cable dielectric cause of artificial sound

Elizabeth,

Chris VenHaus of VH Audio sells a 28 gauge solid core silver wire that's insulated with four layers of cotton serve and has a very uniform outside diameter which would make it very good for twisted pairs or, my preference, braided quads.

It's $59.99 for a 25 foot spool.

se

Agree, audiophiles are often too critical with minor details, but oxidation which occurs at the surface of a conductor must be taken seriously. Electrical signal tends to travel at the surface of a conductor, NOT the center of a conductor as some may think.

It's not so bad as you portray. At audio frequencies the signal current flows through the entire cross section of the conductor, with increasing current density as you move out radially from the center. The difference between the current density at the center and that out toward the surface depends on frequency and the diameter of the conductor.

But so what? As I said previously, all the oxide layer does is effectively reduce the diameter of the conductor by a microscopic amount. This will also reduce its cross sectional area which will have the effect of moving a tad more current toward the center of the conductor and ultimately reduce the effect you're speaking of here.

In other words, the current density throughout the cross section will be very slightly more uniform than it would have been otherwise.

One example is the conductor designed by Analysis Plus, they design a conductor which is hollow in the center.

Sure, that's one approach. Or you can just use smaller diameter conductors. The smaller the diameter of the conductor, the more uniform the current distribution through its cross section will be for a given frequency.

Allowing the surface of a conductor to oxidize over time will change the character of the cable and shorten cable life.

Don't see how it would change the character of the cable in any significant way or shorten cable life. Soon as copper is exposed to the air, it soon gets a surface layer of oxidation. This layer of oxidation actually works to prevent further oxidation

Hell, I have a couple of spools of bare copper wire here that are probably going on 40 years old. Still in good shape.

Oxidation is a reason why air dielectric is not used more often.

I would disagree. But if the reason is oxidation, I'd say it's because people tend to irrationally freak out about it just because they've been told by someone that they should freak out about it

se

Tgrisham

If the issue is that the dialectric potentially changes the sound, and oxidation of copper potentially changes the sound, wouldn't pure copper wire covered in something to prevent shorting, and oxidation, be ideal?

Ideal? I dunno. That rather presupposes that if the sound is in fact to be changed, it must be a change for the worse.

Is this all really just a numbers game when you get to the bottom of it?

I've always found it curious that often the same people who think that a SET tube amp, with horrendous amounts of distortion, high output impedance, limited frequency response, etc. sounds absolutely fantastic, but when it comes to something like wire, everything changes. The wire needs to be the most conductive. It must be of the highest purity. The dielectric constant of the insulation must be as close to 1 as possible.

Just seems a bit schizophrenic to me.

se

Scar

In the world of audiophile where isolation cones, cable lifters, contact enhancers are used, a oxidized conductor would not go over well.

Then I guess it's good that I only worry about what works best for me.

Oxidation shorten the life of a cable when it sound characteristic is changed due to oxidation, yes it does sound different.

Well, given that placing photographs of yourself in your freezer will make your system "sound different," you'll forgive me if I don't consider "sound different" to be of much worth with regard to issues such as the actual physical properties of a cable.

Now, if you could state what the actual change is and how it manifests itself in the signal, that would be helpful.

Your spools of bare copper wire laying around will probaly work for another 40 years, but the quality and sound won't be the same.

Ok, but why exactly would that be the case? What exactly changes beyond what I had said previously that the effective diameter of the wire is a few molecules smaller?

se

Artizen65

Silver has a slightly higher frequency response than copper in the 20hz to 20khz range. Hence why some people perceive silver as being brighter than copper.

This doesn't make sense. Silver being slightly more conductive than copper will mean that skin effect will be slightly worse in a silver conductor than a copper conductor, all else being equal, and therefore have a slightly reduced high frequency response compared to copper.

So lets assume that skin effect exists in the upper frequency range of the audible band 20hz to 20khz. Other than preventing corrosion or oxidation of the conductor the dialectric should be selected for minimum interaction with the electrons in the conductor. It is this reason that air is the best dialectric.

