Newby problem with hum

I'm relatively new to this sick and exciting hobby and need some help from the experts. I am having a problem with hum. I think it's a ground loop issue, but not 100% sure. I get it when I'm switched to CDP and even louder when switched to my LP. I start hearing it when the volume control gets to about 12 o'clock and it becomes quite loud at 3 o'clock. Here's my setup...

Music Hall MMF7 w/ Goldring Eroica MC cartridge
Ah! Super Tjoeb CDP
Kimber Hero interconnects
Manley Stingray Integrated amp
Analysis Plus Oval 9 speaker cables
Silverline Sonatas
Chang Lightspeed line filter

Any ideas would be helpful. If it is a ground issue, where should I start?

Thanks!

Steve