Are all copper cables virtually oxygen free?


I've been talking to folks at Storm Products and Allied Wire and Cable about ac cables -- both distribute and custom build various wires and cables. According to them, newer techniques among American manufacturers virtually eliminate any oxygen in copper. They could not speak to other manufacturers since "not a lot of wire is imported" -- presumably because of the cost dynamics. That means that, for all practical purposes, Romex has similar OFC characteristics to all the cables that are being touted. Of course, there are other sonic characteristics like crystal size (ala Harmonic Tech)and other non-copper impurities. But, is OFC a fait accompli for all cable? What does that mean? I'm way out of my range of expertise here but was wondering if anyone else has heard this and/or knows the implications. Thanks.
ozfly
Let me add another question, Ozfly. Is there really any audible difference between 99.9999% (4 nines) and say 99.999999% (6 nines) purity copper? Just curious. Happy Tunes!
Short answer: Yes. But what's called "oxygen-free" is a little more oxygen-free than the regular stuff (assuming the label is honest). There is no technical reason why that extra purity should make a difference (though there's a lot of mumbo-jumbo from the people who sell it). Indeed, I've read (though cannot confirm) that OFC actually is more resistant than generic copper, which would make it an odd choice.
Parrot: If I'm not mistaken, 4 nines means 99.99%, and 6 nines means 99.9999%. Your question is still a good one, however.
Bomarc's answer is correct until he gets to the purity part of it and purity does make a measureable difference, but for lower resistance....Yes you can hear it as well....