LG C9 + Arc + UB820 / Multichannel PCM for DTS Blu-Ray discs

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I’m running an LG C9 with a Panasonic UB820 Blu-ray player, Sonos Arc + Sub gen 3 + One SL surrounds. The lack of DTS support on the Arc has been frustrating for non Dolby encoded Blu-ray discs, so I have been eagerly awaiting the multichannel PCM update.

It’s finally arrived (thanks, Sonos!) and I tried playing a DTS encoded Blu-ray and… no dice. Still stereo PCM 2.0. Has anyone running a similar set-up managed to get 5.1 PCM output from the Arc?

The C9 supports eARC and multichannel PCM, I’m using 48gbps HDMI cables that support up to 8k60Hz, all of the devices are up to date, I have the C9 set to PCM with eArc enabled, DTS output set to PCM on the UB820… I’m really at a loss here. Any ideas or suggested settings?

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My HDFury DR HDMI 4K arrived today!


Happily, as expected, the device works to address the issue between the 820-LG C9-Sonos Arc. I have set the unit to the 4K max mode EDID. “Green 1 – 4k60-444-600M-HDR-BT2020-3D-FULLAUDIO” - 820 is set to DTS → PCM and Dolby to pass through. All of the media I tested before (see earlier in this thread) played exactly the same way. Dolby Atmos passed through the LG with TrueHD to the Sonos Arc. DTS Master HD and DTSX both were converted to PCM. For 5.1/7.1, they show up on the Sonos as Multichannel PCM 7.1. 2.0 DTS shows as 2 Channel PCM.


Picture is correct for Dolby Vision and HDR and looks great both for 4K native sources (Hobbit & Psycho) and upsampled 1080p and 1080i Blu-ray discs.


So, for me, this $99 (+ shipping) unit handles the handshake issues for at least the C9. Hopefully someone will verify this also works on the CX models too. The Arcana seems to be overkill for the problem (and I will try to sell mine on eBay at some point). 


I will do more experimenting when I have time on the weekend to see how other settings work.



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Here is their final conclusion :


« The factory has been notified. Their point of view is that the problem is with the TV, not with UB820: The recorders do not have EDID. The TVs have EDID and update the audio part with the EDID of the Sonos sound bars. If the problem disappeared by converting the EDID of the TV with a special device, the EDID is "corrected" to conform to the HDMI standard. »



So, for Panasonic, the issue is on LG side.



By the way, this point from Panasonic support team may interest @GuitarSuperstar , who was deeply involved in this topic at some point 😀

FYI - LG have just released an update for the CX (04.40.10) which appears to (mostly) resolve this issue. 


Before, I only got stereo PCM passthrough from the 820 for DTS discs - and had to get the HDFury Dr HDMI 4K and code with a custom EDID to get the full LPCM 5.1/7.1.


However - with the new LG update I can get LPCM 7.1 passthrough without the need for the additional Dr HDMI 4K device. For some reason, the Sonos app is still saying that it’s LPCM 7.1 (rather than LPCM 5.1) - but I guess this shouldn’t be a problem since the ARC is now able to downmix from 7.1 to 5.1 correctly.

N.B. - if I set my Xbox Series X to uncompressed 5.1, the Sonos app now says LPCM 5.1 (before it said LPCM 7.1) so I know it can work as it’s meant to! It must mean that there’s still something not quite right in the interface between the LG CX and the UB820 to cause the UB820 to put out 7.1 instead of 5.1 - but as I said, at this point it doesn’t really matter as what we hear should be the same anyway.

It would be great to hear if this works for anyone else who had the same issue with the LG CX and the UB820! 

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Hey everyone, so I’m a long time lurker/contributor of this thread.

I have a B9 instead of a C9/X, and I understand it has DTS pass through support. So I expected today’s update with DTS support from Sonos to finally mean I no longer need to listen to my Blu Rays in Stereo PCM.

Unfortunately, no luck at all :( I don’t understand why it’s still not giving me DTS of anything better than stereo. Can anyone suggest any steps to take?

What are your Blu-ray player audio settings currently set to?

Ahh, I think I’ve cracked it!!

