TP Link TL-WR902AC

[TheAssassinBlevins]

Hello Eric,

Is there a way to contact you privately with questions?  I would also like to know if you accept donations as your time and work are very appreciated.  I have many more questions but not all are directly related to the 902 so I’m not sure where to post them.

[Eric]

Hallo zusammen,

heute ist der WR802N angekommen.
Das Teil ist nochmal kleiner als der WR902AC!

Ich habe ihn mal konfiguriert und mit einer Xiaomi Powerbank im Vergleich zu meiner WR902AC/Ian Canada Lösung gehört. War nicht schlecht, aber gegenüber der modifizierten WR902AC Lösung keine Chance. Diana Krall war bei Desperado einfach viel zur plastisch beim WR902AC und zu präzise im Vergleich.

Dann habe ich den den WR802AC mal mit einem 5V Linearnetzeil betrieben. Hat am Anfang schon besser gefallen, aber die Stimmer wurde dann zu nervig und nervös.

Betrieben mit einem 5V Batteriepack wurde das etwas besser aber konnte immer noch nicht im Vergleich überzeugen.

Der WR802N hat leider keine GPIO Kontakte, sodass er nicht so einfach auf 3.3V umgerüstet werden kann. Ich habe aktuelle leider keinen unmodifizierten WR902AC, sodass ich mir noch überlegen werde, wie ich den vergleichen kann bei den Messungen.

Beste Grüsse,

Eric

[Eric]

@theassassinblevins

Prinzipiell bin ich über die Nachricht-Funktion auch per PM erreichbar.
Allerdings ist meine Zeit aktuell sehr begrenzt und ich fände es gut, wenn wir Themen und Fragestellung hier für alle diskutieren.

Wenn Du Fragen zu anderen Themen hast, kann man einen neuen Thread starten, wenn es noch keinen passenden gibt.

Beste Grüsse,

Eric

[TheAssassinBlevins]

Wow, you got the 802 up and running quick!  A lot of people are saying it needs to burn in so don’t rule it out yet!  Ok, here are my questions:

1:  You mentioned modifying the internal power supply of the 902… Were you only referring to converting it to 3.3v and eliminating the BS terminations or is there more to do?

2:  I understand Ian Canada is amazing but I would prefer an enclosed linear power supply for the 902…. What brand/model do you recommend?

3:  Should all power and ethernet cables in the entire system be as short as possible even if they utilize ferrites and/or chokes?

4:  I’ve heard 2.4g is preferred over 5g in the 902…. Do you agree and is 2.4g for sure enough?  (I live alone with very little wifi usage).

5:  Will I be able to use the wifi from the router (for my laptop) to control the streamer if the streamer is connected in this way:

a:  Router via ethernet to a 902 AP

b:  902 AP via wifi to client 902

c:  Client 902 via ethernet to streamer.

6:  Assuming the above listed format, should the 902 AP be very close to the router so it has a short ethernet cable, or further away for any reason?

7:  Is there a way to edit our posts after sending them in case we later find a typo?  lol.

[rghanbari]

Unfortunately, the WR802N doesn’t have GPIO contacts, so it can’t be easily converted to 3.3V. I don’t currently have an unmodified WR902AC available, so I’ll have to figure out how to compare it for the measurements.

This too is where my exploration of the 802 ended.  I am tempted to look for a test point or leg of IC, but that would be getting into a pretty difficult hacking (for me and most folks).

Thank you for the report Eric, very helpful to hear what you are hearing….

[TheAssassinBlevins]

@rghanbari

Hello.  Your last post leads me to believe the 802 is not even worth pursuing if it can’t be converted to 3.3v.  Could you explain what improves by converting a 902 to 3.3v?  I’m starting to hear good things about the 3602.  I wonder if anyone here has compared it to the 902?

[rghanbari]

I heard a very significant improvement in sound quality when I switched to 3.3V on the 902.  I’m sure this is a combination of improved power supply (I use the Ian Canada 3.3V mini + UcConditioner combo referenced here), as well as bypassing the 5V->3.3V regulator on the 902.

I did not purchase a 5V Ian Canada supply to test, so difficult for me to decouple the impact of the supply vs bypassing the regulator.

