Yeah I'm not too keen on some of the technical terms of the things but I think it was the preamp tube that was causing a rattling noise. I also had accidently left the amp on for around 4 days. It had 2 power tubes blown out and I had thought that was it but it had lost its original, Marshall, sound...

Hey, thanks man! That really helps a lot, I didn't want to yank it out especially if it wasn't a preamp tube lol. And I blew out a preamp tube; whenever I would play it, it would make this rattling noise really loud and I read for hrs. on end about it and discovered it was preamp tubes, if they're b...

The preampsl tubes label 1 & 2 are good, I took then out (i just put the case back on #1 though) and the third one is stuck. I didn't want to yank or pull at it because I didn't know if that was a preamp tube or not but it has (if it's visible in the pic) a different metal case on it though.

Sorry about that and thanks! Here's the new link:
http://imgur.com/tcEWhIy

I think one of my preamp tubes went bad and I read that I need to replace all of them. In the Marshall amp I own, MA100h, it says that there are 4 Power Tubes and 3 Preamp Tubes, but I can only find 2 preamp tubes. Please excuse my ignorance, but the tube that I think is the 3rd preamp tube won't co...