fuses - the $39 ones or the 85 cent ones

If you stand in front of and away from the mirror a hundred times, you will start to see yourself differently.

If you have to squint to hear a difference, then perhaps there is no difference.

Try "Difference & Repetition" by Gilles Deleuze. It might help.

Agreed!

This puts the naysayers (me, perhaps) in a bad spot. If someone can really tell, say 90% of the time when the hi-fi tuning fuse is installed, than some of the brain trust has to figure out WHY.
Those who try this, please keep track of '
1. number of trials
2. who did the change
3. Results
4. What fuse / used where / what equipment.

That should 'bout do it for now.

Personally I am more skeptical than most but if Dave_b is happy with his fuse experiment it sure as hell doesn't bother me. Does he believe he hears a difference? Yes.
Do I believe there is a difference? No.
Who's opinion matters? Pretty simple really.
Enjoy your $39 fuses Dave.
I'm happy with my system and am not ever going to spend my time trying to improve it with $39 fuses. The amount of time it would take to conduct the experiment is more than I care to invest. If I want to improve it I'll look elsewhere... new amp, new source, tweak the room treatments maybe.

Well, I am late to the dance, but it seems that all the discussion focuses on the Hi-Fi Tuning fuses versus stock fuses. I have always used IsoClean fuses as they came out well before the Hi-Fis and are or were cheaper. I have twice tried the Hi-Fi Tuning fuses versus the IsoCleans. IMHO the Hi-Fis are second best. I also confirmed to my satisfaction that the Hi-Fis are directional but that there is nothing about them that predicts which direction is best. All that you can do is to try all both ways. This is a real pain. The IsoCleans have clearly marked direction and in using about 20 of them, I have never found any mismarked. I first started trying different fuse direction at the request of Lloyd Walker with his motor controller.

I have also committed the sin of treating fuses with AudioTop contact cleaner and most recently with the Enjoy the Music award winning AVM paint. You only paint the glass, of course.

I have found all of this much more important than ac power conditioners and almost as important as lifting all but one ac ground. Although some recommend lifting all grounds, I have not found this to be best.