Question about cothode follower as preamp output

[John Fisher]

Greetings! I wanted to ask how practical it is to use a cathode follower tube circuit as a simple mono out on a tube preamp as opposed to an output transformer.
Any Thoughts?

[Mick Bailey]

It depends what you want to drive and what tube you'd be using for the output. It's practical, but you need to have a definite load in mind. The current available with regular preamp tubes is fairly small and can still only drive a relatively high-impedance load (compared, say to an 8 ohm speaker). You can run two cathode followers in P-P in a Fletcher-Cooke configuration to improve drive capability, but it's still fairly limited output.

Any more current and you need to use power tubes to get a decent output. There have been quite a few designs published for OTL (output Transformerless) designs but they often use now hard to get tubes.

Why wouldn't you pick the signal straight off the plate if its just a preamp?