So far,
everything that has been discussed about guitars has been purely
mechanical, and can be applied to acoustic guitars as well. What sets
apart an electric from an acoustic is the fact that electric guitars
have devices called 'pick-ups'. There are two types of pickups:
humbuckers and single coil. Both have the same underlying principles,
therefore the only difference being the sound or tone it produces.
Starting with single coil pickups, we will see that a pickup is simply a magnet with wire wrapped around it. More precisely, the magnet material is generally alnico (an ally of iron, aluminum, nickel, copper, and cobalt) or ceramic, and the wire is generally copper wire. When current is induced into the wire, a magnetic field around the pickup is created through the phenomena of electromagnetic induction.
Starting with single coil pickups, we will see that a pickup is simply a magnet with wire wrapped around it. More precisely, the magnet material is generally alnico (an ally of iron, aluminum, nickel, copper, and cobalt) or ceramic, and the wire is generally copper wire. When current is induced into the wire, a magnetic field around the pickup is created through the phenomena of electromagnetic induction.
As the
string is plucked and starts vibrating, it disturbs the magnetic field,
inducing a voltage. The mechanical oscillations of the string match the
voltage oscillations of the coil, and these electrical voltage pulses
are translated to a loud speaker and amplified.
Things to be noted are:
1. If too big of a magnet is used, it pulls on the string with a significant amount of force and actually dampens the strings oscillations.
2. The more coils of wire wrapped around the magnet, the more sensitive to disturbances in the magnetic field, and thus more feed back is created.
To solve this, electrical engineers created a humbucker, or a pair of single coiled pickups coupled together. They are wired in opposite directions, and this is the key fact, because now any voltage inductions gets canceled out to a great extent. This allows for a pickup to have many windings and become more powerful without the addition of feed back.
Things to be noted are:
1. If too big of a magnet is used, it pulls on the string with a significant amount of force and actually dampens the strings oscillations.
2. The more coils of wire wrapped around the magnet, the more sensitive to disturbances in the magnetic field, and thus more feed back is created.
To solve this, electrical engineers created a humbucker, or a pair of single coiled pickups coupled together. They are wired in opposite directions, and this is the key fact, because now any voltage inductions gets canceled out to a great extent. This allows for a pickup to have many windings and become more powerful without the addition of feed back.