hey i know pulling two power decreases the headroom alot and i tend to like it at time but i was told that you also have to set the independance to half the value of the cab. is this true, cheers.
Pearse
Overall, what you have to do depends on the amp. Some newer Marshalls do not have chokes, but a power resistor for the screens filter supply. If you remove two tubes, the screen voltage on the remaining tubes will go up, which means effectively you just biased the tube a little hotter (i.e. more current).