Tim O'Sullivan said:Why not pull out 2 of the output valves, and bingo - you have a 50 watt amp. You have to pull out either the outer two, or the inner two.
I've done that with my DSL and 5150, it works, but the sound suffers. The output transformer isn't working as hard as it should be and it does sound different, not just lower in volume. The lower volume wasn't worth the 'bad tone' that I heard, at least in my case.