most likely willing (and able) to spend $3,000 on a piece of audio gear to connect it to. At this point it means you are buying some pretty high-end stuff. Definately not Bose or shelf systems!!
Let us suppose that a power cord can make a difference. Now let me pose this question: How in the world can some one build a piece of gear (say a power amp) that sells for $3,000 and NOT attend to the basics of RF filters, PS design etc that would make it it unneccessary for their customers to incurr the added expense of a $300 power cord?
Looked at another way: IF a power cord can make a difference in sound, it seems more likely that the component that needs it most is a mass market (Sony, Pioneer ...) AVR not a Krell or CJ monoblock! |
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| seangoesbonk |
One of my favorites...
You have thousands (literally) of feet of crappy cable running from where the power is generated (hydro dam, nuclear power plant, etc.) to your house. Even if you could use a "perfect" cable for the last 6 feet, you are only changing 0.0001% of it's path. Even a $1000 cable is not perfect. Is a 0.0001% improvement worth 300 bucks? Not in my opinion. That $300 is better spent elsewhere. |
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| jackinnj |
drinking early.
I love this, they will soon be weaving power cables with teflon insulation for the "node" on that pole outside to your switchbox, then there will be Allen Bradley gold-plated, vacuum enclosed circuit breakers in the distribution box. I can see that illustrious firm Harvey Hubbell (yes, it does exist and makes all the power connectors used in hospitals, you don't want someone frying you when your on the O2 -- these are the guys who make the spark resistant receptacles) making gold-plated AC receptaclesand plugs. Given the crummy performance of the stock, I wouldn't be surprised if they didn't start taking out ads in Stereophile, etc.
Sometime you should walk around the property with a spectrum analyzer and see the **** that's on power lines.
Sometime I am going to go around and determine all the EMI lurking in my personal domicile, it is, in fact, the source of all grunge.
Do those suffering audiophilia ever go to live classical concerts? |
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| dorkus |
| quote: | Originally posted by seangoesbonk
You have thousands (literally) of feet of crappy cable running from where the power is generated (hydro dam, nuclear power plant, etc.) to your house. Even if you could use a "perfect" cable for the last 6 feet, you are only changing 0.0001% of it's path. Even a $1000 cable is not perfect. Is a 0.0001% improvement worth 300 bucks? Not in my opinion. That $300 is better spent elsewhere. |
yeah, that is the logical answer. but as all of us know very well now, the logical answer isn't always the right one.
i hate to admit it, but power cords do matter. i can change the sound of an amp, even a whole system, by changing the power cords around. it shouldn't make such a huge difference but it can. of course, you need a system with very good resolving powers to really hear it, but once you get to that level, everything makes a difference.
if you doubt me, try it yourself. you will find that in a great system, the power cords can make or break the sound. i never thought much of cords until i tried it myself, and i was shocked. i told this to my friend, who then told me i was full of $%!*, but then i swapped cords on him in system and all he could do was drop his jaw and say "what the heck... that makes no sense at all." he heard the difference to say the least. whether you will depends on a lot of factors but some people definitely can.
whether or not a $300 cord is worth it or not is a different question. the price has nothing to do with it, and there is no formula for the "perfect" cord. some cords sound better with one amp but worse with another. it's all about synergy. the reason they cost $300 is that most of them are hand made in very small quantities, the volume of sales is very small, and in order to make any money at all they have to charge a lot. the actual materials don't cost a whole lot, everyone knows that. you are basically paying the person for the time they took selecting the materials/design and putting it together for you (at least in the case of the honest small manufacturers - can't say the same for a lot of big "audiophile" companies). it is very possible that a $5 cord will sound better than a $300 cord, but i doubt they will sound the same, or if one will always sound better than the other in every system. for some, the $300 cord will sound best, and to them that is enough to justify a purchase. oftentimes you need that $300 cord to get the best out of a particular component or system.
the other day that same friend of mine came over; he enjoys my system for for its fast, forward, and direct presentation. i originally was using a Home Depot power strip to supply my entire system, along with a TG Audio cord on the amp. since then i had switched to a very expensive set of power strip and cords i had received for review. he listened to my system, and seemed a little disappointed, but did not know quite what it was. i told him i mellowed out my system a little since last time, and he said, "yeah, but i miss the bright in-your-face sound." so i switched back to the Home Depot and TG Audio cord and voila, back was the sound he liked so much. he could not believe the difference. but it was clearly audible, and he was back to grooving to the tunes the way he remembered them on my setup. this from a person who told me just a few weeks before that i was full of $%!* ;) |
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| dorkus |
| by the way jackinnj, i used to be a classical musician, so not only have i gone to live classical concerts but i've played in a lot of them. i don't buy $300 power cords though since i get to use them for free as an audio reviewer. :p |
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| Peter Daniel |
Dorkus,
I totally agree with your both posts. All I can say to all in doubt and theoretical thinkers is to go ahead and EXPERIMENT. |
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| Bill Fitzpatrick |
| Don't be sad, dorkus, even though you friend will no longer tell you that you're full of "$%!*", which I believed is really spelled "****", I'll be glad to tell you whenever you feel the need. |
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| dorkus |
thanks bill. i'm assumming you don't care to try different power cords, or you have and didn't hear a difference. if it's the latter, you are lucky, as it obviously saves you a lot of time and trouble (and often money). if it's the former than there's no point arguing anyway.
i should add that many components do not seem to be affected by the type of power cord. if this is the case, then you are lucky as well.
HPotter: thanks for the vote of confidence. :)
sam9: power cord selection often has nothing to do with RF filtering or anything of the sort. i can't explain the mechanisms involved (i don't know if anyone can) but it is not as simple as some single electrical property. the reason it may not help as much with a Sony or Pioneer is that those components are simply not as high in resolution, and won't reveal subtle differences. this was the case for me when my system was more modest, and i could not hear much difference at all between cords. as i improved my system more and more, it became more important. that said, in a good system, even a cheap Sony CD player can have its sound altered by changing the cord. |
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| AudioFreak |
Dorkus...
If the power cord makes an audible difference then either the original power cord was unable to statisfactorily supply the voltage/current you require (shouldnt be the case assuming you use a cord rated for the same output as the socket you plug it into) or far more likely the power supply is not well designed. Everyone who talks about directionality in cables ... I might concede that it could make a difference in interconnects etc but forget about it in the power cord you've got miles of wire going back to the power station and i'm sure they didnt take any notice of the 'directionality' of this wire when laying it down. |
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| dorkus |
audiofreak,
try it yourself. like i said, if you can't hear any differences, then you are lucky. :) you don't even need too much of an open mind to hear a difference if it exists though, just look at my friend. he still says he doesn't see why it should make any difference but he admits it is there. he said the same thing about digital cables too, then i showed him how i could "ruin" the sound of my system with the wrong SPDIF cable, and he again was flabbergasted. incidentally, we preferred my $20 Belden 1505A coax w/Canare RCAs over the $500 "audiophile" brand. :p |
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| AudioFreak |
| Like i said above dorkus... design the power supply properly and the power cord really wont matter so long as it is the correct rating for the socket... trouble is very few people know how to design a power supply correctly. I'll just about guarantee that the power supplies in said equipment are not well designed. Most SPDIF outputs these days are not well designed either earth loops are all too common and as always given the square nature of the signal the reactance can have a massive effect by rounding edges and causing ringing both of which are likely to be audible to some degree. |
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| dorkus |
| I have a ME Sound 550 II amp with the high capacitance option (i think about 150,000uF total). you should be familiar with the ME, you Aussie. :p the power cord DOES make a difference here, this is where my friend heard it. i think Peter Stein's supplies are very well designed though, wouldn't you agree? oh, my friend has a Krell KAV300i integrated, and while i don't like the way it sounds at all we could hear the difference there too. i don't think the Krell's supply is that great but it is at least ok. on the other hand, i've seen amps with mediocre supplies that are not affected by the cord. weird eh? |
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| AudioFreak |
| I know about ME and yes they are not bad for what they are but I wouldnt say they are anything worth writing home about. They use the right types of components in the power supply c-core transformers multiple values of caps both electrolytic and pp but they are still just a standard transformer + bridge + caps power supply and ultimately this is still a long way from a well engineered power supply unless PSRR of the amp is very high some residual effects will still get thru ... also these are class AB amps where the effective power supply resistance on peaks can severely effect the sound the power cord is part of that resistance/impedance granted the higher capacitance will help but I still stop short of calling this good engineering it's simply better than some other designs out there. ME also pride themselves on using a protection circuit that uses more devices than most amps now i dont know about you but I wouldnt say that is something to be proud of. As for Krell well lets just say they dont rate very highly in my book. Try a SE amp with truly constant power draw with a well designed power supply and see how much difference the power cord makes then. As I've said before if the power cord makes a difference it just highlights a weakness elsewhere in the equipment. |
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| Circlotron |
Personally I wouldn't buy one because I don't believe they would make a measurable difference, and here's the reason why they wouldn't in *my* case.
