Audiophile Fuses - Are We Certain They Provide Protection?


This thread isn't posted to debate whether sonic benefits can be recognized from audiophile/after-market fuses.  That topic has been well debated through numerous threads already.  What I'm curious about is whether today's audiophile fuses are certain to provide protection to your gear - afterall, that is the absolute main function of a fuse in a circuit design.

I was struck recently reading a thread dating back to 2014 on the Audiocircle forum where the late Roger Modjeski was absolutely beside himself and angered by professional reviewers and manufacturers alike for leading consumers astray (in his opinion) towards use of these fuses, from a first-hand account of damage inflicted on one of his amps.  

Re-posting his message below:

I had several email exchanges with the maker of Tuning Fuses and got the same Red Herring responses. My first experience with his product was in an RM-9 MKII that came to me for service with eight tuning fuses (one for each tube) in place of my specified HIGH BREAKING ceramic fuses. The tuning fuse's inability to do their job properly had blown the wirewound cathode resistor, which I had never seen before. I study every failure and this one caught my attention because it takes a lot of energy to blow that resistor. Its wire is much stouter and of a very high melting material, any fuse should go first.

Of course I opened up the fuse and looked at its construction. It was made in such a way as to be the worst possible fuse for that application. I called the distributor here and asked is it was a high breaking fuse and suitable for a tube fuse. He didn't know what that was. I said well the fuse specified for my amp is high breaking and ceramic. He said that because his fuse was ceramic also it must be OK. This is very naive. He doesn't know and perhaps the maker doesn't know that a high breaking fuse is made a different way, though from the outside it looks the same.

These fuses are totally inappropriate for any high voltage DC application such as a tube fuse in an amplifier. What also amazed me is that these fuses cost more than most tubes. I felt sorry for the owner who had been led down this path by irresponsible magazines like Positive Feedback. Not only did this fuse not protect his tube but it did not protect his amplifier.

The maker of these fuses, like many makers of tweaks will certainly get no admiration from me. What gets me is why so many people want to play with tweaks rather than make real improvements in their system like bi-amping, adding a good subwoofer and simplifying the signal path.

As this experience is now 7 years old I wanted to survey our forum to see whether high-end audio fuse manufacturers are providing data that would give the audiophile community assurances that use of their fuses first and foremost provide adequate protection.  I welcome any input.
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I tend to be cautious where power delivery is concerned and will NOT install any component (fuse, power cable, etc.) unless it's UL-listed.
No listing, no sale. 
I want to know how to test my fuses to make sure they will blow as specified but need to hear MC's methodology for this.  Short of passing say 5 amps of current through a 3A fuse and confirming it indeed does blow and work as designed, what is the method for for confirming the fuse works w/o blowing it!
The easiest way to test a fuse is to measure the voltage drop across it at different current increments (fuse resistance increases with temperature). If the voltage drop stays linear for currents up to and slightly above the fuse's current rating, it will not blow. If the voltage drop increases at the rated current and goes up exponentially a little past the rated current, then it will work. You will need an accurate power supply and a digital multimeter.


Hilarious. Jordan Peterson says never ascribe to malevolence what could be incompetence. I just never dreamed... but there it is. Hilarious.
Is it reasonable to expect consumers of fuses to spend hundred of dollars on an accurate power supply in order to test and trust the fuses they place in gear? Seriously, who does this? Please chime in if you’re testing all of your fuses in this manner. Apparently I'm incompetent in that I don't own a power supply like every other audiophile.