PRS used to have something called a Studio amp that I've always lusted after (that looks like that), but personally I prefer that they breathe more than that (Dave Grissom's Custom PRS amp is practically see through and has two powered fans). I'm sure it's not hermetically sealed, but I'd just like to see more ventilation. Doug -- I'll prequalify this with, I have very weird tastes, in both guitars and guitar amps. My favourite guitar is my Parker Fly Deluxe, which is wood wrapped in a carbon fiber/silicon/epoxy exoskeleton, and it has a delightfully clean and dare I say "hi fi" sound -- it's practically an electro-acoustic, and I don't mean that thin and reedy piezo sound, although it can do that too, but it practically sounds like an acoustic guitar through the pickups. With lots of extension in the treble, and almost no diffusion or saturation. So that said -- my ultimate amp reflects this (PRS MDT Custom). It's not a neutral acoustic amp, it does have a tone profile, but it has neither that vintage mid-forward sound nor the modern ultra-low and ultra-high and scooped-mids sound (although I do tend to lean that way with the bass/mid/treble controls). So..."really warm" not really my thing, but my curiosity in what sort of guitar amp head design you would use is undiminished. Care to describe the tone stack? Especially if it's not that hard on tubes. Is it?