I hate them. but as long as i have one. I have some qustions on them. I have a tube pre-amp. If i want a new tube.....How do i find out witch one i need to get? ive heard of tubes with early distorsion, medium dis. and late distorsion. whats up with that? how does it affect your tone? and i heard you have to re-calibrate your amp or somthing to change your Distorsion rating? im so confused.