What is the science behind audiophile fuses?

@carlsbad2

"So SDFB, designed and built one and did a very nice job."

In our world, $400 for "a very nice job" on something that is actually useful should probably be considered a bargain.

Even if I find the right breaker, finding/buying a suitable box and putting it all together would take hours and even more money. In the end, it still would not have the self-resetting capability of the SDFB. I will probably break down and buy a couple of them for my monoblocks. I would like to consider removing the IEC from one end and hard-wiring a decent power cord pigtail, if that is possible.

That is certainly possible. eliminate the fuse holder is always a gain.  the fuse holders have to be a metal that has spring so they are often a poor conductor. 

Jerry

Re: blowing audiophile fuses. One of my tube preamps will blow a touchy audiophile fuse if the amp's feeding component (dac in this case) is turned on while turning on on the tube amp. In this situation the dac is first turned off before turning on the preamp. This has ended blown audiophile fuses.

@carlsbad2 - Have you experimented with whether different fuse replacement slugs make a sonic difference? I ask because I have a solution coming that will allow me to replace the 10A fuses in my monoblocks, so I was looking at options to replace the fuses. I have a hard time believing the $200-300 Graphene Sluggo offered by Underwood should make any difference at all compared to copper. In fact, I have 6.5 mm (~1/4 inch) OD copper tubing with 0.5 wall thickness here and I suspect that would work just fine. The resulting area would be equivalent to greater than 5 awg, which is far larger than the connecting AC wires inside of the amp. Any experience?

In the entire power chain, from nuclear reactor through to your component, the piece with the greatest resistance to flow is the fuse, at least among the pieces you have any control over. It would logically follow that assuming input power had any effect (a whole other topic!) it would be the fuse that has the greatest effect.