No, I'm not talking about the power supply to the pedal, I'm talking about your power supply in general... as in your whole house. If your amp and your pedals and even your pedal power 2 are plugged into an outlet hooked up to old wiring, your going to get a significant hum at the very least. It can also turn your cables into antennas. In that case, you need something to filter and regulate the power in between the outlet and your equipment.

For $55 you can get a power conditioner from Furman that's pretty good:
http://www.musiciansfriend.com/product/Furman-M8-Power-Conditioner?sku=181115

I got a Monster Power PowerCenter PRO 900 for $100 and it's awesome:
http://www.musiciansfriend.com/product/Monster-Power-PowerCenter-Pro-900?sku=180015

By the way, if you're just playing at home, you don't need 30' of cable either. That can only add to the problem (bigger antenna).