phono amp?

I have a 2A3 power amp,George Wright tube pre,tube phono pre(Project},Thorens td-124 TT,Klipsch Heresy speakers,Velodyne impact mini sub and a Rotel CD player. There is an obvious audible hum from the speakers when unit is on and idle. When switched over to digital source the hum is gone. Are phono preamps inherently the noise makers or is it something else?
You might have gain that is too high for the cartridge you're using. The cartridge could be compared to microphone that picks up any kind of noise that could be mechanical, aerial movements, EMI etc...
If you have the ground wire from your cartridge grounded at the phono pre-amp, try removing it
Joe Nies