MLGrado
500+ Head-Fier
One thing about the wifi connection is it provides isolation. My Mac mini (Roon and HQP server) is connected to my router via LAN cable and then goes into a Gustard switch with a fiber port, so my front end is being fed by fiber (another fiber-LAN converter at the DAC side), which isolates in a similar way.
So if you're going to plug the Mac and PC into the router, I would highly recommend doing the same, with a short LAN cable into a fiber converter, then fiber optic cable to another converter near the Red (assuming it's being used as your streamer), with a short LAN cable from the Red into your DAC. Hope that makes sense.
Another way to approach things is to send the wifi signal to a mesh repeater/booster with a LAN port, then go straight out to the Red with another short LAN cable.
yes, I find that the wifi isolation provided by my iFi STREAM makes a notable difference in quality. I am a big believer in isolation.
It goes back to personal experience for me. At one time I owned a Wyred4Sound DAC-1LE Femto (ESS 9018 chip I think), and although it had onboard galvanic isolation via USB, nothing I could do, including temporarily lifting the PSU ground, could get rid of both a 60hz hum combined with a large amount of white noise.
I purchased an Intona USB Galvanic isolator, and never looked back. It took care of ALL the noise. Dead quiet after its insertion. I am sure several DAC's I have owned since have had no need for the extra isolation; however I have continued to use one anyway, knowing how well they can work.