"John Stewart"

The connexion shown needs to have the common (gnd) connected to the 4R tap
which is the mid-point on the 16R secondary. By coincidence, I tried this
on
a simple PP 6V6 amp (pentode connected) with a Hammond 125E OPT on Sep
9/05.
Here are some results measured with & without this very limited form of
local voltage NFB.

On the 8R connexion the amp internal Z without NFB measured 42.98R, rather
high as one might expect for a straight pentode amp with no FB.



** But a 6V6 is a " Beam Power Amplifier " ( GE Essential
Characteristics) - not a pentode.




.......... Phil