okay, that show me that it should work generaly, but my problem with my ESP32-A1S 2974 ES8388 is that I want to use it as a squeezebox-client. 
Any ideas what could be wrong in my config?
Is there something I can do or I need to do?
In the bottom line of my device is this written:
fw: Muse.16.1036.master-cmake, mode: Muse
Is this the right firmware for my ESP32-A1S ES8388?
Here is my setup:
dac_config: model=ES8388,bck=27,ws=25,do=26,sda=33,scl=32,i2c= 16
set_GPIO: 21=amp,22=green:0,39=jack:0
stereo speaker connecth through headphone-jack.
For install I used the https://raspiaudio.github.io/ webinstaller and choose MUSE.