[lpowell17]

The tubes most certainly need to be replaced. They're getting pretty dim (they're the stock EL34 groove tubes by the way). But they're near a year old and it's always been quiet.

I looked around inside and couldn't find anything that was obviously wrong with it, apart from one of the tubes looked slightly crooked in its socket. I'll probably take it in tomorrow and tell them to look for bad connections and such things.

Thanks for the help guys.