My tubes went blue and have crackling noises

[pbman1953]

I was playing a 2000s last night at practice and I noticed a crackling sound . I thought it was a bad cord and changed that but that wasn’t the problem. I looked in back of the amp and one of the outside tubes was glowing blue. We stopped for a break and I took out that (outside) pair .The amp still worked but didn’t have the same power, of course, and  I looked again and one of the inside pairs was blue but not a bright as the first one. I checked with ED and he said to check the plate resistors (Pin 3) fro the 6550. They all measure 47  ohm like in the schematic. While there I checked all the 1K resistors to pin 5 and they measure up to 1K too.
 
Do I have a tube issue or what should I check next.


Thanks
 

[shooter]

Do I have a tube issue

blue glow typically isn't a problem, crackin might be loose things, arcing from loose stuff.
I did have crackling in tubes, but you could see the arcing.

do a good visual around the sockets, retention, bias reading, plate volts.  If you're confident, chop-stick when the amps idling n see if you can narrow the search

[pbman1953]

You're right, cold solder on a pin 3 of an inside tube. Kind of mad at myself because i replaced all the sockets and really took my time.

[shooter]

Kind of mad at myself

don't be 97% is still an A