The Placebo Effect is a well documented phenomena, not a hoax or a fraud, whereby for example if a person thinks they are getting some wonderful medicine they will often show signs of improvement even though what they swallowed was coloured water. Some not completely understood action occurs in or body and the expected result occurs. This is documented scientific fact, not feeble nonsense.
As far as these enchanted power cords are concerned, who's to say that if someone plonks down their money and plugs in one of these things, and because they are *expecting* something good to happen then something pretty amazing happens to the ear-brain combination (hands up who knows absolutely everything about this, huh?) and the listener really does hear things better, even though the sound coming out the speakers is unchanged?
If there is room for improvement in the way we *perceive* sound, maybe these power cords provide the *expectation*, therefore the *means* to achieve this. As I said, I don't think they would improve the measured sound quality.
GP. |
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| AudioFreak |
| I couldnt agree more. |
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| dorkus |
audiofreak you may be right about it not making a difference w/SE amps, but a lot of us don't use SE amps. =p i for one can't deal with the inefficiency, my electric bill is high enough as it is here in the city.
i'm not arguing with you that a "perfect" supply would make the cord irrelevant. but most amps don't have a perfect supply, partly because it is very expensive to make and partly because some people don't know how to make them. the reality is that most of us are stuck with only "good" supplies, and in that case a cord is a worthwhile factor in sound quality. even if you think you have what you think is the perfect supply, you may still hear a difference. have you even tried it? so far everyone who has debunked cords has theorized but no one has stepped forward to say they can not hear the difference after trying it. try first, then decide for yourself!
the ME is not a perfect amp by any means but i think it is very good and better than 90% of the amps out there, and nothing to scoff at. and yes, the Krell sucks. :p |
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| dorkus |
my friend heard something "wrong" w/my system even w/o me telling him i switched out all my cords. we listened to track after track, i didn't say anything, but he kept saying, what happened to the sound? it was the power cords. he refused to believe it but what can i say, the sound changed.
try it before you debunk it! that's all i ask. if you try some cords and don't hear a thing, then there is no argument! |
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| nk2j |
beauty is in the eye of the beholder...
music is in the ear of the listener .. |
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| Bill Fitzpatrick |
| Again, as has been said, if you have components that are senstive to power line garbage, cables with noise supression capabilities might help. So would a handful of capacitors and inductors installed at the power line inputs of the offending equipment. Isn't this DIY? Get out those soldering irons and install those $1 items. With the money you save, you could take me out to dinner. |
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| dorkus |
bill, yes capacitive cords can provide some filtering, but it is not that simple. try different cords. no filters or anything else, even measure the capacitance if you want, but just a cable w/o filters. make your own, or go to a dealer and see if he'll lend you one of those $300 rip-off cables. then let me know if you hear anything. maybe you won't, maybe you will! but it is not as simple as everyone makes it out to be. just try, and let us know what you find.
p.s. installing filter capacitors in equipment sometimes does indeed reduce the influence of the cable, but it does not eliminate it in my experience. |
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| Peter Daniel |
| quote: | Originally posted by Circlotron
Personally I wouldn't buy one because I don't believe they would make a measurable difference.
As I said, I don't think they would improve the measured sound quality.
GP. |
This is not about what you believe or think, but what you hear. Ever bothered to check it out?:) |
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| Duo |
Hey, did you guys ever think to imagine the possibility that a power cable must undergo "varying" amounts of current? Think of this: You run an amp at maybe 300W from a power outlet, chances are that your cable has inductance and chances are, the variance in power draw can be absorbed in the cable before the amp gets it's current. Also, think about the skin effect. Cables don't really need good filtering (as this should be done inside the equipment as explained by people earlier), but they do have to be able to conduct high current transients to the amp. Also, the thousands of feet of junk cable comming from the power plant are run at thousands of volts and a low current. The high voltage instead of high current causes less inductive losses in cable, also, many transformers in the line are quite good at filtering garbage out of a signal since the inductance is set at it's level by the 60hz and the core saturation effects, it takes a lot of energy for other frequencies to be injected since the inductance isn't very sympathetic to them. This also occurs in larger transformers in amp psu's, they help block high frequencies and interference. The only major problems for current handling are the crappy 14 or 12 AWG wire running from the breaker panel to the outlet to the equipment cabling. This wire handles high current loads exceptionally well IF the loads are static like a toaster or a lamp. Also, when you turn on the toaster and lamp, there is a huge current surge through the inductance of the wire, that's why the lights dim out quickly when you turn on a toaster. The same thing goes for the amp in that it's like a dynamic PSU for you speaker, always turning on and off or in between causing a dynamic load at the power supply and thus into the power wiring in the house. So... Think of it this way, what would happen if you could have your toaster turn on and off 5 or 10 times a second???? just like some music beats, your wires lose a lot of energy as magnetic flux
around the house under dynamic loads! So my point is, go for the Octopus Cable idea, use heavy wires for dynamic loads and don't bother to worry if it's not well filtered!!! This also goes for speakers which is why a speaker cable only needs 400 or 500 watts to get hot if it's 14 gauge on low frequencies and about 1000 watts at high frequencies!!! Also, think of current or voltage lag, this is what an inductor causes, and it's the weak point in audio cabling! Now... I could write a book about this, but I'll stop now cause most people don't generate this much writing in less than three posts! |
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| Duo |
Okay, I'm back again with more babble!:D
I was reading this thread a bit more thoroughly and noticed someone's ideas about the placebo effect. I totally believe that
the placebo has some, if not all, of the effect on the listener, depending on how willing they are to put their money where their mouth is. I do have to make a point though, if you're willing to spend 300 or 600 or even 800 dollars on a power cable just to satisfy yourself and you think you can afford it, then go ahead. There's nothing saying that the placebo effect is "bad" just that it takes the place in the mind where the truth should be by ultimately satisfying the user of the product. There is something to be said about high price power cables in that some actually do sound better, but a lot of the misunderstandings occur because of pure negligence. What I'm saying is, for example, a person A may buy his fancy cable for a class A amplifier and person B will buy one for his AB amplifier. Person A may notice less effects than person B since his amplifier loads the power less dynamically. In other words, class A amplifiers don't change their current draw as much as AB. Another part people fail to consider is that the power supply for person A's amplifier will tend to have bigger PSU caps and thus they slow down current transients before the reach the power supply. This also causes person A's amplifier to have even less dynamic current draw. Since person A's amplifier has less dynamic current draw, his cable ends up transforming less current change into magnetic flux. In person B's case, his amp has a more dynamic load on the PSU and smaller caps, both contributing to a more dynamic current draw. In this case, person A begins to argue with person B that the cable wasn't "as" worth it as person B's. This leads to widespread discussions between people who are willing to debate that the power cable makes a difference. So here's the negligence again, person B may not realize that person B's amplifer is push pull, or, if he does, he doesn't understand it's current loading effects. This negligence thus leads to the latter arguement!
Next point:
think of the difference between "filtering" and "current handling."
Many people, yes even the best, neglect to think about "what" causes a cable to be better than another with their system. They simply are left to believe that the cable is, "just", BETTER, not actually having any real reason to state about their cable's being better. This can couple with the person A to person B negligence within the general population of audiophiles to cause even more catastrophic events of debate.
