Cool.. I knew someone would know something about valves..

All valves have a 6V heater and after looking up the specs none need a whopping 700V.. all are 300V which is present and correct.
I have:
6v6Gt
6X5GT
6AU6WA
 and another I cant read.. need to borrow my wifes glasess.

I did a bit of reading and only requirement I could find for a voltage near 700V is a swinging choke but that would be on the power supply and not the amplifier yes?