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In Reply to: RE: carbon fiber in teflon posted by beautox on November 14, 2016 at 11:59:26
Maybe beautox knows how to solder/terminate carbon fiber wire to its connection?Regardless of the output impedance, 33ohms/m seems very/extremely high to me. What would you consider to be high or very high resistance?
Edits: 11/14/16 11/14/16 11/14/16Follow Ups:
"seems high" is a bit vague don't you think?
In fact it depends on the situation.
A typical line stage will usually have an output impedance of somewhere between a 100 and 1000 ohms. So you can think of it as being a voltage source with this resistance in series (ie in between). So adding 33 ohms of resistance makes little difference to the overall output impedance.
The destination input impedance will be much higher than this, usually from 10,000 to 100,000 ohms.
So in an interconnect system, 33ohms is insignificant. What matters is how well it works, how good it sounds. (In fact the original carbon IC, the Van Den Hul "The First" had a resistance around 300ohms)
Another situation : speaker cables. Well a 33ohm resistance is not going to be good here.. The output impedance of the preceding stage will be a fraction of an ohm typically, and the input impedance of the next stage usually 4 or 8 ohms, so in this situation, 33 ohms will swamp the other impedances.
beautox, can you tell paco and us how to solder/terminate carbon fiber wire to its connection point?Unfortunately I never really liked any of the Van Den Hul carbon fiber cables... 33ohms/m seems very/extremely high to me and 300ohms/m!!!
Also, I can't imagine that 1m of carbon fiber wire is as non-reactive as a 33ohm resistor!
Edits: 11/14/16 11/14/16 11/14/16
So, updating my previous calculation for the VdH cable, you can see that the gain loss is still negligible, a fraction of a dB. The whole point is that you are not transferring power so much as voltage in an interconnect, and voltage loss is a function of current. Not much current = not much voltage loss.
> I can't imagine that 1m of carbon fiber wire is as non-reactive as a 33ohm resistor!
Maybe you lack imagination! Or rather, technical knowledge (without which imagination can lead to imaginary results.) There are formulas that let you calculate the inductance and capacitance of wires, and these formulas do not depend on the wire's resistace.
I think a more valid comparison is a 1 metre length of normal wire. Look at it this way.. in a CF wire, the resistance will be much larger than the reactance, so the overall impedance will be largely real (ie resistive) . At the other extreme, a zero resistance wire would have a purely imaginary (reactive) impedance. A normal low resistace wire would be somewhere between the two, but likely closer to the latter.
Using as a SPEAKER wire will instantly destroy the damping factor.
Tube amps already have fairly low damping factor and with the right speaker you might be able to get away with it. Of course, you WILL suffer some power loss which is calculable.
As an interconnect? Sure, why not? But maybe not with a passive linestage where gain might be an issue.
Too much is never enough
Well yes, it's no good as a speaker wire. That was the point of the comparison..
With a passive linestage the output impedance will typically be a lot higher than an active linestage, so the CF resistance will be even more insignificant, so there's no reason to worry.
Gain loss is negligible in either case; (suggest learn some basic electronics..)
Let's assume some numbers that are the worst likely:
Output impedance : 50ohms
Input impedance : 10kohms
With a normal wire interconnect, a 1V signal from the line stage will produce 0.995025 volts at the input device (ie amp)
With the carbon fiber interconnect, the voltage will be 0.991768V
So the gain loss is roughly 0.028dB (compare to the roughly 1db-per-click on a typical volume control, that's 1/35th as much)
Van Den Hul The First : imho they sound like an old tube amp - lush midrange, tubby bass and rolled off top end. They do have a certain musicality though, but it's hard to get past the weaknesses.
'learned' a long time ago. No need to be snarky.
Have fun with your new wire.
Termination would appear the next hurdle. Did I read some suggestion of Silver conductive epoxy? Will that stick to Teflon? VDH doesn't sell bulk wire for this reason.
I think a DOPED (addition of a conductor, in this case) Carbon Fiber to lower resistance MIGHT be in order and make it useful as a speaker wire.
In the future, I'd be looking forward to GRAPHENE in a variety of applicaitons.
Too much is never enough
Silver conductive epoxy... that sounds interesting! Where can you get that from? I guess it must be quite common?
Why is graphene any different from carbon fibre? Why not simply use quality copper or silver wire?
We used it to 'bond' quartz tuning forks to the substrate. This was in the early 70's when I worked at STATEK, an originator of this style of quartz oscillator. Our bread-and-butter product was a watch crystal which oscillated at 32,768hz. = 2e15
You can get it on Amazon or even RadioShack these days. Ours came cold packed in styrofoam with dry ice.
My understanding of Graphene is that it is (potentially) a SHEET product of x number of atoms thickenss. It MIGHT be useful to make planar speakers like Magnepan or perhaps Electrostats.
Small size applications would be in headphones or tweeters. I'd even think a RIBBON Tweeter element could be fabricated.
This material should be 'doped' in specific patterns, so in the case of magnepan, for example, NO wire would have to be 'glued' to the surface to provide a conductor. This ultra-lightweight diaphragm in conjunction with Neo magnets would (or COULD) have pretty good sensitivity and power handling.
New, and currently only imaginary designs are possible, too, I suppose. STay Tuned!
Too much is never enough
Sounds really interesting!
I'm not current since the 'state-of-the-art' changes fairly quickly.
I'm not sure if ANY applications are out of the lab yet.
I'm hoping for a room temp superconductor. But CarbonFiber might be better. I'm thinking REAL high voltage lines for long distances. Current practice is to us Aluminum for weight savings over copper.
Link to some light reading.
Too much is never enough
I would imagine that as graphene or carbon fire gets warmer/hotter the resistance will dramatically vary and get higher (probably, which should be an interestingly unstable effect), whereas I believe when copper or silver get warmer/hotter the resistance gets lower (should be an interesting effect)?
Edits: 11/14/16
Why use imagination when you have Google?
Temp Coefficient Copper 0.00386, Silver 0.0038, Graphite -0.0005
So the sign is right, but the magnitude of carbon's temp change is one seventh of copper or silver, so not what I'd think of as dramatic. If you increase the temp of this carbon interconnect by 10C, the resistance will decrease by about 0.1 ohm
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