Next Point:
Go and survey as many audiophiles as you can and find out how much "real listening" experience they have, as most have very little... I believe that "good" audiophile should know the difference between a good piano and a bad piano simply by listening to them. A "good" audiophile should have gone to a studio or hall or whatever and listened to as much live music as he can. Also, this audiophile must audition lots of equipment before he can begin to make assumptions about it. Another thing that may make a good audiophile is to be a musician. A violinist must be able to judge from hundreds of levels of pitch and be able to tell if a note is sharp or flat and how much so. This musician may develop exceptionally good abilities to "listen"
While another point I must state, good hearing is only have of the game. If you can hear well, you mut also listen, which takes much practice and fine training. This simply leads back to what I said about auditioning gear, it's to get the "feel" for the sound of certain types of equipment, also, to know what to listen for when listening.
Next Point:
When coupling of knowledge, hearing, listening ability, taming of the ego, elimination of the placebo effect... Only then can you even begin to know whether it's the power cable that's making the difference, or your tricky mind, or just that fact that the weather is good. Only then, can you scrape the surface of really telling "THE DIFFERENCE"
So, generally, I hope I make my point clear. Don't be undereducated unless you want to perform inaccurate asessments.;) |
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| Duo |
| Jeez, I think I just defied my statement about writing a book earlier. Sorry guys, but my opinions have lots of details that I hat to leave out of the picture. |
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| Circlotron |
Why do people try to justify the purchase of an expensive power cord by saying "The sound is so much better". If they just came out and said "My new power cord puts the icing on the cake when I'm sitting listening my hifi. I enjoyed listening to it before, but now even more so." well that would be fine. Nobody buys a painting and hangs it in their loungeroom for it's technical merits, but for it's aesthetic appeal. If a nifty power cord has aesthetic appeal too, because of it's superior materials and construction - great! I'd buy that idea at least. If you enjoy something purely for it's own sake, that's not a crime. But to justify something like that in purely logical terms sounds silly to me.
GP. |
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| Duo |
I agree with Circlotron on this one. That's a really good point.
I would agree that, it may make the sound better, but it's not the whole system in itself. It also may be pleasing in the same way as a piece of art hanging on the wall! Just "AN ADDITION" to something that's already good!;) |
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| dice45 |
To those unbelieving Thomases,
this is a DIY forum. You have forgotten that!? May i suggest that anyone sceptic that power conditioners and/or power chords have sonic influence goes ahead and tries it out himself!
For instance: grab some solid copper wire of appropriate Xsectional area, insulate it with heatshrink, twist it, maybe add a 3rd cable for protection/shielding ground, mayb add a shield braid (suiting the cable religion you are following) mount two plugs on it and try it out for a while against the cable currently in use.
Or:
hook two filtering chokes (speaker XO inductors maybe!?) in the two power lines of the power chord and 5µF/240V ac cap in between after the chokes (to form a low pass) and try it out .
Or:
take a huge industrial insulation transformer (ratio 1:1) hook it between power outlet and your amps and try it out
Or:
combine the ORs above. You ll be surprised! Provided you are not the victim of the negative placebo effect ( it will not be what cannot be).
One thing is sure for me: i would never spend more money than the raw materials cost and i throw in my time.
I was hoping to learn something new about power chords in this thread -- instead i find crusader talk for and against it. How boring!!!
Alas, my contribution: any of the ORs above made nice improvements for me and in my system. My power chord is unshielded, heatshrinked, 3-line enamelled copper wire of 2.5mm^2 Xsectional area. And my insulating trannie has 5KVA and is only running in the winter (dissipates too much heat, pulls 1A ac without load). And the speaker XO in the power line was a nice smoother when i tried it.
Before i forget it. In times of changing the power chord's position frequently, i use ordinary, multistranded PVC-insulated PC. Solid wire is not meant to be bent more than 15 times. And its use is illegal for power chords over here. Probably in any other country too. Forbidden fruits taste best :) |
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| nar |
For the starter of the thread....I think some type of high quality amps need some high quality ac cords.The only thing thats stays is to know if: 1)Do your amp really need it,or not/vs. design
2) You can DIY that kind of cable,so i think it is not worth buying it already made.Too expensive in my opinion ;)
Regards
Anael |
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| Duo |
Hey dice45, why does your 5kva 1:1 get warm???
I have a 5kva xformer and I can run it steady at about 3 kva
and it takes about 5 hours to even feel noticeably warm to the back of the hand... What gives? |
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| Circlotron |
| quote: | Originally posted by dice45
Forbidden fruits taste best :) |
Identical reasoning to: "Fancy power cords sound best".
No difference in either the fruit or the audio hardware, just the state of mind of the eater / listener. Thank you for that.
I rest my case. ;)
GP. |
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| AudioFreak |
| quote: | Originally posted by dice45
my insulating trannie has 5KVA and is only running in the winter (dissipates too much heat, pulls 1A ac without load). |
Assuming that is a toroidal transformer...
That's either an extremely poorly designed transformer or it has a fault even at 5kVa rating it should only be drawing a couple hundred mA at idle.
If it's EI, R or C core i could forsee that kind of idea current. |
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| Circlotron |
Is it a 120v or 240v tranny? That woud make a big difference to the current! I have a 5kVA 240v EI iso-tranny feeding my bench at work. No load it only gets ~20 deg above ambient after running all day. I'll measure the current tomorrow if I can.
GP. |
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| promitheus |
If you think the last 1-2 meters of your power can make a change than maybe you found something new. What about the rest of the kilometers to your house ? Don´t they bother you ?
Please.....give me a break.
If you wan´t an improvement isolate your system from the mains.
Use a transformer and after that a good filter. That realy makes a difference.
but uuppps I guess this was bad for some people trying to sell some cables.... |
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| dorkus |
nobody here is trying to sell some power cables. i happen to use some very expensive cables because they were provided to me and they happen to work very well, but i did not pay for them. had i not received them for free, i probably would have never tried them. in fact, i have made my own power cords from raw materials in the past. the fact is that the "rip-off" cords often work better in my system. i'm not saying that someone couldn't build them for $20 themselves, but again you are paying for the time and trouble someone took to come up with a cable that works well. i'm talking about small honest companies like TG Audio, Power Chord, Ensemble, etc. etc. i'm not talking about AudioQuest or Monster here.
while an AC cable is obviously not in the direct signal path, the power feeding a system eventually becomes part of the signal. like any signal it can be modulated, and that modulation is audible. it does not matter if there is 1000 miles of cable before it, the last 2 meters can still change the way the power is modulated. just think about distortion in a system. we sit here tweaking our JFET buffers and Aleph amps to reduce distortion from .05% to .01%, yet the distortion of our speakers is 1, 2, often even 10 or 20%. why would .05% to .01% make a difference then? it still does. the same argument goes for the power cords. YES there are better places to spend your money and i am not telling people to go out and buy $500 cords but i'm simply saying not to dismiss them because you think they're irrelevant and the people selling them are con artists. that is simply not the case. there are many cons in the wire business but that does make the entire business a fraud.
i have no interest in the wire business either. i did not pay a dime for the majority of my cables. i use whatever works best. my editor sends me boxes of cables from time to time so i can play around and see what works. often i'll try a cable, having no idea what it is, and it'll sound great. just the other day i looked one of them up (an interconnect) and found out it cost $500. i couldn't care less how much it cost and i would never pay $500 myself for it but hey it sounded great, and my friend concurred having no knowledge of the value of the cable either. this is how i found out about power cords, i did not give a rat's a$$ about them but i had half a dozen of them lying around so i started playing with them. initially i heard nothing, but then i left them in my system for a while, then switched back to my old cords and WHOA did the sound change. and i'm not saying expensive is better - remember my Home Depot power strip beat out the expensive "audiophile" one?
oh well, i think i will just give up arguing here now. no one seems to want to try it. they keep theorizing and theorizing but no one has come out and said "look, i tried it last night with a few different cords and it didn't do sh!t." i would be perfectly willing to accept that as an answer, assumming the person made an honest attempt to experiment. but instead everyone uses the same "logical" arguments over and over again. mind you, people could have said the very same thing about interconnect cables a couple decades ago, but we all know better now (or at least i hope we do). |
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| dorkus |
here is what is in my system currently.
the Ensemble power stuff from Switzerland is beautifully made but to be honest i'm not so sure it sounds all that great in my system. i'm still in the process of evaulating it. the big box in the front is a digital isolation transformer for transport + DAC.
other cables i have that seem to work well are TG Audio HSRii and Power Chord. my friend actually has the Power Chord at the moment.
again, i'm not advocating anyone go out and buy these things but if you have the opportunity to try it, go for it. you may be surprised, or you may not be. but that is the whole reason we are here, to try new things! |
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| Peter Daniel |
To interrupt crusader talk for a moment I throw some obsevations of my own.
