[Arran]

I've seen the values of filter caps for AC/DC sets all over the map, some are 30/50, others 40/40, 40/50, 50/50, and even 80/100, I don't think it makes as much difference as people think. Almost all of these AC/DC sets use half wave rectification, with a pi filter, so they can probably use as much filtering as you can stuff in there.
I know that the tube manuals suggest certain values as an input, but I've used photoflash capacitors in AC/DC sets, such as 150-160 uf at 330 vdc, for years of use and never noticed the sets eating rectifier tubes. Maybe in the old days the filter caps had a much higher ESR then the modern caps do so the high value caps were harder on rectifiers? Maybe it's because these were photoflash capacitors, designed to charge and discharge rapidly? Who knows?
Regards
Arran