I was doing some work on a 1964 Fender Champ and it needed a new fuse. The amp requires a 1 amp slow blow fuse (written on the back of the chasis) so I went up to Radio Shack and purchsed a few 1 amp slow blow fuses. Well, they turned out to be WAY too small for the fuseholder in this particular amplifier and did not work -which surprised me because these were the only 1 amp fuses the store had (I figured a 1 amp fuse is a 1 amp fuse). So I went back to Radio Shack and got some 3 amp slow blow fuses and these worked perfectly. Amp works and sounds fine now, but my question is: First of all, why are fuses smaller now than they were in the 60s? Secondly, am I making a mistake by running a 3 amp fuse when the amplifier clearly calls for a 1 amp? Logic tells me no, but I want to be sure.