Originally Posted by
anthonyTD
Ok,
If this only happens in that one position with any valve you put in there, then it is not the usual heater filament diffrences you get in diffrent types of valves that's causing the valve to come on bright, its posibly a heater circuit issue, especialy if this amp has DC heaters on the first valve, which many amps do!
I am not saying for certain that your amp does indeed have an issue, but i just find it odd that it only seems to do this in one position. A look at the schematic for this amp would be a useful start.
A...