Something For The Fuse Guys ...

Had to think twice before posting here as I may be perceived as a heretic. But I think just for the sake of people who stumble across this thread looking to learn something it has to be said that any amplifier which sounds different after you change the fuse has some pretty dodgy engineering.
Fuses are there for one reason - to protect you and your equipment from harm. A design engineer has put them there for a reason and if they've done 1/100th of a decent job they will have no impact on the sound whatsoever.
I would never design an amplifier without correctly rated fuses and I would never put them in the signal path... To qualify what I mean by the 'signal path' I mean the conductors that carry the signal - power supply rails are not part of the signal path (I have a feeling that some people here would claim my fridge is in the signal path because it's plugged into the same ring main).
Let's assume that the fuses we're talking about are between the transformer and the rectifier, that would mean that any small change they make have to survive the AC signal being chopped up by the rectifier, smoothed out by the reservoir capacitors and ignored by the ripple rejection designed into the amplifier... and that's before they even get near the signal path.
Running off batteries is a different matter, they deliver a clean DC supply with a low impedance and regardless of fuses may show an improvement to sound particularly with phono or headphone amps.

BS tweak vendor Geoffkait (Machina Dynamica)

Just looked at the website... that's hilarious, I'll bow out gracefully now. Geoffkait, feel free to have the last word.

I was going to stay out of this but some of these posts are irresponsible...

has anyone ever burned his house down because of a faulty fuse? Has any amplifier every blown up 💥 because of a faulty fuse? Has a house ever burned down 🔥 or amp blown up because someone bypassed a fuse?

Yes, yes (depends what you mean by 'blown up', but bang, smoke and fire are all possible) and yes... incorrectly rated or bypassed fuses are a fire hazard. There is a possibility that any component in your amplifier could fail at some time - whether that component fails open (safe) or closed (short circuit) is down to the component and the particular failure mode. In the event of shorted power rails the fuse will blow to both protect the non-faulty elements in the circuit and ensure that the current is stopped. If a 100W amplifier fails short then that 100W energy needs to go somewhere and it creates heat, the traces in a circuit board or a wire may not be able to dissipate the heat effectively and that is when you are at risk of starting a fire. The fuses are there to prevent damage and injury, if you bypass them or replace them with incorrectly rated fuses you are increasing the risk of both.

It's worth noting that amplifiers often use slow blow fuses which will tolerate the current surge whilst the reservoir capacitors charge. This means that if you replace a 1A slow blow with a 1A fast fuse it may well blow during the inrush. If you then decide to go with a higher current rated fast fuse that will tolerate the inrush it may not blow under fault conditions.

There's no reason not to experiment with fuse types (other than you shouldn't expect the audio performance to change at all) just remember that you're experimenting with a device that is there to protect you and your belongings.

 Is there anyone left on the planet that doesn't know to unplug their equipment before working on it? How many of us learned not to stick our fingers into an unused wall outlet by the age of two?

Unplugging is the first step... reservoir caps will remain charged for some time depending on the size of the bleeder resistors and are able to dump their load almost instantly. You can weld a screwdriver to the terminals if you use one to short them, I've done it (unintentionally).

I've no problem with people taking risks themselves (we've all done it) but we shouldn't advise others to do the same without highlighting the risks.

Just curious, pragmasi ... have you tried any of the after-market fuses in your system? 

I've used many different fuses in many different designs but not the ones referenced here, I would remember if I'd spent $120 on a fuse. I don't wan't to spoil anyone's fun and if they have the money and want to give it a go and make their own decision that's great, just select the right ratings and take a few sensible precautions.

I'll try and answer your questions as well as I can.

I design and build amplifiers, and although I shouldn't admit this given my previous sermon on health and safety - I have tested designs with no fuse at all during the early prototyping stages. I have a two stage approach with testing a design, the first uses lab equipment to ensure the design performs as designed and is stable in all likely scenarios. The second is extensive listening tests (I think I'm well over 200 hours on my latest design that hasn't even made itself into a proper chassis yet). 
My engineering knowledge tells me that fuses will play no discernible part in the sound of the system and my experience bears that out.

I guess an analogy is that when I play pool I never feel the need to move the beer chiller further away from the table in case it's gravity affects the balls' trajectory. If someone told me I ought to then I'd not be pressured into doing it and if they told me that they'd done it and it improved their game then I'd just move to another table and try to ignore them.

Just out of interest and I don’t know the answer to this... do any ’high-end’ manufacturers use boutique fuses in their amplifiers?..'he says failing to walk away from the table.'