Cable directionality & cables

There are two issues here:

A cable being grounded at one end and not the other as is the case with a number of so-called "pseudo-balanced" RCA interconnects. VDH does it a lot. Here's their explanation about it:
http://www.vandenhul.com/artpap/groundend.htm

However they do stress:

They suggest that it's normally better to have the grounded end at the source but they do say to try either way and see which is best. I did try both ways with my VDH D102III RCA cables (now in use in my office system) and didn't hear any difference. However I'm inclined to think that there could be differences with this.

As VDH say though, this has nothing to do with the cable itself being directional which is, I think, what James is on about. I personally agree with him that it's a load of bollox.

Exactly. This applies just as much to differences between cables and all manner of other tweaks that apparently make a huge difference

Michael.

 

Well, I'm surprised to see some guys attempting some half pausable explanations.
I'll be honest here, is there an explainable theroy in Physics that will 'fit the bill' in this instance, or is pure hokus pokus marketing bull ?
Electrons travel there own way right ?
Directionality, physco acoustical, good chance, actual difference well according some yes, others NO.
We personaly listen to all our i/c's before they are treated, and then decide which way they go (really)
Digital i/c's seem more sensitive to directionality then the others.
Also as Sid made of his point of materials, yes we have found some do indeed exhibit the symptoms of 'which way round guvnor' to a greater extent than others.
I'm offering no evidence to prove or disprove it, you ears will tell you weather there a noticable difference or not. Wm

 

Of course with XLR cables and mains cables it's not an issue as they only fit one way around anyway so you don't have to wonder and worry if you've got it "right"

Michael.

 

Yes - pretty staggering wasn't it James.

His post did however conflate two entirely separate issues. I'll try and translate into less patronising terms.

1) Shielding.
a) Any conductor will pick up and induced AC voltage from their surroundings to a greater or lesser degree. Due to different physical locations of "out" and "return" paths the amount of pickup in each of these will be different at any instance in time, and any circuit attached to these will see an interference voltage equal to the difference. (If you're happy with magnetic flux lines, the voltage is proportional to the rate of change of numbers of lines contained within the conducting loop formed by the out and return wires). The idea of a shield is to divert all that external induced voltage off to somewhere irrelevant (the theory being that the electric field in space fully surrounded by a perfect conductor is zero - if the shield is perfect, then the signal cables will see a perfectly quiet surrounding and so experience no induced noise - as nothing's perfect there will be some leakage).
b) In order to prevent ground loops the shield is connected at only one end of the cable. The shield is then an aerial, which needs to dump its picked-up noise somewhere
c) directionality comes in by deciding where it's best to dump this unwanted noise. If ground were perfect then it wouldn't matter, but as it's not there may be a difference in which way round it goes (i.e. which component has better signal-ground isolation). In the case of e.g. the TNT DIY recipies he actually connects his shields to a completely separate ground.

(Ah just seen Michael has said pretty much the same)

2) Cable crystal structure.
Totally different concept - and one that I have a severe difficulty with myself. (I'm not an electronic engineer or semiconductor physicist - so I may be missing something here, but I think I've got the basics right). The only way I could see how crystal boundaries can cause directionality would be if drawing it somehow gets positive charge carrier doping on one side and negative on the other. This would then give some kind of directional semi-conductor effect, with a transition band of high resistance at low voltage. The problem here is that the signal it is carrying is normally AC, with no DC component. Such a semiconductor will resist passing current until the voltage exceeds a threshold, which may be different in each direction (if the doping thing above actually occurs). This transition band will cause distortion in the low voltage parts of signals (just like crossover distorion in class B amps). The problem here though is that the directionality effect would just change the exact point of the distortion - i.e. reversing the cable would just shift the origin of the distortion to the opposite phase of the waveform - but unless the waveform is strongly unipolar would not change its overall effect. To completely avoid such an effect you'd have to strongly DC bias the whole thing - such that the signal passage becomes effectively single ended. Note though that this is not just biassing the whole cable wrt ground, as the important thing is voltage differences across each crystal junction. You would need a voltage difference between the ends of the cable greater than the maximum value provided by the source. As the cable is pretty low resistance to start with this could well result in a huge bias current!

Actually, I seem to remember Lilolee telling me someone (Thorsten again?) transformer isolating all his cables and then providing a continuous bias current through the cable

So I think 2) is BS too - although any metallurgists out there who would care to differ?

 

Actually Mike, XLR's are a sod, (unless you know exactly which way the wire is wound off the reel), I usually build 2 pairs per new reel of wire, and we treat both and then listen and then decide which is the more 'right' to our ears.
Mains, the cables we produce, are multi stranded units are the installed in the same vein.

 

Things are about to get interesting the orginal & still the best ? debuker is in the house Cue ADB

 

Yes, but it means the consumer doesn't have to fret over whether they've got the cable plugged in the "wrong" way around. A whole level of audiophool insecurity is removed

Michael.

 

I agree entirely. I tend to dismiss tiny 'differences' as being probably psychological in origin. Things like switching displays off for 'improved sound quality', and the like. Besides which I can't hear 'em!

My main criteria for assessing improvements in clarity & separation, for instance, is when you can hear a 'new' instrument which was previously not separately audible, or make out lyrics clearly, when they were previously obscured by 'mush', for want of a better expression.

I think that the old favourite A/B test is seriously flawed because if you play a track twice, it always sounds better the second time round. This knowledge can be exploited by salesmen.

P.S. thanks to GrahamN for an erudite posting.

