I am thinking about getting a Mark V. I like the sound of 6v6 amps. I have read the manual and understand that the Mark V can be operated with 4 x 6v6 tubes (w/ variac power setting). Has anyone done this? Can any of the many Mark V modes/channels produce the classic Fender 6v6 tone? I would be interested in operating it in the 10W mode also. What would the power output be with the 6v6? Would it be around 4W?