So . . .
electrical phenomena science has yet to discover . . .
fuses printed with electrical schematic symbols unknown to any professor at MIT . . .
fuses that need 200 hours of "burn in" . . .
fuses using "passive Quantum Inductive Coupling" methods . . .
I'm out of here. Heading down to the used record store to buy a stack of CDs instead of a fuse made of placebonium.
Welcome to my, apparently "uneducated", universe. One where rules and not magic govern the laws of physics. I love Harry Potter and Lord of the Rings for entertainment purposes, but I am not ready to believe that swishing a wand will make my components sound better, ESPECIALLY when the wand is a $2000 gadget and the one telling you it will work better is the one making the profit from the wand.
Your questions is what I look for: where is this 'directionality' coming from? From the fuse printed by the company to charge you $500 for it. Sure! Believe them, don't believe science! What do researchers know, let it all in the hands of marketers to just sell you air.
Hey! There's an idea!!! I will box air and say that it has better sound transmission characteristics than your house's air, and that sound will be much better if you unbox the air prior to a serious listening. You would need to give the air 20 minutes to just get in the same temperature as the air in your home, and then you will enjoy much clearer sound. I bet lots of people will swear as to hearing the difference!!! I could actually manage to turn around the phrase: "sell air" into something really profitable! I just need to label the box so it has directional arrows and I'm golden.
Heck, I don't mind sounding arrogant! I am always willing to be proven wrong, but by something more tangible than: "only I and my super gear can hear the difference, you must be deaf or have poor equipment". Can it be measured? Is there any logic behind that?
I asked the same questions as you: if a fuse has a directionality, it can surely be measured, as in: current will flow in one direction and not in the other. If that is the case, one way will transmit energy, the other wont. Its a: it either works or it doesn't type of scenario. Its not a: in this direction the sound is much better, in the other the current worsens the sound. That is just absurd, no matter how hard companies selling $500 fuses for printing over a $2 fuse an arrow try to convince me otherwise.
And I will try to keep people from being cheated by that mentality. I may save a person from wasting their hard earned money.