 

Well, yes Mike, there's no guess work, it's been done for you, weather you believe or not

 

if a cable has directionality its called a diode.sorry but it goes against everything i ever learnt about a.c theory,and have experinced in practise.

 

I'm with Mick Parry.
The whole cable/interconnect thing is total bullshit and directionality is seven greater bullshit.

There has been so much written about the charlatans who try to foist this garbage on to audiophools that it is amasing that it continues to be an issue on forums.

There are in fact very few recordng engineers who give any credence to the cable/interconnect myth (unless they are getting paid for it). They are in fact almost universal in their ridicule of the fairy tale.

Serious engineers such as John Dunlavy (of Dunlavy Speakers) wrote an excellent article on the subject. He is in good company with other qualified engineers (and audio enthusiasts) such as Peter Aczel and Robert Moddaferi who rubbish the whole idea.

In fact, Peter Aczel publishes the names of tricksters and charlatans (MIT, Monster etc) who prey on the stupidity and ignorance of the gullible over this very issue and he hasn't been sued ... even in litiguous America.

Do some reading and save a lot of cash .... unless you really want to have pretty coloured cables with macho looking blocks of aluminium on them (with nothing inside them) and bold looking connectors on them.

If you're are happy to spend megabucks on eye candy, that is anyone's choice. But dont pretend it makes any difference to the sound.

 

:ffrc:
So cable makes not one tad of difference eh?
i assume your running the freebie cables that came with your kit??

 

I wouldn't know about John, but I highly suspect that Mick is...



reg

 

Yes

Mick is running his kit on the cables that Naim supplied and will continue to do so until something better comes along.

Regards

Mick

 

i would think the standard naim cables are of a higher quality than the bell wire crap you get with RCA equiped components

 

Pennance

Naim NACA5 speaker is about £6.00 a meter and interconnects are about £60/£70. They murder stuff costing several times as much.

It also demonstrates Naims integrity, they could sell it at 5 times the price but they don't.

I don't lose sleep over my cables because Naim sorted it out for me, so I won't get conned into buying bright coloured cable by some con merchant.

Regards

Mick

 

I see problem with statement and discussion like these. It does not only apply to cables but to a lot of claims in HIFI industry.

Before you can even try to provide a scientific explanation maybe audiophile should go back to basic and ask is there is actually such phenomenon call electrical cables directionality.
In what situation does it happen? How many people could hear it? Is it real and is it just another one of those assumptions that have spread around without anyone knowing the origin of the claim? What is the evidence it does occurs?

From my observation a lot of hifi believes has been spread around and only now more people has the confidence to ask if they are actually true. Is there real evidence for these believe? What study that has been made that proves any of these claims? Are the studies carefully conducted in the first place?

Statements like my friends try it yesterday at the hifi show and they think it is real is not good enough. Neither is try it yourself and see. This type of observation is just anecdotal.
They do not provide real progress. If you do not know if is real or why its works then how do you know how to improve on the design of the next cables?

I also do not understand statement like if so and so think these directional cables makes there own hifi set up sounds better so why does it matter to us all. Is their money so let them spend it the way they wish?

Well actually that is not what we are asking is it? Devil is asking if the cable directionality is a real phenomenon. Before we goes into the science as to why is may be reason or perhaps not be the case should not be the first question is HOW MANY PEOPLE ACCUALLY COULD HEAR THAT ELECTRICAL CABLES HAS A DIRECTIONALITY.

If only a few golden ears could hear it and only with ultra sensitive equipments does it really matter in the real world? Are we sure that the golden ears are not imagining it because they assume it does exit. If they could prove it is not imaging then finally the boffins will try to measure it and seek explanation why it does occurs. And finally manufacturers could think of ways to make progress next year.

Yeap. I think you could guess what I am going to say next.

 

Am I missing something here. Why dont people find out whether the cable is making a difference? Can the waveform from the cd player not be analysed on very good oscilloscopes/whatever they use to analyse waveforms and the differences be noted? or are you all saying that it is such a small effect that only ears hear it and equipment cant pick it up. If thats whats being said I've gotta say its BS.
Also why arent all shields grounded to a proper earth?

 

Good for you John, get it out your system mate Bell wire & bullets the only way

 

I think this is evidence of a condition that may have a name but which I shall call "audiophile vanity" (hereinafter AV). I believe this disease to be especially prevalent among magazine reviewers, but it also infects wider swathes of the hi-fi community. Basically it takes the form that. as one becomes more knowledgeable about things hi-fi, one comes to regard oneself as superior to the common herd with their boom boxes and midi systems.

A sign of such superiority is the ability to hear much more than the common herd. For example, one can hear when the cables are the wrong way round, when a few cm of new power cable make a stupendous difference, etc., etc. And once these myths start, they spread. Someone (a small Austrian expatriate, name of Hitler, I believe) once said that if you tell a big enough lie often enough, everyone will believe it. So the word gets around that, say, cables are directional, and the little bit of AV in us all takes over, and suddenly we all hear it. we hear what we want to hear. My hand is up for having been guilty of my share of AV, but my recovery is proceeding very well, I'm glad to say.

Point is, we WANT to be seen and thought of as knowledgeable, so we go along with the latest received wisdom, and as James has already said, the power of suggestion is enormously strong. It's the emperor's new clothes all over again. And the hi-fi industry takes advantage of it. Personally, I've put myself in reverse. I'm on my way back to the days of the late, lamented Peter Walker of Quad, who, when asked what sort of cable should join speakers to amplifier, said a bit that's long enough. My sort of guy.