Re: Fuse Blown in Subwoofer
.63 amps on the AC input is not a very big fuse, in consideration that the original fuse blew and the .5A fuse blew immediately upon plugging in the sub chances are there is something wrong with the amplifier.
I really doubt that a larger fuse will help, but if you want to try a .75 or a 1 amp fuse its probably not going to hurt anything. I would not just keep putting bigger fuses in it though since eventually there may be a fire hazard.
Wal-Mart has a good selection of fuses in the auto section.