Years ago I was also sceptical how is it possible that the cable change after the fuse box or even more, the cables you connect to AC receptacle in the wall can make an audible change.
My first improvement was done after influenced by an article in Sterophile (and I believe that everything they write about is true;) ) I changed all in wall wiring from my fuse box. I run 3 separate, dedicated lines to my system, 30A ea. with gauge 10 wire. One line for left channel amps, second for R CH amps and third one for sources. I used orange, hospital grade receptacles from Hubbel, available from Home Depot for $10. The biggest change was more tight and better defined bass, which was recognized even by my non audiofile brother in law. Highly recommended.
I'm not really crazy about AC cables to the amps and I'm using the same stuff I put inside the walls which is gauge 10 solid copper wire. For sources I'm using Audiquest Type 4 speaker cable as AC cords.
Some of you might noticed that I got interested in power regeneration recently. However, I was not willing to spend $800 for power conditioner (and certainly not $300 for power cord) so I experimented with computers UPS. Some of you expressed opinion that it would not work with audio because of the crappy build. I bought mine surplus for $60 and it's made by Best Power Technology. It works quite well with my sources. Now some observations. Initially I was using A75 amps for mids and highs. The optimum setup was like that: DAC, transport and active crossover connected to conditioner and conditioner run from batteries ( wich lasted for 80 min), Enokido plug connected to conditioner and my home made capacitor plug (influenced by Harry Haller) connected to the wall. That was optimal setup. Now for anybody doubting in Power Cords I made another experiment: I was using 14 gauge regular cord to conditioner and thought that making it really short would improve situation, so I cut it to 1' lenght. Guess what, it sounded worse, also 16 gauge cord to conditioner sounded worse (in case conditioner was not run from batteries).
After I built my Aleph and put it in a system it appeared that conditioner sounded better when run from the AC and not batteries, also I had to remove H.H. cap from the wall and connect my CD Transport directly to the wall as well.
All that experimentation is very time consuming but it is also very rewarding and listener educating experience. Through all that time I also improved my listening abilities.
It really makes me angry when somebody tries to figure it out theoretically without making slightest effort to experiment. Those guys are to me, like blind people trying to talk about colours.
;) ;) |
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| jgwinner |
I don't think it makes any difference other than asthetic (as noted earlier), and the mechanical properties of the plug might make for better conduction.
| quote: | | It really makes me angry when somebody tries to figure it out theoretically without making slightest effort to experiment. Those guys are like blind people talking about colours. |
I see this type of quote over and over, and it sounds good and true. However, it's missing the point to a double blind test. Everyone agrees that a power cable will sound different. It just won't BE different. :D
== John ==
P.S. I'm a "Prophet"? No way! |
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| phishead8 |
It seems to me that there have been many different "hocus-pocus" ideas thrown around on this site. Everything from directional wires to magic interconnects. I've heard people describe their own AB tests, which support the claims of these fixes, while others have linked to AB testing which yeilded a null result. Obviously, this is not something which can be settled easily. It seems that the only thing to do is find out for one's own self. But, on the other hand, I simply don't have the time. I find that anything DIY takes about 10 times longer than I thought. Between school and work, I can barely find the time to warm up my soldering iron. Trust me, I am a scientist at heart and by profession. But, I cannot chase every idea that someone waves in front of me. I do not, however, automatically dismiss these ideas. I just place them in my "highly-speculative" pile unless a solid explanation can be given. Magic AC cords go in that pile.
As a scientist I've learned to try and explain the behaviours of my surroundings. I encourage anyone who has noticed the differences in AC cords to venture an explanation. C'mon the worst that can happen is being wrong. I know I've walked that line many a time.
-Dan |
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| Ian Macmillan |
Just to add a little more grist to the mill... I've tried several different types of power cord and most make little (positive) difference. However, in my experience Kimber cable is an exception and I use these on all my Hi Fi components. The magnitude of the effect varies depending on the component in question, but the result has always been positive.
I don't think there is any mystery, snake oil or whatever here. There is a perfectly sound scientific reason why this stuff works. It uses copper with little impurity, insulation with good dieletric properties and most import has a particular weave that cancels RFI. I beleive the latter is the most important aspect and is the reason why a little on the end of a long length of very ordinary wire makes a difference: it acts as a filter. The longer the Kimber portion, the greater the effect. Very good for equipment that outputs noise on the supply too, e.g. old Linn valhalla boards. Anyway, best shut up as I beginning to sound like a salesman (which I am not, neither do I have any affiliation with Kimber).
Doubtless there are other products (chokes and the like) that have the same effect and they may be cheaper too. I can't speak for these but I know I would not easily be parted from the solution that I have discovered through much experiment and listening (Kimber).
Ian. |
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| alvaius |
It typical diyAudio.com forum tradition, this topic has gotten completely off topic so I will try to bring it back.
First) Don't knock it until you try it. I can remember in 1982 people saying these "new" CD Players were far superior to records and essentially perfect. Well 20 years later this bulletin board still exists to prove that statement wrong.
Two) To the poster who said what about the other 1,000 feet of **** before my stereo. You are right to some degree. However, keep in mind, that the power bar you are using, or the wall outlet, whatever, is the single point of interconnection of all your chassis grounds, not to mention your actual AC power connections. We all know about star grounds for analog. This is really no different. Perhaps I should have said that. My whole goal with the Audio Octopus, was to create as perfect a star ground for the chassis as I could.
Three) We did blind tests. Not only could we tell the difference, but we could tell which was which, all the time. I must admit, I could not tell in the first few seconds, but after 5 minutes, I always knew.
To some degree audio designers do their best in power supply design to remove the **** coming down the line. But what about the **** that couples through the chassis into the audio path? Or from the chassis into the power supplies, etc. I can't say that is as well conceived. I have seen some very good equipment with little signal conditioning to remove **** on the chassis ground from the analog signal ground. A $2,000 amplifier had a funny ground loop that was just perceptible created by the Cable TV connection to my television, the audio connection from my TV to my AV processor, and my AV processor to my amp, and my AV processor to my VCR. Cut any connection and it would go away..... as it did with a little bit of circuit modification. |
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| dice45 |
Ian,
i know several guys using Kimber teflon-insulated speaker cable as power chord and swear by it.
Unfortunately i cannot try it out. have not enough left of it.
AudioFreak,| quote: | | Assuming that is a toroidal transformer... That's either an extremely poorly designed transformer or it has a fault even at 5kVa rating it should only be drawing a couple hundred mA at idle. If it's EI, R or C core i could forsee that kind of idea current. |
it is a transformer intentionally bad designed to cut off the HF. The tape plate on it says 120/240 : 120/240Hz, 5kVA, voltage depending on windings wired in series or orn parallel.
It works nice as an ordinary trannie at 170V and the huge EI core (M-Core?) is driven into heavy saturation at 240V. I have looked on it on a scope: a pure sine wave at the secondary, no matter what the load might be, no matter what garbage you try to inject t into the primary.
Such trannies are used for industrial computers to protect the computer from huge power-switch-on surges thru the power net, and also to protect the good environment from the evil computer.
They are at -140dB suppression at 1kHz, so i was told. They act as filter. The bigger the better, but put them on rubber feet. Mechanical hum noise, and the term noise is justified here.
