John Curl's Blowtorch preamplifier part III

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Do I really need to mention the other end of the resistor returns to the battery?

Yes, in fact you do. It makes a very significant difference how the return current gets back to the battery.

You are claiming something with respect to prop velocity, but not worried about the entire current path? That is not how it works..

Velocity of propagation requires both conductors, as you are speaking about the e/m field moving along the conductors.

A large loop carries with it higher inductance.

jn
 
Well as I see it one ampere of current is a coulomb of charge passing through a conductor per second. Now for some confused folks this is not the same thing as how long it takes an electron to do that. The electron that enters the conductor carrying the charge is not the one to quickly leave.

In my one meter long cable it takes about 30 nanoseconds for a charge to first enter before one leaves due to the finite propagation velocity. As a coulomb per second is 6.24e18 ish charges per second 30 nanoseconds worth would require about 1.87e11 charges to be in transit in the one meter wire per amp of current.

In my test apparatus there is a test signal of around .01 volts driving the cable under test and the load is over a megohm or a current of less than 1e-8.

That would leave 1.87e3 charges transiting through a one meter test cable at any instant.
 
Huh? The topic of discussion has been around cable construction, as silly as it is, where propagation velocity is going to be constrained by the dielectric. And also this is entirely meaningless within the essentially DC bandwidth known as audio. Even respecting what jneutron cites about extremely small phase changes with frequency.

How about my question, if 90-100% of cables used from the artists to the LP/CD are PVC, why are we trying to improve on that? What do we have to gain? Are we "losing" something in sound for every increment of dielectric after the original process? Did the recording studio lose something because they don't have fancy cables? 🙄

What function of audio playback system has an issue with propagation? Do we have a dysfunction because some slew rate is too slow but it would equal out with improved propagation speed? What is the *problem* it would fix, if any?

Now, don't get me wrong, I like insulation that is easier to deal with... And I don't want high capacitance. But we aren't talking about using garbage, at least I don't think anyone is...
 
Well as I see it one ampere of current is a coulomb of charge passing through a conductor per second. Now for some confused folks this is not the same thing as how long it takes an electron to do that. The electron that enters the conductor carrying the charge is not the one to quickly leave.

In my one meter long cable it takes about 30 nanoseconds for a charge to first enter before one leaves due to the finite propagation velocity. As a coulomb per second is 6.24e18 ish charges per second 30 nanoseconds worth would require about 1.87e11 charges to be in transit in the one meter wire per amp of current.

In my test apparatus there is a test signal of around .01 volts driving the cable under test and the load is over a megohm or a current of less than 1e-8.

That would leave 1.87e3 charges transiting through a one meter test cable at any instant.

Hmm. I think I misplaced something here...what was it.. Hmm..

Oh yah...the other wire. Remember, the one where charge is going the other way??

Hmmm. Some dead guy comes to mind..Norton? Thevenin? Kirchhoff?? That's it. Kirchhoff, captain of the enterprise....space charge, the final frontier...


Jn
 
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Ed.. Imagine a sphere around your battery. At every instant in time, the number of electrons within that sphere remains constant. Electrons that cross that imaginary sphere outward in one conductor are balanced exactly by electrons crossing that sphere inward on the other conductor.

For a step function, the current is dependent on the reactance between those two wires.

Jn
 
Ed, they won't let this go, current has to flow in a loop and how it gets back affects what happens as much as how it gets somewhere. Therefore you will need to specify something, wire over ground, coax, twisted, etc. It matters when you get down to arguing about edges and wave equations, etc.
 
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