Help needed: No audio playback on Uniti Atom from Sony UBP-X800 Blu-ray through Digital Coax

About half a year ago, I entered the wonderful world of Naim when I purchased a Uniti Atom. I think the Android app still has some issues that need to be worked on, but otherwise I am extremely happy with it. What a great piece of gear!

I need some help though, because I am unable to play CD’s using the Atom. Since 99% of my music playback is file based (using either the attached SSD drive or a streaming service), I did not bother with a dedicated CD player. Instead I purchased a Sony UBP-X800 Blu-ray player, which should be of decent (audio) quality and supports all disc formats.

My Atom has a HDMI ARC module, so for Blu-ray playback I switch the Atom to the HDMI input and it picks up the audio signal from the TV. This way I am also able to play CD’s, but of course I don’t wan’t to switch on the TV when listening to music.

So I bought an AudioQuest Forest Digital Coax cable and connected the Digital Out of the Blu-ray player to the Coaxial RCA connector on the Atom (Digital 1). So far, so good.

However, whatever I try, I cannot get the Atom to get an input signal from the Blu-ray player using Digital Coax. Within the settings menu of the Blu-ray player, I have set everything to PCM / Stereo / 2ch, but no luck…

Does anybody (perhaps someone with the same Blu-ray player?) have any suggestions? Or is this just not going to work this way?

Many thanks in advance for your help.

Have you tried a different cable?
Set Digital Audio Output to PCM (if not already)

On blue ray it seems side you set it right. On Atom side did you select the appropriate input?, examine Atom settings is my advice…

I’m wondering if this is something to do with having both the HDMI connection and the Digital (S/PDIF)output connected to the Atom. It’s not clear from the manual whether the Sony will send the audio via both the HDMI and S/PDIF output at the same time. Does it work if you disconnect the HDMI cable from the Sony and just leaving the coax connection in place ?

Thank you for your replies guys!

@ robgr
Good suggestion. Unfortunately I don’t have any other Digital Coax cable, but I’ll see if I can borrow one. Then again, what are the chances of a brand new AudioQuest cable being faulty?

Yes, I did. The input should be Digital 1, according to the manual. Of course I also tried Digital 2 and Digital 3, but neither of them works.

Great suggestion. I just tried it and disconnected the HDMI cables both from the Atom and the Blu-ray player. Still no luck unfortunately.

Ok - very strange. I’d try another cable as the next step as you’re starting to run out of things to test with. Do you have anything else you could either use as a digital source to the Atom or another DAC / AV receiver you could test the output from the Sony with ?

I have the very same player connected to my superuniti via coaxial /pcm 2chnnl and have had no problems apart from the TV powering up when I switch it on…but that’s due to the hdmi cable being connected also…one thing to check maybe is that in the audio settings select 48khz for the pcm output signal from the digital out…I put it up to 192khz and got no sound.selected 48khz again and it was fine.

@ james_n
I have tried two other RCA cables (strictly speaking not ‘Digital Coaxial’, but they should work anyway) with no luck, which leads me to believe the cable is not the problem. Unfortunately I have no other devices with Digital Coax connectors.

@ Skinnypuppy
Good to know you have the same player and it works. At the same time, this makes it even more puzzling. I had already set the audio output to 48 kHz (although over HDMI, CD’s also play fine when it is set to 192 kHz).

Did you get this fixed? The last entry was over a month ago? What was the solution?

Not solved unfortunately. I asked for help on the Sony forum, but to no avail. My dealer had no idea either. Someone from Sony suggested that it could be the Blu-ray player sending out a 48kHz signal and the amplifier only accepting 44.1kHz. But the Coaxial RCA input on the Atom is specified as up to 24bit/192kHz, so that cannot be the problem. The only thing that I have not been able to rule out, is the Coaxial RCA input on the Atom being faulty. But what are the chances?

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Are you sure that the Sony is set to output PCM rather than multichannel Bitstream?

Can you borrow an old CD player from somewhere or do you perhaps have some other device with a 2 channel PCM s/pdif coaxial output? Easy way to check if the Atom s/pdif is faulty.


Yes, the output of the Blu-ray player is set to PCM (Sony actually suggested leaving it on Automatic, but that does not make a difference). I can also see on the TV screen that the output signal is 16bit/44.1kHz, when playing a CD.

Unfortunately I have no other devices with a S/PDIF Coaxial output. I have looked at borrowing a CD player somewhere, but the machines I found are all so old they do not even have digital outputs… LOL. But since this the last (?) option, I will try another source at some point.

I know this sounds very basic but have you tried another cable?

Yes, I have.

Have you tried an optical cable?

Could you not just use the analogue op from the bluray into one of the Atoms analogue input,

The Blu-ray player has no optical or analogue outputs, only coaxial and HDMI.

I have this Sony Player. I use the Toslink optical cable to get audio to my TV. Not familiar with the Naim Atom, but if its got an optical input, give that a try.

I have had a few DVD’s with this player that need the audio signal advanced, not delayed. Have not figured out how to do that yet.


Are you sure you have the same player? The UBP-X800 has no optical output. See page 7 of the manual (Rear panel), which I have linked to in my first post.

Do you by any chance have Bluetooth enabled?