What is the science behind audiophile fuses?

@curiousjim

Ok, here goes:

How can a fuse have an audible influence on the signal, when the signal does not even pass through it?

I don’t believe that a fuse does have an audible influence on an audio signal, for the reasons presented in my previous post, among others.

How can a fuse be "directional" when it deals with alternate current?

I don’t believe that an input fuse subject to alternating current would display any different properties or sonic signature regardless of which way it is oriented. While electric current flows from higher electric potential to lower electric potential, in the case of alternating current, the flow of electrons is bidirectional, i.e. electrons flow in both forward and backward direction.

In case of direct current, flow of electrons takes place in only the forward direction so the flow of electrons is unidirectional. Therefore, if there were directional differences in fuses, they would likely only show up when used in a direct current application, IMO.

@reimarc also asked about our experiences. Although I hear differences in a variety of different equipment, all speakers, and, to a lesser extent, cables, I have yet to hear what I consider a meaningful sonic difference between fuses after trying many including SR, Furutech, ACME, several from HiFi Tuning, and others.

Also, I have yet to read a comprehensive explanation of how a power line fuse should change the sound of an audio component given that regardless of the materials used, it’s job is to pass current up to a given amperage to a power supply consisting of a variety of other parts. I have also never read about any listening tests where the listener reliably identified different fuses without knowing which they were listening to.

Finally, you asked for opinions and I gave you mine. My system is posted (but not quite up-to-date) so you can see the gear I am using to develop my opinions. I do not care what others here believe or how they spend their money, so for those here like @rodman99999 who want to turn this into a contest or dispute of one side against another, I simply don’t care.

@reimarc -

      Being so familiar with the LHC: you should also realize that the goal of it's use by the planet's best Physicists, is to determine (HOPEFULLY/one day) to determine what makes up the 95-96% of the universe, that the best in the world can't explain and how it all works.

       They and it utilize " the same basic electricity and electro-engineering principles, all the way to superconductivity. "  because that's the best they've got, to try to answer the questions how it all works.

        As I've repeated constantly in these threads: For centuries; humanity’s seen, heard, felt and otherwise witnessed phenomena, that none of the best minds could explain, UNTIL they developed a science or measurement, that could explain it.

         Anyone with a background in any of the natural sciences should be aware of those facts.

           And the Cargo Cult wants definitive reasons for a fuse to make an audible improvement?  

There is actually a reliability difference in fuse TYPES. ATO fuses are more reliable than 3AB or 3AG.  Yes, in my days doing failure analysis, I found termination issues in 3AG fuses. There is a tiny tiny inductance with some cartridge fuses. Sonically? I think that was covered.   🤣

Some "Madison Ave. Engineers" suggest breakers sound better.  Hmmm, resistive bimetallic, small point contacts, inductor and magnet?   Not sure I would bet on that. 

Jan Didden has a lot to say on fuses and protection circuits. Cordell and Self a little.  Like everything, you have to pick tradeoffs. There is no perfect answer. Fuses may protect your speaker, but I can verify first hand, they so not protect MOSFET outputs!  They do not protect for instability. They do not protect against over-heating.  They do not protect for DC leakage or bias inaccuracies.  My take away is you should use a fuse or breaker in your mains line where it has zero sonic effect and go to more advanced parameter monitoring for everything else. 

 My original question should have been more focused perhaps: "Can anyone in this esteemed forum share  experiences - good or bad - with so-called audiophile fuses?" Formulating my question in this way should exclude theorizing on either side of the opinion-spectrum, namely dogma without supporting or damaging evidence. And to satisfy this demand, we do not even have to resort to Einstein or Maxwell, or Lord Kelvin with his infamous statement about human flight. No, we just have to sit down and listen: do we enjoy what we hear? Do we enjoy it more after exchanging one fuse for another? Do we perhaps hear new things in a familiar recording? It's really simple, actually, and quite down-to-earth. But it requires ear-wax removal - in the literal and metaphorical sense - to lead to accurate and valid and reproducible results. That's the only information I was after when posting my original question. Only AFTER we have the data from these experiences - hopefully with more users having similar experiences  (moving towards statistical relevance here), should we begin to make sense of our observations, and perhaps even formulate a new hypothesis trying to explain what we observed that cannot be accurately explained by existing theories. That's how science works, not the other way around.

                                          Why didn't you say so?

     If you're looking for a survey regarding whether others have found them efficacious: I'm certainly not alone in my experience and enjoyment of improved fuse technology.

      It's only logical; if audiophile fuses didn't serve to improve the presentation of more than just a few folks' systems, there would be no supply and/or demand, AT ALL.

       Personally: my experience began with the Hi-Fi tuning Gold, which was the least expensive and easiest to obtain, installed in the Mains and B+ protection of my Cary tubed monoblocks.  The improvement was obvious, with a marked difference in what I term "organics" (more real/less electronic, across the board).

        Next were their Supreme fuses, with which I found even more openness, naturalness and texture of presentation.

        Those last were experimented with, next to a pair of Synergistic Research SR20 fuses, only in the amps' B+, which I thought imparted an unnatural effect on my system's high freqs.    Back to the Supremes and relaxation.

         Last time a power tube went South and took out a B+ fuse, rather than wait to enjoy my sounds: I reinstalled an SR20 in that amp and found it to excel in presentation, over the other (RT to LT).    However: by then my main speakers had morphed from Magnepans to a pair with coincident horn tweeters.    A happy combination/variable.   In went the other SR20 and: they've remained

         I've always simply been certain to install all fuses in the same direction (according to labeling).    So: never having experimented with swapping them, I have no experience to discuss.    

         I do have science to explain WHY such MAY make an audible difference, which will follow.

         Were I not familiar with the theories, hypotheses and experimentation, that's gone on for so many decades before and since my years of higher education; I might never have tried a more expensive fuse.

          That's just my experience with the fuses in my Main amp.    There's been much more, in every other of the system's components, which have all had power supply modifications/upgrades (ie: faster/quieter rectifiers, capacitors, etc), before and after fuse swaps.

           It's been my experience, the better the rest of the power supply: the more obvious the fuse's contribution to sound.