audiophil2020 OP
Don’t get caught up in this snake oil fuse voodoo, do some homework, and you find out that AC mains is "Alternating Current", and it changes it’s direction 60 x a second, so it’s impossible for an AC mains fuse to be directional!
All you need to know about fuses.
The only way a fuse can sound better, if it replaces old crusty one that seen too many switch on surges over time, doesn’t have to be $200 fuse, should be $2 same one but new, and the same result will happen, and switch-on surge ageing will be the same for both $200 fuse or the $2 fuse
A slow-blo fuse ageing over time right to left
https://ibb.co/8XGQf2z
A fast-blo fuse ageing over time left to right
https://ibb.co/QcKk94M
Your better off spending $2 on a "new original fuse", and save hundreds.
Cheers George