For joy of tube diy, I re-wired my Eiclone to Kevin Ward's pp KT120 design, but using 7F7 and 7N7 at the front, and no NFB. I love it :banana:
With NFB, it produces LF oscillation, whichever value I tried!?
From the pic above, the feedback wire is unconnected and coiled up at the top left...