In article ,
N_Cook wrote:
No user switchable option. I can see its possible to rewire the vibrator
so you still get right polarity for the anode supplies. Heaters
presumably happy enough powered the other way round but how to change
the biasing of the valves ?

No need if it's a mechanical vibrator. That produces AC...

--
*Procrastination is the art of keeping up with yesterday.

Dave Plowman London SW
To e-mail, change noise into sound.