As some of you know, I like to mod my amps almost incessantly. Usually it's for well thought out reasons like "MOAR POWER" or making it go to a figurative eleven. Occasionally, I try to take a more tactful route than sticking 6550's in everything I see. My question is in regard to minimizing heater draw off of a pair or quad of 6550 or KT88. Are there any brands with lower draw? How about new production versus old stock? Does it matter at all? I know of guys who run 6550 in V4's without issue but I've also read that they're running near the limits of the PT's capabilities. I'll be picking up a VT-22 later today and like most things, I want to put 6550's in it down the road. I just want to know if I can minimize extra wear through my choice of tubes or if they're all close enough it won't matter. Thanks guys!