[EdHolland]

OK, no worries. what I was trying to say is that the original 0.047 uF coupling caps form a high pass filter. The AC output signal from each inverter passes through the cap, and drives not only the grid of its output tube, but also works in to the resistive bias network which is eventually decoupled to ground in the power supply by the caps there. That means there's an inherent bass roll-off in the signal reaching the grid. More coupling capacitance could, in theory, lower the corner frequency of that roll-off.

...And of course, among the hi-fi tinkerers, more is better, even if some of them don't know what they are doing.

I do hope I'm not coming across as difficult or contrary, it isn't my intention at all. Above all, I appreciate the advice and discussion.

Lastly, I am happy to report that before the receiver was ever plugged in, all electrolytics were replaced - top to bottom through PSU, output stage, and FM circuits. They were not in good shape at all.

Cheers and good night,

Ed