Lots of pops and clicks even after normal fixes applied

I am trying to set up a Volumio install to work with my stereo system. I’m using a RaspberryPi Model B and trying to use a USB-connected High Resolution Technologies MusicStreamer II+ DAC. The Pi is powered by an Apple iPad supply (plenty of current) and the DAC is connected via a powered USB hub. The Pi is connected to the network via ethernet. I have configured Volumio to access the music files (Apple Lossless Codec) from the NAS (SAMBA share) and it outputs data to the MSII+ DAC to produce audio.

However, I’m facing two problems.

  1. The audio quality is quite poor, far worse than connecting the MSII+ to my MacBook Pro and using BitPerfect for playback. It’s no better than a normal computer sound card output in fact. I can work this one out in the future, I’m really only including it in case it’s a hint as to why #2 might be occurring.

  2. The audio very frequently clicks and pops VERY LOUDLY.

To try to resolve #2, I have done:

a) Added dwc_otg.fiq_split_enable=0 to /boot/cmdline.txt and confirmed it was active by looking at the boot log. The result of this is that the Volumio will not play music at all, it sends nothing but an extremely obnoxious buzzing noise to the DAC.

b) Created the file /etc/modprobe.d/usb-dac.conf and put the line “options snd-usb-audio nrpacks=1” in it. I confirmed this was active by cat /sys/module/snd_usb_audio/parameters/nrpacks. Note that I have no lines in /var/log/syslog at all, so I don’t have any “estimated delay: X actual Y” messages. This produced no change at all.

c) Edited /etc/auto.nas so that my NAS mounting line has the arguments: -fstype=cifs,file_mode=0777,dir_mode=0777,iocharset=utf8,sec=ntlm,rsize=2048,wsize=4096,cache=strict,username=username,password=password ://192.168.25/sharename

What else should I be trying to eliminate the pops and cracks during playback?

Make sure that you are using a SD Memory Card marked Speed Class 10.

After switching from Raspyfi to Volumio I made the mistake of using a Class 6 SD Card. The result of this was a lot of pops and clicks. I almost deviated from the project but as a last effort I switched the SD Card for another one. Now I have regained the big smile one my face as I enjoy the Sun and turn up the Volumio just a little more!

I switched from class 4 to class 10 but it didn’t help.

This is the only way that I can stop pops and clicks. Do it immediately after a fresh installation:

sudo apt-get update
sudo apt-get install binutils
sudo apt-get install rpi-update
sudo rpi-update