[Tom Schlangen]

Hi Patrick

Most ppl think the UL connection for EL34 always means 43% screen taps.
This % was always regarded as optimal because triode like THD is
achieved and Rout reduced to give Rout = RL. But this was mainly for
class AB PP amps.

Yeah, and most winders wholeheartily will agree that 43% percent is ideal
because it is just the end of the 4th winding block of a 7-way
interleaved design (means 14-way interleave for PP), hence easily to
manufacture. Same with 50%, 40%, 33% and 25% (depending on number of
interleaves).

So much on "magic UL% numbers", honi soit qui mal y pense (I don't mean
you personally).

Regards,

Tom Schlangen