Aftermarket Fuses

It's a fuse, and if it is functioning as designed, to protect the component, it will have zero impact on the tonality or performance of any audio component, regardless of what people think they hear in "premium" fuses. Standard Littelfuse products are all you need, the rest are simply a scam to sell you things. You're welcome.

The only aftermarket fuses I own are some I bought in perhaps a crazed moment like eight years ago (when they had to have been only like $25 each, No way would I have paid more). When I cleaned up my Magnepan 3.6 to sell, I noticed the HiFi Tuning fuses in the 3.6.So I took them out and stuck them into my new 20.7 Maggies. The tweeter fuse was the exact same. The 20.7 midrange is 5 amps instead of 4 like the 3.6 But Too small is not big deal. So I stuck it in anyway. I never play very loud music anyway.
So I have a few old forgotten fuses and the main Question: "Do they make a difference?" I have no idea. I stuck them in while the speakers were breaking in so I never tried to compare, and since I am lazy, I ain’t gonna bother swapping them around to find out for sure. (because I do not care). BTW I noticed the HiFi Tuning fuses are directional.                    
Anyone can totally discount my ’qualifications’ for any audiophile blather by pointing out I always use a $40 five disc CD changer for all 5" silver disc playing. (And the fact I Toslink the data to a $7000 SACD player I used as a DAC.. Through to a newly purchased Conrad Johnson ACT2 I use as a "fancy tube buffer" clearly bonkers.) So don’t mind me and fuses.. But I have bought in to high end AC duplex. just not fuses so much.

Well I jumped into the deep end here this afternoon & purchased one $20 fuse for my preamp. The kids will still eat wolf (LOL). I'll let you know what I think after a hundred hours or so.

We get a lot of 'show me the measurements' requests to what we hear. We are not engineers or whatever it is you need to be to have measurements. But we do trust our ears. Then some say you cannot trust your ears. So I thought this had a nice reasonable comment on how this gentleman feels. I think he has some credentials to say what he does.
At about 9:30 in the video this man states how he feels if you cannot measure something yet still hear it.
https://www.youtube.com/watch?v=grzoqEb2KMk&feature=youtu.be

Hello guys,

from my experience, simply cleaning the fuses contact points and the plus with acetone can reap very noticeable improvements. Treble becomes more airy and bass more defined and visceral. Therefore I am in no doubt that fuses can make an appreciable audible difference. However, the pricing is ridiculous. If these greedy manufacturers weren’t so stupid and priced their products reasonably, they would sell a lot more and some of this resistance against such tweaks would fade away as more people would witness the audible difference. 

K