François Yves Le Gal wrote:
....
I'm pretty sure that the Chinese 274B has arced because of the combination
of too little R on the B+ windoings (vintage valves call for at least 100R
series R) combined with too much capacitance in the first filtering
stage
4µF is recommended, 8µF is max).
....
So, indeed, the expected life span of a Chinese rectifier in again a
Chinese design might justify for an prologued insurance. More so since
this amp is equipped with a regulated PSU: four '2A3' triodes @50mA
each, 10% headroom for the regulator gives 220mA and that's quite a lot
for vacuum. WTH is a Lose True Degree 8[]