If you don't have a way to run pedals at 18V, try getting your hands on an ICL7660S or a MAX1044 and slap them in there used as voltage doublers (schematic can be found on the net, e.g. in their datasheets).
You don't need non-polarized caps in there btw, good polarized ones will do the trick as well, although using a non-electolytic 1uF cap on the input would work just as well. I doubt one can hear the difference between those (1uF, 10uF, polarized/non-polarized/non-electrolytic) though.
DIY Effect Makers #20 | Ibanez ATK Club #233 | GK Club #1025
Originally Posted by JTE
Life is too short to waste any of it on bad beer or bad drummers