Sovtek EL84

wont fit certain amps. Only buy if your chassis has a big enough socket or are able to competently modify your sockets with a metal rasping tool.

I've used sovtek valves for years as emergency get out of jail free valves when in an emergency I need to replace any in my amp. I wouldn't rate them as a long term replacement, Electro harmonix do a gold pinned set for power and pre amp valves, they seem to have a brighter quality than most other valves I've tried. But the sovteks are a suitable set if you need valves changed quick.