@charles1dad I don’t want to argue semantics and even yield that you are probably correct in the way you define it. (pentode vs ultralinear). but to me the sound isn’t that much different between them.
I recommend the simple, single output tube per channel, directly heated triode, single ended, tube amp to get the nimble, crystal clear, and dynamic sound we chase. But you have to have speakers that are compatible.
BTW, I own an excellent example of the pentode push-pull amp that sounds excellent. I'll be getting rid of it in favor of the SET I prefer.
Jerry