Audio Grade Ethernet Cable

+1 @cleeds

There’s no case to be made for a router being co-located next to your audio gear as having any benefit compared to say 30’ away if we are talking about a wired connection.  

On the other hand, picking up noise from the internal CPU and power supply is possible. I admit to having an Ethernet switch behind my rack, but given the number of devices I have it’s pretty unavoidable.   Is it better? Only because of the convenience of attaching my TV, DVD, receiver and music streamers together with short Ethernet cables. 

My router on the other hand is located for the convenience of the cable modem and data closet, far away. 

Keep your wifi router and  network related wall warts away from your stereo! 

Cheap-o Ethernet 6 will be just fine. 

The most realistic concerns are over radiated RFI from inside the Wifi router.  It's job is literally to radiate radio frequency interference.  The other issue is wall warts.  If you must have any network related gear near your audio gear use low noise versions such as those from ifi Power.  Especially try to avoid putting a wall wart on your clean side of a power conditioner as they can re-pollute the AC. 

If you must do more then I suggest an Ethernet/fiber/Ethernet conversion.  Asus makes routers with built in fiber ports (SFP?) but you can get inexpensive converters.  Fiber is galvanically isolated, immune to RFI/EMI and lightning surges. Still use a good power supply near your streamer.