Th30 issue

[Reelman955]

I purchased a new TH 30 head January 2016. I love it. Today when I fired it up, found my dirty channel dead. Clean channel functions perfect. Dirty channel is dead. I switched to 15 and 7 watts same story. Amp has funtioned perfect till today. The head has not been abused. It is sitting in the same location since I first brought it home. Has less than 50 hours on the head. I opened the back and all the tubes glow. Any thoughts

[Jondog]

Probably a bad preamp tube. Pull out your clean channel 12ax7 because you know it works, and swap it in and out of the dirty channel preamp tube positions to see if the dirty channel starts to work again. If it does, the tube that you replaced is bad. It won't be the fx loop or phase inverter tubes because if they were bad, the clean channel wouldn't work either.