TungSol KT120 Matched Pair
KT120 is a monster tube capable of generating more output than 6550, KT88 and even KT90. This is made possible by employing high current cathodes and large inner structure, making this tube taller by 0.5" (13mm) than KT88-EH.
KT120 is plug-in compaible with 6550, KT88 family of tubes, but does draw higher filament current (up to 0.3A each).
Please check with your amp manufacturer before substituting with KT120.
Price is for a matched pair.