I was at my local music store talking to one of the guys there, and they were telling me about this kid that plugged the output of one amp into the output of another amp. Obviously, this is not good, but what actually happens? I guess the senario went as follows: kid plugs into amp 1, turns it on, then plugs the speaker output of amp 1 into a bass amp 2's speaker output while it is still on. Amp 2 shuts down immediately. I suggested they try changing the fuse, so they did, powered on the head, and it shuts off right away. They took out the fuse, and that was blown as well. They tried one more fuse and again the amp shut off and the fuse is blown. Interestingly enough, amp 1 is just fine, nothing seems to be wrong with it. Now, this is something I never thought anyone would ever do. It just seems like common sense not to do this. But I'm curious, what actually happened here? One amp is putting out power, and trying to force that into the output of the other amp. Why wouldn't they both shut down? Why is one still working and the other isn't? Why is "amp 2" blowing fuses as soon as it is turned on (no other cables are in it, only the power cable)?