Voodoo Lab

I know I would have to make a little junction box to do this, but technically this should be possible.

Just wondering if there were any concerns from the Voodoo lab side?

You can series connect as many outputs as you want. I do wonder why not use two 12V outputs though?
Also, three 9V outputs together will yield at least 27V. (Since the outputs are actually about 9.3V, on paper you would be just under 28V.)

Good Luck!