cable dielectric cause of artificial sound

I have to throw in with Steve, and agree that surface oxidation is not necessarily something to be afraid of.
It's important to remember that most wire used in audio is annealed, and annealing takes place at high temperatures, which can cause functionally significant oxidation within seconds. However, this can be controlled somewhat by manipulating available oxygen levels and cooling times.
When considering stranded wire, such as that used in speaker wire and power cables, a small amount of surface oxidation can actually reduce the negative effects of strand interaction and eddy currents, without the higher dielectric losses seen with strand coatings.

Tim

LeVasseur Audio

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

Scar,

I am afraid I agree with a lot of what Steve says. Below is a post with 2 links in it I suggust you read.
http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1160450950&openmine&zzArtizen65&4&5#Artizen65

What you are refering to is skin effect. Now in my training 100mhz and above is where skin effect really starts to matter. In the link above it deals with skin effect in the audible frequency range. Now I have been told by an EE friend of mine that it is a weak proof.

Not that I now necessarly agree with him at this point in my life strictly from a theoretical stand point not a mathimatical one.

If you start at 1hz the electrons use the whole wire as the frequency increases the electrons migrate to the outside of the conductor. It is not untill your reach the upper frequency's that you actually get into the skin effect theory. It is at these frequencies that the dialectric becomes more of a factor as the electron interaction between the conductor and dialectric becomes more acute.

It is at this point where I might disagree with Steve from a theoretical standpoint. Oxidation will decrease the interaction between the conductor and dialectric and could possibly affect the upper frequency range of the cable. This could have a positive affect or a negitive affect it depends on the frequency and the level of oxidation and or corrosion. IMHO in the lower frequencies it should have no affect at all.

Three major things things come into play with the conductor, material used, purity and quality of the extrusion. Imperfections in the conductor be it purity or vairing raidi of the conductor will affect electron flow through the wire. This will have more of an effect at higher frequencies than at lower frequencies.

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.

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 by nature attracts the fewest electrons from the dialectric or has the least negitive impact by passing stray electrons to the dialectric which allows the electrical signal to stay more completly in-tact as it travels down the conductor. Keep in mind this has a lot more affect in the upper frequencies than the lower frequencies.

Ok I am all tapped out for now although there is more I suggust you read the two links posted in the other thread.
There is also a paper on the same site about wire topology.

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