One thing left to be tried out here: on 240Volts, i can wire the secondary's center tap to protection ground (provided protection ground is clean enuff, else bury a copper rod in the garden and wire the center tap to this rod) and let the power of the audio system be symmetric +/- 120Volt. I got hints indicating that the power plug turning game is futile then. Curious. At the moment turning the power plug makes a small but audible and pleasant difference (some European power plug systems, the German and Austrian among them but not the Swiss one) allow the plug to be plugged 3:00 or 9:00 position so the hot pin /ground pin can be swapped). |
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| haldor |
Hi alvaius,
I look at this from the other end. I agree with the posters who dismiss the effect a 2 meter line cord could have on the AC power delivered to an amp at the end of a 1000 kilometer power transmission system. However there is the issue of noise being conducted/radiated out of equipment that can then be coupled into other gear in the system.
Most power supplies are going to draw low duty cycle, high peak value current pulses from the AC mains It is not unreasonable that the EMI generate by these current pulses in the line cords could influence nearby equipment. The typical AC line filter is designed to meet FCC or CE interference requirements which is limited to a minimum frequency of 9 KHz for conducted and radiated emmisions. You can conduct or radiate pretty much however much power you want below that frequency and still get agency approval. Noise below 9 KHz is not likely to interfere with other people which is the point of emmissions regulations, but who's to say it won't effect your own stuff.
Check out the FCC regulations 47CFR15 for yourself if you would like. http://frwebgate1.access.gpo.gov/cg...action=retrieve
If your system is anything like mine then you have a rats nest of power cords and interconnects jumbled up in back and who's to say how much EMI is being coupled from power cord to power cord or to interconnect cables. A foil shield is virtually transparent to low frequency EMI. The only thing that will stop EMI is distance or thick metal (steel conduit or double braided shields are nice). Balanced interconnects will help prevent coupling to the line level interconnects, but will not stop coupling through the line cords.
I am an EE by profession and tend to the end up on the objectivist side in most debates, but I can see legitimate concerns that could be addressed in specific instances by power cords. There is undoubtedly some placebo effect going on, and it's possible that just unplugging and plugging a cord in could change things. It is also difficult to eliminate other variables when swapping cables. Every time cables are swapped, it is possible you are also changing the orentation and relative positions of cables which can effect the magnitude of noise coupling problems.
My point in all this is that if the positioning of harnesses inside an amp can effect the sound quality (which I have observed), then perhaps specific line cord design can make some systems less susceptible to interaction between cables. If noise coupling via cables isn't a problem in a particular sound system, then the line cord would be a lot less likely to make a difference which also agrees with what Dorkus has observed.
We don't need to be looking for reasons to beliitle or bash on each other. I admit to chuckling about some of the claims I've seen posted for various tweaks, but that doesn't mean that I dismiss reports of audible improvements from changing cables out of hand.
Phil |
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| mrfeedback |
Hi All,
Equipment with detachable two wire power cable with fig 8 end (ala portable radio cassette power lead ) allows connection of 240V in either of two polarities.
I have observed polarity to cause a small audible change in every piece of gear that I have tried this on, including radio cassettes, cdps, shelf systems and amplifiers.
Are the replacement high quality power leads reliably wired in correct polarity, and when plugging them into their systems, are listeners installing them in reference polarity ?.
Silicone insulated heavy guage 3 wire industrial power leads sound very good IME, and very flexible too.
To you naysayers - do not criticise that which you do not understand, or tried.
Eric.
PS - There is not much point in the naysayers referring to double blind testing, because DB testing is hopelessly flawed in the usual implementation, so of course the results will tend to 50/50 results. |
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| dice45 |
Phil,
agreed. although i wonder why my fancy isolation trannie makes the relatively biggest difference and not the power chords. But your thoughts sound logical to me. And, distance indeed is better than any shielding.
Eric,
No need to re-heat a calming-down discussion. And, there is a Lenco TTquestion for you (and Jocko) on the Analog forum. ;)
Agreed about polarity, that's what i meant with the power-plug-turning game in my post. No, polarity is not observed by most manufacturers. 1 exception i know of:: Switzerland, their standards require it. Right polarity can be predicted by unpluggin any interconnects and speaker cables and measuring housing ground currents with a µAmperemeter between devices. Plug polarity with lower and faster decaying current is the right sounding one. Do this potential/charge comparison between all devices. |
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| jgwinner |
Dice:
Are you saying PLUG / household current polarity, or sound polarity? |
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| haldor |
Hi Dice,
Actually I would expect that an isolation transformer could be better than a cable. I use to install process control systems and learned pretty quickly the value of the Sola UltraIsolation transformers in an industrial setting. These things work in both directions, noise doesn't get in and it also doesn't get out.
Interesting about your line cords not being polerized where you live. In the US we have probably the worst power sockets anywhere, but at least they are polarized now (didn't use to be). With any recent (made within the last few decades or so) line cord there is no way to get the hot and neutral reversed on most peices of gear without snipping part of the plug off.
Phil |
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| jackinnj |
I did, it's wonderful watching the havoc wrought when the air conditioning turns on, when the furnace blower turns over, etc.
Before spending a fortune on power cables, consider spending a modest sum on some #4 braided copper cable and earthing the system. Also, make sure that the ground at your distribution box is truly at ground potential, that the ground at your outlet box is at ground potential. Elsewise you are just hooking the system into an erratic antenna. I would venture to guess that a good ground would have the same ameliorative effect as a power connection measured in dollars per foot.
At one time the ARRL suggested driving a 6 foot length of steel pipe into the ground and attaching the ground here. Of course, the immediate area surrounding the pipe had to be soaked with copper sulfate and water. |
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| GRollins |
<i>Sigh...</i>
The last time this came up--sometime this past winter, I think--I suggested a test to try to find a measurable difference. I forget which thread and don't have the time or patience at the moment to slog through all the unrelated stuff the search function will drag up. Perhaps someone will remember the thread. It was not based on the wire between the power station and your house; it was based on stuff completely within your home and listening room. Someone had the test equipment on hand and was going to try it out, but I don't know whether they ever did. Might be a starting point for those who feel that if they can't measure it, then it must not be audible.
Bernhard,
Isolation transformers made a huge difference in my system. I got a few 480VA isolation toroids cheap from a surplus place and put them on all the low current (preamp, crossover, etc.) pieces. Some of the best money I ever spent.
The rule of thumb for determining AC line polarity (for units with two prong plugs, you'd have to temporarily float the ground for a three prong plug, I suppose, then rewire inside the chassis if necessary) used to be to measure between chassis ground and a known ground. Flip the AC cord. Whichever orientation leads to lower voltage offset between the chassis and known ground is almost always going to give you better sound. Easy to see, as ground currents flowing through your system aren't going to do your sound any good.
The isolation transformers allow me to float the smaller pieces in my system, which would allow them to get, at least in theory, to equilibrium with the heavier current pieces--which are grounded, hence less ground current.
This is in addition to the usual ideas like high frequency filtering of incoming hash on the AC line due to limited bandwidth of the transformer, etc.
People who claim to be scientific and/or logical in their approach but refuse to try things because they 'obviously' can't work automatically refute their own claims to authority. That's not how science works.
I quit making any claims to infallibility once I heard interconnect cable direction. Clearly, obviously, and without a doubt it cannot, should not, and will not make a difference. Right? But it does. Why, I don't know. Drives me crazy to think about it, but it exists. Takes a damned good system to hear it, though, as the effect is subtle; about on a par with absolute phase (that one was proven, by the way, for all you folks who can't hear it until after it's been made 'scientific').
Note that the price of the cables doesn't come into play, as you already own them. Expectations drop out, because the cable pretty much looks the same either way, excepting perhaps the writing on the jacket--can't see anyone getting alarmed about that. And it's repeatable, with different people agreeing on what they hear and which way sounds better.
And, yes, just for the record, I would like to know why, but I'm not going to let lack of an explanation tell me that it ain't there. Sooner or later, someone will figure something out. I've got about six thousand things that are more important to me at the moment than working myself into a dither over not knowing why. If, later in life, I end up with a lot of spare time on my hands and no Aleph-X amps to build, then perhaps I'll go tilting at windmills. Until that day, I'll just let that particular question sit on the shelf. It doesn't bother me to say,"I don't know." Other people, mostly control freaks and religious zealots, feel that they always have to have an answer as that gives them the right to run others down from their position of <i>soi disant</i> authority. In the meantime, I'll just keep saying that I don't know, and let people who think that that amounts to an admission of weakness froth at the mouth. Science means having the courage to say you don't know. It's a strength, not a weakness.
