I have a Marshall JVM 410H amph head which I bought in 2009. A few months back I was noticing that the amph was cutting out every so often. Took to my local guitar store they replaced all my tubes. Brought it home and a few days later the same thing was happening. So went back got my $$$ back. Took it to another place, again said tubes were bad. Brought it home and again...cutting out. So went back to 2nd guy and he refunded my $$$. So shelved the Marshall head. Bought a Peavey Valve King II Micro. And yesterday noticed the same thing AGAIN happening!!! I've got the head connected to a Marshall MG 412B cabinet. Now I'm wondering could it be something wrong with the cabinet??? A loose connection or something. I don't move the cabinet around it's been in the same place sine 2009. Any input would REALLY be appreciated.