does anyone a diagram? and i'm thinking about getting one of these, but i'm used to buying complete retube kits from Eurotubes, but they dont have them for the powerball, ive emailed them with some questions about special ordering a kit but just incase that doesnt work out i wanted to know some more i guess my question is what tubes would be the best to put in this amp for a metal player? and what tube should i use for V1? and more importantly, should i really even buy this amp? or maybe something else in the $2000 and under range?