Timbersnake,
Quick question: Did you exercise the servo before hooking up the cables? Did it/does it make the same noise?
I have found that the higher torque servos tend to make a little more noise than standard servos. Don't know about digital though...
With the little extra noise the high torque servo makes together with the resonance chamber, called a fuselage, and the guitar strings attached to the servo running the length of the resonance chamber, you will have a louder sounding noise.
That is what I came up with regarding my Cap 232.

Just a thought...

Jeff