Thanks to everyone for all the information and thoughts on cheater plugs. I was able to correct the hum without using a cheater plug.
I attached a wire to the ground screw on my adcom ac enhancer and touched each piece of my equipment with the opposite end of the wire. The problem turned out to be my dvd player. I scraped off a little paint around a screw for the cover in order to get a good ground and the hum was gone. If you try this, make sure you touch the bare wire to bare metal. On my first attempt, I touched the bare wire to the painted surfaces of the equipment and nothing happen to the hum.
Again, thanks to all.