6L6 guitar amp tube questions

[kramden66]

The tube tests good and works in the amp but has a blue glow inside. Thought maybe it was the socket so swapped it from the push go the pull socket and it is the tube. Should I be worried or just let it be?

[Eric H]

If it's just on the inside of the glass it's normal, I see this all the time in the 6BG6 sweep tubes on TV's. (the 6BG6 is basically the same as a 6L6)

If it glowing a neon purple between the plate and the grid then it might be gassy, though I doubt it would work in that case.

[zeno]

Not unusual. My Fisher has 7591's IIRC & all four
do it a little. Audio will knock down walls...........

73 Zeno

[kramden66]

Ok ignore glow. Now here is a question these are 6l6wgc and what would happen if I put in old standard 6l6 tubes? Would it not sound as good or are the ones in threre required?

[SwizzyMan]

You most likely could use just a 6l6. My fender amp calls for 6l6's but i use the 6l6GC sounds no different to me.

[Gregb]

Originally Posted by kramden66

Ok ignore glow. Now here is a question these are 6l6wgc and what would happen if I put in old standard 6l6 tubes? Would it not sound as good or are the ones in threre required?

You have to be careful here, a standard 6L6 installed in a guitar amp could be overstressed. The first 6L6 tubes had a lower plate power and voltage rating then the 6L6GB and 6L6GC. Guitar amps tend to run a pretty high plate voltage and push the output tube to the max. You could destroy a good set of tubes, watch out.

Gregb

[Celt]

Also 5881's are often an option.

[Gregb]

Originally Posted by Celt

Also 5881's are often an option.

If the 5881's are vintage true 5881 tubes they may or may not be ok. The 5881 is about the same as a 6L6GB, a 5881 is rated for 360 plate volts at 23 watts if your amp uses 6L6GC tubes, these are rated at 500 volts and 30 watts, you could damage the 5881 tubes. You should check the specs and see if you can bias the amp down some if you are going to try this. Some of the new tubes that are branded 5881 are not true 5881 tubes and they may be ok but again check the specs before giving them a try.

Gregb