Ethernet Cable or Not?

Thanks for your feedback, I’ll check out these options. 

Hope everybody has a great weekend!

If you go the Linear Power Supply route, I encourage you to consider a LPS that offers multiple power outputs.

You did not specify your ’router’ (I’m assuming it is both a modem and router)... it is likely also DC powered.

A LPS, when used to power BOTH the ’router’ and your "WiFi Receiver" (Tunebox), will only add to the upsides with respect to performance and sound quality!

It appears your ’router’ is near enough (7 ft) to allow for one LPS to power both ’components.’ If not, and you like what a single LPS does for your system (with the Tunebox), simply add a second LPS to power your ’router’ at a later date.

All the best. Report back on the route you choose and the results.

Additional clarifying points.

1. You are already isolating your ’router’ from your "WiFi receiver" by using WiFi. This is a good thing.

In this scenario, a single LPS to your "WiFi receiver" is a good first step.

2. IF you choose to run ’wire,’ i.e. the LAN cable from your ’router’ to the "WiFi receiver"....

Then, powering your ’router’ with an LPS becomes more critical...for the reasons @almarg highlighted in his post.

Having a LPS that can power both is ideal and also allows you to test cable vs WiFi (to determine which one you prefer).

Uncle D, if you are going to try a quality ethernet cable I suggest an Audioquest Cinammon. It's not real expensive and it made a noticeable difference to me (over generic) that I liked.

Quality of cable is important but remember that you are working with 1000baseT, not 10GbaseT. That means you can achieve perfectly good results with well-made cabling that is rated for 1000baseT, which CAT5 (not even CAT5e) is rated for. The benefits of higher category cables are lower near-end crosstalk and (in certain categories) better common mode interference rejection and lower loss due to capacitive coupling between pairs. CAT6a (augmented) is called for on restricted runs for 10GbaseT, so forget about anything beyond CAT5, 5e and 6.  Buy factory made patch cables that have been certified by well-regarded manufacturers such as Leviton and Hubbell. Above all, don’t waste your money on “audiophile grade”  network cables - they are overpriced and may be lacking in quality and longevity, especially if they are made of solid core cable, which does not accept crimped RJ45 plugs very well.