Go to the LITTEDOT TUBE ROLLING GUIDE lots of stuff to read about over there i already gave you the link a few post back if you want to learn about the better power tubes go to page 201# 3007 but we started using 6SN7 as power tubes with adapters they sound really good probably the best sounding so far for the price.. http://www.ebay.com/itm/1pc-Gold-plated-6SN7-6n8p-CV181-TO-6CG7-6FQ7-tube-converter-adapter-/201115946751?hash=item2ed371ceff:g:J2oAAOSwQjNW-kSg
Where do you recommend getting 6SN7 tubes to go with those adapters? Also, I see they have different versions, GT, GTA, GTB, EH, etc.... Which tube would be the right one? What brand is considered best? Lots of questions about this, any answers are appreciated.