Those are great cables and they are shielded very well... I seriously doubt it's the cables.

It could be the pedal but it's most likely your power source. Crappy wiring in your home or flourecent lights nearby are pretty much guaranteed to cause noise... A distinct hum at the very least. I had to get a power conditioner to solve that problem.

Did you happen to purchase the cables from Mark at lavacable? I'd send him an email asking about it. He knows his stuff, he's very helpful and qill get back to you pretty quickly.