the $20 homemade acoustic guitar pickup

How to make your own acoustic guitar pickup for cheap.  This way you can plug your guitar into a PA or an acoustic guitar amp.

Required tools:
soldering iron
electric drill
wire cutters
coping saw

Required parts:
buzzer piezo from Radio Shack (The Shack) $9
Switchcraft Nickel End Pin Jack $11
3M double-sided poster tape
1 foot of audio cable

Optional parts:
250k potentiometer
guitar wire

1.  Remove the strings and drill a 1/2 inch hole in the bottom of the guitar where the strap button is.  The nice thing about the Switchcraft jack is that it acts as a jack AND a strap button.  Be careful when drilling not to damage your guitar.

 2.  Take apart the buzzer.  This might require a coping saw to get through the plastic casing, careful not to damage the flat metal piezo.

3.  Solder one end of the audio cable to the piezo.  Positive is the top ring, negative (or ground) is the large bottom ring.   The two plates are separated by crystals, when given a current the produce a noise, when given a vibration they produce a current, we will be using the piezo for the latter.

4.  Solder the other end of the cable to your jack, positive is where the tip connects in the jack, negative is the sleeve or ground.

5.  By nature, the piezo is a very bright-sounding pickup for an acoustic, so we'll be using some 3M double-sided poster tape to attach this thing to the underside of the bridge.  Because it is made of thick foam it dampens some of the brightness.  Stick a piece of it to the top and bottom of the piezo.  Mount the bottom of the piezo to the underside of the bridge.  Then install the jack in the bottom of the guitar.

You could use the pickup just the way it is, but I chose to have a tone control to get a little warmer sound out of it.  Use the following wiring diagram to solder a tone control into your circuit (advanced skills required)

I chose not to drill another hole in my guitar for the tone control so I used some more of that poster tape on the back of the tone control and stuck it just out of sight in the sound hole, if I need to adjust tone at any point I can just do it with my fingertips through the sound hole.

Reinstall the strings and test it out!!