Ethernet

@kevn    Your posts about the battery-operated router caught my interest.   My WiFi streaming chain is fairly tricked out for noise reduction- both TX/RX.  The SQ is very good.  I also have a battery-operated DAC.  When it goes into the recharge mode, the DAC continues playing on AC.   I can hear the SQ become slightly noisier.

My streaming head-end has two routers - in-line - after the modem. A Netgear Nighthawk - and then a Fidelizer Audio Airstream - setup as an access point.   All of my noisy household WiFi devices are connected to the Netgear WiFi router.  Only the streamer is connected to the Fidelizer Airstream - via WiFi.    So, there’s audio-only traffic on the 2nd unit.

Last night, I experimented by powering the Airstream with a regulated 12 vdc battery power supply - very beefy.   Sure enough, the SQ improved.   More natural/organic.   No loss of dynamics - which can be a common downside of using a small battery. Since the Airstream is only used when playing music, I should be able to turn it off via the power bank to save the charge when not in use.   My household devices will still be functional since the Netgear router is powered by AC power.

It seems that this might be an interesting solution for noise abatement.  Two routers - or one router & one switch.   The 2nd unit being powered by a battery for the streamer only.   This unit might be perfect - since the voltage is regulated.*  Theoretically, it should work well for both hard-wired and WiFi.    The key is to remember to turn it back on - wherever it’s located - when firing up the system for a listening session.

Thx for your informative post.   Sometimes, these discussion threads can lead learning something new.   🙏

- - - 

* This is another type of a battery bank - but the DC voltage might not be regulated.   AI says that routers require a regulated voltage.

FWIW, I’m going to scrap the TP-Link because it wouldn’t connect to the internet except for being hardwired. After beating my brain, I’m going to stay hard wired or wifi. Once the DAC arrives I’ll see if I have any issues with interference. For now I'm going to try the iFi LAN iPurifier Pro & see if I can improve on my Wiim Ultra.

@danmar123 - don’t give up just yet : ) - regardless of what the 902 supports, it just requires the correct configuration - a few others reported problems connecting it. I don’t know how to link to keithc’s directions in WBF, so here they are, cut and pasted wholesale from his informative post - 

Setup WR902AC:
1. Look at the back of the unit. It should say the name of the device Wifi.
2. Power up the unit using the 5V micro USB. Give it a minute.
3. On a computer select the 2.4Ghz Wifi from the TPLink. Type in the password, this is on the back label on step #1.
4. Once you’re connected, go to http://tplinkwifi.net
(If this step does not work use a fresh browser after deleting the cache)
5. The first time it will force you to set a new admin password.
6. Once you’re in the menu, cancel the quick setup.
7. On the left bar go to the Wireless 5Ghz. Turn off this radio.
8. Go to USB settings. Under Storage Sharing and FTP Server tabs disable both.
9. Go to System Tools, Time Settings, and click on Daylight Savings, Save, Get time from PC, Save. Close the browser.
10. Unplug the power from the TPLink.
11. On the left side of the device move the physical toggle down to CLIENT.
12. Reattach the power. Select the TPLink wifi again and connect.
13. Open the browser again and go back to TPLinkwifi.net
14. Go to Quick Setup. Click Next. Now select CLIENT. Next.
15. There should be a list of your home’s 2.4Gz wifi channels. Select your Wifi with the highest signal strength. On the next screen it will ask for your Wifi password. Click Next, then Next.
16. At the end of the setup it will ask you to click FINISH. Then the device will reset. This will take 2 minutes.
17. At this point the TPLInk Wifi ID will disappear from your computer’s Wifi list. The TPLink is now an extension of your home Wifi. If you connect your computer to the TPLink via LAN it will be an ethernet hotspot (turn off your computer’s Wifi first!). Run a test by opening a browser and you should have normal internet access.
18. You’re all set up! Connect the TPLink to your music server using a dedicated low-noise battery and enjoy! Make sure the battery back is detached from any charging input as that can add noise. 

You will want to reset it before running through the steps. For the best possible way forward, check in on the thread at WBF I indicated in my first post here. Trust me, you won’t want to miss out on this super value for peanuts uptick. Many long termers on WBF have called this the best thread ever on that forum ; )

sorry I couldn’t reply sooner - audiogon has something in place that prevented me from messaging you direct : (

In friendship - kevin
 

@steakster - no thanks to me, I’m merely the messenger of a messenger - it’s Eric of ethernet-sound.com and keithc all the thanks goes to : ) 

on a related note, try replacing your fidelizer with the 902 - it’ll cost the lower side of usd50 - and with an even lower ripple power bank like the romoss pea40 pro - you might well be amazed how much noise is created by the fidelizer in client mode. You may not hear a difference, but my bet is that the tplink pocket router will outperform the higher powered fidelizer on pure account of the noise created by power corruption. The thread on WBF has massive pushback from keetakawee of fidelizer passively disparaging the findings of the cheap tplink902, in obvious fear that if more audiophiles catch on, many manufacturers of higher priced routers and switches will find fewer takers of their products - issues keithc has very graciously and respectedly responded to in post #423 on the WBF thread. My take on this is that the understandable concern from manufacturers about this discovery will push them to create cheaper AND higher performing products for source signal delivery to servers and streamers. It’s a crazy lovely sight to have the cheap white plastic tplink right alongside my solid copper rigs ; ) Seriously, do read that entire thread if you haven’t already. The original research on this tplink902 is in the original thread  of the German site at ethernet-sound.com under Eric, but you might find it easier to read through the ongoing discussion on the WBF thread as it doesn’t require translation and has moved the goalposts just a touch. 
This discovery is going to cause a rethink on power management and noise isolation by many manufacturers, I believe. It’s great you already had your air gap between home router and client router, now get that tplink wr902 to see the added difference it will may make - and please report your findings! ; )

In friendship - kevin