Roon downsamples when playing to a naim muso through an iPhone endpoint [Answered]


I m using my iPhone 6s as a Roon endpoint connected through UBS to a naim muso to play hi res files. It downsamples the signal to 24 44 from 24 192. Not sure why as naim ubs input can accept 24 192.

Could be wrong, but I think on iOS devices, playback is Airplay rather than RAAT - hence the downsample.

Thanks Steve. I m open to correction but my understand from other threads is that iOS Roon endpoints are able to receive and pass through full hi res files which imply they are RAAT compatible. Also it does nt downsamples the bit rate which it leaves at 24. Airplay is only capable of 16.

Mu-so is not a RAAT endpoint like the new uniti streamers. It’s limited to an AirPlay connection which is why you are getting down-sampling.

Your audio settings should show what the connection type is.



It s possible to airplay directly to the naim muso from Roon using airplay at 16 44.

However I want to play hi res files at full resolution through it. To achieve this I m using the iPhone as a Roon endpoint and audio shows the connection type as RAAT. I m then connecting the iPhone to the usb input of the naim muso using a lightning to usb connection. The USB connection of the naim muso is capable of 24 192 inputs. I would have expected the full resolution to be passed through to the naim muso from the iphone bno downsamples

I suppose the Muso is connected via the iPhones Lightning jack, with a Camera Connection Kit? There are no limitations such as airplay or limited resolution in this case. Try the Device Settings Advanced and post a screenshot please?


Muso is connected to the iPhone through a standard lightning to usb cable. Muso accepts and plays the stream from the iPhone. Not using a camera connection kit.Would this be the reason for the downsampling?. Device set up below


Ah, yes, thats the culprit. By using the lightning-usb cable you are using the iPhones built in digital audio (or analog output) and its internal DAC is limited to 48Khz. If the Muso has got a USB B input you most likely could connect your phone to that (via the camera conn. kit) and achieve any sample rate you’d like, bitperfect.

Many thanks Mikael

I ll buy one and try it next week

I dont have any iPod-aware hardware available today. But looking at your second screenshot it seems the endpoint could take up to 768Khz samplerate?
I still believe you would have to use a camera connection kit to acheive the higher resolution playback.
Anyways, looking forward to hearing if this fixes your issue! :slight_smile:

Thanks Mikael. Will let you know how I get on next week

Hello @Gerry_Lynch,

Unfortunately, the Naim Mu-so does not have the proper type of USB input to function as a high resolution USB DAC. While the Naim Mu-so can play files off of a USB stick at high resolution, it does not support connecting another computer, or iPhone in your case, to the unit and controlling playback from the connected computer/iPhone.


Thanks everyone for your assistance here

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