Hi! Seems that many people have swapped the power tubes and I'm interested as well. I talked to Charlie at Bogner and he said that no mods are needed, just biasing. I just got a couple of questions: - Will EL34s tame the highs of the KT88s? - Does the overdrive channel still retain that Marshally flavor? - Do EL34s work well for quiet playing at small gigs? - What brand of EL34s do you recommend? I love the 20th already but I'd like to take it to the next step if possible Thanks guys!