Imagine that the DAC 'recording' the incoming audio is like a microphone and re-emit's this to the BL. If the mic is too sensitive you hear noise. (Cooky analogy but should make sense) What is the quality of the cable's? Is the receiver grounded? I'm not sure how to adjust these setting, ask the dealer.

in thinking about this.  the issue is not the receiver, but the transmitter.  it still sends a hiss even when i unplug the RCA cable from the RJ45 adapter.  ill look in the settings file for the transmitter and see if there is something to adjust.

I have the same problem. My Transmitter 1 settings are the same as yours. If I turn the preamp up high the speakers work fine, but loud - not a real solution. Have  you been able to change the Transmitter 1 settings and do you have any suggestions for what to change? I am having problems doing that - it won't accept my changes via USB.