I read myself in circles last night researching cathode biasing. Seems like maybe it's not as straight-forward a conversion as I thought? From what I read (what I remember at least) cathode biasing is fairly simple in a class A amp, but gets more complicated to do in a class AB amp? I have a Sundown amp that I'm using as a "live it and learn it" project. I converted the PCB into a hand-wired tag board. Now I'd like to investigate cathode biasing. The amp uses a 2x 6550 power section, fixed bias in class AB. How do I figure what size resistor to use if I wanted to convert to cathode bias? I read last night that with the tubes alternating cycles as they do, it's harder to run as a cathode biased amp...or something. Most of the sites I find when googling are hi-fi based. They are a lot more worried about uber-clean power and stuff. What's the scoop for a guitar amp? Straight resistor or bypassed with a cap? I'm just plain confused now. Any hints?