If you are interested in exploring the piezo and wondering where to find them,
here are some sources:
There are a few in the closet in W123. (immediately to the right as you enter the room)
Look in the gray plastic storage "cabinet" with ~ 20 little drawers (there are 2 such gray plastic storage "cabinets", the piezo elements are in a drawer in the one that faces you as you open the door. These were purchased from electronic goldmine (link below)
You can Order them from :
(these come with 2 wires already soldered to the piezo disc and are sold ~ $1 each)
(these come with 3 wires already soldered to the piezo disc, you use 2 of these wires. They are sold ~ 3 discs for $1)
Locally you can call AxMan to see if they have any in stock. I recommend buying only the piezos that have wire leads soldered to the discs. Some will have 2 wires, some have 3. You will use 2 wires, but can choose 2 of the 3 wires as we did for the amplifier project.