What is the science behind audiophile fuses?

Fuses have to heat up and blow to protect the downstream equipment.  So they have to have a significant resistance (to heat up) and as current goes up, they heat up, resistance goes up (a property of all metals) and they heat more and blow.  This isn't a problem for electric motors or household equipment.  but a high end amplifier can have dynamic changes in power requirements over a very short time which can be limited by the fuse.  If this happens to your air conditioner, it will still cool.  If it happens to your amp, it will still make music, it just won't be as dynamic. Bass will suffer as well.  

An audiophile fuse supposedly has less resistance and limits current less.  I have never bought one and don't plan to.

I replace fuses with slugs.  an overcurrent situation in an amp is very unlikely and when it does happen it is usually caused by user error.  There is a very audible difference in most amps replacing the mains fuse.  This is especially true of tube amps.   Also if your amp has fuses on the rectifiers they should be replaced.  

No your amp won't burst into glorious flames but if you can't get this image out of your head, keep your fuses.

I have tested the Swiss Digital Fuse Box that replaces the fuse with a magnetic current sensor and a relay, thus there are no heated components in the power circuit.  My opinion of this piece was that it was better than any fuse but not quite as good as a slug.  It is also cheaper than an audiophile fuse.

Jerry

@carlsbad2 when you refer to slugs what exactly are they, do you make your own or where do you get them?  Curious minds want to know 

@noromance 

Visiting Chuck Miller's Millercarbon room at PAF gave me the opportunity to check in on Townshend Audio, a quirky British manufacturer of audio gear best known for its well-engineered and very effective isolation products.

Not entirely clear whether MC had a room with his personal kit that happens to use Townshend products, or whether his was actually a room representing Townshend. 
It seems Townshend would want to have a say in the gear used to display their products since the resulting SQ would represent the brand - maybe they did?

BTW, back to fuses, I have done the Teflon tape thing, and also used small orthodontic rubber bands across the tops of the fuse holder tynes to insure a secure connection, after first treating the end caps with a conductive material (i.e., ProGold, etc.).

Audiophile fuses are generally supported by those who spent a pile on them and are wallowing in expectation bias. Magic Fuses have never gained acceptance by the vast majority of audiophiles and certainly not gear manufacturers as there is simply no need to use them when companies like Litttelfuse and others make great fuses that work properly. Fuses are simply tiny wires designed to protect your gear and are not part of the signal chain...period.  However, if an expensive item that has no impact on the sound of your system makes you feel better I suppose that has some value.

@tksteingraber Slugs are solid copper jumpers that replace the fuses.  No protection.  --Jerry