I think it might be all the noisy digital gear attached to the network which causes noise. Even the Ethernet switches seem noisy. Maybe a point to point system with 2 PCs with linear power supplies. I don’t have answer but I was serving up files from a Microsoft server across a house network...
I have a good friend which ran an IFI USB isolator and also saw an improvement. What he also said was the isolator blended the sound of the 2 USB cables so you really need 2 good USB cables. He tried several different USB cables and was frustrated cause he could heard the sound of the other...
The problem with streaming is you cannot control the noise on the network unless you are talking about streaming from one component to another across one wire like an I2S.
The only problem I see with using the IFI USB is it requires 2 good USB cables. I run a Purist Ultimate USB cable and don’t want to buy a second one. Otherwise I would own one right now. My other problem is I am running a home built music server without a PCI express slot so I need an old...