Tube Amp Archive

Yup, it was a bad cap - replaced and no more blue... Of course now I have ground hum(s) to trace!

Thanks, guys. I'll check that cap when I open it up later this week.

Hi, first time poster here... I just pulled my 100w Plexi clone/build out of storage and noticed the power tube plates on just one side of the "push/pull" division (both sockets) have a slight blue glow which steadily gets brighter as I turn up the volumes. Swapping tubes doesn't have any effect so ...