What do the different tube amp types mean?

Hi Mlsstl. An ultralinear amp in not necessarily push-pull. I have seen a circuit diagram for an ultralinear single ended amp.

An amp is ultralinear when the screen grid is biased from an center tap on the primary side of the output transformer. I think the only thing we can say definitively is that a ultralinear amp cannot be an OTL amp, but it most certainly can be single ended if you can source the right output trannies.

Regards
Paul

Hi BDChem, everybody posted some good info. Being vain, I’ll post some more. ;-)

Vacuums tubes used for audio reproduction can be triodes, tetrodes or pentodes.

To make things a bit complex, tetrodes and pentodes can be wired to run in triode mode, pentode mode or ultralinear mode.

For all combinations of the above tube tubes and how they can be wired, they can be deployed in either single ended or push pull configuration in an amplifier.

So you could have a single ended tetrode amplifier or a push pull pentode wired in triode mode. I believe there are 10 possible configurations?

People like Ralph makes things even more complex by building tube amps that have no output transformers. So now you can have any combination running with or without output transformers. (Note. I don’t believe it is possible to have an OTL amp that is ultralinear.)

And then some amps allow you to run in a hybrid mode. Cary’s V12 series amps can be run in partial ultralinear and partial triode mode.

I believe they all sound very different. I say I believe, as I have not heard all the possible configurations and probably never will.

Regards
Paul