I'm designing a power supply for hybrid amplifier (tube + discrete semiconductor power amplifier). I need 30V for power amp and 60V for tube. Also I need 6.3V for the filament (6DJ8 dual triode doesn't allow series connection of filaments so I can't use 12V power supply).
Let assume I have a transformer with two secondaries rated to 15V each. I can connect windings in series and get 30V directly and 60V using voltage doubler.
To obtain 6.3V for the filament I can utilize transformer's midpoint and use a linear regulator. In this case all filaments' current will pass through single winding. Can I spread this load to both windings? Filament power supply may float.
Edit: I think something like this may work. Values are nominal, regulation is omitted.