I have been in contact with support, but it seems ALAC files with a high bitrate 'chokes' or resets the ND5XS.
Example: Noel Gallagher's High Flying Birds album "Chasing Yesterday", the fifth song "The Dying of the Light". streams at 3469 Kbps (according to the Naim app). While it is playing, the Naim app stutters, form time to time the spinning wheel is visible. Around 2:50 the ND5XS quits playing and the Naim app tells me the room cannot be found, meaning it has lost connection to the player.
File is played from an USB stick.
Converting it to FLAC does not deliver any problem. Curiously, I used XLD to do a ALAC 24/96 to ALAC 24/96 conversion and it resulted in a file playing at 3367 Kbps without a problem. It is a few MB's smaller on disk.
Also, the FLAC file sounds a bit different than the ALAC file. It is a bit dryer and flatter, the ALAC a bit more spatial sounding. At first I thought I was hearing things, but I compared a few files and they all expose the same difference to my ears. To rule out XLD as the source, I downloaded the same files that I previously downloaded as ALAC as FLAC from Qobuz. The XLD converted FLAC file and the Qobuz FLAC file sound the same, as do the ALAC files (when playing).
Which leads me to the speculation that within the player FLAC and ALAC are handled differently? Does anyone know if there is an upper bitrate limit for ALAC files?
Posted on: 27 March 2015 by DavidDever
I'd ditch the ALAC and stick with FLAC - older versions of iOS and OS X set a maximum sample rate / bit depth for ALAC transmission (via AirPlay) at 16-bit / 48 kHz, and, while it appears that that has now changed, it is entirely possible that an older version of the codec which was optimized for AirPlay may not be able to handle bit rates associated with the higher sample rate / bit depth.
There is nothing mathematically in the current Apache-licensed ALAC codec that prohibits playback of high sample rate / bit depths, by the way.
Posted on: 27 March 2015 by Mike-B
What USB "stick" make/model are you using. I've found large differences in the speed that they upload/download. I had a cheap USB loaded with some .wav files for my car, it struggled with the high res files, changed to a another stick & its runs OK.
My NDX I can play 24/192 .wav plays faultlessly at 9216kbs from a USB-3 - I now use SanDisk SDCZ80 Extreme Flash Drives for all my stuff, its USB-3 & reads at 245MB/s.
Final question, what firmware rev does your ND5 have ?? if its not 4 series, it needs to be upgraded.
Posted on: 27 March 2015 by jmtennapel
David, it is the Naim ND5XS that struggles, my iMac Play is without a problem. So, why would an airplay optimized file cause this, since airplay cannot stream 24 bit 96 KHz files And the file is served on a fast USB drive and the FLAC derived from that file plays without a hitch?
and why on earth do they sound distinctly different? It is the same DAC!
Posted on: 28 March 2015 by Dambor
Most of my files are ALAC, some of them hi res I don't have any problem playing them with my ND5 . I'm using streaming over wifi, though. Haven't tried USB.
Posted on: 28 March 2015 by pete T15
I'm having the same problem with my ND5 ever since the last software update , I mainly use USB sticks and the whole operation is very sluggish . I wish I hadn't done the update to be honest but my understanding is that it is being worked on .
Posted on: 30 March 2015 by jmtennapel
Can anyone confirm it is only the USB input that causes problems with ALAC files at high bitrates? It would surprise me, since the WAV files with even a higher bitrate play without a hitch form the same drive.
the wifi connection is not fast enough to be able to play such files from the UPnP input.
I suspect the decoder for ALAC files is the problem, because the ND5 seems literally to choke and reset itself.
