Tomas Danko wrote on Fri, 25 February 2005 18:19 |
danlavry wrote on Fri, 25 February 2005 17:10 |
?Multi stranded slow drawn oxygen free copper...crystal bell-like clarity, sense of "air" and realism, musical detail and speed, and overall delicious musicality?
The operative words are SLOW DRAWN. What will happen if you draw it too fast?
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A friend of mine...Simply because if you draw it too fast it might create cracks on microscopical level, and that could lead to a non-perfect result.
Sincerely, Tomas Danko
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Thank you for your comments.
Since I am not a mechanical engineer, a chemist, or a material specialist I am in no position to argue about fast drawn and or oxygen free copper having better or worse mechanical properties. In fact, as a user of copper wire, I do not care if the copper was drawn or glued or hammered, I do not care if it was heated to 500 degrees or 1000 degrees.
I do care about the mechanical specs such as flexibility, and I want wire that is not fragile.
However, these are not the claims that we heard. In fact I do not recall any statements referring to mechanical characteristics (not that I would believe a single thing they say). Instead the claims are MAKING A CONNECTION between slow drawn and or oxygen free to electrical and sonic characteristics.
So what is your point? I am certainly open to arguments that a different manufacturing processes may yield different characteristics. But it is my business to know the electrical side of the story, and electrically speaking, copper is basically just copper, with very little variation. For example, an 18AWG hard drawn copper yields 6.385 Ohms per 1000ft at 20 degree C, and weighs 4.917 lb per 1000 ft. The same 18 AWG annealed copper yields 6.640 Ohms per 1000ft at 20 degree C, and weighs exactly the same - 4.917 lb per 1000 ft. The difference in resistance is 4%, which is less then the tolerance in wire dimensions (thus in resistance). The inductance is the same for hard drawn and annealed, the capacitance for identical mechanical configuration is also the same.
So given that the conductive material (copper) is virtually the same, one can have it made into solid wire, or stranded wire, round, square, triangle… One can have more cross sectional area or less (which will affect resistance and inductance), one can insulate it with Teflon PVC or other materials (and that will change cable capacitance), one can shoot for more surface area (effecting skin effect at high frequencies)….
Given inductance L and capacitance C per unit length, the characteristic impedance is pretty well pinned down (square root of L/C) and the propagation delay is also pretty well known (square root of L*C)… Yes the model can be refined a bit to account for high frequency losses (FREQUENCIES WAY ABOVE AUDIO FREQUENCIES)….
Of course there are a number of wire and cable variations and features and many of them have to do with MECHANICAL properties.
Many of the cable makers know that they can not sell someone a very expensive cable on the grounds that it will not break, or that it can withstand 1000 degree C, or that it flexed well. So they “invent” all sorts of “sick theories”, trying to pray on people’s ignorance. It is outrageous for anyone to put a 12 AWG in parallel with a 14 AWG to provide low and high frequency paths.
Who writes such BS? If it is written by a professional EE, it is clear deceit. The other alternative is that the material is written by a non technical type and presented as technical facts. This is still deceitful. What would happen to those guys if they made similar claims for gear sold in the medical field?
Regards
Dan Lavry
www.lavryengineering.comIn times of deceit, telling the truth is a revolutionary act.