just wanted to know if the triple x has the same biasing system that the 5150 has. i heard that you can bias the 5150 head yourself, or just pop in the new tubes.

afaik the 5150 doesn't have a poti to adjust the bias, but you could put one in pretty cheap. the 5150 just runs very cold stock.
i don't know if it's the same with the xxx or if it has a bias poti.

5150 Combos are biased warmer than the heads.