amplifier
ALTERNATIVE NAME/S: amp
DETAILS/DESCRIPTION:
Generic term used to describe an electronic device that receives a signal and converts it into a larger one. Applications include radio, television, high-fidelity audio and computer uses. In most applications, sufficient broadcast requires a chain of amplifiers, each increasing the relayed signal before passing it on to the next. This is called multi-stage amplification, or cascading.
This first amplifier was developed by Lee De Forest* in Chicago in 1906. De Forest’s invention, which he named the ‘audion,’ was a trio of electrodes, or “triode,” encased in a vacuum tube. In the late 1950s, amplifiers using solid-state transistors began to replace vacuum tubes because they proved cheaper, smaller, and more durable.
ONELINER: The amplifier
OTHER CONNECTIONS: None
BIBLIOGRAPHY:
EB, ANB
History
The first electric instrument amplifiers were not designed for use with electric guitars. The earliest examples appeared in the early 1930s when the introduction of electrolytic capacitors and rectifier tubes allowed the production of economical built-in power supplies that could be plugged into wall sockets, instead of heavy multiple battery packs, since rechargeable batteries wouldn't be lightweight until later on. While guitar amplifiers from the beginning were used to amplify acoustic guitar, electronic amplification of guitar was first widely popularized by the 1930s and 1940s craze for Hawaiian music, which extensively employed the amplified lap steel Hawaiian guitar.[1]
Tone controls on early guitar amplifiers were very simple and provided a great deal of treble boost, but the limited controls, the loudspeakers used, and the low power of the amplifiers (typically 15 watts or less prior to the mid-1950s) gave poor high treble and bass output. Some models also provided effects such as an electronic tremolo unit. Early Fender amps labeled tremolo as "vibrato" and labeled the vibrato arm of the Stratocaster guitar as a "tremolo bar" (see vibrato unit, electric guitar, and tremolo). Some later models included an onboard spring reverb effect, one of the first being the Ampeg Reverberocket amp.
In the 1950s, several guitarists experimented with distortion produced by deliberately overdriving their amplifiers, including Goree Carter,[2] Joe Hill Louis,[3][4] Ike Turner,[5] Willie Johnson,[6]Pat Hare,[7] Guitar Slim,[8] Chuck Berry,[9] Johnny Burnette,[6] and Link Wray.[10] In the early 1960s, surf rock guitarist Dick Dale worked closely with Fender to produce custom made amplifiers,[11] including the first 100-watt guitar amplifier.[12] He pushed the limits of electric amplification technology, helping to develop new equipment that was capable of producing "thick, clearly defined tones" at "previously undreamed-of volumes."[11]
Distortion became more popular from the mid-1960s, when The Kinks guitarist Dave Davies produced distortion effects by connecting the already distorted output of one amplifier into the input of another. Later, most guitar amps were provided with preamplifier distortion controls, and "fuzz boxes" and other effects units were engineered to safely and reliably produce these sounds. In the 2000s, overdrive and distortion has become an integral part of many styles of electric guitar playing, ranging from blues rock to heavy metal and hardcore punk.
Guitar amplifiers were at first used with bass guitars and electronic keyboards, but other instruments produce a wider frequency range and need a suitable amplifier and full-range speaker system. Much more amplifier power is required to reproduce low-frequency sound, especially at high volume. Reproducing low frequencies also requires a suitable woofer or subwoofer speaker and enclosure. Woofer enclosures need to be larger and more sturdily built than cabinets for mid-range or high-frequency (tweeter) speakers....