I have run both Ruby EL34BSTR and Sino EL34Bs in my Quick Rod. Its getting time to grab another quad to at least have on hand to put in on failure of the current quad thats been in about a year. I am thinking of trying something different just to experiment and see if I can get any more aggressiveness and bite out of it. I plan to toy with some different pres too, but the purpose of this thread is to see what others run in the Power section. What do you like? What have you compared? I like some of the description of the Svetlanas. I play hard rock from the 80s to present and look for the most raunchy crunch I can get.