ETHERNET CABLES

It was the Ethernet from the switch to the Aurender.    Someone mentioned a while back that CAT 8 could cause issues and I said yeah right.  I took it out and the annoying pop when switching digital inputs was reduced greatly to a "tick"    

@oddiofyl now the connection makes more sense. I doubt it was the ethernet cable.
Some DACs will pop. My bryston dac popped every time it was about to start playing DSD file. 

@oddiofyl 
Some DACs produce mechanical clicks (pops) when changing sample rates or when you pause / resume stream. This is normal, I don’t think it has anything to do with Ethernet cable or Aurender streamer. 

Yeah, its totally fine.   Just a little tick 

Interesting.  I don’t know what to think.