9V to 18V can be handled by something like the Godlyke Power Pump. But for 12V...
I know there are power supplies that can achieve it without any voltage doubling; the Voodoo Lab Pedal Power 2+, for instance, has a few outputs that are switchable between 9VDC and 12VDC.
BTW... what kind of cables are coming out of that thing?
EDIT: Oh... I think I see. It's a close-up shot of a really tiny box, I think.