This is the subject of some debate, actually. Some people report that their Nova runs fines off of the L6 outlets with the DIP switch "ON". But, it didn't work for me. The Nova would power up (and function normally) but i got a massive hum. Went back to using the TC power supply.
The new Voodoo Labs ISO 5 has a dedicated high-power outlet specifically designed for the TC Nova pedals and Eventide Factor pedals.