Special Investigation: Electronics

The electronics are what make an electric guitar, and give it the potential to be amplified without a microphone. Usually, the main components used in the circuit of an electric guitar are the pickups, potentiometers, pickup switch and the output jack.

The pickups on an electric guitar are usually made of a magnet wrapped in copper wire, which convert the vibrations of the strings into an electric signal, which is routed through the jack output on the guitar. The copper wire wrapped around the magnet is typically looped around several thousand times, and can be wrapped around more times to increase the output of the pickup.

There are many different types of pickups you can find on electric guitars, and famous designs:

• Single Coil Pickups- Single coil pickups were the first to be invented, and consist of one magnetic core coiled in wire. These were used on all early electric guitars throughout the early 1930s until the invention of double coiled pickups around 1955. Single coil pickups create a bright and clean sound, with clearer note definition than other pickups. Gibson manufactured some of the first single coils, with the Bar pickup and later the P90 which featured on many Gibson models including most of the hollow body guitars, early incarnations of the Les Paul and the Epiphone Casino. Fender also manufactured many successful single coil pickups that feature on many of their guitar models, including single coils on the Fender Jaguar which had casing to help prevent interference noise coming through the pickups.

• Double Coil/Humbucker- The single coil pickup had one main fault, as it was prone to picking up interference and noise from the room around it. However, it was discovered that having two single coil pickups connected with the magnets polarised in opposite directions, would cancel out the hum which gave them the name humbuckers. Because humbuckers have two single coils, they pick up on more signal and as a general rule produce a louder and heavier sound than single coils. An early design of the humbucker was the Gibson PAF which was the first to go into mass production and featured on famous and successful lines of guitar such as the Les Paul and SG. Fender also produced their own humbucker to compete with Gibson, this was called the Fender Wide Range and featured on all of the Fender custom and hybrid guitars which had humbuckers. The Wide Range tried to bring cleaner Fender tones to the heavier Gibson sound, but has never been used on a mass scale. Epiphone created the mini-humbucker, which was a smaller humbucker that could fit into the space on guitars designed for smaller single coil pickups. The mini humbucker also came with the added advantage of having its own unique tone somewhere between single and double coils as a result of its smaller size, and has been used for a long time in many Epiphone models and the Gibson Firebird along with semi-acoustics in the Gibson ES Series. Humbuckers are favoured by many players for their warm tones and low level of noise interference as well as their natural muddier output which has its uses in many genres of heavy music like punk and grunge.

• Active Pickups- Active pickups work in a different way to passive pickups, as they require a source of power to work. This source of power is usually a 9 volt battery inserted into the guitar or pickup. Active pickups have an electronic preamp inside them which helps give them a higher output and pick up less interference at high volumes and high levels of distortion. While more commonly used on bass guitars, active pickups are used on some electric guitars, with famous pickup designs including the EMG series (81, 85) and Seymour Duncan pickups. The main disadvantage of active pickups is the reliance on electrical power, and on top of this active systems are more expensive than passive systems. However they do have many redeeming features such as multi band digital EQ on the guitar, a higher output and better dynamic range than passive systems. Many heavy metal players prefer active pickups for their higher output and the ability to reach higher levels of distortion and still retain clarity. Outside of metal, some players pick active pickups purely for their noise free qualities in genres ranging from pop to jazz.

The pickups are then wired to the potentiometers which are used to control the volume and tone. Potentiometers, often called pots, sit inside the body of the guitar and are controlled with the volume and tone knobs on the body. Pots are a form of variable resistor in the electric circuit on the guitar, and work by increasing or decreasing resistance which changes the amount of electrical signal going from the guitar to the amp and therefore changes the volume or tone depending on its position in the circuit.

Most pots have either 250 or 500 Kilo Ohms resistance, with 250 being the standard for single coils and 500 being the standard for humbuckers. One Mega Ohm is the highest possible resistance for volume pots on guitars, and 25 Ohms is the lowest resistance commonly found and is used on active pickups. Pots do affect the tone of a guitar, with high resistance pots giving guitars a brighter sound and lower resistance pots giving a warmer tone which does lead some players to change their pots to change their tone. This is commonly used as a method of trying to take out some of the brightness in single coil pickups.

On electric guitars, the pickups are usually positioned in multiple places between the end of the neck and the bridge, with the various positions giving a different tone because of where the pickups are picking up the string vibrations. Most guitars have two or three pickups, with the one closest to the bridge being called the bridge pickup and the one closest to the neck being called the neck pickup. The bridge pickup generates a much brighter tone, while the neck makes a warmer tone and middle pickups will be somewhere in the middle. To select which pick up is in use, electric guitars will come with a pickup selector which sits in the electronic circuit and on most guitars sits as a switch on the body which allows the player to switch between pickups. Most pickup switches are either a three or five way selector depending on the number of pickups on a guitar. For example, a Les Paul has a three way selector which allows choice of bridge pickup, neck pickup and a middle position which makes a combination of both pickups. A Stratocaster however, will have a five way selector allowing choice of bridge, middle, neck and two middle positions between the neck and middle and the bridge and middle. The middle positions on a five way selector are particularly useful at giving guitars a funky tone. Some guitars have a slightly different method of pickup selection, such as Fender Jaguars and Jazzmasters which have a switch for every pickup which turns it on or off, this has the added advantage of being able to have any combination of pickups on, as well as being harder to move by accident while playing.

Guitars use different combinations of pickups to get their sound, and are written out as a combination of the letter H and S, H standing for humbucker and S standing for Single coil. Some of the most popular pickup combinations are S S like a Fender Telecaster or Mustang, S S S like a Stratocaster and HH like an SG or Les Paul. Some rarer pickup configurations include H H H like on the Gibson SG3, H S H like on the Ibanez Jem and H S S.

All of this circuitry then leads to the output jack socket which is how a guitar sends the electric signal from the pickups. The standard output for electric guitars is a ¼ inch mono jack which can be used to send signal to an amp or desk via a jack cable. A more recent innovation in technology is the creation of MIDI guitars, however this is a very new and still developing technology which is still flawed and extremely rare.

#specialinvestigation #unit43 #433 #435