Fuse degradation?

I have had my MA-2275 for 5 years. Probably sat around mostly idle for the 10 years before that.  Turned it on prior to a listening session yesterday to let it warm up. While waiting and fiddling around something happened with our electrical grid. No storm in the area. Power goes out but then our generator kicks on. After 30 minutes or so, generator goes off and house goes back on electricity from our utility service. Wasn't paying attention to my system so uncertain when this happened but eventually notice the MA-2275 had no lights on. Check it out and hopefully only a blown fuse which it was. Pull fuse out and wire snapped. 5amp, 250v, 5X20mm fuse. I look on line. Go to local hardware store and find same Bussman fuse for $3. Plug in and OMG it is like a brand new and completely different amp. Sounds nothing like it did prior to old fuse going out. Crisp with an edge and the subs seem to perform so much better.

Question is this, do degrading fuses change the sound of the system before they actually snap? I replaced a $3 fuse with a $3 fuse with dramatic improvement. I will probably get one of the Synergistic fuses to see if I can tell a difference but my sound has improved so much with an equally priced swap that I can only think that the previous fuse was going bad for a quite a while and I just accepted that as normal.

@fuzztone, +1.
Also, OP should realize that equipment not used for extended periods will require for caps to reform. In fact, I would have a look inside to see if they are still looking as they should, as this would be one of the first points of failure.
Get the new Synergistic Purple fuse. Or if you don't want to spend $200 then the QSA Light Blue from https://www.tweekgeek.com/ for $71 is excellent.
I went to silver plated fuse holders for my equipment that still has fuses. It's most likely a contact degradation issue, fuse holder and fuse itself. In my opinion, purple, orange, blue or whatever color, is a waste of money. I've found, whether high or low current, connectors are the weakest link in electronics, period.
Oh my, the three dollar bushman fuse will get you by, but if you want to hear even more detail and resolution,  try a QSA or SR fuse.  It makes a difference....agree with MillerCarbon.  I can't speak to SR purple because it is brand new but I have had SR Red, Black, Blue and Orange.  I now have QSA yellow.  
The new Synergistic Purple fuse is $200, see Franks review. I have one ordered to compare with QSA Violet. The QSA Light Blue from https://www.tweekgeek.com/ for $71 is also excellent.

I and nearly 100% of audio technicians believe what georgehifi has been saying about AC fuses below all this time. I’d suggest you;
1: “Just re-new your fuse with the same amperage if it’s old and has seen many turn on cycles, with a quality one like Bussman or Littlefuse. 2: And clean the cradle fuse contacts and maybe squeeze them in a little for a tight fit. And definitely don’t be sucked into any $$$ boutique hifi fuses

3: Just change the fuse if old for a quality brand EE industry standard 50c fuse, as fuses (even the $200 boutique one) also age after many turn on cycle surges.”  
4: And there is definitely no such thing as direction with an AC mains fuse.

Quick blow fuses aging  https://ibb.co/SyyVR6P  Slow blow fuses aging left to right. https://ibb.co/hKNfZ8r


ACME too, I've used ACME gold for over 30 years. The new 20.00 fuses they offer are quit the bargain.

Mercy george junior, of course fuses and cable both have a direction. The question is weather you want to hear the improvement or not. That has been settled by many stereo buffs a long time ago. Weather YOU, are a believer or not, doesn’t change the increased SQ by cable/fuse direction being observed.

You can look at any cable magnify the wire and see which direction the cable was put through the die, if you then condition the cable in the direction of the die pull vs against the grain so to speak, increased SQ is pretty apparent. Cook the cable the WRONG direction vs the pull of the die, the same cable will NEVER sound the same as the cable conditioned in the correct direction..

You don’t have to believe it. BUT don’t put a Boutique fuse in backwards and then expect it to work correctly either. Kind of like driving a car backwards and wondering why it takes so long to get where you’re going.

You can do it your way alright.. I don’t know of a single technician that doesn’t believe in quality fuses and quality cables, NOT one suggest coat hangers. Most I know will install new fuse holders with silver, nickel, gold or rhodium and any fuse you want..

It’s like telling a hot rodder not to add crap to his car, you must be kidding.. :-)

The new Synergistic Purple fuse is $200, see Franks review. I have one ordered to compare with QSA Violet. The QSA Light Blue from for $71 is also excellent. I would link to where it can be bought but we need to be mindful of the tenuous psychological balance of some of our more easily triggered members.