If you can’t hear the difference between a Buss fuse and a SR Blue fuse
then your audio system is not that resolved ,or have a hearing Problem !!
Naaaaa, ya gotta get this right, it’s more that you don’t have any expectation bias because it wasn’t you that paid >$150 for a 50cent fuse, but your gullible buddy who owns the fuse did poor sod.
And just to add before it comes, "AC mains fuses are not directional", as the mains changes it’s direction 60 x a second that why the US it called 60hz mains frequency, in Australia it’s 50hz.
Cheers George