[patrick-turner]

I will look at schems. Some older ideas can always be revisited with a fresh approach to see what happens. But age old discipline is still required to see if anything can be done to justify the visitation.
Patrick Turner.

I just had a look at schem with paralleled 6SN7 driving 6F6 with Ia at 13.65mA and Ea at +250V. Maybe not much class A PO?
Sure, trioded pentode with DC drive to g1 connected to g2 does give tube more gain than usual, and high THD, and much FB must be used and I could not see any.
Patrick Turner.