I have a near new DV 336SE, 100 hours of use. I have a small collection of good testing 6sn7 tubes, some hum and others don't. I would like to do the Fitz mod, if someone can point me to the origianl post of how to do the mod I would appreciate it. I've searched several times with several terms , but nothing comes up.

Any help appreciated.

Any help appreciated.