Hum in system when only amp is on

I do normally turn the pre on first. However when a dvd is inserted there is a hum until the bit stream is sent to the pre. (this system does dual purpose HT/2channel)

I did try removing the ground, and the hum went away. But I see that is not advised by Theta. I will use automation to mute the pre to solve the hum problem.

Also I will switch the direction of the IC's.

Thanks for all your help. You all are very helpful. I thought I knew how to set up this system, but now I see there is so much more to know when dealing with seperates.
As always enjoy the music...

Ian