replacing preamp tubes in twin reverb reissue.

[linuxpng]

I've developed a little bit of a crackle in my amp when it's out of standby and from what I've read it seems most likely to be a preamp tube. I understand the process is supposed to be simple but for the life of me I can't find any detailed instructions on the process.

I'm not an electrician, but I know the big tubes are the output tubes, what a transformer looks like and to not touch capacitors. I see the preamp tubes have a metal cover on them and it looks like 2 screws hold that cover in place. Can someone explain to a newbie the safe, correct, way to replace a preamp tube?

 

[Tyrant]

Try this: http://www.kcanostubes.com/content/newsletter_details.asp?ArticleID=5

Winged =C= 6L6's sound great in my '69 Twin.

 

[linuxpng]

Having never attempted to even look at the covers for the preamp tubes I didn't realize it was a push and twist cover. Got the tube replaced and all is well again.