Amplifier



Amplifiers are used to emit the sound played by guitars. Amps do this by converting the electrical signal of a pickup to sound, where the amp will then "amplify" the sound. Amplifiers can modify the guitar's tone significantly by removing, or adding (Or 'emphasizing') certain sounds of the vibrations. Doing so allows for distortion and special effects to be added.

Amps are generally used for electric guitars, since electrics depend on them to create noise. However, acoustic guitar's also can use amps to create louder sounds.

The following section of this article is inspired by Ernie Jackson's article here.
Through out history, electricity has been a mystery. But, by 1930, people were very familiar with electricity and knew that the movement of metal through a magnetic field caused a disturbance that could be translated into an electric current by a nearby coil of wire. Electrical generators and record player pickups already used this principle. However, the obstacle of using this understanding of pickups into guitar's was a challenge.

After several months of failed attempts, the Hawaiian 'steel-guitar' player George Beauchamp — who, with Adolph Rickenbacker, formed the Electro String Company in the early 1930s. They developed a pickup that used two horseshoe magnets. The strings passed through these and over a coil, which had six pole pieces concentrating the magnetic field under each string.

When the pickup seemed to work, Beauchamp enlisted Harry Watson, a skilled guitar maker for National Guitars, to make an electric Hawaiian guitar. It was nicknamed "Frying Pan".

From the beginning of the company's history, Electro String developed and sold amplifiers. (Pickups are useless without and amp) The first production-model amp was designed and built by a Mr. Van Nest at his Los Angeles radio shop.

Soon after, Beauchamp and Rickenbacker hired design engineer Ralph Robertson to work on amplifiers. He developed the new circuitry for a line that by 1941 included at least four models. Early Rickenbacker amps influenced, among others, Leo Fender, who by the early 1940s was repairing them at his radio shop in nearby Fullerton, California.

Today, the amps would have been very weak. With a max output of 10 watts, which is pretty low, they used radio technology, vacuum tubes, and small loudspeakers. However, the popularity of the electric guitar was growing, so there was a demand for louder amps.

That demand was fulfilled by Leo Fender in 1949. He, and his engineer, Don Randall, worked to produce the first 'Super Amp' model amplifier. With the Fender solid-bodied guitars (the Telecaster and Stratocaster) in general production, and the introduction of the Gibson Les Paul in 1952, the demand for amps went through the roof as the popularity of the solid body grew. Output rose to a reasonable 50 watts, with twelve-inch speakers, still the norm for guitar amps.

By the late 1950s, the British company Vox had produced the AC30, which is as much a classic amp today as the Fender Twin Reverb. The Vox was particularly popular with blues and rock musicians because it produced a warm tone, which musicians such as Jimi Hendrix, Jeff Beck, and other heavy-metal rockers discovered could be over driven to create the fuzzy, distorted effect that has come to define the early 1960s rock guitar sound.

Splitting up a combo amp into individual components came about during the rock era of the 1960s. The amp became known as the head, and the speakers became known as the stack. You could get more powerful amps and much bigger speakers this way, and by combining various amps and speaker combinations, musicians could produce more volume.

As the 1960s wore on, and rock bands played bigger and bigger venues, power and volume once more became a problem. This was solved when the British engineer Jim Marshall produced a 100-watt amp connected to a stack of four twelve-inch speakers. Pretty soon the Marshall stack was the norm for rock concerts.

By the 1970s, the vacuum-tube technology of the 1930s was finally being replaced by cheaper solid-state transistors, although musicians complained about the coldness of the sound as compared to the warmth of the tube amp.

The transistors' brittle sound was offset by the wider frequency range and the ability to play cleanly (without using distortion) at higher volumes. Different tubes could produce different sounds, but they needed to be replaced periodically because they came loose or burned out.

By the 1980s, amplifier makers went back to creating a valve sound, often creating hybrid models that featured tube preamps and solid-state power amplifiers, getting the best of both worlds. Today, a traditional guitar amp combines an amplifier and a loudspeaker in one unit, called a combo. They are compact and relatively easy to transport.