Egnater tweaker 40 issue, vol cutting

[bluesstrattone]

Volume started to cut out with SED wing C 6L6,
Swapped them with GT, not so much, after bias.
Volume is lower than usual, breaks up sooner in clean channel.
Swapped the tubes again with the original tubes, which are still good.
Same symptoms.
The amp had been biased at 65 more less and zero issues before.

 

[webrthomson]

Volume started to cut out with SED wing C 6L6,
Swapped them with GT, not so much, after bias.
Volume is lower than usual, breaks up sooner in clean channel.
Swapped the tubes again with the original tubes, which are still good.
Same symptoms.
The amp had been biased at 65 more less and zero issues before.

Swap out your preamp tubes too - try V1 and V3, V2 is the loop so probably not that