Periodic replacement of Audio Grade Fuses?

We tend to think of fuses in an almost binary sense, ie the circuit is closed or open depending on fuse state.

But fuses are resistive devices designed to essentially "burn out" at the right time. Heat is generated to various extents at all times by design to accomplish that goal as a result of resistance designed into the fuse . I suppose its very possible the heat alters the composition and electrical conductivity characteristics of the fuse element prior to "blowing" in a manner that might effect the sound as a result in changes in electrical properties at some point perhaps compared to "new".

I'd be willing to bet that this is perhaps a reason why some hear a difference when replacing an old fuse with a new one, especially an "audiophile" type fuse where one is perhaps tuned in and listening for a difference by design when making the change. Better electrical contacts at the fuse holder as a result of the replacement operation is likely another at least as significant as anything else. Some report "Better sound" replacing a fuse with even a fresh conventional fuse compared to some fancy fuses.

It's all about as clear as mud but this makes as much sense to me as any other theory or reason why different fuses might sound different.

Replace all components the moment they are fully broken in, because after that point, degradation is surely occurring.
Knowing this you will never be able to just enjoy listening to music.
Jeeze, Louise...

Another fuse thread, oh no.

I do not suggest that this manufacturer is correct, however fuses do wear, depending on how close to their rating they are used. Typical fast blow fuses are spec'd to carry the full current rating continuously (well almost, for more than 1 hr), and burn at 2x the current rating in about 120 seconds. If you operate a 1 amp fuse at 1 amp current for, say 30 min, you will notice the element deforming as it is close to melting. For most common fuses that don't have precious metal fuse links, this deformation occurs at high temperature and will induce oxidation in the fuse link, potentially increasing it's resistance. However, one would think that a manufacturer using gold, Pt, Ir or other PM wire would not see this effect.

And of course, to see this effect the fuse needs to run close to its rating, or even above routinely. For conservatively designed equipment running well below the fuse ratings, I doubt if the fuse "wear" would be descernable.

A common application where fuse wear is really noticable is in many older German cars (BMW, VW, Mercedes) where those open construction ceramic "bullet" fuses were common. After many years, you will see twisted and distorted elements, even though the fuse has not "blown".

Thanks for all of your responses. I plan on keeping these fuses in my amps for as long as they function. The note on their card does make me wonder how many customers do actually replace every 6 to 12 months though.