piter75 thanks a lot, now it works as it should.
Be sure to ask the developer to fix this in the following distributions.
Do you know how to get the standard audio output to work?
Aplay -l command output:
**** List of PLAYBACK Hardware Devices ****
card 0: Dummy [Dummy], device 0: Dummy PCM [Dummy PCM]
Subdevices: 7/8
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
Subdevices: 7/8
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
Subdevices: 8/8
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
Subdevice #4: subdevice #4
Subdevice #5: subdevice #5
Subdevice #6: subdevice #6
Subdevice #7: subdevice #7
card 2: realtekrt5651co [realtek,rt5651-codec], device 0: ff880000.i2s-rt5651-aif1 rt5651-aif1-0 [ff880000.i2s-rt5651-aif1 rt5651-aif1-0]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 3: rockchiphdmi [rockchip,hdmi], device 0: ff8a0000.i2s-i2s-hifi i2s-hifi-0 [ff8a0000.i2s-i2s-hifi i2s-hifi-0]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 4: ROCKCHIPSPDIF [ROCKCHIP,SPDIF], device 0: ff870000.spdif-dit-hifi dit-hifi-0 [ff870000.spdif-dit-hifi dit-hifi-0]
Subdevices: 0/1
Subdevice #0: subdevice #0