Hi Ste77,
USB Dac’s should be plug and play, the Linux ALSA subsystem should detect the card type and configure itself. Because the pops/cracks are continuous/random it indicates that USB Dac/ALSA handshaking and configuration has not completed correctly. I see two possibilities where this could go wrong:
1. ALSA has two commands for card mapping ‘device ”hw:
<card number>,
<device number>”’ and ‘device "plughw:
<card number>,
<device number>"’, there are differences in the way they work. The first uses an input = output scenario, the second forces ALSA output to be compatible with the output device (this may involve resampling or bit depth modifications).
2. The Pi 1 kernel is quite old and an upgraded version of ALSA may be required to make everything work with this Dac. If it works, this is the preferred solution as it will ensure bit-perfect processing.
1. Try modifying /etc/mpd.conf manually to replace the line ‘device ”hw:1,0”’ with ‘device "plughw:1,0"’. When you next reboot this file will be restored to the standard settings, you will also lose any configuration details which you entered in the MPD screen.
Access the Pi with SSH. First make the file writeable with:
chattr -i /etc/mpd.conf
Then edit the file to substitute the line ‘device ”hw:1,0”’ with ‘device "plughw:1,0"’ with nano:
nano /etc/mpd.conf
In your Rune web interface go to the /dev page (URL: runeaudio.local/dev). There is an option in the lower half of the screen ‘
mpdrestart’, click this. Then test…
If this works there are potentially some complications concerning sound quality. Report back, some more tests are required.
2. Try using this image with your Pi 1, it was built for the Pi Zero but should work on all single processor Pi’s:
#371175
Then test…
If this doesn’t work try modifying /etc/mpd.conf in the new image.
janui
