Hi-res tracks are silent on HiFiBerry DAC+ Pro

Core Machine (Operating system/System info/Roon build number)

NUC8i5BEH running ROCK, Roon v1.7 (build 667), connected directly to router via Ethernet.

Audio Devices (Specify what device you’re using and its connection type - USB/HDMI/etc.)

  1. RPi 4B (2GB) with Ropieee connected to Core via WiFi ⇒ Schiit Modi3 DAC
  2. Sonos Play:1 speakers in two locations
  3. B&W Zeppelin connected via AirPlay
  4. RPi 4B (2GB) with HiFiBerry OS and HiFiBerry DAC+ Pro HAT, connected to Core via WiFi⇒ powered speakers

Description Of Issue

When I play a 24/192khz track to the HiFiBerry DAC+ Pro endpoint, and it follows a track of a lower sample rate in the queue, no sound is heard. There is every indication in Roon that the track is playing (timeline advances and signal path light is purple) but, just silence. No clicks or pops between tracks, just silence.

Again, this only happens when a lower sample rate is played first (sounds great) and then a 192khz track follows (just silence).

I can play 192khz files with great sound if it starts the queue or follows another 192khz track.

This happens regardless of storage location (both local files and streaming from Qobuz), and only on the HiFiBerry DAC endpoint.

Other 24 bit files are ok, the problem only occurs with 24/192.

FWIW, this problem has been occurring since I first deployed the HiFiBerry DAC a few weeks ago.

Troubleshooting steps taken so far, none of which produced any changes:

  1. Rebooted everything, checked HAT properly connected to RPi board.
  2. Used Resync delay in device setup (even up to max value).
  3. Connected endpoint using Ethernet instead of WiFi.
  4. Ran endpoint using RopieeeXL instead of HiFiBerry OS.

Thanks in advance for any thoughts, ideas or suggestions to fix this problem.

FWIW, I experience the same problem from time to time with the DAC+ Pro XLR

Hello @Peter_Deschamps, and thanks for your report! Does this happen with your HiFiBerry consistently? Also, can you elaborate on your network setup for me such as what router you’re using? Lastly, could you please reproduce the issue one more time and reply here with a timestamp (your local time) and the name of the tracks you used? I’d like to enable diagnostics for your account, thanks!

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@nuwriy, thanks for your reply and here is the information you requested:

Yes, this problem happens with the HiFiBerry consistently when tracks are in the queue as mentioned above (eg, 24/192 track plays after a lower sample rate track).

Router is Actiontec MI424WR Rev I (supplied by Verizon FiOS)

I played the tracks in sequence shown in screenshots below starting 9:01am today 7 NOV.

The first track “Surrey with a Fringe on Top” (16/44.1) played normally. Next track, “Witchcraft” (24/192) was silent. Third track, “Flute Concerto” (16/44.1) played normally.

Thanks for taking a look at this, and I look forward to your response.

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I experience the same thing. I’ve also found that I can reproduce the problem by toggling Roon’s upsampling on while playing a 44.1 kHz track.

Here’s my configuration:

# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplus], device 0: HiFiBerry DAC+ Pro HiFi pcm512x-hifi-0 [HiFiBerry DAC+ Pro HiFi pcm512x-hifi-0]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

# uname -a
Linux the-bar-pi 5.4.51-v7+ #1333 SMP Mon Aug 10 16:45:19 BST 2020 armv7l GNU/Linux

I don’t have the same problem with my HiFiBerry DAC2 HD. I don’t believe I’ve experienced this with my AMP2 either. Something unique to the DAC+ Pro hardware since I think the AMP2 uses the same driver.

