tested with these cmds:
arecord -D "plughw:4,0" -r 48000 -d 5 -f S16_LE -c 2 -t wav test.wav
aplay -D "plughw:4,0" -f S16_LE -r 48000 -c 1 test.wav
and on Armbian system, you need set alsamixer manually, on our debian system you need not set it manually.