Hi Mark
Interesting, we are actually both right, as the inclusion of R8 on your board applies to
board M12890-6 where it is 10 ohms at the base of T9, but board 12890-4 misses out on R8 in that position altogether
but then has availability but not fitted for what is labeled R8 where I described between TR1 collector and base.
I have both models. I think Quad were thinking of a divider between R6 and the negative supply 6v8 with the design of
12890-4 by providing space for R8. Its resistance value then is much higher as to not confuse the purpose of R6 - will
report if I have success.
R26 is the Zobel resistor which needs to be 10 ohms applying to both boards.