The 802 is interesting as well and I had purchased one to play with.  When I didn’t see an obvious way to bypass the regulator on the 802, that project went on hold as I started to play with OpenWRT and using a second 902 as an access point

Very eager to hear others experiences with the 802, and revisit that project at some point if folks are hearing positive things.

 

[Eric]

Hallo Brandon,

hier ein paar Antworten zu den Fragen:

1:  You mentioned modifying the internal power supply of the 902… Were you only referring to converting it to 3.3v and eliminating the BS terminations or is there more to do?

Nein.
Die Installation von OpenWRT habe ich inzwischen nicht mehr gemacht, da der anfängliche Fehler der mit den 100ms Beacon Störungen in den aktuellen Versionen nicht mehr auftreten. Link: https://ethernet-sound.com/open-wrt-betriebssystem-auf-dem-tp-link-tl-wr902ac-v3/
Es wird Leute geben, die anfangen auf dem Board mit Kondensatoren zu Tunen oder auch meinen, das man die Clock des TP Link WR902AC austauschen soll – ich würde mich durch sowas nicht verrückt machen lassen oder mich darum scheren.

2:  I understand Ian Canada is amazing but I would prefer an enclosed linear power supply for the 902…. What brand/model do you recommend?

Meinst Du für 5V oder für 3,3V?
Für 5V und wenn Geld nur untergeordnet eine Rolle spielt: Farad Super3 Power Supply https://faradpowersupplies.com/super3/
Wenn das Budget knapp ist dann: https://www.aliexpress.us/item/2251832708134464.html

3:  Should all power and ethernet cables in the entire system be as short as possible even if they utilize ferrites and/or chokes?

Für Ethernet würde ich das nur für die Strecke zwischen WR902AC und Streamer so auslegen – solange das der einzige Ethernet Weg in Richtung Deines DACs ist.

4:  I’ve heard 2.4g is preferred over 5g in the 902…. Do you agree and is 2.4g for sure enough?  (I live alone with very little wifi usage).

Ich selbst nutze nur 2.4G – ja, das ist ausreichend.

5:  Will I be able to use the wifi from the router (for my laptop) to control the streamer if the streamer is connected in this way:

a:  Router via ethernet to a 902 AP

b:  902 AP via wifi to client 902

c:  Client 902 via ethernet to streamer.

Wenn der 902AP wirklich als Accesspoint konfiguriert ist, sollte dies funktionieren.

6:  Assuming the above listed format, should the 902 AP be very close to the router so it has a short ethernet cable, or further away for any reason?

Ich würde ihn nahe am Streamer platzieren um das Kabel kurz zu halten – wenn dir so viel daran gelegen ist, das letzte rauszuholen, musst Du ein V2.5 Drosselkabel hier einsetzen. Allerdings würde ich den WR902AC mit der Länge des Drosselkabel entfernen vom Streamer um nicht zu riskieren, das hier EMI Probleme vielleicht entstehen.

Ich lese ab und zu mal im Whatsbestforum – allerdings nur punktuell, da ich nicht die Zeit für alles habe. Die Idee von einem Mitglied, zwei WR902AC direkt nebeneinander zu setzen in ein Gehäuse wurde auch schonmal hier von mir andiskutiert und hat vielleicht darüber den Weg ins WBF gefunden. Ein Tip für die Mitleser: Hierbei werden natürlich auch Störungen durch EMI von einem Gerät auf das andere übertragen die dann über Ethernet weiter wirken – egal ob das Gehäuse ein Metallgehäuse ist.

7:  Is there a way to edit our posts after sending them in case we later find a typo?  lol.
Es gibt eine Edit Funktion, aber vielleicht ist die nur mir als Admin zur Verfügung.

[Bosko]

Hi everyone, happy new year!

It’s been a while since my last post, but considering comments on using dedicated access point it seems like a perfect time to share my findings. First, a bit of context…

I had a total rollercoaster with my WR902AC and wifi streaming setup.  There was lots of joy, but also lots of anger and despair! I had two WR902ACs, one as an Access Point (stock firmware) and one as the client (openwrt) with Eric’s isolator and a throttle cable 3, feeding my PS audio junior DAC/streamer. The client WR902AC was powered by a xiaomi battery and streaming is done via a Roon ROCK NUC which is connected to ethernet in a room 15m away from the audio equipment. When everything was good, it was simply unbelievable how much of an improvement it was over an etherregen/network acoustics Eno combo…. the soundstage, the depth, the silence, the explosive dynamics and most of all a massive reduction of glare (Thank you Eric!).

