Microphonic Film cap?

[Five_E35]

Fired up the 5E3 with GZ34 & 5881's last night. No howling or oscillation, but the whole thing became extremely microphonic - chassis, filament line, all tubes, pots, etc. Almost seemed like the rectifier tube(?), but swapping it made no difference. Tapping with a stick didn't help, but using the soft end of a long tape-deck cleaning swab, the .02 cap in front of the PI seemed to be the culprit. Next I moved it ever so slightly and the problem stopped. Reflowed the solder connections anyway, checked for DC leakage & the cap is still doing it's job, and all is quiet. Now I'm wondering if I should just replace it. Any thoughts - it's a 6PS polyester film Orange Drop?

Earlier I tracked down a hum problem to the first preamp tube. It seems it want a tube that's reasonable well balanced side to side for least hum. Is that because of the shared cathode arangement?

Didn't get a chance to play it, but can't wait to hear it this way.

[Bruce / Mission Amps]

That is the one cap that seems to be slightly sensitive to location.... some guys remove it (and the single wire underneath the board from the cap to the 1m resistor) and use a smaller radial cap directly from lug 1 to lug 7 of the 12AX7 socket...