For those interested in a Hifiberry DAC+ sound card / shield: it seems to work fine for me after some tweaking.
I bought a Hifiberry DAC+ light and installed it on top of my Raspberry PI3. I configured the files like described on the Hifiberry website and rebooted, but after that i wasn’t even able to access it via ssh. I looked at the GPIOs that the Hifiberry uses (GPIO 18, 19 and 20) and that was conflicting with my LCD (GPIO 18 in my case..If you are using the original samplerbox version, GPIO 18 is used by the preset buttons). After I reconfigured my LCD in samplerbox.py the Hifiberry came to life.
I only played around with it for a couple of minutes but it works great. So no more USB stuff hanging off the back, which is great if you plan to put your sampler box into a keyboard or sth.
Note: the light version of the Hifiberry has no volume control in Alsa mixer. If you use the great HansEhv version of samplerbox, you have to disable the volume control part in samplerbox.py Or simply buy the normal or pro version of Hifiberry..
And don’t forget to edit samplerbox.py to use the correct device ID (0 in my case, since configuring the config files for Hifiberry disables the internal audio out).