Oxygen free Cables

I had read an article saying that there really is very little or no audible diff between 99.5% and 99.9%OFC. But there is a tonal diff between some cables if not all.

and then again if you did get a pair of good copper interconnects and a pair of interconnects with OFC from the same vendor, would you attirbute the difference heard to the OFC part or other details taken care off during construction like insulation, sheilding, soldering, connectors ????

manek.

OFC is more to do with capability to avoid corrosion rather than conductivity. corroded copper ie Copper oxide is a bad conductor.

once it is made OFC this tendency to go green reduces and hence has a good conductivity as well.. thats about all

Thats why some folks prefer silver cables since silver does not corrode.

BTW I have heard folks discussing about 99.9 Vs 99.9999 % differences


Additionally the difference in conductivity of 99% pure copper and 99.9 OFC is less than 2 % initially. but woith time the resistance of the Non OFC copper can increase..

To compliment what Arj wrote:
I also understand that when the cable undergoes the process of becoming oxygen-free, there is also an effort made to increase the grain size of the copper. I believe that an American of Japanese origin or a Japanese citizen by the name of Dr. Ohno developed this technique. It is widely used in a number of cables such as TARA Labs, Harmonic Technology, Analysis Plus to name a few. By removing the impurities of the Cu, the long grains of Cu attach to each other form one long contiguous strand. This has the effect of producing less distortion in the cable as there are significantly fewer boundaries with with non-Cu material. Metal cables are susceptible to a number of distortions & this one technique does its share in reducing these distortions.

Now, can you tell the difference of OFC cable?
This is a loaded question & IMHO depends on a number of factors such as how well the listener's ears are trained to pick up such cues, how good are the electronics in the listener's system, how clean is the power supplied to the listener's system, how learned is the listener about the timbral accuracy of the instrument(s) in that piece of music to know when the sound is distorted & when it is not & of course, what knowledge does the listener have about the recording of that piece of music.
Re. the very last item: I just read in Stereophile that side #1 of the classic "Kind of Blue" by Miles Davis was recording off pitch because the tape recording machine was at fault & did not receive the tuning it needed before side 1 was recorded! Side #2 is recorded at the correct pitch because the technician was called in & was able to service it before side #2 was recorded. So, if you guys can tell, side #1 is supposed to be off-pitch.
Now, how many times have you guys listened to "Kind of Blue" by Miles Davis? Did you realize that side #1 was off-pitch?
Before you guys slam me I am *not* saying that I can detect these distortions & you cannot. Please, I know better than to make such a statement! All I'm saying is that it depends on several factors. So, just 1 listen is not enough. Probably need to debug your system & find out if the other factors are optimized or not before you attempt such a listen w/ & w/o OFC cables.

bombaywalla has raised a very interesting point here.

If someone says he can hear a difference and another says he cannot, would you give the benefit of the doubt to the 1st person or would you go by what you feel is right ?

The answer to the above would give you a very good idea as to how you would react to any of the controversial audio debate

BombayWalla,
You are talking about "OCC" cables..."ohno continuous casting" method of making copper cables. Yes, they are said to reduce distortion and behave more linearly across frequency.

If you guys want to test them out, I believe Audioplus(korean brand) and DAC(designer audio) have PC-OCC versions of their interconnects and speaker wire as well.

I did take a listen at those cables but found my simple OFC VDH's to be much better. But then again thats only my humble opinion.

I would also pay attention to how the cable is constructed and not just whether OFC or OCC copper is used, though theoretically(as per some dope on the internet) OCC copper cables have the potential of being better than OFC, but can we here the difference ? and can we pin those differences we hear down to the properties of OCC ?

I wonder.

Manek.

there is also the concept of Single crystal cables..
one of the proponents is Ecosse cables ans they have a pretty interesting read on that aspect here

http://www.ecossecables.co.uk/Tables/table_frameset5.html#mono

of course keeping in mind that there would be some marketing involved as well.. but on the whole these folks are much more subtle and balanced in their approach.

Manek schrieb:

BombayWalla, You are talking about "OCC" cables..."ohno continuous casting" method of making copper cables

Manek, you are correct!
However, I believe that these 2 things (OCC & OFC) go together. Atleast for the manuf whose cables I have (TARA Labs) where they use long-grain copper construction & supposedly 6N pure copper at the same time.

To compliment what yourself & Arj wrote: there definitely seems to be a lot of marketing hype surrounding OFC & OCC cables esp. in terms of their purity. I was once on the phone talking to another cable manuf who told me that he was a trained metallurgist & knew a lot of purity measurements. He said that when he was employed as a metallurgist (before he moved into audio) he had some the best equipment in the world at his disposal & some of it even custom designed in that company that employed him. Even then, using the best techniques available, he was having a hard time certifying purity above 4-5N. The reason was that to certify metals to 4-5N, the equipment itself had to have a noise floor of 6-7N or better! And, he felt that it would either be incredibly expensive to build such a machine or nearly impossible to. Hence, he advised me to take all these claims of 6N pure Cu & Ag with a big grain of salt. Thought I'd share the story. FWIW.

bombaywalla, yes the OCC process does involve the process of removing oxygen content out of the CU, read a bit about that somewhere.

Thanks for the tips about the N purity ratings.....


Manek.