I have a EA Doubler which powers a Bergantino HD 210. This rig sounds fine with my Rob Allen Mouse and super with my Pedulla Buzz. I am not however, happy so far at least, with how my new Carvin PB 4 sounds through this rig. I regularly jam in two different studio situations where I play through either a GK 112 combo or a larger rig with an older GK head. I have to say that the PB4 sounds better overall through these GK rigs. This Carvin has also sounded great through an SVT with an 810. The Carvin seems to sound overly transparent and kinda bland through the EA Doubler with little punch, growl or grind. Perhaps I need to EQ this head differently? I can't imagine that the Berg cab is the ptoblem?