First thing's first-- load some sound on your Audio FX Board! We've formatted a mono OGG file containing close to 30 minutes of coffee shop white noise:
Follow the Audio FX Board guide to transfer the sample file (or a file you make) to your device.
Next it's time to breadboard the circuit. We highly recommend grabbing two audio boards and saving one for breadboard prototyping. It saves a lot of time and frustration to work out a circuit on a solderless breadboard before soldering your components together. Ask us how we know!
Solder the headers and screw terminals onto your amp, and solder wires onto your speaker:
On the lipoly backpack, cut the trace connecting the switch pads, and solder two quick-connect wires in place. While you're there, add a solder bridge to convert the charger to 500mA where marked.
Since the switch has to be installed from the outside of the cup, it'll be hard to connect wires to it inside the cup. That's where these arcade button quick-connects come in handy! See how they tightly grip the pins without any soldering? Cool. Take a good look now, since we can't quite get our camera lens inside the cup to see them later:
Solder the lipoly backpack to the audio board with the included long headers. Trim the rest of your headers and solder them in place on the audio board. See how the lipoly backpack headers come up short on the underside? You may want to insert the headers from underneath the audio board if you want them to be the same depth as the others (for inserting into a solderless breadboard). This was the second board we assembled for this project, and in prep for the final circuit the header depth descrepency wasn't a problem.
After prototyping, remove the potentiometer from the solderless breadboard and solder on three wires (with heat shrink tubing) to prepare for installing in the coffee cup.