Hi, I have a problem with the PCM1794 USB DAC (the system sees the Bravo-X USB Audio device), which turns off every few or several minutes. The system is Pi4, USB DAC Pcm1794 (15V-0-15V), LCD Waveshare 7.9" hdmi, 5V linear power supply. When the sound stops playing, the display then shows “ERROR. Failed to open audio output”, then the system detects the audio device again, the message “USB DAC conected” and “Configuration update The player has been restarted” appears and you have to turn on the playback again. I changed the Pi4 to another one, I changed the power supply to another one, I changed USB cable, I changed the Volumio version and nothing changed.
Have you had a similar problem?
I know from bitter experience that not all USB interfaces are the same. We can check from the logs what is being captured from the kernel events. Ensure that the DAC drop happens more than once. Please update this thread with link to logs from.
Thanks, link updated
There is a message
reset full-speed USB device number 3 using xhci_hcd
which usually is shown, where power delivery budget is exceeded and internal bus received reset.
USB HID v1.00 Device [SAVITECH Bravo-X USB Audio] on usb-0000:01:00.0-1.3/input0
USB HID v1.11 Device [WaveShare WaveShare] on usb-0000:01:00.0-1.4/input0
Can you describe:
- what power supply are you using including specs?
- what USB ports is your Touchscreen connected to?
- what USB ports is your DAC connected to?
Currently, the LCD touch and dac are connected to USB 2.0. I tried changing the USB ports, also to 3.0, with no change.
Power supply specs:
- LT1083CP linear voltage stabilizer
- Input voltage: AC from 0 to 34 V
- Output voltage: DC from 1.25 to 48 V (adjustable)
- Maximum output current: 10 A
- 4 rectifier diodes (Greatz bridge)
- ARK screw connector
- LED indicating power supply
- Dimensions: 80 x 53 mm
From the logs:
VOLUMIO_VERSION=“3.512”
Linux version 5.10.92-v7l+
which is quite old.
Do you think you can upgrade your Volumio to the latest stable 3.616 and run the test again?
Linux proto 6.1.69-v8+
Of course, I can upload the new version and test it.
I installed the latest version of Volumio and the problem still occurs, but it seems to be less frequent.
There are interesting events:
Feb 25 12:00:20 volumio79 kernel: usb 1-1.3: reset full-speed USB device number 3 using xhci_hcd Feb 25 12:00:20 volumio79 volumio[732]: ---------------------------- USB Audio Device Detached Feb 25 12:00:20 volumio79 volumio[732]: info: touch_display: Setting screensaver timeout to 120 seconds. Feb 25 12:00:20 volumio79 volumio[732]: info: touch_display: Setting screensaver timeout to 120 seconds. Feb 25 12:00:20 volumio79 volumio[732]: ---------------------------- USB Audio Device Attached Feb 25 12:00:20 volumio79 volumio[732]: info: Setting mixer PCM for card Bravo-X USB Audio Feb 25 12:00:20 volumio79 volumio[732]: info: Updating Volume Controller Parameters: Device: 5 Name: Bravo-X USB Audio Mixer: PCM Max Vol: 100 Vol Curve; logarithmic Vol Steps: 1
Feb 25 12:41:28 volumio79 volumio[732]: info: touch_display: Setting screensaver timeout to 120 seconds. Feb 25 12:41:28 volumio79 volumio[732]: ---------------------------- USB Audio Device Detached Feb 25 12:41:28 volumio79 volumio[732]: info: touch_display: Using Xserver unix domain socket /tmp/.X11-unix/X0 Feb 25 12:41:28 volumio79 volumio[732]: info: touch_display: Setting screensaver timeout to 120 seconds. Feb 25 12:41:29 volumio79 volumio[732]: ---------------------------- USB Audio Device Attached Feb 25 12:41:29 volumio79 volumio[732]: info: CoreCommandRouter::executeOnPlugin: alsa_controller , usbAudioAttach Feb 25 12:41:29 volumio79 volumio[732]: info: Setting mixer PCM for card Bravo-X USB Audio Feb 25 12:41:29 volumio79 volumio[732]: info: Updating Volume Controller Parameters: Device: 5 Name: Bravo-X USB Audio Mixer: PCM Max Vol: 100 Vol C
It looks like screensaver causes reset. As a matter of test - can you disable screensaver and check if the USB DAC drop occurs?
Hello, I turned off the screen saver and still no changes. I changed the power supply, updated Volumio again today and the playback stops after some time.
I am attaching another link to the logs after turning off the screen saver.
From the logs - it is still resetting xhci_hcd.
Let’s try something different:
Please place in the volumioconfig.txt under [all] section:
dtoverlay=dwc2
dr_mode=host
and test further after reboot.
Hi, unfortunately it didn’t help.
For a moment I thought it was ok because it didn’t turn off for two hours, but then more and more often, and today it turns off every now and then and still the same message on the LCD “Failed to open audio output”.
Let’s try to understand what is happening with your DAC.
Connection - USB cable quality is a must for any Raspberry Pi, since all PIs are very sensitive to rf noise. There are plenty of forum discussions worldwide highlighting the importance of good shielding USB cables, to the extent that the ones that work with PC are too noisy for RPi. Do you know the exact model/type of the USB cable between RPi and DAC?
For the testing purposes only - let’s change audio hardware priority:
Edit /lib/modprobe.d/aliases.conf and update
from
options snd-usb-audio index=-2**
to
# options snd-usb-audio index=-2`
and test after reboot.
I would recommend a Roline GOLD USB A to USB B cable (ref. 11.88.8802-Gold), they are inexpensive and of excellent quality (double shielding). They are available in 1.8 m, 3 m and 4.5 meters.
Norstone also offer a very good cable, a little more expensive, the ARRAN CABLE USB available in 0.75 m, 1.5 m and 3 meters (SKU : NORARRUSB75) or the JURA CABLE USB (SKU : NORJURUSB75).