Riddle me this: how is carbon a conductor?

Well, Sean (welcome back), that's my point:

1) Why is carbon in the signal path?
2) Given that carbon is ~30db poorer in conducting the signal: are we not hearing differences in the the conductor geometry and dielectric loading of the cable? (which are material to the sound of a cable)

Herman,

Impedance is a combination of capacitance, inductance, and resistance. The best you can hope for in a complex conductor is to make it purely resistive, so you're still left with the physics of carbon being a poor conductor. (which is why it rejects RFI & why they use in in the Stealth, and all the other nonrelevant "technical" descriptions loop back to conductivity)

Best,

A material can be broken down into one of three categories, a conductor, a semiconductor, or a non conductor(insulator).

Metals are conductors, which is why we often mistake conductors as having the characteristics of the good conductors(silver, copper, gold, etc.). We sometimes forget that things like W(tungsten), used in light bulb filaments are not good conductors.

Semiconductors have two natures; sometimes they are non conductors, and sometimes they are conductors. While this seems hard to understand, consider a material such as tin oxide, which is an insulator. Pure and simple, it will not conduct electricity. But, dope it(add a VERRRRRY minute amount of) with things like platinum or palladium and it WILL become a conductor when placed in the presence of a reducing gas. In English, this is how carbon monoxide sensors and breathalyzers work. In the presence of CO or alcohol, the conductivity of the doped SnO2(tin oxide) skyrockets, and this sets off the alarm.

Resistors ARE conductors. Let's get that out of the way from the start. And, conductors ARE resistors. The best conductor, silver, can be used as a resistor, but you would need a very long length of it to do the same job of resisting the electrical flow as a very short length of a more traditional resistor, such as carbon, palladium - silver, or ruthenium.

So, after this way too long babble I have put forth, carbon is, FOR SURE, a conductor. It's not as good a conductor as silver or copper, but it is still a conductor. Whether I would use it as a power cord or not, is irrelevant to this argument.

These cords mix silver conductors with carbon, so the low impedence silver would probably swamp out any contribution from the carbon.

steve

Herman: Are you actually reading what that article says and understanding it or are you taking it at face value? A child with basic electronics knowledge could tear that article apart piece by piece.

Since the link that you provided primarily discusses AC, i'll stick to that. Suffice it to say that showing some type of a picture-graph of a 480 millivolt square wave at 6 MHz has very little to do with how well a given product / conductor will perform at 60 Hz and / or near the audible range passing a Sine wave.

As far as i knew, people were using filters / power line conditioners / regenerators to try and narrow the bandwidth of the AC path. According to that article, it apears that we should be trying to achieve a wider bandwidth that would act as a more linear conduit for RFI to enter into our gear. After all, we want a pure sine wave that is very limited in bandwidth and nothing else.


How one could think that anything in that article ( pertaining to AC ) is beneficial is beyond me. With gibberish like this invading this forum, i'm going back on vacation. Sean
>

PS... To switch over to signal carrying cables, if you want to insert yet another source of signal loss into your system, why not just use a carbon resistor of the same appr value? You'll dissipate the same amount of signal with no chance of recovery. On top of that, you'll simply be adding to the divergence between input and output impedances between the mating gear. This reduces power transfer, increases ringing, slows transient response, etc... Then again, maybe they are counting on the "lossy" nature of this type of conductor to not only "lose" some of the primary signal, but also damp / absorb some of the reflections. I guess that we will never know as the people writing their ad text are not technically competent and / or they don't display any pertinent info to the subjects being discussed on their website.

mPrime, your math is flawed to say that you get 20dB or 30dB less signal passed through a carbon conductor. The ratio of carbon's conductivity to that of copper is not the proper way to look at it.

What we are concerned with is the amount of voltage that is delivered to the next stage. If a perfect voltage source has a 1 volt output, and I use a cable with 1 ohm of impedance hooked up to a 50K ohm input impedance, I will get 99.998% of that 1 volt delivered to the load. If I use a cable with as much as 1000 ohms of impedance I will still get 98% of it, which is -.18 dB.

As far as characterizing carbon as a "poor conductor," it has more resistance than copper but in the grand scheme of things it's really not that much. I looked at the Van Den Hull website and they state a 38 ohm/meter spec for their metal free, carbon fiber interconnects. This would result in -.006 dB/meter in the example above.