Getting a fair amount of hum in the FX loop with my DSL 50 head.
It's not the pedals. No problem in front.
Is this a common failure?
Tubes are good, and bias is at about 43mv, and even.
Try putting a patch lead between the send and return and see if the hum is present, if there is a hum we would suggest that you have it looked at by an engineer as there could be a fault in the effects loop circuitary.
