I have a Barber Dirty Bomb which is more of an 80s metal sort of sound, kind of Mesa Mark II. I was wondering if there was a pedal or preamp that would capture the "German" kind of metal amp sound, Diezel, ENGL, or other heavy non-Mesa type sounds. I'm also a big fan of the rougher sound of a JCM900. Instead of trying to look into getting a new amp that'll be too loud for bedroom use, I think this could be a better idea.

I've been considering amp modelers just to get this kind of sound at managable volume and cost, but I also realised that preamps could be a good solution. I know ENGL make a very affordable poweramp version of one of their amps that's essentially the whole thing in a rack module for $500 or so.
there's an MT-2 "Diezel mod." doesn't really sound like a diezel, but it's kinda' in the ballpark of that German sound.