I built a simple USB DAC board to improve sound quality on my headphones. The board is based on PCM2707 IC and the schematic is based on its datasheet.
You can download for free the gerber files to produce your own. You will also receive stl files to 3d print an enclosure for the pcb.
Here you can find an interactive BOM for the board.
Enter your email to receive the gerber and stl files.