Phantom RAAT after firmware 2.14.4 update plays not 96k/24 lossless, only shows it

[streamy]

Hey guys,

Have you also seen that the Phantom using RAAT play 96k/24 hires without conversion! Only 192k/24 is converted to 96k/24 and 176.4k/24 to 88.2k/24. What a great surprise! Well done Devialet!

Correction: Unfortunately, it only shows in the ROON signal path 96k/24, but downsamples to 48k/24. This is by now corrected in the latest 2.16.1 firmware version, in which the signal path shows correctly the downsampling to 48k/24.

[struts]

Hey guys,

Have you also seen that the Phantom using RAAT play 96k/24 hires without conversion! Only 192k/24 is converted to 96k/24 and 176.4k/24 to 88.2k/24. What a great surprise! Well done Devialet!

Steady on [mention]streamy[/mention]!  We’ve been here before, remember?  Are you really sure?


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[ogs]

That makes a lot of sense! I am not happy with the 48kHz limit. Really hope this is correct!

[ragwo]

Seems to be correct. That's great news!
   
Thanks @streamy!

[streamy]

Seems to be correct. That's great news!

Thanks @streamy!

You’re welcome! Currently suffering some hearing loss (unilateral) but it starts recovering. So maybe at some time I’ll need the 96k

[streamy]

Hey guys,

Have you also seen that the Phantom using RAAT play 96k/24 hires without conversion! Only 192k/24 is converted to 96k/24 and 176.4k/24 to 88.2k/24. What a great surprise! Well done Devialet!

Steady on [mention]streamy [/mention]!  We’ve been here before,  remember?  Are you really sure?


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Yes, indeed! Could be interesting to measure if there is a change in what gets now as acoustic wave out of the phantoms? 27 kHz it should be as of specs for ‘Gold’ or 108dB Phantoms. So far I could measure roughly 23kHz as of the limited/cut sampling frequency of RAAT streams. And also all other protocols were even more restricted. Interesting times

[ogs]

Wow that is really great! Thanks guys! Also the down sampling seems power-of-2 based so no longer 48kHz for everything.

[struts]

Hey guys,

Have you also seen that the Phantom using RAAT play 96k/24 hires without conversion! Only 192k/24 is converted to 96k/24 and 176.4k/24 to 88.2k/24. What a great surprise! Well done Devialet!

Steady on [mention]streamy [/mention]!  We’ve been here before,  remember?  Are you really sure?


Sent from my iPhone using Tapatalk

Yes, indeed! Could be interesting to measure if there is a change in what gets now as acoustic wave out of the phantoms? 27 kHz it should be as of specs for ‘Gold’ or 108dB Phantoms. So far I could measure roughly 23kHz as of the limited/cut sampling frequency of RAAT streams. And also all other protocols were even more restricted. Interesting times

Well, I measured my K28 Phantom I Golds running firmware 2.14.4 while playing @streamy's test signals at 24/96 (and 24/192) on Roon/RAAT.  Just to be sure I also played the same files from Audirvana via UPnP.  

The test comprises five 30-second FLAC files containing test tones at 1kHz, 1kHz and 25kHz mixed, 25kHz, 20kHz and 22kHz.  The purpose of the 1kHz tone is to act as a 'control' and to facilitate analysis of harmonic distortion. The purpose of the 20kHz+ tones is to determine if and where low pass filtering is being applied.

The 1kHz, 20kHz and 22kHz files all played correctly showing a clear spike on the RTA plot.  In no case was there any sign of the 25kHz tone, indicating that this had been low pass filtered somewhere along the way:

   

So my initial conclusion is that the Phantoms are still downsampling to 24/48 prior to DAC and are not lossless at 24/96, although this is not being shown in the Roon signal path so it is presumably (my assumption) not being correctly reported back to Roon:

   

@streamy, your thoughts?

[streamy]

Thanks @struts for doing the measurements and showing the plots here. Indeed, what I can see from your attached pics indicated clearly that nothing has changed when it comes to what can be heard acoustically. That’s a pity! No advantage in streaming higher than 48k to the Phantoms, same as before the update.
Still sufficient for me as I can use all the power of Roon’s DSP to adjust hires sources to my room and keep downsampling to unload the network.

[struts]

Thanks @struts for doing the measurements and showing the plots here. Indeed, what I can see from your attached pics indicated clearly that nothing has changed when it comes to what can be heard acoustically.

I logged tickets with both Devialet (7th Feb) and Roon (31st Jan) on this issue. While Roon support has yet to even acknowledege my request Devialet picked it up within 2 days and today I received this email from Paul at Devialet customer service:

Paul (Devialet)
Feb 22, 2022, 5:01 PM GMT+1

Hello Struts,

I hope this mail finds you well.

Our team has found the origin of this issue, and a fix will be provided with a future update 🙂️

We do not have any release date yet, so it will most certainly take several weeks.

I'm keeping your file open until then, to inform you when the update will be available, and to check with you the downsampling step is correctly shown afterward.

Kindest regards,

Paul | Customer service & support Devialet

So:
1. Full marks to Devialet for their handling of my ticket. Prompt, courteous and completely satisfactory for me at least. Thank you Paul! I’ll be keeping an eye out for the fix in the next maintenance release.
2. Downsampling to 24/48 is definitely still taking place as shown by my measurements. It was, as suspected, simply a regression bug in the Signal Path reporting in RAAT introduced in firmware 2.14.4.

@streamy you might like to edit the subject of this thread to show that this turned out not to be true. Would save folks browsing the forum getting their hopes up!


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