Player settings (UB820):

DTS/DTS-HD - Bitstream

BD-Video Secondary Audio - Automatic


LG B9 settings:

Digital Sound Out - Passthrough

eARC - Off


Turning the eARC off seemed to be the thing that pushed it over the line. I haven’t tried DTS:X Blu Rays yet, but my DTS-HD 5.1 and 7.1s are now showing as ‘DTS Surround 5.1’ instead of the old ‘Stereo PCM’. They sound gorgeous!

Wow, I have no idea whether turning off eARC is gonna cause other problems for me, but I can’t believe I finally have DTS surround sound, with the UB820 as well!

Hey everyone, so I’m a long time lurker/contributor of this thread.

I have a B9 instead of a C9/X, and I understand it has DTS pass through support. So I expected today’s update with DTS support from Sonos to finally mean I no longer need to listen to my Blu Rays in Stereo PCM.

Unfortunately, no luck at all :( I don’t understand why it’s still not giving me DTS of anything better than stereo. Can anyone suggest any steps to take?

What are your Blu-ray player audio settings currently set to?

Ahh, I think I’ve cracked it!!

Player settings (UB820):

DTS/DTS-HD - Bitstream

BD-Video Secondary Audio - Automatic


LG B9 settings:

Digital Sound Out - Passthrough

eARC - Off


Turning the eARC off seemed to be the thing that pushed it over the line. I haven’t tried DTS:X Blu Rays yet, but my DTS-HD 5.1 and 7.1s are now showing as ‘DTS Surround 5.1’ instead of the old ‘Stereo PCM’. They sound gorgeous!

Wow, I have no idea whether turning off eARC is gonna cause other problems for me, but I can’t believe I finally have DTS surround sound, with the UB820 as well!

I can confirm this also worked for me. Beam Gen 2 (with the DTS update), UB820 and LG C9. 

UB820 set to bitstream DTS. With the C9 set to eARC on, playing DTS-HD gives the unsupported audio format error. Setting it to off causes the TV to pass the core 5.1 DTS to the Beam. 

i was disappointed that the Sonos update wasn’t sophisticated enough to detect the HD stream, but then just play back the lossy core. But this at least gives me a simple workaround, without the need for extra hardware. 

Hopefully this will improve with further Sonos updates. Fingers crossed this is just the beginning, and that HD and X are on the roadmap to come!

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I have filed a ticket with Panasonic on this issue, giving them extensive notes and links to this thread and others which report the issue. I have noted that other players are correctly outputting MC PCM audio with the LG C9/CX and Sonos Arc combo. That was filed today, and I do not expect an answer soon. I specifically asked that the email be passed to their audio engineering team as a customer support rep will not be versed in this area.



Update: I received a pleasant reply from the Panasonic support team apologizing for the issues and asking for a bit more information including proof of purchase. We’ll see where this leads next.

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Some are getting it to work. Maybe set the Bluray player to bitstream and let all the devices sort it out.



I’ve got the same setup. Can’t get it to work either for DTS blurays. Have run out of settings to try on 820 and C9. Nintendo switch and PS4 gaming is fine and outputs LPCM 5.1/7.1. 

Same for me. I have a LG C9 and Sonos Arc with 2 one sls. I can get multi channel from my PC, PS4 and PS5; I set the the Sonos Arc to Passthrough, the devices to LPCM and the app shows that I amn receivng 5.1 channels. However. my Panasonic UB820 shows as PCM stereo when I set the DTS to PCM. I’ve tried leaving everything unplugged overnight and tried other settings but no joy.    

I also have the same setup. Instead of losing more hair, I finally gave up and purchased the Sony UBPX700, which also has Dolby Atmos and Dolby Vision.  It’s very inexpensive and it works. I am now getting LPCM 5.1/7.1 when playing DTS discs.  Until the issue is fixed, I will use the Panasonic for Dolby encoded discs and the Sony for DTS encoded discs.

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One thing to check is what type of DTS track you are trying to play. I was checking the 420 specs and it can't decode DTS:X only bitstream it. It can decode DTS-HD tracks. The 820 will be same I'd expect.

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I have a Sonos Arc and UB820, and I get multi-channel LPCM audio playing through my Arc from ALL of my DTS-HD Master Audio Blu-ray discs. More than likely, the problem is your TV, HDMI cable, or TV settings.

