Once upon a time, I was anal about fuse and interconnect directionality, mad really but I thought I heard a 'difference.' What killed it for me was replacing a major item I'd 'tweaked' that way with something 'straight out of the box' that out-performed it in every way, making all my so-called 'tweaks' redundant at a stroke.

The interconnects I often use now (NVA) have absolutely no direction to them and even other cables I thought had, seem to 'settle' into whatever 'way round' they're placed within a very short time. Worst by miles was the long obsolete Chord 'Solid' which when raw, was so bad that if one of a pair was placed the 'wrong way round,' the perceived stereo image shifted over - these cables were microwave frequency cables I remember with a solid silver? core in a flexible copper pipe.

You see chaps, so many of you lot are talking about the effin' SOUND all the time and NOT ONE COMMENT about the music! Twenty five years ago, I had a system capable of excellent 'sound, realistic dynamics and levels of 115db in-room (excruciating but well able to do a well recorded drum kit justice in real life dynamics). Today, my geriatric antique stereos play THE MUSIC's emotional connection to me superbly and enable me to suspend disbelief in whatever gear I'm listening through and 'HiFi Sound' be damned. Lest you think I'm going mental, my opinion is that most valve-n-vinyl lovers do this automatically and in all honesty, don't effin' care, despite objective repeatable fact supposedly telling us these sources and amps are 'inferior' to the best available today...

If you really derive great pleasure from replacing a mains fuse, even in situations where it's not strictly necessary and you can afford this kind of expense, then fine, but just remember that a few years down the line, you'll wonder what all the fuss was about after some components have been upgraded.