![Image](http://i.imgur.com/MO6Nk.jpg)
I guess I have to replace my power amp valves now, right?
![Think :think](./images/smilies/smile%20think.gif)
I have no idea when and why it happend. Everything works and sounds just fine. There is light in all of 4 power amp valves. Power attenuator is ok. But when I turn on auto-bias I can hear quiet pops in cab.
Added little poll about which valves should I choose - 6550 or KT88?
![howdy :howdy](./images/smilies/howdy.gif)
P.S. There is no need to make any mods with amp to replace original 6550 with KT88?