10. Solder the optional transformer -
If you want to use the USB-to-SPDIF conversion feature of the SkeletonDAC, solder the transformer in place now.

If you don't need a USB-to-SPDIF convertor, then skip this step. The SkeletonDAC will perform flawlessly without this optional component.

11. Solder the mini-USB jack -
Careful with the small five pins - they can bend easily. They're also embedded in nylon, so be careful about applying to much heat for too long.

However, fill in the snap-in tab holes completely with solder, until it wicks up the side of the jack body. This is a mechanical connection and a strong solder joint will ensure that the jack lasts through thousands of plug-ins.

13. Solder C6 and the output capacitors C13 and C14 in place -
C6 should be a very-low ESR type capacitor, preferrably a gel-organic or similar. Careful that the height for this capacitor and C13/C14 do not exceed the inside height of the Hammond 1551HTBU case.

Solder your selection for output capacitors in the C13 and C14 positions. If you are using the SkeletonDAC for direct connection to headphones, be sure to size the capacitors accordingly. Most likely, you'll have to bend electrolytics over to the right so that they are horizontal and parallel to the PCB in order to fit into the Hammond case.

DONE populating the PCB!!