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I have the same issue.

I have the LG C9

Got the Arc last week

and got the UB820 today.

Have tried everything but can only get PCM 2.0 output.

UB20 set to output DTS as PCM

TV HDMI is set to Bitstream (tried PCM too); Sound output is set to eArc and pass through.


I’m not an expert at this but reading elsewhere I understand, the Arc needs to be able to receive a LPCM signal for multi channel surround, as opposed to PCM (which is 2.0 channel only?)

Can the UB820 definitely do multi channel LPCM?

There is a difference between PCM and LPCM, but both can carry 5.1 or 7.1 channels. Since GuitarSuperstar is getting PCM 5.1 or 7.1 from the UB820 as described above, then it sounds like a handshaking issue to me since the only difference between our set-ups and settings is the HD Fury Arcana...

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For what its worth I dont think its 'just' the player or 'just' the TV rather the two seem incompatible when passing LPCM for some reason. 

I have C9 TV and my player (Oppo) is able to convert DTS to LPCM meaning I get LPCM7.1 or LPCM5.1 depending on DTS soundtrack used on disc. The HDMI port for TV from bluray is set to bitstream. Setting the TV to PCM results in downgrade to 2.0.

Others are stating the Panasonic player works seamlessly with other TV brands.

Userlevel 2

Just thought I would share my experiences. 

Same problem as everyone else. UB820, GX, Arc. Can only ever get the UB820 to output PCM 2.0 for DTS soundtracks.

Considering the cost of all of the equipment, it is absolutely not acceptable to have to fork out another £200 for an HDFury Arcana just to be able to use functionality which I have already paid for.

And I bought the UB820 specifically for this setup, to get around the lack of DTS support in the GX and Arc. 

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I received my HDFury Arcana today and I have some positive preliminary results to share, certainly in regards to the Panasonic 820 output. I need to do more tests. But so far, success with DTS multichannel to PCM Multichannel into the Sonos Arc while retaining correct Atmos playback in True HD format.


Here is my set up:


Panasonic 820 4k Player

Apple TV 4K

Tivo Bolt

(I have a Nintendo Switch, but I have not connected it to the TV to try with this.)


Display: LG 55” C9 (2019)


Audio: Sonos Arc 5.1 set up

All devices are on latest firmware.


The Arcana arrived via DHL from Taiwan. I ordered on Jan 1, it shipped on Jan 4 and arrived today, Jan 8. Product arrives in a blister pack and includes the Arcana, a USB cable and a power plug (with US plug in my case). No documentation - that is all online. Firmware came as .79 (which was released in Nov in parallel with the Arc’s update to support PCM multichannel audio). I updated, via USB stick, to the December release which is .80 and that fixed some Xbox items according to the notes. Arcana build quality is fine. Not super great, but survivable for a part that likely just sits without much interaction. Menus are nicely laid out and easy to read on the OLED screen.


Happily, my theory that I could use the TV as switcher was accurate for the non-820 sources! 


My set up now:

820 via 8k ethernet HDMI cable to the Arcana HDMI in (I doubt I need this high a cable for this, but it is what I had)

Arcana HDMI video out to LG input 2 (ARC port), with a 18 gbps /ethernet cable 

Arcana HDMI eARC output to the Sonos input via 18 gbps ethernet


AppleTV 4K to LG input 1

Tivo to LG Input 4 

(the 820 used to be in 3 on the LG, hence the gap)


820 has Dolby tracks in bitstream format for output

820 has DTS tracks going out via PCM for output

BR Secondary audio is off


From the Hobbit 4k disc, I get Atmos (True HD) to the Sonos - as expected

From the LA Phil 100th Anniversary Disc, I get 2.0 PCM from the 2.0 PCM track AND….

7.1 (but only 5.1 source) from the DTS MA track. (This disc features a 2D and a 5.1 mix.)

From the new Eiger Sanction blu-ray release, I get PCM 2.0 from the DTS MA track (which might be in 1.0 format)

I am sending 4k 4:4:4 picture (native for the Hobbit, upsampled by the Panasonic for 1080 sources). The Arcana can do this too, but I did not see the need for that.

