The "HP" I installed it on a Fender 65 Deluxe Reverb, it has nothing to do, I gained into heat, sound, melodic bass short I rediscovered my amp ... and grain to cry, a marvel, was a former HP Jensen C12K Ceramic, now I understand better why it is the favorite HP Kravitz, it is not too Gouré the guy, marriage is perfect, otherwise there is the Fender 65 Deluxe Reverb with a Jensen P12Q Alnico (wine red) for fans of the Deluxe Reverb or replaced if your HP by this one, it is definitely worth