Soniqs SAX caps

[Richard]

Hi, yes PPX range are 250v and in my case, Phono3 cathode follower op coupling, the cap sees 110v running and, as there is no direct connection to the HT, nothing if the valve does not conduct, so never more than running voltage.

In yours it would be useful to see the circuit but if the cap has a direct connection to the HT, even via resistors, it should be rated for the HT voltage. The reason is that valve heating and HT voltage rise and fall at different times during switch-on and switch-off. If the HT rises before a circuit valve conducts then it may not be dropped by the resistors and the full amount may be seen by caps that only see a smaller amount during normal running. Then, at switch-off, the heaters may cool, so the valve stops conducting, but the HT may stay up so again some caps may see voltages they don't usually see.