(Note, I tried to adjust the Panasonic to match the disc channels - e.g. 5.1 for 5.1 - but it seems to always want to send 7.1 - even when I changed the down mix settings. I need to tweak more.)


When I switch to the Apple TV on input 1, the LG correctly passes the bitstream back to the Arcana via eARC, which routes it to the Sonos. (I think it’s crucial to the have the Panasonic off for this to work.) I can get 5.1, Atmos (DD+), and 2.0 PCM - all as expected based on the programming source. Picture is 4K Dolby Vision when the source allows.


Here I have a flag on synchronization between the TV and Sonos. I feel like when I watched Rise of Skywalker via Disney+ that the Atmos audio was slightly late which would be attributed to the extra hop through the Arcana. However, when I watched the same movie via my Apple iTunes Movies version, it was in sync. I looked at Rebecca on Netflix which has Atmos, and it seemed in sync or very close. I did run the Wireless Sync on the AppleTV. but I am not sure that impacts wired connections. There are no settings on the TV that I know of to make the picture lag - only to make the sound lag which is not helpful. I tried both Passthrough and Auto for the ARC Out setting (and with bitstream as the format).


I only flipped through a few channels on the Tivo and it all seemed in sync. The Tivo is sending Dolby Digital through and it seemed in sync.


So, I think I have what I want. Great 4k player that can drive the LG and Sonos with any disc I want to play and with the correct channel output and nicely upsample lower res images. Ability to use multiple sources with the LG and not need a switcher as well.


More to follow as I play around more this weekend and watch feature length content. 


And do I think this should be necessary? Heck no! As noted in a previous post, having to spend $200 more to solve a connection problem seems wrong. But if the issue is with the LG CEC, my instinct is that they won’t fix a 2019 problem such as this unless it were impacted a number of players. They might for the 2020 CX line, and perhaps for whatever they announce next week at CES. 


Hope my initial tests prove reliable and repeatable over the next few days!


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I chatted with HDFury’s team on their Discord server. Basically, I am using the Arcana, as I thought, just like a DR HDMI 4K - basically the way I have set it up is only fixing the EDID problem causing the handshake issue. According to the person who responded, my set up is fine to use it this way. 

Obviously, $100 more expensive is not ideal (Arcana vs. DR HDMI 4K), but again, at least it all works until we get a true fix from LG (or Panasonic if they can fix it on their end). 

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I agree with the frustration (and am on a similar timeline on returning the 820). But the picture is great, and there really aren’t any other players I prefer. The Sony ones require manual switching Dolby Vision. The LG one cannot send out PCM for just DTS - it’s all audio or none. The Samsung and Oppos are not made any longer.  


Hi all I've sent LG and Panasonic an email about the problem with a link to this topic. Can anybody confirm the the hd fury Dr hdmi 4k works? 

Setup is LG c9

Ubp 820

Sonos arc


Thanks for any help 😉

I’ve got a GX, arc, and ub820ebk and have ordered a dr hdmi 4k, which is cheaper than the Arcana. Will update this thread when I’ve tested it. 

My setup is the UB820-LG CX-Sonos Arc and I got tired of waiting for a solution from Panasonic or LG for the multichannel LPCM problem so I purchased DR HDMI 4k and tried it a few days ago.

I was hoping to just set the unit to the 4K max mode EDID. “Green 1 – 4k60-444-600M-HDR-BT2020-3D-FULLAUDIO” and have it all work, but for me it wasn’t quite that simple. Using this mode did allow me to get 7.1 channel LPCM from the UB820, but I noticed 2 problems:

  1. I wasn’t getting Dolby Vision indicatations by the LG CX. Only HDR indications even for disks that supported Dolby Vision (and that I had seen Dolby Vision indicated when I wasn’t using the DR HDMI).
  2. For certain disks, I would get no audio when the playback first switched to multichannel LPCM (decoding DTS). For example the UHD Bluray menu may have started in DD 5.1 and only switched to LPCM for DTS when starting the actual movie. The UB820 indicated 7.1 LPCM being sent out, but the Sonos app would indicate no audio being received. Forcing the DR HDMI to restart a handshake fixed the problem each time.