These days I frankly have a hard time imagining how adhesive dots, Radio Shack clocks and such will make a difference, but will you catch me saying 'no way!' No way. I had to eat my words enough times along the road to where I am. I haven't tried all the tweaks out there, but until I've tried it I don't voice an opinion.
Grey
P.S.: Lotsa people swear by ordinary 10/12/14/whatever gauge wire for AC cord. Yes, it's stiff, perhaps illegal--I've never checked. But it's cheap, and supposedly works very, very well. No, I haven't tried it. Yet. So no opinion.
It also works well for speaker cable for subwoofers... |
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| Circlotron |
| quote: | Originally posted by dice45
It works nice as an ordinary trannie at 170V and the huge EI core (M-Core?) is driven into heavy saturation at 240V. I have looked on it on a scope: a pure sine wave at the secondary, no matter what the load might be, no matter what garbage you try to inject t into the primary.
Such trannies are used for industrial computers to protect the computer from huge power-switch-on surges thru the power net, and also to protect the good environment from the evil computer.
They are at -140dB suppression at 1kHz, so i was told. They act as filter.
One thing left to be tried out here: on 240Volts, i can wire the secondary's center tap to protection ground (provided protection ground is clean enuff, else bury a copper rod in the garden and wire the center tap to this rod) and let the power of the audio system be symmetric +/- 120Volt |
AHA! So you have a *ferroresonant* transformer. It would have a cap of 10-20 uF connected to it? That explains the heat, the current draw, etc. If there is one kind of tranny everybody ought to have for their amp, it's one of these for sure. In '88 to '90 I used to work for a company called Sola Basic here in Oz, whose namesake, Joseph Sola invented these kind of trannies back in the 1930's. They are goooooood! A 2kVA one was about the size of a 10kVA normal one and would pull a measured 440 watts no load. You can put a square wave into the primaries of these things and still get a sinewave out! The UPS's we made there using SCR inverters did just that in fact. Short circuit proof too.
Earth the secondary ct and put a stake in the dirt close by the amp location? You bet! :) This is proper power engineering.
GP. |
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| dice45 |
jgwinner,
i mean plug polarity, sorry, no neetif speeka, Eric gave me the term.
Absolute polarity (sound), that also is clearly audible IMO, but off-topic here
Phil,
thanky our for seconding. BTW, i am not the only one loving these insulation trannies. Vinylsavor has three of them to feed 3 phases into his system and he dumps anything after tryout not proving to be a long-term lasting improvement. He did dump magnetic voltage constanters (weird from a trannie) but he did not dump the isolation trannies.
Power plug: you are right, stupid standard to have the plug reversable. Just for convenience of plugging 0° and 180°, only reason. "it doesn't matter, its AC".
But i had discussion with a Swiss EE who told me details about havng the protection grounding simpler and more effective. both, for the house and the device.
Apart from that, German and US technical standards cannot compete concerning stupidity. Standard organisations always put out a certain percentage of stupid standards (you can hear me complain about every 1 out of 3 DIN standard), but nevertheless ANSI would win hands down having the the most stupid standards and in larger count than DIN/ISO. Just to mention AWG, inch system, sheetmetal gauges, tap pitch and gear pitch, 110Vac ... :)
jackinnj and GP,
good grounding makes almost the same nice audible effect as the isolation trannies, maybe even nicer.
GP,
dunno if you intended to appear ironic, i do take your remark concerning the stake in the dirt serious however.
Back then when i was living in my parents house, i had the copper rod in the garden connected to my power outlet bar's protection ground. Good! Even my parent house's protection ground had too much grunge on it, due to µC of the oilburner, 3 fridges, TV set, you name it. On the wire from the copper, utter silence.
This is measurable and visible on the scope, not only audible.
Now i live in this 7th floor honeycomb in Munich, house built 1960. Protection ground rotten (if present). And a lot of garbage on it. I long for my copper rod grounding.
Concerning my iso trannie, well, there is no cap at all, just a huge tranformator with split primaries and secondaries too big for the voltage and the core and several electrostatic shield windings. No idea if this is a ferromagnetic resonant trannie.
Concerning size, you are probably right, this trannie looks huge for *only* 5kVA, core size 190x160mm,stack 160mm high. plus huge bell endcaps. Weight over 50kg.
Grey,
while i agree with your measurement suggestion concerning Voltages and plug flipping, i strongly suggest to use a microamperemeter as ground currents can be measured with better resolution, moreover they decay faster or slower and this is clearly observable on the µammeter.
Which BTW usally has the most sensitive measuring range on a DVM, also on my Fluke 123. Been there, done that, i prefer to measure µA instead of guessing if there is a mV change and where does it come from with 10MOhm or more input impedance.
As for the rest of your post, fully agreed, seconded, thank you. :) complained about crusade talk before. |
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| Duo |
Hey, I noticed the note about Sola transformers, I have a bunch of these. They were for tube equipment and I use them for my tube amps, they're wonderful cause they regulate the output voltage within 1%+/- with a wide range of input voltages. They also don't let any noise whatsoever come in or escape into the electrical system. The way these work is by using a cap on it's own winding on the transformer to keep the core saturated, this is why they draw enormous amounts of power just to run alone.
One thing about power for a good audio system is that it doesn't always have to come from the local power grid. Why not get a battery powered UPS, I am making one for my system that will supply up to 5000 watts of power and will keep itself charged by trickling off of the power grid through a huge filtered switching power supply. This way, I'll be at two advantages, 1: I may run my system to full power without any electrical noise except for the minimal amount generated by the ups inverter. and 2: I may also listen to music or keep the fridge running if I want to when the power goes out. I find that battery power makes most good systems sound better by a good bit:) BTW, solas and similar saturation transformers do tend to get very hot and noisy, they also use them for HID lamps in street lights since the gas tubes need good regulation. |
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| Peter Daniel |
| As I mentioned before I'm using UPS for my sources. It sounded better from batteries when I was using A75 amp but switched to AC power when I started using Aleph. It just sounded better that way. |
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| Duo |
| Yeah, it probably worked better case the aleph might draw heavier current... |
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| Circlotron |
| quote: | Originally posted by dice45
jackinnj and GP,
good grounding makes almost the same nice audible effect as the isolation trannies, maybe even nicer.
GP,
dunno if you intended to appear ironic, i do take your remark concerning the stake in the dirt serious however.
Back then when i was living in my parents house, i had the copper rod in the garden connected to my power outlet bar's protection ground. Good! Even my parent house's protection ground had too much grunge on it, due to µC of the oilburner, 3 fridges, TV set, you name it. On the wire from the copper, utter silence.
This is measurable and visible on the scope, not only audible.
|
This is the smartest and simplest clean-power-for-your-amplifier idea that I have heard for a long time. I have personally seen 160v of HF noise on a neutral line that is supposedly at earth potential.
I reckon the ideal setup would be a copper box buried in the ground and internally divided into two chambers and have an isolation transformer with the primary in the left side and the secondary in the right side and only the earthed iron core passing from one side to the other. The earthed copper sheet bulkhead would separate the primary and secondary but not go completely around the inside of the core like a shorted turn, just enter it from each side with a little gap between the ends that almost meet. The secondary would be centre tapped and run this ct to earth. Run a couple of microfarads of X cap (X caps are ac mains rated and safety certified etc, don't use ordinary caps, although if ordinary caps did catch fire inside your subterranean copper box it would hardly be dangerous) from each end of the trans secondary to earth to minmise any remaining HF's. Naturally, also run an earth line from the quiet side of your copper box to the power outlet you will be using. Also, put a really big metal oxide varistor on the input side to clamp any uncouth mains borne transients. This would have to the nicest power box ever. Local, low impedance earths with HF bypassing to them have a lot going for them. Once your earth wire gets more than several feet it isn't really at earth potential for HF's anymore. That's the benefit of the copper box. Kill the HF's to a perfect ground BEFORE they come out your power outlet so you aren't limited by the earth connection HF impedance.
GP. |
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| mrfeedback |
Hello Bernard and Graham, I entirely agree that good grounding and an isolated power feed is good, indeed mandatory.
