I power mine with a Voodoo Lab PPII, but here's the deal.....the connection cable has to have both ends wired opposite of each other. That's why they suggest the adapter.
If you want to power the unit with a DC power source like a one spot or PPII, you need to Email Voodoo Lab, tell them you bought the PPII and they only gave you one cable. For some stupid reason, the PPII has 2 Line 6 outlets, but they only supply you with one cable! I Emailed them, and they promptly sent out another for free.
Just do that, and you'll get one for free.