I ended up fixing this by copying the LG EDID that was being sent out into the special bank for this in the DR HDMI. Then I used the DR HDMI utility on my PC to copy the EDID to a binary file, and then used an EDID editor (with GUI) on my PC to find the Dolby Vision “Vendor Specific Data Block“ EDID that was being provided by the LG and copied that info into a side file. Then I copied the “Green 1 – 4k60-444-600M-HDR-BT2020-3D-FULLAUDIO” bank to a binary file, and I used the EDID editor to start with that as a base and then added the Dolby Vision support info that I saved off in a side file. Then I saved off the resulting modified EDID into a binary file and then used the DR HDMI EDID utility to save that to bank “Custom 1”.
(I’m a little surprised the utility provided by DR HDMI doesn’t have more support to actually “decode” the binary into a GUI that figures out each field and includes a description)

When I used Custom 1 from the DR HDMI 4k, now I could see the LG confirming that it was getting Dolby Vision and not just HDR. But I was still getting the problem of not hearing the LPCM 7.1 for some disks unless I restarted the handshake of the DR HDMI.

So then I went back and looked at what the LG was sending for supported audio and modified the EDID I was using in Custom 1 to have matching audio support (this involved things like removing audio support for things like DTS/DTS-HD/1-bit SACD audio as well as 192k and 96k support for LPCM). After I saved these changes to the Custom 1 bank of the DR HDMI and used this, now my audio worked right away all the time for LPCM 7.1 coming out of the UB820 (no need to force the DR HDMI to reinitialize a new handshake). I wonder if the UB820 was trying to send out 96k LPCM for DTS-HD on some disks initially and only redoing the handshake somehow got it to send LPCM in a format supported by the LG and/or Sonos Arc.

I also mention that when I examined the EDID being sent by the LG CX, when I looked at the audio data block section of the EDID, I couldn’t find anything wrong. So its not obvious why the UB820 couldn’t figure out that it could send multichannel LPCM based on the EDID from the LG. There must have been something else wrong or different about the EDID being sent by the LG compared to the DR HDMI 4k max mode that is messing up the UB820. Oh well, now that I have something that works, I don’t think I’m going to bother investigating that any more.

I hope this helps anyone else with this setup that doesn’t get things to work exactly right when using the built-in modes of the DR HDMI.

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Hey guys, can anyone confirm that the Arcana doesn’t have the Dolby Vision issue?


I can 100% confirm that the Arcana works - you just need to set the device to pass the audio to the HDMI Out port and you do not use the eARC output port at all. You use the device just as a passthrough, similar to the intent of the DR HDMI 4K. This is my set up now and has been stable for weeks.


I can also confirm I am running into the Dolby Vision issue with the HDMI DR 4K. So, in my rushed eval on Monday, I missed this was not working with the built in EDID. I see now that the HDFury site has different EDIDs listed for the banks than what is on the sticker on the physical device. I have more to check on this and to get an EDID editor going for my personal interest.


And finally, I have chatted briefly on the HDFury Discord server with them. They are very fast and you can scroll through a ton of old chats too which can be helpful.


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I just wanted to add a little more info here:

I have a C9, Sonos Arc and had the Panasonic 820. While many DTS UHD discs has a core lossy stream (Gladiator plays perfectly fine on my setup for example in lossy DTS 5.1), all releases from Arrow Video don't. Both Donnie Darko and Pitch Black only has a lossless DTS stream, and won't output any audio when playing the discs. The only option is to turn on PCM, but that only gives you 2.0 audio.

I returned my 820 and went with the Sony 800m2. Seems like the best option now. Or an Xbox. 

I have never been able to pass LPCM 5.1 7.1 from the Panasonic 820 through my LG CX to Sonos ARC. only PCM 2.0. Thanks to someone else’s post in this community, I found the very affordable $150 Sony X700/M player w/ great IQ BTW will pass LCPM 5.1/7.1 from the player through the LG CX TV and to my Sonos Arc for my DTS: HD only blu-rays. It was too late for me to return the Panasonic, so I use the Panasonic 820 for all my Dolby Atmos blu-rays discs HDMI 3 and the Sony player for DTS only blu-rays HDMI 4. 

