Elduende, if you decide to buy a new hi-end fuse try this before installing it.
Remove the current fuse, wipe the tips clean, and re-install it. See if that alone provides some improvement. Then, try the new fuse and see what you hear.
My guess is that in many cases, just cleaning the current fuse contacts accounts for most or all of the improvement. However, since most don't try this two step process, they attribute all of the change mistakenly to the new fuse.
Remove the current fuse, wipe the tips clean, and re-install it. See if that alone provides some improvement. Then, try the new fuse and see what you hear.
My guess is that in many cases, just cleaning the current fuse contacts accounts for most or all of the improvement. However, since most don't try this two step process, they attribute all of the change mistakenly to the new fuse.