Oxygen Free Cables

Oxygen free is old hat, you can buy them in Coles Supermarkets. The new ones are cryogenically frozen, polarised, have battery powered biased dielectrics, different size strands for different frequencies, and need to be "broken in" for extended periods before they sound the best.

Dave :)

An easy way to tell Oxygen rich cables is "They turn Green". Copper oxide (or sulphate) is an insulator therefore the copper *has* to be oxygen free or it just don't work.

Bit like Ford saying "New Falcons made from Oxygen free steel". Duh! Who would buy a rusty car?

Think about it.

Cheers TT

Thanks for misleading this NG once again Terence the Tosser. There is copper and oxygen free (a misnomer as it is actually very low residual oxygen copper) copper, but no such thing as "oxygen rich" copper. Oxygen free copper is created under a near vacuum where very little oxygen is present. Copper is akin to Aluminium in that the corroded surface is thin and very stable.

Your predisposition to making shit up when you don't know something is becoming a tad boring TT.

That's nice Dave. I must get some.

This reminds of a really interesting thing I read a few years ago in "Upgrading and Repairing PCs" by Mueller. I assume it is correct but haven't verified...

The rage these days seems to have gold-plated connectors for this, that and the other. The interesting thing is when connectors are mixed. Apparently, a problem has been seen with RAM where the pads on the SIMs are gold plated and the socket on the MOBO is tinned. Some odd metalurgy occurs that actually causes a breakdown in the connection - and requires the SIMs to be removed and reseated every now and then. So, if this is correct, it is possible to create a poorer connection by using gold -- unless you make sure the mating connector is also gold-plated.

Cheers Glenn Glenn Pure Canberra, Australia Web page:

Yes, along with other hyped specs like low capacitance low inductance and such. "Low resistance" is the only spec that matters for speaker cable used in the home. Oh, if you had runs several kilometers long you'd start to care about inductance and capacitance, but nobody's house is that big. I use power cord suitable for 15 amp service (AWG #14). Inexpensive and effective.

After the wife starts screaming about the money you wasted.... :-)

You are right to be sceptical about "oxygen-free" -and indeed that most claims about purity of the conductor make any difference to the sound. The usually quoted explanations for effect of purity are changes in resistance and diode effects.

You have to add a lot (certainly more than the ppm cable manufacturers rabbit on about) of impurity or other crystal defects to affect the resistance - it was a technique used in the Dept of Tribophysics of CSIRO based in Unimelb in the 1950s to study metals (before my boss in Cambridge/Oxford developed electron-microscopy techniques for more direct examination of such defects in metals). Put simply, the conduction electrons are effectively detached from their atoms in metals (hence they are called 'free electrons') and there are so many of them (of the order of

10**22 per cm**2) that they only have to travel very slowly (mm/sec) to conduct even the largest of the currents likely to occur in audio ( less than 100 A). You have to put a lot of barriers in their way for them to notice any difference in resistance - and this can always be compensated for by making the conductor slightly thicker.

Likewise you have to work pretty hard to dissolve enough oxygen to form copper oxide precipitates inside copper . Oxides are semiconductors (i.e. they have fewer free electrons) but this does not automatically create 'diodes' - and any such effect would in any case be short-circuited by the metal around them.

On the other hand, the dielectric around the conductors will affect the propagation of the electromagnetic fields which drive the electron currents inside the metal, for reason explained in earlier posts - see

This article also explains why thickness of the conductors may be important through 'skin effects' - AC currents become increasingly concentrated on the surface as frequency increases, even at audio frequencies. Likewise the geometry of the strands will affect the AC capacitance & inductance of the cable (and as Hawksford explains, you generally have to trade one off against the other).

I have certainly heard differences between cables but it tends to only become important in high resolution hifi systems.

Rod Dr Rod Crawford

**Capacitance is unimportant, but inductance may well be.

"Low resistance"

**Really? Where did you study electrical engineering? I hope you didn't, because you can be shown to be wrong, very easily.

Oh, if you had runs several kilometers

**Several km? Are you certain about that? So-called 'zip' cable has an inductance of approximately 0.75uH/Metre. At 1kM, with 8 Ohm speakers, the attenuation will be around 3dB at around 1.5kHz. At 100Metres, the attenuation (with 'normal' 8 Ohm speakers) will occur within the audible range. When dealing with VERY difficult speakers:

or

The attenuation will occur with MUCH shorter cable lengths. As little as 10 Metre cable runs may show some audible degradation.

And, of course, capacitance doesn't matter one whit, with any competently designed amplifier.

I use power cord

**For you, perhaps. Do not presume that what works for you, is appropriate for everyone. **Yeah, well, they all do that.

Women, can't live with 'em, can't kill 'em.

--
Trevor Wilson
www.rageaudio.com.au

"Trevor Wilson"

** Mr Casey is an expert on work creation - following him around usenet correcting all his asinine postings is almost a full time job. ** Even a 5 metre length of twin wire ( gauge is irrelevant) has enough linear inductance to become quite audible when the load impedance drops to 2 ohms near 17 or 18 kHz - as it does with the Quad ESL57. With "stacked" ESL57s, impedance drops to 1 ohm making even as little as 3 metres of heavy gauge twin lead audible.

BTW I am not referring to some subtle effect that takes practice to ear - but a very audible loss of signal that amounts to 1 to 3 dB @

17 - 18 kHz !!!

Also, when viewed on a scope, there is serious ringing of a square wave at audible frequencies ( 10 to 25 % amplitude - depending on cable length ) at the speaker end of the cable that it NOT there at the amp input end.

The ONLY solution I know to cure this is to use a low inductance, inter-woven cable like Tocord.

Using 5 metre long Tocord leads, with single ESL57s, high frequency loss is reduced to under 0.5 dB ( resistance loss alone) and ringing all but disappears.

........... Phil

Commonly called stalking.

etc...Snip..

Fascinating Rod. Many thanks for that............A M.

Would explain why my RAM goes ratshit every few months with that exact fix.

-mark

"Fred At Home"

** For any audiophool - doing that is as automatic as defending one's wife, children, dog etc ....

............ Phil

Since you have no wife, children, dog, post a picture of your "etc".

etc = "Electrical Trainee Certificate" perhaps?

TT :-))

On a related topic: look up "Tin Whiskers" and "Zinc whiskers"

Ok group it appears we now have 3 foul mouthed trolls.

See what happens when you tolerate one - more appear.

Regards TT

What a hypocrite you are TT. The majority of your posts are NOT audio related. You spend most of your time criticizing others who are far more knowledgeable than yourself. Face it. Do you enjoy being a pig-ignorant fascist?

Well 'Fred'.I you're not PA in drag you sure have mastered his turn of phrase to a remarkably accurate degree.