Thanks for that explanation made easy for me to understand...yeah it was a 33Uf cap not 330Uf as i said & yes its parallell to a resistor so that must be feedback resistor then and in series with 0.10 uf cap from OP tran, I had a switch to disconnect that whole network for no feedback at all, which had higher level but wasnt much tho ?? had thinner cleaner sound, didnt sound as nice for vocals as the fuzzyer none feedback...overall I think the BA2A has nicer sound.
The BA2A has no feedback at all ...does it ??
Tubes are wire different way ? so work in different mode ??
Triode

maybe .... In treading in the dark here as you gathered..
Both amps are single ended....?
Th e other thing i notice about the amp is the huge OP tran I have {was expensive} it has to take full HT thru primary...is that why it is big
Before I saw the BA2A schematic I was wondering what to do with this transformer as it was gettin no use in the BA1A
Anyway I ramble on { in the words of Nat King Cole} thanks for your knowledge Im learnig lots its very interesting