Mesa Boogie TriAxis Pre Amp
Paired with a sim class 2-90 this is one formidable bit of kit, classic tones and a never ending array of choices.
Once you get your head round how this thing works you can dial in just about any Mesa sound you can think of. To be honest if you really master it you can just about dial in ANY sound you want. Particularly good at doing classic VOX sound as well.
It can be a bit fiddle at times and a bit of a labour of love, but its not got a legendary reputation for nothing!