Crackling noise!

[RADE01]

I get this crackling noise everytime I turn on my RM100 from cold, it's just as the power tubes are really warming up, so about 2-4 mins after switching on the power. I even had a wierd bit of a feedback noise last time too.
This amp was only repaired about 4wks ago. Brand new screen grid resistors! Tubes have all been tested, one bad one was replaced after a hunt for the right match. This noise has been there since early this year, which first alerted me to thinking something was wrong. But it still does it after having repairs! I'm using my trusty old 5150ll for gigs because I know it won't let me down.
Any ideas? Anyone had this before?

 

[wesarvin]

Welcome to the club. Mine is actually moody about the crackles. Maybe chocolate would help?

 

[SacredGroove]

If I'm reading your post correctly, you get crackling noise, along with feedback noise (squealing?) only during the time your tubes are warming up? After that, it goes away?

 

[RADE01]

If I'm reading your post correctly, you get crackling noise, along with feedback noise (squealing?) only during the time your tubes are warming up? After that, it goes away?

Yes sir, except there was only one time when I got a quick little bit of a feedback noise.