I have a fuse holder in all my units connected the same way (current source inside fuse holder) and found that two purple fuses of the same value but purchased from different vendors sound best at different direction.
One fuse market T (Trage for German market) sound better when put according to letters, and the other fuse marked S (Slow for US market) sound better installed in reverse direction against the letter.
is it possible that tunneling direction may vary from fuse to fuse or it should be rather consistent and all fuses should sound better either according to letters or against the letters. Thank you.