Also that the first step is to keep any junk on the power mains competely out of the secondary side.
Just straight supply side power filtering pays fantastic dividends.
Even better maybe is the secondary side with grounded
centre tap balanced power feed mentioned,
Regarding earthing, if you can provide a dedicated ground stake and associated dedicated connecting wire, you will get the best and quietest replay (and recording) system that you are going to get.
My prior musings include things like using a HD coax with the centre wire as the system ground conductor, and the shield connected to the ground stake only.
There are voltage nodal points all over the ground so the choice of positioning of the reference earth stake is critically important if you are to go to this trouble.
The obsevations mentioned so far include an observable difference in the AC ground leakage current of the active connection WRT the neutral.
With conventional transformer winding techniques this is to be expected and is indeed old knowledge.
So methinks is there a method of winding secondaries and more importantly primaries so that they exhibit a completely symmetrical winding to earth leakage characteristic ?.
Re the saturated primary/cap loaded secondary mentioned - is this constant voltage transformer ?.
Regards, Eric. |
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| dice45 |
Eric and all,
| quote: | | Re the saturated primary/cap loaded secondary mentioned - is this constant voltage transformer ?. |
my books say yes, i haven't slaughtered mine before i sold it. Constant voltage transformers are second best, i can tell form own experience as well as from Vinylsavor's one. He omitted ihis one and did so with mine. Best are those huge isolation transformers, they have no capacitor inside and they do not regulate voltage.
GP,
Copper box: interesting thought. But i reckon there would be the speaker XO LP (i mentioned it earlier) necessary right be fore the audio power outlet. Just to kill the HF the power line has picked up between copper box and house. |
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| Peter Daniel |
| Nobody mentioned here cold water copper pipe as a reference ground. How good is it? |
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| Circlotron |
While waxing poetic on the merits of buying and burying an isolation transformer in a partitioned copper box I overlooked the obvious. If you were really keen and used the amp in one location only, you could actually put your *power tranny* in the box instead and earth the low voltage centre tapped secondary as described previously. Maybe have the rectifier bridge and snubbing components in their own little partition too and then finally + / - a few thousand microfarads for the rails. Feed the pos, earth and neg rail wires through the floor to your amp where the remainder of the filter caps reside in close proximity to the power stage. Providing you properly fused the setup, it would probably be just about the ultimate in fire safety too.
_______________________________________________
You would have to be dedicated to do this, but given some of the pics I have seen on this site I expect someone would do it. Now that I think of it, why not just have the box buried below the floor as before but some feet away from the amp, and have the house floor made of one big sheet of copper lying directly on the ground. A *real* ground plane. Then you could solder the copper amplifier case to the floor for an exceptionally short and low resistance / inductance / impedance connection. The floor could also double as a really good heatsink. And just think what the polished copper floor would do for the oh-so-necessary Spouse Acceptance Factor. ;)
GP. |
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| dice45 |
HPotter,
water pipes can be very good and vaaers bad. Better look with your scope on what happens on them, they can have all the gagbage of the houses ground.
Circlotron,
drawingdrawing! Curious! |
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| Aud_Mot |
I have a theory not mentioned on the subject. I admit I have not read every word of every post, just done a quick skim.
Instead of looking at what a given component GETS from the power line when using fancy power cords. How about what a given compenent DOES NOT GIVE to your power line, and thus to your influence other components.
It is very interesting to see how much THD different power supplies put onto a power system. Example: Switching power supplies can be horrible. Enough switching power supplies can had 3,000% THD to AC line and load down the line by what appears to be a phantom 40%.
Conventional transformers also add distortion, but typically not as severe and a "different type" of distortion. Supplies using choke input filters are different than capacitor input filters.
I do not claim to be an expert on the subject, but power supplies putting distortion back into the house AC is real. If there is an expert who can help out, please do.
Also critisize my amature theory about the AC cord being a filter, but in the direction of component to line.
Now, back to my perpetual motion machine,
Aud_Mot |
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| Duo |
Aud_Mot: You mentioned that switching PSU's can put up to 3000% onto an AC line... How did you get this number? How can the distortion be over 100%?
I do agree that most equipment interferes with the line quite a bit. If I had my way, every piece of equipment in my system would have it's own Sola regulated isolation transformer and use special filtering on each line. I've had cd players and computers that put some bad interference out, but I've also had HID lamps and air conditioners that will bend the 60Hz sine wave all out of shape! I do use a 5kva isolation transformer for my complete system, and most amplifiers get their power right from that. But my transport and phono and front ends are all seperately run from medical grade saturation transformers and they simply eliminate back emf and interference from or into the individual pieces of equipment. This results in the ability to turn the volume and gain up quit high and hear no hiss whatsoever in the speakers. Music also sounds much more real and clean. Much less coloration! |
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| Aud_Mot |
Dou,
I will double check the number with the co-worker that provided it. I know it was over well over 100%.
To give a simplified example:
If you had a signal 100v RMS with a harmonic that was 1v RMS, you would have 1% THD. Now you have a harmonic that is 50v RMS, 50% THD. 100v RMS harmonic, 100% THD. 200v RMS harmonic, 200% THD. All you have to have is more harmonics than fundamental to get over 100%. Throw in 2nd, 3rd, and 4th order harmonics, >100% isn't so hard to imagine. I suspect guitar amps can do that.
I know of a TV station that had to increase the capacity of their house UPS system, even though they were cahnged to lower power equipment. This is the story that gave me my 3,000% THD. The extra power was neded to "buck" the THD. To get 100 watts out of a power supply, you might have to buy 140 watts from the power company.
As I said, I do not claim to be an expert on the subject. I do know power supplies interact with your AC line, which can affect other components in your system. The power cord being the path back to other components MIGHT explain how they can make a difference.
I have tried speaker cables and interconnects, they can make a difference. Fancy power cables and hospital grade plugs and sockets, until I personally try it......... I will only speculate.
Aud_Mot |
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| gromanswe |
We are many, and are getting many more,
that doesn't find any reason for any other
power supply cables than what you use.
About hear or not hear,
here is a link:
http://www.csicop.org/si/9505/belief.html
groman
cant see like an electron-microscope and
not hear what he can't see with oscilloscope |
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| dice45 |
Aud_Mot
you are quite on track. I remember my friend MHuber recommends super-expensive Schottky recitfiers for any audio related PS. Not because it is doing so much benefits to the device they are used in. But mainly because of the garbage that ordinary rectifiers shoot back into the power line and Schottkys avoid this.
In this respect, it makes sense to have one big isalotion trannie to protect the audio system's power line from the evl world and between each device and the power line a speaker XO filter like descibed above to protect the audio devices from each other. |
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| gromanswe |
| quote: | Originally posted by HPotter
This is not about what you believe or think, but what you hear. Ever bothered to check it out?:) |
But what about
What you think and believe that you hear?
http://www.csicop.org/si/9505/belief.html
gromanswe
the great Pretender |
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| Peter Daniel |
| Hear Nothing, See Nothing, Say Nothing. |
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| Peter Daniel |
What about
What makes you to know that what you hear
you like it or not?
HPotter
trying to get a grip on reality |
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| gromanswe |
The critical-thinking unit is the second component of the belief engine, and it is acquired -- acquired through experience and explicit education. Because of the nervous-system architecture that I have described, we are born to magical thinking. The infant who smiles just before a breeze causes a mobile above her head to move will smile again and again, as though the smile had magically caused the desired motion of the mobile. We have to labor to overcome such magical predisposition, and we never do so entirely. It is through experience and direct teaching that we come to understand the limits of our immediate magical intuitive interpretations. We are taught common logic by parents and teachers, and since it often serves us well, we use it where it seems appropriate. Indeed, the cultural parallel of this developmental process is the development of the formal method of logic and scientific inquiry. We come to realize that we cannot trust our automatic inferences about co-occurrence and causality.
gromanswe
born magical thinker |
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| alvaius |
People on the forum still seem to be missing the basic fact that I did double blind testing and could always tell the difference. Sorry, but that is the truth, no matter what the naysayers our here are saying. I am not claiming a difference to justify cost, I am saying that there was a real and noticable difference in two set ups with more than one listener. This is fact and undisputable. The reasons for why it happened of course are not. Power supply noise, cable-cable interference, etc. are no doubt playing a part here. Essentially all I did was create a very good star ground for the AC part of the system. No, I was not filtering the miles of **** up to that. However, I think that a lot of good quality audio equipment most likely does. With cheap equipment you are not likely to notice as there are far more audible problems.