BUT, there were hours when everything was just sublime and then suddenly it would become a disaster, the glare comes back, everything starts sounding brittle, and sometimes I would get stutters and dropouts. It was very discouraging, but after many months of tweaking and testing I have solved the issue and am posting it as it might be helpful for other forum members with similar symptoms.

If you sometimes have issues streaming high-res (192/24) content due to stuttering or drops, or feel that the sound changes while streaming to your WR902AC then read on …if not, go grab a beer and know that I am extremely jealous of you because you have a perfect wifi setup😊

Few months ago, I was listening to music and had the web interface of the access point WR902AC open. I was playing around with the access point signal strength and quite easily heard a change in sound. Originally, I had everything at the lowest setting but noticed that increasing the power made everything calmer and improved the bass response. I thought I was going crazy, but repeated the test the next day and noticed the same change in sound. Combining this experience with fluctuations in sound quality I assumed that a bad or an inadequate signal is making the client WR902AC work overtime causing additional noise in the signal. After switching through various 2,4GHz channels on certain days it was better and on others it was worse so I downloaded a WIFI Analyzer app for my phone. To my surprise, I realised that my living room is in a WIFI warzone! Only in the 2,4GHz spectrum I have 8 strong signals out of which 2 use 40 mhz channel width!

Considering this wifi chaos I decided to get a higher quality access point to be able to manouver through all this wifi chaos. Searching around the net I found the dejitterit web page (https://dejitterit.com/SwitchX/WiFiX.htm) where substantial work seems to have been done on identifying a quality access point for audio environment. Based on what I read on the page I decide to order a refurbished Aruba IAP 325. This access point has a steep learning curve as nothing is preset and it has tons of settings. After spending many hours on Aruba and Cisco forums I managed to get it to work properly.

The biggest benefit of this Aruba AP was that one can monitor the quality of the wifi transmission in much more detail than the standard signal strength and noise floor. What you can track is: frame per second THROUGHTPUT in both directions, frame per second RETRIES in both directions, frame per second DROPS, and frame per second ERRORS.

This was an eye opener as I saw a correlation between the RETRIES, DROPS and finally ERRORS with the sound fluctuations and stream dropouts. Even though, in the IT sector up to 20% frame per second (FPS) retries is considered normal, when it comes to audio streaming, trouble starts already at 5% retries rate where the sound starts becoming brittle and eventually leads to errors and stream dropouts. This makes perfect sense as Tidal, Qobuz, Roon all use TCP protocol as the transmission backbone and this protocol has zero error tolerance (no buffering like in Netflix or similar). I am not and IT person, but my assumption is that the sound fluctuates as the TP link is working overtime to put an error free stream together and eventually fails due to all the packet delays.

Since this revelation, I have only the TP link connected via wifi to the Aruba AP, have bought a fritxtender directioinal antenna, connected it to the TP link, found a 5 GHz channel that nobody uses in close proximity and with many, many tweaks in the Aruba AP, placement of both pieces for optimal signal, I managed to get zero RETRIES when streaming 44.1kHz/16bit, and less than 1% when streming 192 kHz/24bit (Tidal via Roon). Keep in mind that when streaming via Roon the files are uncompressed so it uses around 20% more bandwidth then when streaming direct from Tidal. To reduce interference, I am using a 20 MHz channel width and it gives more than enough speed for streaming. I did try the 40 MHz, and yes, it increased the speed, but it also made the signal slightly less stable. I even bought a second directional antenna to use in tandem with the existing one. It bought an extra 3db, but made it much harder to set proper orientation. Also, my conclusion is that the best sound comes from the channel with least interference. It does not matter whether it is 2,4 or 5 Ghz (the antenna power setting on my TP link is 6db on a 5ghz channel)

In summary, if you sometimes have issues streaming high-res (192/24) content due to stuttering or drops, or feel that the sound changes while streaming, my suggestion is:

1.      Get a wifi analiser on your phone and find a channel nobody is using

2.      Connect only the TP link client wirelessly to your AP (which should be on the channel not used by anybody)

If you live in an area without too much interference, these two steps could solve all the issues.

