12 VAC for both AC heaters and DC B+ via voltage doubler?

[MarkER]

I've built small guitar amp using space charge tubes:
Sopht amps - all tube 30v amps
I was using parts on hand and have a 12 VAC/3500 mA wall wart. It works great on the heaters that use plenty of current, but was wondering if I could also run a voltage doubler to give the 24VDC for the B+. I realize that it will generate more than 24VDC, but would bring it down with a suitable dropping resistor. Currently using 3 9V batteries in series for the B+.
Thanks in advance.

 

[Austin Translation]

I wouldn't worry about the dropping resistor, it's going to sag. A voltage doubler puts off a pretty chopped up form of dc and rc filtering will fix it but it's going to sag some with any load at all on it.