They don't make them like they used to...

[jordan86]

Just replaced the filter caps in my newly acquired 65 BF Showman.  Had quite a bit of 60hz and 120hz, which the new caps don't seem to have fixed. I tested them all for fun after the fact. Ironically, the cardboard wrapped originals seem to be in tip top shape. Newer ones that were already in there have significantly worse ESR. The expensive Sprague being the worst of the bunch :)

Side note I temporarily paralleled in a new bias cap on the bias board and that knocked the hum down about 50%, so that will get soldered in next.