Will there be any 'Arrow' mark in a Fuse holder?

Sid, my feeling is that a blind test would be unlikely to accomplish anything.

Most blind tests that have been reported in the past, involving things that would seem more likely to make a perceivable difference than fuse orientation (such as cables and even amplifiers), have resulted in a finding that no differences were perceivable.

Assuming that would be the outcome, the believers would allege that the skeptics did not hear a difference because of negative placebo effect (i.e., they did not expect to hear a difference so they did not). They would also claim, perhaps with some legitimacy, that they themselves did not hear a difference due to lack of familiarity with the sound of the system, or due to listener fatigue that might develop during the course of the tests, or due to other aspects of the test conditions.

Also, I would not characterize conducting such a test as "easy." Eliminating the possibility of differences being caused by extraneous variables, such as the ones I mentioned in my earlier post, would require very careful control of a lot of things. And at least several test subjects would have to be involved, to eliminate the possibility that the test result might be the result of guesswork (while not requiring any individual listener to go through an unreasonable number of trials, that might lead to listener fatigue). The inclusion of several test subjects again raising the issue of lack of adequate familiarity with the sound of the system.

Sebrof, yes we are talking about the ac mains fuse on the component. My suggestion would be that if you think you hear a difference, go back and forth a couple of times to confirm (allowing a few minutes for warmup between each reversal).

Best regards,
-- Al

I find it's harder to be skeptical if there is a rational hypothesis provided that's at least loosely grounded in the physics, acoustics, or material sciences.

How a fuse that's conducting AC, especially one that's not in the signal path, can have a real affect the sonics escapes me.

Should be able to measure SOMETHING about the fuse's conductive differences, right? Those of you with means, and one of these exotic fuses in mention, O-scope the fuse's A.C.(60Hz) input and output (with your component powered up), then flip the fuse and measure again!

Bdgregory, I too find I am skeptical without some explanation for why a tweak might work, but I am also convinced by a demonstration. I have heard nothing that would explain why fuse direction would matter, nor why there might be differences between fuses except for the materials in fuses, etc. My experiences with tweaks run the gamut from worthless, such as copper tubing over the pc entering the IEC, to minimum value, such as the Brilliant Pebbles, to a great improvement, such as isolating the pcs from the floor and walls, and variable tweaks, such as quartz disks made by Acoustic Revive and others. In some placements, they do nothing, in other they do wonders, and yet in others they are terrible.

Tgb, with 100s of customers reporting, results with pebbles vary, with best results circa 50-200%.

For those bringing down the curve, most likely operator error.