Guys, this is part of the issue I am asking about in my other thread...

Cool, good to know, cleeds thanks for the info..

Regards

12A @ 120V is an 1800Watt loading, for the majority of domestic amps that would be some failure to blow that.

Radio Shack

Might be worth your while to check the owner's manual to make sure you (or someone else, if you bought used) didn't "accidentally" replace the fuses with the wrong values at some point in the past.  Nothing worse than having your equipment (or your house!) burn up if the fuse doesn't blow when needed. 

From the pictures online it looks like a 3AG fuse holder.  The cap unscrews and the fuse is held in a cup on the cap.  The 3AG fuses are 1/4" diameter x 1 1/4" long.  Which are just about the universal glass fuses used.
Usually they manufacture will mark ampere rating by the holders.  If not check the manual. Or
Remove the old fuses and look around the silver ends of the fuse. Usually engraved is 3AG, 250V and some number with an A after it.  This is the amp rating of the fuse.

However!   Power input fuses may be a "slow blow" type to handle turn-on Inrush current. You can tell a slo blo fuse by the extra stuff inside the fuse. The standard fuse just has a wire running across.  Your amplifier may have been supplied with like an 8amp slo blo input fuse. Someone replace it with a standard 8 amp and it blows frequently upon turn-on. If not immediately. So they upped the rating of the fuse. Wrong way to go.

Search ebay for 3AG fuses.

FYI   Also available are Fast Blow fuses. Those fuses have a white ceramic cover instead of glass.