Volume problem solved!
Everything plays at the same level (depending on how studio-quality the recording is)
Thanks for your support.
Unfortunately, the joy was premature. The constant hum and crackle when changing tracks has not gone away 
.
This only applies to the USB input, I tested Coaxial and Toslink and everything works fine.
The experiments continue. After listening to dozens of different tracks, I have noticed the following regularities.
There is a noise (a loud hum in the background of the track being played) when changing tracks, as I wrote earlier.
The type of file (flac, aiff, etc) does not matter, the sampling frequency does.
- change 16/44.1 â 16/44.1 - no noise
- change 16/44.1 â 24/44.1 (and vice versa) - no noise
- change 24/48 â 24/48 - no noise
- change 24/48 â 24/96 (and vice versa) - no noise
- change 24/96 â 24/192 (and vice versa) - no noise
- change 24/48 â 24/192 (and vice versa) - no noise
DSD to anything (and vice versa) - always noises
44.1 to anything ( and vice versa) - always noises
For the tests I uninsatlated all the plugins.
I observed an interesting phenomenon after reinstalling the MPD_OLED plugin.
After installing and running the plugin - the noise stopped (of course DSD didnât work, but thatâs a plugin issue). However, when I did a reboot of the Volumio with the plugin installed and enabled, after the reboot all the noise returned. I checked this several times.
When I switched off the plugin, did a reboot and then switched it on again there was no noise. And after another reboot the noise againâŚ
Info: (apart from the above) native DSD works, volume level the same for all file types.
As I wrote under Win and Ubuntu the noise is not present.
No ideas what else to test and how to solve the problem⌠
Returning to the issue of unbearable humming when changing songs (as I described earlier), this occurs with the âPLAYBACK OPTIONSâ; âMixer outputâ settings:
- Software: no noise (DSD does not work)
- Hardware: on both PCM and PCM,1 - noise
- None: noise
How do you understand this? Is this any indication of a solution to the problem?
As I said before, I think the problem is related to the way the DAC handles the frequency switch internally. The driver used for USB Audio playback is the same for all DACs under Linux, and other DACs do not show this problem using the very same driver.
Another test you could do, is to try Volumio X86-64, booting from a USB stick on the very same PC you have used for the test with Ubuntu and Windows (no need to install it on the internal SSD, botting from USB will be enough).
Anyhow, better to contact the manufacturer, asking for support.
I did the test as you wrote (dell laptop).
Everything works fine, no noise at all.
âPLAYBACK OPTIONSâ; âMixer outputâ settings:
Software: no noise (there is a short pause between switching tracks)
Hardware: on both PCM and PCM,1 - no noise
None: no noise
http://logs.volumio.org/volumio/f9y8MzH.html
Regards
OK, this test is very interesting
the usb driver for the DAC is the same on RPi and X86-64, if you have problems with RPi and not with x86-64, the issue is most probably related to the RPi-DAC combination at HW level.
Maybe it is a peculiarity of the USB Interface: Comtrue CT7601.
XMOS is more common. I have it in my Taga Harmony DA-400 DAC and everything works fine.
From what Iâve read the ComTrue is becoming an interesting option to the XMOS for cost reasons.
Regards
It could well be an issue of the firmware for CT7601 developed by Emotiva
Iâm very familiar with this chip, and I donât have such problems with RPi with the firmware I developed for it.
I have one observation, maybe it will be useful for something.
I tested my RPi 4 with MoOde and there is the same effect as I described before (plus MoOde somehow works slowly).
Then I installed PiCorePlayer (32-bit) + LMS and interestingly everything works without problems (it doesnât support native DSD, but DoP works fine).
Nothing noisy when switching, works smoothly.
I donât know what the explanation for this phenomenon is. I am still testing.