Hello Vince, I am having some trouble figuring out how to use the outputs on my EA-5 simultaneously for Airplay out to the C4 8AMP-1B We hooked both sets of stereo and both digital outputs on EA-5 via RCA to all four inputs on the amp, made all the necessary connections and when we switch the airplay sources, the matrix in the amp gets confused. Or the EA5 output is not switching correctly. Anyway we don't get the desired sound in the desired room. We have Airport drivers in each of the rooms with speakers and have make the proper attachments. Other than that, we understand there is no other programming to be done. We believe the info here https://www.youtube.com/watch?v=_HYkqprtpEY&t=608s to be correct. Composer and controller are on 2.5.3 Is there any help or better understanding of this situation you may be shed some light on?? This has kept me up a few nights..... Wasn't sure where to put this post, I just seen you are offering to help a lot on this forum.