I strongly suspect that it is the circuitry in your house rather than both devices. It may be very localized - have you tried using different electrical outlets throughout your house? Can you test it in another house/location?

You may need a power 'cleaner'. I don't know exactly what they're called but there are products that will eliminate hum.

I am definitely no expert but I I have a pocket pod (which I love) and the same thing happened to me re loud hum, but I changed the fairly high maximum output mains adaptor for a low 300ma maximum one I got with a zoom pedal, and the hum went away! It shouldn't make any difference what the maximum amp load is, and maybe that wasn't even the problem, but using a different adaptor totally cured it - why I don't know, but maybe it's worth a try..?