Very good AES presentation on inter connects and ground loops.

As helpful as Amir is, and he is a real engineer, there are some gaps.

I have no issues using PCs as music servers, but I use correctly designed isolated USB DACs and "decent" cables.  All my system is plugged into the same power DC blocked and filtered power strip.  No problems.  HDMI on the other hand is a disaster and who ever designed the plug needs a dope-slap. Other than going to fiber transceivers, not sure how to fix HDMI issues. 

There is  much more to. It then that ,myself and many others in our audio club some are true electrical engineers. ,for. Example digital noise can  travel house to house that is why I isolate the coaxial filter, plus the Ethernet the Ethernet hub I use has low noise regulators ,linear-power supply,as well. As A  OCXOover controlled precision clock feeding the Ethernet cable , and put in a upto date Modem router combo ,I bought the Motorola 8702 which has docsis 3.1 which is much faster, bigger buffer , even the wifi for the tv is better , and having a Quality LPS power supply to the router a 12v 4+ amp is night and day better sounding then the garbage wall warts that come with the router ,I have -0 wall warts in my system 

and quality Ethernet cables over $4500 the 2 Ethernet, and usb cables Ethernet switch and LPS , efore the dac and streamer .if you want great digital performance 

to surpass turntables youhave to spend $$ with the same precision you give to any

high quality turntable arm and stylus leave no weak link in the chain  ,

and with XLR if all components  are truly balanced for each item then sonically  it’s much more quiet. Transformer coupled. This too cost $$ to do it corrrectly.

Folks, because something CAN, does not mean it DOES.  Listen to your system yourself and see if you have any of these problems only copious amounts of money will solve.  With my preamp turned all the way up, I hear dead silence right next to my speakers.  

Totally false assumption all wall warts are the same. For instance, JDS uses AC transformers only. 

XLR transformers do in fact have higher CMRR as they are truly balanced if that is your problem. Great for 100 foot runs. They also have higher distortion.  My DAC to preamp cables are less than 6 inches.  I don't have a problem. 

I too am an engineer. I learned to solve problems that do exist, not because they can exist.  So, have you re-wired your house with hot and neutral twisted, separate ground, pulled into thinwall?  Do you use only commercial grade outlets? 

I have an AES input on my Schiit Modius AKM4493 dac. I’ve been tempted to purchase a transport with an AES output to use with the Modius, such as the Shandling ET3. As for using computers for streaming music, I have been using Amazon Fire tablets for the past few years, with outboard D to A converters, with excellent results. IME, sound quality seems to be more dependent on the quality of the digital sources than anything else. Many sound unimpressive. However, the better quality higher resolution source material can sound quite exceptional.