One of the highest-output 8-pin pentodes available. Originally manufactured in the United States by G.E., it delivers 35 to 50 watts per tube and was original equipment in amps during the ’70s and early ’80s. A big, clean, tight tube with amazing headroom and performance and great power and dynamics. The highest-output power tube in this family.This 6550 is slightly easier to push into distortion than the original G.E. version and has a harder response than the "C" for tighter, quicker response. Good for bass amps and metal, when more pronounced note definition is desired with just a touch of distortion.