Nuts and Volts

The electronic portion of the guitar is really very simple (see the schematic in Figure 1). It consists of a three-position selector 2P3T switch which selects the neck pickup (for a more bassy sound) in the forward position, the bridge pickup (for more treble) in the rear position, and both pickups together in the middle position.

The middle volume control governs the overall volume of the guitar, and the tone control rolls off the highs (via a first order R-C low pass filter) as it is rotated counterclockwise.

■ FIGURE 1. Guitar schematic.

You can see the finished wiring of the controls in Photo 10. The two black wires are connections to the pickups. The middle heavy wire is the ground for the bridge which is necessary or the guitar will hum when you touch the strings. The wire on the left is the shielded wire going to the output jack.

The orange item between the pots is a 0.047 µF capacitor for the tone control. NOTE: It is very important to have a single ground point for all of the wiring. This helps to eliminate ground loops and hum. Here, all ground connections are soldered to the back of the volume pot.