On Nov 3, 6:12*pm, Ian Jackson
wrote:
In message
,
Engineer writes

(snip)


But what does the invariable negative feedback (from the OPT secondary
to an earlier amplifier stage) do to the output impedance?
--
Ian

Ian, it reduces the source output impedance of the amplifier as a
voltage generator (increasing the damping factor) but does not affect
the speaker impedance to be used. The speaker impedance determines
the O/P tube plate (anode) load via the OPT ratio.
Cheers,
Roger