with the support of Michelangelo and the work of Lintweaker I finally compiled the kernel module needed to get the Mytek 192 DSD Dac to work with Volumio. Almost.
dmesg shows that the module load without errors and the DAC makes a lock with the USB 2 port connected. However, when starting playback, Volumio gives an
Error, Failed to open audio output
message. Dmesg after the playback attempt reports
usb 1-1.4: error stopping streaming while setting samplerate 44100
Anybody an idea why that? Might it be a mpd configuration issue that could be fixed somhow or is it the kernel module itself?
On my Ubuntu Laptop the playack caused no issues using this driver.
If anybody is interested to try the Mytek DAC with Volumio, just le me know, I’ll be happy to pass the kernel module
Nov 22 18:46 : alsa_output: Failed to open "USB Audio DAC" [alsa]: Error opening ALSA device "hw:1,0" (snd_pcm_hw_params): Connection timed out
Nov 22 18:46 : output: Failed to open audio output
Nov 22 18:46 : player: problems opening audio device while playing "NAS/Public/Test.flac"
lsusb:
Bus 001 Device 014: ID 25ce:000e
Bus 001 Device 004: ID 0cf3:7015 Atheros Communications, Inc. TP-Link TL-WN821N v3 802.11n [Atheros AR7010+AR9287]
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
the DAC is device 014, but no name is shown here. Could this be a hint whats going wrong?
The driver works, I know that much. I also know that people have used the DAC with the RPi on Debian/Raspbian. I’ll reach out to someone I know with the DAC and see if he can help you. I doubt whether he uses VolumIO. I suspect he won’t have even heard of VolumIO, but I will try.
so here’s an update about the mytek driver issues.
finally I got it to work (more or less), I just switched from rpi2 to rpi3, because I observed some buffer underruns on the rpi2, just wanted to see how same setup performs on pi3. It’s now playing files up to 192khz and even DSD over PCM, but sound quality is extra bad, glitches all the time and even some strange pitching during playback from time to time, which I’ve never heard on any digital device so far. Native DSD (without dop) is played back in 192khz, which is sort of strange, too.
mpd is configured like
audio_output {
type "alsa"
name "alsa"
device "hw:1,0"
dop "no"
where hw:1,0 is
hw:CARD=USB2,DEV=0
Mytek Stereo192-DSD USB2, Mytek USB2
Direct hardware device without any conversions
first I suspected some conversion is going on somewhere, and the rpi3 might not be capable of doing this proper on the fly, but at least is capable of playing with bad quality, unlike to the rpi2 which completely failed. Then I stressed the cpu to almost 100% with another process while playback, but sound quality didn’t get worse by that, so cpu seems to be not a factor. Also system load is quite low while playing back.
It’s more or less the same issues with 44,1 192 and DSD over PCM, maybe a little better with lower sample rate, but not that it is pointing in any direction. When I’m back from work in 3 days, I’ll have a closer look whats going on, lets see what happens when I use airplay or usb device…
still strange that it didn’t work at all on the raspberry pi 2, and now it’s playing even 192khz on the pi 3. for me, this points to a performance issue
