FLAC background noise via I2S DAC

Help and Support Help
21

Hi!
I have updated mpd with the last version compiled for Volumio. It seems the problem doesn’t exist anymore… :smiley:

22

Wow! You did what? Like this written here?

https://volumio.org/forum/update-mpd-t2656.html

23

No . Follow that https://volumio.org/forum/mpd-update-available-t3200.html

24

tnx, I will try.

25

Unfortunatley this MPD update didn’t work for me. The noise persists. :frowning: Or maybe I didn’t update it Ok. I was logged in as root user, then I typed in that update code… How do I check if it is MPD updated to latest version?

26

You can use the command

mpd -V
27

tnx, ning-yu. mpd is updated on the latest version. Buzz is still there. :confused:

28

:frowning: :cry:
I have tested deeply… And you are right, the buzz is still here with some file, in Flac in my case 16b/44khz. But lower than before …
Sorry for the wrong info…

29

I would think is kernel\driver related. Unfortunately every new kernel brings in some new issues in certain conditions…
What you can do is try to update the kernel following this procedure:

sudo rpi-update

If you receive an error, try:

sudo curl -L --output /usr/bin/rpi-update https://raw.githubusercontent.com/Hexxeh/rpi-update/master/rpi-update && sudo chmod +x /usr/bin/rpi-update
sudo rpi-update

After that, reboot, then change the i2s driver to something different, hit save, then set your I2S DAC and hit save. Then reboot, let’s see if that solves the issue.

30

It should be interesting to put an oscilloscope on the I2S lines and see what is happening when nothing is playing.
I suspect that the driver is still sending some data to the DAC and it is interpreted as noise. Unfortunately I do not have an I2S DAC (but I do have plenty of oscilloscopes at work!) so I can’t test by myself.
Maybe MPD maintains an opened sound device even when nothing is playing?

31

the problem is with USB DAC also, not just with i2s… Tnx michealangelo, I will try.

32

Kill the mpd process and hear if the noise is still present (sudo killall mpd). The monit daemon will restart the mpd process so if it is dependent to mpd you will here the noise again.

33

Hi!
I my case the noise start only when I press the play button and only with flac file 16b/44. ( I haven’t test all kinds of files).

34

Hi, has anyone fixed this issue? Or does anyone tried Volumio 2 if this issue still exists? I am currently using a workaround with USB (M2Tech hiface 2) but I would like to use i2s. Someone wrote that this issue also appears with USB DACs… I can not confirm this! It seems only be relates to i2s with 16bit files (no matter if flac, mp3, alac)…and Sabre 9018???

Andy