Tube Amp Archive

Okay, so what is the reason for using a 5Y3 in the DR?
Would it be best just to install a GZ34?
I have attempted bias adjustments, but can't get rid of the
annoying papery distortion.

Thanks for your reply

I am having a similar harsh overdrive issue with an AB763 Deluxe Reverb. I have replaced several components, swapped tubes, (kept all originals to reinstall after finding the problem); that is, I've replaced everything except the rectifier tube, which in this case is a 5Y3, where the schematic calls...