It's not the electrons that the dielectric interacts with, at least not directly. It's the electric field that the dielectric interacts with.

se

Sean

The dielectric becomes more conductive / lossy over a period of time. As such, the electrons DO interact with the dielectric, both in terms of conductivity and magnetic field. The measurements that i mentioned above pertain directly to this subject.

Well, since you didn't provide any information whatsoever about your measurements, there's no way to evaluate your claim.

se

I think people freak out too much about copper wire oxidizing. Unless it's oxidation between mechanical contacts, I haven't found it to be any problem at all. It's only a few molecules thick and I find that much more preferable to a whole hell of a lot more plastic extruded over the wire. Even the thinnest enameling is orders of magnitude thicker.

Some say copper oxide isn't very conductive. Yeah? So what? Teflon isn't very conductive either. Nor the air surrounding the wire. Essentially all the oxide is doing is effectively reducing the diameter of the wire by a few molecules, which is nothing compared to the variation of wire diameter due to manufacturing tolerances.

se

Several cable manufacturers are using cotton dielectric. Has anyone identified a sonic signature for cotton compared to PTFE?

I'm not much of a "sonic signature" kind of guy, but I do prefer cotton over plastics, including PTFE. And ultimatley prefer silk over cotton.

One thing worth noting though is that the dielectric constant given for cotton, saying it's even lower than Teflon, is somewhat misleading. The figure that's given (1.3 to 1.4) is for cotton in its raw form, i.e. balls. In its textile form, i.e. woven into thread and fabric, is higher and more akin to that of silk at 2.5 to 3.5.

So for those who are obsessed with numbers, unless you string your wire through a bunch of cotton balls, you're not going to get that 1.3 to 1.4 dielectric constant.

Reference Audio Mods sells braided cotton sleeving in various sizes and vt4c.com over in Hong Kong sells braided silk sleeving (as well as cotton).

And as I mentioned previously, VH Audio sells a 28 gauge solid silver wire with a quad serve of cotton insulation (serve means it's wrapped directly around the wire rather than being a braided sleeving).

se

Scar972

It seems our point of view is different, you're looking at it from the technical side, mine is from an audiophile talking about audiophile cable.

I don't know what that means, "an audiophile talking about audiophile cable."

You have made a number of objective claims of fact, none of which have been substantiated with any sort of objective evidence or proof.

Some of you sound like many of the electrical types I've talked to where everything has to be proven with numbers and measurements.

Well, when one makes objective claims of fact, the substantiation of those claims must also be objective. If you have no objective substantiation for your objective claims, then you're doing little more than trying to pass off opinion as fact.

Is that what it means to be an "audiophile talking about audiophile cable"? To pass opinion off as fact?

These people will never believe two audio cable can sound different because it can't be measured.

It has nothing to do with whether it can be measured. It has to do with first establishing that there is in fact an actual audible difference between them.

Audio cable is NOT and never an exact science, I repeat NOT. While skin affect does occur at frequencies above 20khz, differences can still be heard.

And here is yet another objective claim of fact. When exactly was this established as fact?

High End cable designers don't come up with a design so that their cable will only sound as they intend after oxidation has occured, they do their best to limit oxidation with the use of Teflon & PE, this is why we don't see many exposed copper in high end cable design.

How do you know this is necessarily the case? How do you know they don't do it simply because many people have been prejudiced against it by people trying to pass off opinion as fact?

My point of all this rambling is, oxidation has to be taken seriously in a high end cable because the signature sound that the designer intended will be no longer be after corrosion occurs. I don't think audiophiles want to spend hundreds to thousands of dollars on a corroded cable anyway.

Now here you are spouting off while demonstrating you don't even know what you're talking about.

First, oxidation and corrosion are not one and the same. Corrosion is a two part process that requires both oxidation and reduction, where material is actually lost.

Copper actually RESISTS corrosion. This is what gives it such high value in applications such as roofing material and water pipes.

As I said in a previous post, the microscopically thin film of oxidation that quickly forms on the surface when it's exposed to air actually acts as a protective barrier against both further oxidation and corrosion.

So please, before you go trying to scare people about "corroded cable," get your facts straight.

se