Hope this helps! And if there are any WFI/network engineers reading this, please chip in… this is all based on trial and error and hours reading up on workings of wifi.

Now I can finally start focusing on the power supply😊

[Bosko]

Forgot to mention in the previous post that now there is practically no difference in sound between Roon, Audirvana or UPNP. Before, when using a wired setup, the sound differences were quite obvious. Actually, I only hear the difference between Roon and UPNP, but this is on the level of comparing a wave file vs the flac version of the equivalent.

[Eric]

Hallo Bosko,

wow – das sind wirklich interessante Erkenntnisse!
Vielen Dank für das Teilen!

Ich muss mir mal die verlinkte Seite anschauen mit dem WiFi Access-Point.
Aber es scheint wirklich so zu sein, dass das WiFi Netzwerk auch eine Auswirkung hat.
Ich hatte ja mein Musik-Netzwerk komplett getrennt vom restlichen Netzwerk und auch nur ein spezielles, minimiertes Handy für die Steuerung in das Netzwerk eingebunden und hatte leichte Unterschiede gehört.

Bin gespannt, was sich an dieser Stelle noch tut.

Beste Grüsse,

Eric

[rghanbari]

Fantastic post @divinely !

I’ve always been drawn to these more security conscious digital kit, mainly because of the obsession on minimizing any correlated noise or any noise.

Your report makes me very tempted to revisit the AP side of my chain.  I had a small but unambiguous improvement with a 902 on 3.3V running OpenWRT as my AP, but I have a relatively clean 2.4GHz environment.  Love how you approached tuning things to eliminate the problems in your environment

[Bosko]

Hi Eric,

The dejitterit portal was simply beneficial as the proprietor extensively measured end explained why he uses the ARUBA IAP 325 in the modified kit he sells and why wifi 5 (ac) is the last „non-harmful“ (to cabling and equipment) technology. Luckily the Aruba and the AC902 use the ac wifi 5 technology:)

Also, if someone has only one access point in their listening area then the way to set it up is to create two SSIDs on this AP, one on a 5GHz and one on a 2,4GHz channel and give them separate credentials. Then use one of those SSIDs to connect to your TP Link and the other one for the phone (the controller). This will have no wifi interferrence as each SSID is on a different channel.

Actually, the Aruba has a really cool feature – one can block broadcasts from devices in the network. In other words, in my setup, the only broadcast that arrives to the TP Link is from the Roon server. Everything else is blocked. Even the phone (the controller) only communicates to the roon server. I literally have to give it clearance if I want to modify something on the TP link.

Cheers,

B.

[Eric]

Hallo Bosco,

die Trennung des WiFi Netzes kann bei dem in Deutschland sehr oft verwendeten Router „FritzBox“ sehr effizient durch das einrichten des Gast-Netzwerks erreicht werden. Hierdurch besteht zusätzlich der Vorteil, das ein komplett eigenes IP Netzwerk hergestellt ist, was nicht durch andere Geräte mit Broadcasts etc. gestört werden kann.
Vielleicht ist dies auch bei dem ARUBA in der Art machbar.

Ich habe noch News bzgl. dem WR802N:

Ich habe ihn soeben auf 3.3V Input modifiziert. Da das Gehäuse sehr klein und wenig Platz für einen DC Stecker bietet, habe ich die eigentlichen 5.5V Schiene mit der 3.3V Schiene verbunden. Jetzt muss man über MicroUSB 3.3V einspeisen.

Messung habe ich noch keine gemacht, aber erste Hörtests und diese waren nicht schlecht.

Beste Grüsse,

Eric

[Bosko]

Hi Eric,

You are right, I also have a Fritzbox as my main router, and have been doing exactly that until a few weeks ago when I found out about this network isolation option on the Aruba. With the Guest option i could never isolate all the devices as some of them, like a security camera, nvidia shield… needed to remain on the main network. Now when it is 100% isolated I can’t say I hear any sound difference between the 2 options. It just makes me feel good:)

Cheers,

B.

[Autor]

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