Those darned fuses again?

"My amp blew a fuse. The back of the amp says to replace it with a 120V-AGC-3. The only AGC-3 fuses I've been able to find are 125v, and every time I turn on the amp the fuse pops. What could be wrong?"

The difference between 120v and 125v fuses is not significant. We must remember why we have fuses. If something fails the fuse is there to protect additional components inside or outside of the device. When you replace a fuse with the proper replacement and it fails, that is a sure sign that your equipment is broken. You need to have it repaired.

If you consistently blow fuses while playing, but your equipment isn't failing, you may have a situation where something is causing your amp to stress periodically. Obviously this is going to happen when playing loudly, and if the tolerances of the amp are off just enough sometimes a fuse can just blow. It's still a good idea to have a service technician check out your equipment to make sure nothing is wrong, but sometimes a solution is to cheat on the fuse rating a little bit. If you have a 3 amp fuse and it is blowing you may want to try a 3.5 amp fuse. It should still do a good job of protecting the equipment if something fails. Obviously extreme care and common sense must be applied here. Don't get the idea that fuse ratings are arbitrary. They are just sometimes slightly conservative. There's much more info about the types and ratings of fuses in our TTOTD from 2/16/99.