|
I suspect that that point might hit over 500V before the other tubes in the set warm up and start drawing current, so two 350V caps in series would provide a 700V rating. I don't think that 600 or 700V electrolytics were available. I think that to a certain extent, Dumont over engineered the design, to promote longevity. Since the set was likely quite well filtered, replacing the "40" with a 10 probably worked ok, perhaps introducing only a slight amount of hum. The ESR of the 10 was likely less than the two 80s in series, as well.
jr
|