I thought I might be able to reproduce the issue locally using SoX, but both of these commands produce a tone that I can hear on the DAC+ Pro:

# play --bits 16 --rate 44100 --channels 2 --null synth 1 sin 440 vol -10dB

  Encoding: n/a
  Channels: 2 @ 16-bit
Samplerate: 44100Hz
Replaygain: off
  Duration: unknown

In:0.00% 00:00:01.02 [00:00:00.00] Out:44.1k [      |      ]        Clip:0

# play --bits 24 --rate 192000 --channels 2 --null synth 1 sin 440 vol -10dB

  Encoding: n/a
  Channels: 2 @ 24-bit
Samplerate: 192000Hz
Replaygain: off
  Duration: unknown

In:0.00% 00:00:01.00 [00:00:00.00] Out:192k  [  ====|====  ]        Clip:0

SoX can save the output of these generated tones to files:

# sox --bits 16 --rate  44100 --channels 2 --null a-16-44.wav  synth 1 sin 440 vol -10dB
# sox --bits 24 --rate 192000 --channels 2 --null a-24-192.wav synth 1 sin 440 vol -10dB

# ls -l a-*.wav
-rw-r--r-- 1 root root  176444 Nov  7 11:20 a-16-44.wav
-rw-r--r-- 1 root root 1152080 Nov  7 11:21 a-24-192.wav

I can then play these two files back-to-back locally with:

# play a-*.wav

…and this also works as expected (I hear both tones). However, when I import these two files into Roon and play them to the DAC+ Pro via Roon, I only hear the first tone.

As a workaround, enabling DSP Upsampling with “MAX PCM RATE (POWER OF 2)” seems to allow everything to play, but I’m really curious to know why the DAC+ Pro and Roon are interacting this way…especially now that I know that this is not unique to my setup. :slight_smile:

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Since I’ve attached myself to this issue as well, I’ll share a bit about my configuration.

Roon Server, running on a Kaby Lake NUC (NUC7i5BNK) under Windows 10 Pro. Wired Ethernet connection to a Netgear GS108Tv2 access layer switch.

UniFi USG, connected directly to a UniFi US-16-150W PoE distribution layer switch.

Raspberry Pi 3 Model B with HiFiBerry DAC+ Pro XLR DAC HAT. Running DietPi v6.33.3. Wired Ethernet connection to another Netgear GS108Tv2 access layer switch.

Network Topology
All client devices are connected to access layer switches or Wi-Fi access points which are uplinked to and powered by the UniFi US-16-150W PoE distribution layer switch. All Roon components (Core, Controls, Outputs, Displays) are on the same VLAN and subnet.

Thanks for the corroboration … and good that it’s not a problem with DAC2 HD as that may be my next move :wink:

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Hello @Peter_Deschamps, I enabled diagnostics the other day for your account but it seems like your core hasn’t connected to our servers in that time. Could you please use the directions found here and send us over a set of logs using a shared Dropbox link.

@nuwriy, here is the link for logs on Dropbox

Hello @Peter_Deschamps, and thanks for the logs! I’ve added this information to the team’s investigation and will return shortly with their feedback!

Hello @Peter_Deschamps, I wanted to ask if you’ve spoken to HiFiBerry about this issue since it started?

Yes, I posted on their support forum on the same day I posted here - no reply from them yet, and I just asked them for an update.

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@nuwriy - please see my comment here:

As you can see, I’m not able to reproduce this problem locally via the SoX command-line. So far, this problem has only happened when playing tracks via R.A.A.T., so I don’t see how this can be a HiFiBerry driver problem.

@nuwriy, here is a link to the post on HiFiBerry support forum. It appears that HiFiBerry team is investigating. Thanks again @David_Snyder for your comments and feedback on both forums, I’m sure your information will assist in troubleshooting.


@nuwriy, HifiBerry team was able to reproduce this problem and posted the following message:


HiFiBerry team Tuesday at 11:28

It looks like the DAC chip doesn’t switch correctly between external clocks if this happens too fast and Roon seems to be the first software that seems to be that fast. We should find a way to work around this behaviour.

Is Roon working with HifiBerry to resolve this?

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From what I understand, this is entirely in HiFiBerry’s court.


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