Network Switches

The only times I've had network gear affect sound quality seemed to be related more to their power adapters and whether they are in or out of the cleaned power zone. 

oh, and try to route your ethernet cables away from all audio cables, especially power supply and interconnect cables.

I think that the quality of digital transmission is hard to improve upon. DAC receivers have also in the last few years become excellent at jitter and ground loop isolation.

However, the noise emitted by the switch mode power adapters, as well as the Ethernet cables themselves can make its way easily into linear components.

So, I suggest using shielded power cables for all components. A linear power supply for digital and inexpensive power strips that have great noise reduction features to keep the network components in their own dirty sandbox.

My thoughts and recommendations here:

https://inatinear.blogspot.com/2019/04/power-management-for-frugal-audiophiles.html