Do the comment about 3000% harmonic distortion. Please check your specs. However, I have seen current spikes that are 10 times the average current for poorly designed switchers and you can certainly throw a lot of **** back on the line. It is somewhat regulated by FCC\DOC\IEC, but only to a degree.
On the comment about high quality schottkly diodes. I think that depends where you are using them. On a power supply, they can actually contribute to more noise and distortion as they turn on and off very fast and that is not good for keeping the noise low. It is great for keeping the efficiencies high and protecting data lines.
Another note on power supplies is those massive power supply capacitors used in analog equipment don't do much to filter high frequency power supply noise, i.e. like out of a switcher. Good designers will use a range of capacitors to cover the whole frequency gammet. Even though the signals can be low frequency analog, you don't want any coupling back to your sensitive digital circuitry (to timing at least). The problem with audio equipment in general and why power cords may make a difference is that you are connecting a range of diverse equipment that is generally designed without huge considerations to what effect it will have on the equipment upstream or downstream.
Thoughts for the day... |
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| gromanswe |
Use a mains filter at the inlet of every device
in your sound system.
If you do so the choice of power cord
would be of secondary importance.
Comparing prices, I would think this is a more costeffective way.
But main reason, it is magnitudes better
than no filter
regardless of price of power cord.
Sorry to say, I have to agree with you, alvaius.
This is sadly overlooked by producers of Audio Electronics.
The solutions they have in their products
are too bad in performance,
if they even exists.
A circuit like this is a minimum,
at least for equipment that call themselves HIFI.
http://www.schaffner.com/index.asp?...EC+Inlet+Filter
gromanswe
has to filter some incoming answers
they could disturb his performance |
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| Duo |
| alvaius: How do imagine that bigger caps can't filter out higher frequencies??? The higher a frequency across a cap is, the mroe the cap reacts to it. That's why you don't need very big caps in a switching PSU, cause there's little or no low frequency coming out of it. |
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| haldor |
Hi gromanswe,
Did you take a look at the frequency response of this filter? The power filter is at unity (no filtering effect at all) by the time it gets down to 10 KHz.
Like I said in my earlier post, equipment line filters are designed to prevent RFI, not EMI.
Phil |
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| gromanswe |
But the mains filter stops RFI.
Good isn't it?
Shields, on cables and enclosures is natural to use.
Keeping distance between cords is also easy to acheive.
Then leaves the only path for diturbances is via
the magnetic field inside the trafo, and via the influence
the primary and secondary windings have on eachother.
Which frequencies this remaining coupling
are capable to transfer, and to what degree,
that is what I'd like to know.
I wait for the ;) expertise :D to arrive and
share me some tutorials. |
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| alvaius |
To DUO
Please look at a data sheet for virtually any capacitor, and specifically at ESR for instance. You will see that the ESR initially goes down as you would expect linear w.r.t. frequency, i.e. 1/2piFC. Then it plateaus for a while, and then it starts going up.
Capacitors, like every other electronics component exhibit parasitic effects. I true model for any capacitor includes not only capacitance, but inductance and resistance. Capacitors only behave like capacitors up to a given frequency and then their internal inductance starts to swamp the capacitance. For big capacitors, this starts at a relatively low frequency, possibly in only the 10's of kilohertz.
W.r.t. your comment about switching power supplies, there is a good reason that high frequency switching power supplies use Tantalum or even MCC Ceramics instead of Aluminum electrolytics which would have a much greater capacitance at a given frequency. It is because the Tantalum and MCC Ceramics behave much better at higher frequencies, i.e. like a true capacitor.
Happy designing...
Alvaius |
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| Duo |
I've never even seen a switching supply with anything other than electrolytics, and I've had more experience with switching PSU's than most people. I usually end up repairing vcr's, computers, etc that all have these PSU's. I've also worked on a wide range of switching bench supplies big and small, I even have pair of 40 amp battery chargers and a 30 amp one and so far every filtering cap i've seen after those boring schottky diodes is electrolytic.
I do understand what you mean about inductance swamping capacitance but you'd have to feed these caps pretty high frequencies to make this happen. However, I've never heard of this effect but I believe it. It gives me some design ideas to incorporate into my system I'm about to build which I want to have streneous filtering for everything. Especially with cd players and 600 watt amplifiers that could interfere with eachother! |
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| alvaius |
| I could probably count somewhere on the order of 15-20 switching power supplies with about 3-4 of them being AC-DC and the rest DC-DC. AC-DC are generally lower frequency and hence electrolytics work. However, take apart your laptop power supply, one of the small ones and you will not find run of the mill lytics, but often OS-CON. For high frequency DC-DC switching supplies, Tantalum and MCC Ceramic are more the norm. A good example of this would be the switching power supply that drives the P4 or Athlon in your computer. The cheap ones are based on lytics, in better computers they will use Tantalum and MCC both for size, and also for longevity. |
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| alvaius |
| I should add that most of the supplies I have designed of late do not even use schottkys, but use a second FET that is switched on and off. This is called a sychronous configuration. It is done for higher efficiency. |
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| Duo |
| Well, first of all, I'm not talking about DC-DC supplies, and second, I'm talking about hgih current, easily in excess of 1 or 2 amps. I think tantalum caps are sh*tty anyhow, they always short out or blow up, or both. And usually it is schottkys, just ask a tech and you'll see that mostly thery use shottkys in switching PSU's. |
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| alvaius |
The DC-DC supply for your computer processor can put out as much as 50Amps depending on the processor requirements. AC-DC switching supplies are really just DC-DC with a rectifier up front.
I have never had any problem with Tantalum capacitors. In a well designed circuit with good quality components, they are not an issue. You mention VCRs, etc. as something you work on. The quality level of some of the component suppliers in China and the like leaves much to be desired. If you stick to quality suppliers such as KEMET, AVX, Murata, and you use the chips as intended, they work fine. Often these off-shore OEMS will put too few tantalums into a power supply circuit causing them to overheat and degrade. Yes, they do fail catestrophically where as aluminum electrolytics may not fail as catastrophically, but they fail non the less.
Schottkys or high speed recovery diodes are common in general purpose AC-DC and DC-DC supplies where either the output voltage is high and hence the diode does not contribute much to the efficiency losses, or where high efficiency is not required or the output current is low. For high efficiency DC-DC convertors, synchronous conversion has become popular over the last few years as a way to increase efficiency. Dual FETS for switching supplies have come down to the cost of a FET plus a diode and hence there is not really a cost premium any more.
Now here is another thought. If you use a synchronous configuration and control the turn on and turn off times of the switching FETS, you can trade off efficiency for low noise performance. If have done this to achieve low noise and ripple at reasonable efficiencies.
Alvaius |
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| nania |
A simple way to have a RFI defeating power cord:
Use four conductors (6' 14 gague) with the two gound conductors connected at the outlet end and disconnected (one inch from the) device end. The second ground wire will "ground the ground" and act as a decent RFI line noise filter. If you can hear any improvement with this method, you can go one step further and add a small ferroresonant toroid to the device side. I made such a cable from scraps, taped it together and put it on my friends DNA-1. There was spatial improvement, better focus and the upper midrange was smoother and less spitty. I can understand why a reduction in RFI would clean up the highs but why would the image improve? It beats me. Anyway, I'm just offering a cheap way to try out the whole "magic power cable thing". I never tried it on any other amp but I can tell you that it was noticeable on that one.
Duo
I have read many of the posts you put up on this thread. They have been insightful, informative and without bluster or condescion and I have to say that my initial impression of you has been forced to change as a result. You have a pretty good knowledge of North American power delivery and that was definitely handy in this thread. I learned something here for sure. What I am saying is that I guess you aren't such a blowhard after all:p |
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| nania |
Edit
Use four conductors (6' 14 gague) with the two gound | | | |
