Kind of noob question here, but does switching of tubes affect amp's capability to drive planars? Will tube rolling change output amperage? I've been drooling over LCD-2's or LCD-3's but for a fear of wife and wallet i cannot justify change of amp. Which of those (in other words, lower or higher impedance) would be better match for LD IV se? I'm running C3g's now, would 6sn7's or even 6080's with external power source help?