I just bought a HifiBerry AMP2 and try to install the Roon image (version 1.8) from your site.
I get the following error on my screen (and in the boot.log):
Failed to start dhcpcd on all interfaces.
See 'systemctl status dhcpcd.service' for details.
As it flashes on the screen I'm not able to do the suggested systemctl ...
When I flash the official Stretch Lite image on my SD card, everything works OK and I get a network connection (but of course no Roon connection). So it has to do something with your image.
Any suggestion welcome, because I'm stuck now...
P.S. I use a network cable, so no wifi