After searching through a 3 foot stack of Tech Notes,
I can't seem to find one concerning the early (6BQ5 rev. drvr.)
VK. I swear there was one issued for this amp (that involved
a resistive G1 anchor and etc.) but the only one I can find
refers to adding capacitance to G2 of the 6V6-version (TN 97-5).
If you have the revisions or the Tech Note, can you
kindly share it?