How To Set Up A Rock Pi S - Part 3: The Sound

After the 2nd part of the Rock Pi S setup, I was confident to get some sound out of the board after I made a little hardware hack and connected it to my speaker (with amplifier). Unfortunately, the command

speaker-test -t wav -c 2

did not bring any sound out of the Rock Pi S. So there still was a problem left and I had to google it once more.  Thanks to DIYprojecz in Radxa Forum ... I was once more able to fix a problem. For details see https://forum.radxa.com/t/audio-support-rock-pi-s/1686/28.

What needs to be done:

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

The New Problem

After the kernel update above, it was no longer possible to install snips.ai. In previous attempts by me, this was successful on the Rock Pi S (but still complex). The current status of this project is:
Partial Successful.

If you also want to use Snips.AI, please proceed to the dangerous and challenging part 4.