What is the science behind audiophile fuses?
There were many threads on the topic of "audiophile fuses" on this forum, and I sure don't want to open old wounds and trench warfare. The fuse on my preamp blew suddenly two days ago, which prompted me to search for a replacement. That's when I came across the term "audiophile fuse" and the fact that they demand far-out prices. Deeper curiosity brought me to several other fora, where users posted glowing praises about their Zero fuses and other exotica. Now I am a scientist, but not a physicist or electrical engineer: so please enlighten me! How can a fuse have an audible influence on the signal, when the signal does not even pass through it? How can a fuse be "directional" when it deals with alternate current? I mean, if I recall my university physics, a fuse is basically a safety valve and nothing more. Am I completely missing an important point here? My scientific field is drug discovery, and because of this background I am thoroughly familiar with the power and reality of the placebo effect. I that's what I am seeing here, or is it real physics? I need objective facts and not opinions, please. I really appreciate your help!
@mitch2 I've trusted copper. I make my own slugs from high conductivity copper I buy from Mcmaster. It isn't very expensive. I haven't bothered with silver or graphene slugs. I know people trying slugs made of worse conductors like brass or even steel alloys. these are much worse conductors than copper but much better than a fuse (becasue of the cross sectional area). So I know there are lots of opinions here but I stick with copper. Jerry |
@pproctor You are correct. the fuse is indeed the biggest resistor in the entire line. (there is some voltage drop over the long lines). so that is why we want to repace or eliminate it. The best option is to find something that provides protection but isn't a resistor--thus the SDFB. I like on many components that I don't expect to fail, to just raw dog it with no protection and replace the fuse with a slug (some think this is crazy, they are entitled to their opinion). and finally, there are expensive boutiques fuses that try to protect your gear with less negative effects, with limited results. Jerry |
When my amps were finished in 2020, SMc Audio had begun doing away with power switches (mine have none) but it wasn’t until a year or two later that they found magnetic breakers that they were comfortable with using to replace fuses. Apparently they ruled out more than a few manufacturers/models that didn’t sound so good, until they found one they liked. The magnetic switches they use, like in my SMc DAC-2, serve three roles:
Their source is proprietary but I am going to receive two of them (10A) that I plan to use for a solution external to the amp chassis, but that will not require an extra power cord like the SDFB. |
My experience using Sluggo’s is that they are similar to tubes or cables. Each metal has it’s own sound signature. Copper warmer, silver more detailed and revealing, silver/rhodium hollow in between. But the graphene/copper slug was another “Oh My” moment and made the biggest improvement in SQ. Sluggos take many hours to break in and as crazy as this sounds some sound different if you switch their direction after break in. I am somewhat in Carlsbad2 camp where I only use the SDFB for my tube components with rectifiers. All other components with power input fuses I use sluggs without protection. I feel the very low risk of failure and the cost to repair the component is cheaper than buying more SDFB’s. I have never had a power input fuse blow just internal fuses protecting rectifier failures. Some are connecting a single SDFB to a splitter or outlet box and plug in multiple components with the same amp rating to avoid buying a SDFB’s for each component. Not sure of the science to it all but Sluggos do make a noticeable difference in SQ. |
Reading through this thread leaves me open to the possibility that line fuses, being essentially variable resistors, may have a discernable effect on sound quality. If so, the difference is likely to be confined to fuse vs. no fuse, such that replacing a Bussmann fuse with an "audiophile" fuse is likely to be of no import since the latter is still a variable resistor. So I would have to agree with @carlsbad2 's quote above. The best way to achieve this, though, is not to install slugs of various metals that can’t possibly make any audible difference, insofar as they are cradled in uber-cheap fuse holders made of common steel. Desoldering and tossing that 10 cent fuse holder and jumpering a length of appropriate gauge wire in its place, thus essentially hardwiring your power cord to your equipment's PCB as @mitch2 suggested, seems the sensible way to go. As far as the Swiss Digital Fuse Box, it answers the safety question, but it seems highly unlikely that any device sitting inline with your power cord AND needing a 2nd power cord in order to function would not impart its own sound signature onto your system, just like power cords themselves have their own sound signatures. Can the Swiss Digital Fuse Box be truly neutral sounding, or is swapping it for a fuse a case of robbing Peter to pay Paul, so to speak? How about magnetic breakers, can they be free of effects on sound quality? It is of course easy to take the fuse thing to absurd extremes that attract scorn and ridicule, but there is a sound case to be made for eliminating them - in a way that ensures safeguards remain intact of course, or are even improved. Fuses are not that good at doing their jobs anyway, so it is interesting to read about what can be done to improve upon the current situation. |
