Sound drops / cuts Pi3 and Hifiberry Digi+

[patb]

Hello,

I am experiencing occasional signal drops. The sounds stops for a second and comes back on again. I have the digi+ connected to a Naim Ndac via coaxial cable but also tested it with optical and coaxial cables, different input sockets, different PSUs etc. and the signal keeps dropping regardless of these changes. No signal drop occurs with other signal sources (a TV via optical for instance) or if I am using a direct USB input on the DAC.

I might add that I feed data from an external HDD connected through Pi3's USB inputs. I have tried mounting the HDD using the router and feeding data over LAN rather than directly through USB and I still experience the same issue. I have now also tried a PC folder share and I get the same drop of signal after a couple of minutes. I have tested WAV, FLACs, MP3s - all cause the same issue.

The only time the sync light light remains on with no signal drops (please read below) is when I play 24bit source material. Naim NDAC has a sync indicator on the front panel which (as per the manual): "The sync indicator illuminates to indicate that the DAC’s internal clock is precisely synchronised with the input data stream. The DAC will continue to operate if synchronisation is lost but its audio performance may be compromised. Synchronisation loss is generally caused by an out-of specification clock in the source component." I was also told by Naim that when the sync light switches off, it indicates that at some point the connection was lost i.e. a drop in feeding the data has occurred and caused a temporary loss of music.

I hope that all the extra information is going to be helpful in troubleshooting the issue.

I am running Linux version 4.4.11-1-ARCH (builduser@leming) (gcc version 6.1.1 20160501 (GCC) ) #1 SMP Thu May 19 18:46:14 MDT 2016

Many thanks!

Pat

[PeteB]

[patb]

Hi Pete,

The image I am using is RuneAudio_rpi2_rp3_0.4-beta_20160321_2GB.img
I did a manual update as suggested in this thread: digi-rune-and-usb-drive-channel-swapping-t3570.html as I had experienced the random channel swapping issue. The channel swapping has been fixed but I am now experiencing the loss of sound.

[PeteB]

[patb]

Perhaps it is less than a second, it's a drop then the music comes back on. No pops though.

I'll try to increase the buffer, although, this would be more about throughput issues, like you say. 24bit files are even larger and cause no such issues.

[PeteB]

[patb]

Hey,

I welcome all suggestions. I also tried increasing the buffer just in case with no improvement, unfortunately. Your input and the quote from Hifiberry forum re the single crystal and its native frequency is something that finally makes more sense. I've found no leads despite searching across different forums. Interestingly enough, I found a similar post here:

https://support.hifiberry.com/hc/en-us/ ... _207293165

NDac does not display the sample rate, the only indicator is the "all meaning" sync led light

Is there any way to make sure that MPD does not resample the files? Check in the Debug info?

Your input is much appreciated!

[PeteB]

[PeteB]

You could also look at what the Naim DAC lists as compatible formats, just in case there is something to be learned from that. Here is a link to a utility that can be used to do that:

https://lacocina.nl/detect-alsa-output-capabilities

Pete

[patb]

I will test the Hifiberry with a friend's Pi2B first as his setup is identical (apart from Pi3B) and he experiences no such issues.

On replicating the issue, I have monitored and timed the drops and they seem to happen at around 6mins and 15secs of playing time.