Determining current flow to install "audiophile" fuses.

Tbg  you're right, there are numerous observable phenomenon yet to be explained by our current knowledge of physics.

This is true, but if you've not tried to correlate that voltage drop across the fuse and its holder, you don't know if a simple explanation is the cause.

IOW assuming that what you hear is due to some sort of woo factor without trying a simple measurement is likely going to result in an incorrect conclusion.

  I know physics has not totally mastered natures laws, so you cannot say there is no physical explanation in EE for why fuses would differ.

This statement seems self-contradictory. Is this really what you meant to say??

Note the quotation marks around "many." How telling. There isn't even any actual evidence that SR "quantum tunnels" (man…nice choice of terms there SR, as not only does it not make sense, it sounds great!) anything with their silly claims of having their Chinese factory treat this tiny wire with "2,000,000 volts" of unobtainable juice, any rational explanation of why they would do this, or why the ratings on the fuses is apparently dangerously incorrect ("buy the higher rating just to be sure it works" has actually been suggested by the promoters of what is essentially a safety device). People's imagined claims that these fuses do something and then do it better reversed should be regarded as the weirdly imagined nonsense that it is, and the rabid promotion of these products by a few zealots is a shameful fraud. Buy a reliable Littlefuse and save the 100 bucks for some sandwiches…you'll feel like everything sounds much better...

Reading all these INSANE claims about audiophile fuses / directional fuses has convinced me that I'm in the wrong business. I could literally be getting fused knocked-up in some Chinese factory for a few cents each and sell them to the gullible "audiophiles" for $30 each. And you know what, while it would be a complete bunch of snake oil, the crazy audiophiles would be happy with their black & gold colored fuses, their brains would somehow hear a difference, and we'd all be happy. So, I COULD actually live with myself/sleep at night! 

+1
Never a truer word said, also AC is Alternating Current, which changes 60 x a second, or 50 down here in Au.

Cheers George