That Nasty Hum
I am sure we have all heard the annoying hum from a single coil guitar. This is because the pickups in our guitars become antennas for radio interference. Any time you coil a wire it is possible for this to happen. Remember the old AM radio antenna? it was a simple coil of wire wrapped around a core. Our guitar pickups are the same thing multiplied by thousands. While it is not common (it IS possible) to pick up radio stations with our guitar, the most common noise we can hear is the 60 hz hum from the power in our houses or gig venues. This can be made worse by fluorescent lights, neon lights, televisions and other nearby power supplies. How do we fight this?
How Humbuckers Work...
If you will recall our blog post about phase
, you will remember that running two coils out of phase will cancel certain matching frequencies.
This is how humbuckers work. They consist of two coils wired electrically out of phase with each other. The signal enters the pickup through the start wire of one coil and exits through the finish. It then enters the second coil through the finish wire and exits through the start wire. The coils are electrically out of phase with each other. Since 60hz hum is fairly constant, MOST of it gets cancelled. Because no playing conditions are ever perfect, there will always be a little bit of hum remaining.
The Side Effects of Humbucking
Since we are dealing with two coils in the same pickup you can probably imagine the tone will be different than a single coil. First, there is usually more. Humbuckers usually have a higher output than single coils (not always). The second side effect is, because of the phase cancellation that rids us of hum, certain frequencies in the audio signal are affected too. This will be discussed further in another blog post.
Referring back to our blog post on coil splitting
, we can use the two extra wires (if they are exposed in your pickup) to do cool things like coil splitting, serial, and out of phase sounds.
We will also discuss these in the future as well.