Just got my iFi Lan isolator. I have two choices. Wav files stored in hdd connected to iFi zen streamer. 2nd is Apple lossless music streamed via Airplay to iFi zen. After adding the isolator, i found the Apple music slightly sharp in vocals. I did back and forth between hdd and streaming few times. I could definitely hear the difference. The streamed music sounded more natural. Especially the vocals. Music from hdd was ever so lightly smothered. I am yet to do more testing. Looks like i am a believer in galvanic isolation of ethernet. Now I need to find a solution for my hdd. lol