Issues with playback to Audiolab M-DAC+

Hello @support team !

I am having the same audio output issue with Roon running here. In my setup Roon runs on a QNAP NAS. In the beginning things are fine and Roon renders sound via its USB-connected DAC (an Audiolab M-DAC+). But at times - and not sure why as I cannot systematically reproduce - the next song would just remain silent - and the ones after will just go straight to the end without rendering any sound either. The DAC says ‘unlocked’ at that time - just as if it was not connected to any USB source.

To get rid of the issue, I have to reboot the NAS running Roon. Powering the DAC off/on does not help, but reading this post today, I just figured that unplugging/replugging the USB cable actually does the trick too.
Note that rendering to other Roon output devices works, so the issue is local to the USB device / Roon output.

The RoonServer logs are totally silent about the issue but the RAATServer logs show an “error in snd_pcm_hw_params: Input/output error (-5)” when the problem starts. See the log below.
This issue happens more and more often. I don’t believe seeing any before the 1.3 release either. Any idea ?

10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] alsa output setup: format is pcm 44100/24/2
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] opening [hw:CARD=A20,DEV=0] 44100/24/2
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] prefer larger samples = 0
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [ALSA] [hw:CARD=A20,DEV=0] using hw pcmformat S32_LE bitspersample 24
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [ALSA] [hw:CARD=A20,DEV=0] Requesting 2 periods
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [ALSA] [hw:CARD=A20,DEV=0] Requesting 1764 frames/buffer (882 frames/period)
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [ALSA] [hw:CARD=A20,DEV=0] Initialized with 2 periods with 882 frames/period and 1764 frames/buffer
10/21 23:57:57 Error: [RAAT::AUDIOLAB USB Audio 2.0] error in snd_pcm_hw_params: Input/output error (-5)
10/21 23:57:57 Warn: [RAAT::AUDIOLAB USB Audio 2.0] [lua@0x7f6e38004a38] [127.0.0.1:33469]  setup failed: RAAT__OUTPUT_PLUGIN_STATUS_FORMAT_NOT_SUPPORTED
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [lua@0x7f6e38004a38] [127.0.0.1:33469]  SENT [6] {"message":"RAAT__OUTPUT_PLUGIN_STATUS_FORMAT_NOT_SUPPORTED","status":"UnexpectedError"}
10/21 23:57:57 Trace: [RAAT::AUDIOLAB USB Audio 2.0] [lua@0x7f6e38004a38] [127.0.0.1:33469]  GOT [7] {"request":"setup","format":{"sample_type":"pcm","sample_rate":44100,"bits_per_sample":16,"channels":2,"sample_subtype":"none"}}

hello @support team. I haven’t heard anyone back on this topic . is anyone listening?

Hello @Christian_Chateauvie,

It appears to me that this behavior is related to a known issue with XMOS USB chipsets on Linux. We will be sure to reach out to Audiolab and let them know about this.

In the meantime, you may be able to avoid this behavior by enabling the “Headroom Management” feature in Roon’s DSP Engine.

Here is a post from our CTO with some further information on this issue

-John

Thanks @john So does this mean that this is an audiolab bug that could be potentially fixed through an audiolab firmware update or is the problem in the hardware and cannot be fixed by software update? Should I also open a ticket with audiolab ?

Hi @support
Am still interested in understanding if this is an audiolab bug that could be potentially fixed through an audiolab firmware update or if the problem lies in the hardware and thus cannot be fixed by software update. Should I also open a ticket with audiolab ?

Btw I have enabled the “Headroom Management” feature in Roon’s DSP Engine and so far I haven’t seen the issue occur again. Thanks for the hint to bypass this bug.
Cheers

Hello @Christian_Chateauvie,

I am unable to comment on Audiolab’s capability to issue a firmware update to rectify the issue. What I can say is that other manufacturers have issued firmware updates that fix the behavior, and that we have made Audiolab aware of the issue and they told us they are investigating. In addition, Roon is also exploring possible options to help mitigate the issue for impacted devices.

-John

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I see. thanks. please keep me posted !
have a great weekend