I would think that it should work with the voltage doubler. I've been reading about this on
DIYSB Forum, all 166pgs, and a lot of guys have used one. Not to mention the number of mods people have done, like input switch, boost switch, putting a SHO in hit the tube with more input to overdrive it more. It's a good read.
I would love to not just see the valvcaster, but the twincaster, which is basically two valvcasters back to back.