[Ian Iveson]

Tom wrote:

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).

As originally coined, the term "ultralinear" applies to an
optimum. If it isn't at that optimum ratio, it isn't UL. So
it seems to me, anyway. Patrick's imaginary "most people"
are possibly quite right.

"25% screen tap" is a clearer and more accurate description
than "25% UL", and isn't much harder to write.

Thing is, if we conspire to trash the meaning of
"ultralinear", then we lose an important distinction in our
language, and get nothing in return, just because some folk
think that jargon adds grandeur to their tedium.

More gain allows more feedback. Other than UL, where you put
your screen tap is Hobson's Choice when it comes to final
THD, surely?

However, it could be that, if you chose a particular
harmonic, or blend of harmonics, rather than THD, you might
find a different optimum power/distortion ratio at some
different screen tap ratio. That might be a bit interesting.
UL(3H+5H) might be a good idea.

Al's getting dafter, incidentally. Al, wake up! Everyone
needs power.

Roughly in proportion to room size, speaker technology, and
the number of friends you've got.

So wrote I.

Yearning for the glory days of plain text.