The Xotic BB Preamp is a absolute MONSTER. If it's a booster, then the matching dirt pedal would likely make me shit from every pore, heh. VERY VERY LOUD with loads of big pulsing hairy balls. The moment I hit my strings, I immediately felt AC/DC begging to be played.
I never did get the diode switching to make much difference, though.
For a straight up Marshal sound, however, I prefer the Nick Greer Sucker Punch. Simple and straight to the point.
That said, I intend to build the Ramble FX Marvel Drive and see how that goes in comparison.