EL34/6L6, p-p, UL - What B+ is safe for driving those tubes?
I've done a pretty good search of the forum here and have found that the general consensus is that UL is much tougher on the screens when really driving the power amp compared to pentode mode. I saw one post where Dr.Z informed someone that you need to use a saggy power supply to help with that.
I'm wondering where you would need to be to not worry about driving the power tubes in UL. I'm not looking for a specific power level, so much lower voltages would be OK. I'm looking at the Weber PT here: https://taweber.powweb.com/store/022723sch.jpg
I figure this would give me around 410vdc when rectified with a 5AR4. With the 200mA ability of the PT and the 5AR4, it wouldn't really be that "saggy".
Does anyone know if either a 6L6 or EL34 are built with screens that can take this better than the other? I know Dr.Z has stated he doesn't like 6L6 with UL, but he said it was because of the way it sounds. This was probably ten years ago or more and he didn't go into any detail.
So I guess I'm wondering three things:
1. Considering a B+ of 410v, would UL be harder on the power tube screens than pentode. This would be a typical AB1 guitar amp scenario. Not even getting into source followers with mosfets for AB2 right now (although I've always been intrigued with that idea).
2. Does either EL34 or 6L6 tubes stand up better than the other under UL abuse?
3. Has anyone here really seriously messed with UL guitar amps? Maybe better would be to ask why UL isn't more popular here on ampage. There certainly is no technical difficulty involved. But that would be four questions, and I said I was only wondering about three.
TIA for any advice or opinion.