UPDATE OK, after n attempts this is what finally worked for me, to get the soundcard recognized. However, only left channel works.
sudo su
route add default gw <your.gateway.ip.address> eth0
echo "deb http://apt.radxa.com/stretch-testing/ stretch main" | sudo tee /etc/apt/sources.list.d/apt-radxa-com.list
wget -O - apt.radxa.com/stretch-testing/public.key | sudo apt-key add -
apt-get update
apt-get upgrade
apt-get install -y rockchip-overlay rockchip-fstab
apt-get install -y linux-4.4-rockpis-latest rockpis-dtbo
apt-get autoremove
chmod a+r /etc/group For some reason, apt-get dist-upgrade and apt full-upgrade left me with loopback devices only.
Then I modified /etc/asound.conf as posted by @xfjx earlier, and reboot.
You could at least drop the entitled act and stop assuming somebody asking a question in a thread didn’t read said thread and didn’t follow steps described in the thread before posting a question. With such attitude, why don’t you re-read the topic and wiki instead of pestering @jack with your questions? Also, if I was so low opinion of you as you are of others, I would assume you didn’t check which side of the audio header has GND and wired it wrong, which would explain why you have no sound on second channel.