first thanks for this excellent Board. I have learned so much. My Name is Tobias and I am from Switzerland.
Currently i am working on a 5" Portable. After investing a lot of Time (And Money

After investing much more Time ... this is the first Prototype:
It contains a PCM 2704 USB DAC and TPA2016 Audio Amplifier all the Pins for external Buttons and i2c Control of the Amplifier are routed to the PIN Header.
Also it contains a Headphone Jacket which switches automatically to Headphones as soon you plug in
Youtube Video: https://www.youtube.com/watch?v=qy0PXclmHKc
It sounds absolutely amazing i am very happy with the board