Instead of the elaborate active preamp/ headphone amp combo I used one of the wiring diagrams that came with my pickup (they had a diagram for what seemed like every combination of components imaginable.) The diagram I used was for a single pickup with tone and volume potentiometers. Most pickups (or websites where you can buy them) will have similar diagrams for the many combinations of pickups, pots and switches.
The wiring went relatively smoothly beyond the normal problems I have with soldering, such as needing another hand or two to hold everything. The pots were the most diffcult to install and solder since there is so little room to inside that cavity. I did as much of the soldering outside of the body as I could This included such the connections between the pots and the connection with the capacitor. Since the wires to the output jack needed to stay short due to space limitations and the connections with the pickup threaded through the body, these connections had to be made with the pots installed in their cavity. This led to problems getting the wires, my hands and the soldering iron all in proximity to the pots in their tiny cavity so they could be attached. With a bit off patience and at least one complete retry from the beginning, I was able to solder everything up.
Shielding the Cavities
I didnít shield any of the cavities in my mandolin even though I probably should have. I canít tell that there is a huge amount of static but it wouldnít hurt. I mostly ended up not shielding the cavities due to my change in plans for the electric setup at the last moment. I planned on going back and rewiring the mando with active electronics, so I though I was would be able add the shielding when I was redoing everything. Since Iím not adding anything more to it now, I ended up just not going back and taking everything apart to add the shielding. The two types of shielding I have seen are conductive paint and conductive tape. I donít have a concrete preference since I havenít tried either type, although the paint seems like it could be messy.