Possible tube issue with Herbert

[xmartx]

Hello,

last band practice I noticed that one of my power tubes does not glow like the others, I'm not 100% sure but either its not glowing at all or just way darker than the other five. Can this be normal or should I better replace the pair or is there anything else I can check to make sure my Herbie is alright?
The tube LEDs on the back are all off and I did not notice a sudden change in sound or anything else out of the usual. The tubes are JJ KT77 installed by Peter last April so I'm sure they have been replaced properly.

Cheers,
Martin

 

[shadow070]

i would just wait. If it sounds the same and there is nothing out of the ordinary, just let it be.
Just keep a spare set off tubes just in case

 

[i.ak]

Keep on rocking...but be prepared to replace the power tubes at some point...maybe in week or month or year.

 

[cheftie]

I don't think there is anything to worry about if the fuses LEDs have not lit or there has not been any change in sound.

 

[steve_k]

Easiest way to some piece of mind is to check the bias, if you know how. You may have had a tube go out of balance with the others.