Vandersteen Quatro Hum

I hooked up my Vandersteen Quatros and I am getting a hum as soon as I turn on my Ayre V-5Xe amp that powers the speakers. I think it is some kind of ground hum/loop. Any ideas about how I can eliminate this problem?
Go to your local hardware store and buy adaptors that lift the ground on the 120v plug. Use these on the speakers, if that doesn't work, try them on the amp, preamp, etc.
Vandersteen Quatro and M5/ 5A will hum with Ayre amps if you are not using balanced cables. Also make sure that you have the right setting on your X-overs.
Thanks guys. I called Ayre. Initially, they were unsure of what the problem was. Then I talked to Charlie Hanson and he informed me that it was a ground issue on the amp and that if I sent the amp back it would be upgraded for free.
Note - I was also able to eliminate the hum by plugging the amp into a Running Springs Haley power conditioner instead of the wall.