A new day ! 

For the first time ever…I am now able to pass through Multichannel/LPCM 7.1 from the Panasonic 820K  playing a 4K UHD DTS:HD disc through the LG CX TV to my Sonos Arc 🤩🤩

Something changed via recent firmware probably with the LG CX TV since the  Panasonic 820K has not received a firmware update in some time.

With the LG CX TV sound set to “pass through” I now see Multichannel PCM 7.1 when playing both of these 4K UHD DTS: HD discs on my Sonos App:

"Jurassic World Dominion"4K UHD DTS:HD

"The Revenant" 4K UHD DTS:HD

Previously I would only see PCM 2.0 pass through the LG CX TV with these DTS discs played on the Panasonic 820K player. 

My setup is Sonos Arc (14.10 firmware) + LG CX (04.40.10 firmware) + Panasonic 820. After updating to those firmwares the Sonos app is now saying Multichannel PCM 7.1 (and the sound output sounds multichannel now too). My audio settings on the CX and 820 are set to their respective defults. Glad to be able to finally use my equipment fully.

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I wanted to share some new experiments. All of this is preliminary!!!!

I just received the hardware to make adjustments to the DR HDMI 4K EDID custom units. I went with both the Bluetooth module ($49) and a USB cable (only $10). At this point, I am all about the experimenting so caution continues to be thrown to the wind.


Reminder, I have the Panasonic 820, the LG C9 55” and the Sonos Arc + Sub + Surrounds (2). All units are on current firmware releases. Symptom: Inability to send multichannel sound from DTS tracks (converted at the Panasonic) through to the Arc. Dolby formats and 2.0 tracks all work fine. I want to retain Dolby Vision and HDR format compatibility for 4K discs.


With DR HDMI 4K in the signal pathway, I can fix the audio problem, but I lose Dolby Vision. With the HD Arcana, everything works fine although I am using the device in an odd format vs its intended use. 


My thesis is this: 

I would like to use the EDID output from the LG but edit it to fix whatever issue is causing it to not output MC PCM audio. I prefer to use the LG EDID because all other aspects seem to be working (video formats, color gamma, Dolby audio). 


Using the DR HDMI 4K, I copied the EDID from the LG to the SINK setting. I then transferred that file via the HDFury iOS app (via the bluetooth dongle) to my iPad. That was then moved to my PC (via cable) and imported into the Advantiv EEditGold program. I also saved the HD Full Audio EDID profile that produced the correct audio (but was missing the Dolby Vision ability) for comparison. 


Looking at the two files, I focused on the audio sections. I do not want to touch video because it works in the original profile.


Here I found two differences. They both seem to be necessary, but I need to keep playing to know how much has to match.

First, the audio formats on the LG EDID are missing the 1 bit audio. This is SACD so it seems odd this is needed, but I added it back in and adjusted the listed order to match the working EDID.

Second, and I believe at the heart of the matter, the LG EDID does NOT include the speaker table. This section tells the player which speaker locations are available for output. I added this block (see image) and enabled the same channels. 


I exported the new EDID block to a .BIN file and reversed the pathway back to the DR HDMI 4K, using a custom slot. 


Voila! This change enabled both desired states - at least with my limited testing. Dolby Vision working for those UHD discs. HDR for my 1 4k disc that only has that instead of Dolby Vision. Dolby Atmos still working all the way to the Arc. And LPCM 7.1 audio output (from 5.1 or 7.1 tracks) Upsampling from 1080 images to 4K working. 24 fps, 30 fps and 60 fps all working.


More to follow as I want to really nail down the minimal fixes to make this work. 

Again, for ease of use, the Arcana is the way to go. For those brave to follow this, it is possible to get there with a DR HDMI 4K and a likely a $10 USB cable (although I still need try that exact path). 


More testing tomorrow.

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@Surge My UB820 is connected from the HDMI audio/video out port to the HDFury Arcana and I get multichannel PCM audio playing out of the Arc.


I too am also getting 7.1 audio from the 820 through a DR 4K HDMI through my LG to my Sonos Arc. The only time I get 2.0 audio is when the source material is in 2.0 format.


After Panasonic asked for more info on my ticket, they have not further responded.