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Riddle me this: how is carbon a conductor?

I'm confused....

M. Wolff has a powercords, and now interconnect cables, made with "carbon ribbon". But when I look up the conductivity of carbon, it's a thousandth of silver's. Almost the same delta for copper.

So why use this stuff in the signal path?

It makes no sense to me (other than he also uses silver) that this is a good design call. Is not what one hears with these designs the non-carbon conductor geometry rather than carbon ribbon?

Really, this is not a shot across your bow, Michael (or to any who is satisfied with the product), but an attempt to understand why use such a poor conductor in the signal path?

Curious, 'cause I'm in the market for IC's and power cords, and attempting to understand the product offerings.
mprime
herman
2,277 posts
 
On the other hand, why do you feel that lower resistance would be better?
rockvirgo
587 posts
 
FWIW, carbon filaments are common in automotive spark plug leads. They generate less radio interference than stranded copper. Back in the 60's and 70's racers replaced carbon filament for stranded copper because copper is less fragile/more reliable under extreme conditions. YMMV :^)
oxia
51 posts
 
van den Hul has used carbon and carbon-metal hybrid conductors for years. With respect to its application in ICs, the high resistance is of little consequence since you are dealing with low current. On the upside, carbon is RF transparent, will not degrade over time due to oxidation, and the filaments used are so thin that they have virtually no skin effect.
mprime OP
92 posts
 
Oxia,

Carbon's RF transparency is directly related to it's conductivity!

Rock,

My understanding of carbon in spark plugs is that it is used *because* a spark gap is and extreme situation. An interconnect, however....

Herman,

Now my physics gets a little foggy (or perhaps it is the beer :-), but you do raise an interesting question. My inital cut is that for the resistance (which is important to IC's) is 1000 times greater than the other conductors (assuming equal conductor area and length). Thus, this presents a 1000 greater load on the source component. Moreover, if you're using carbon along with these other conductors, the effective resistance chucks the carbon component of the "conductor" into the noise: it's the metals which will relay the signal to the load.

So why is it there?

Let's just say we have 10 the cross sectional area of carbon over the metals. We still have 20db less signal being passed through the carbon. At this point, don't conductor geometries play a larger role in what is audible?

Thanks,
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