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.