1.
Magnetic cartridge
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Phono cartridges, also known as pickups, are electromechanical devices which convert mechanical energy into electrical energy. The cartridge contains a removable or permanently mounted stylus, the tip of which physical contact with the records groove. In popular usage and in disc jockey jargon, the stylus, the electrical signal generated by the cartridge can be amplified and then converted into sound by a loudspeaker. The first commercially successful type of electrical phonograph pickup was introduced in 1925 and its tracking weight was specified in ounces, not grams. The use of short-lived disposable metal needles remained standard, sapphire and diamond then became the standard stylus tip materials. The high compliance also reduced record wear and they soon became standard in all but the cheapest component audio systems and are the most common type of pickup cartridge in use today. The cartridge consists of components, the stylus, cantilever, magnets, coils. The stylus is the part that, when in use, is the interface with the record surface and it is typically made of a small polished diamond or other industrial gemstone. The cantilever supports the stylus, and transmits the vibrations from it to the coil/magnet assembly, the former is typically made of boron or aluminium, and previously beryllium although some manufacturers market models with exotic gemstone cantilevers. Coupled to the tonearm, the bodys function is to give the moving parts a stationary platform so that they can track the groove with precision. In high-fidelity systems, crystal and ceramic pickups have been replaced by the magnetic cartridge, compared to the crystal and ceramic pickups, the magnetic cartridge usually gives improved playback fidelity and reduced record wear by tracking the groove with lighter pressure. Magnetic cartridges use lower tracking forces and thus reduce the potential for groove damage and they also have a lower output voltage than a crystal or ceramic pickup, in the range of only a few millivolts, thus requiring greater amplification. In a moving magnet cartridge, the cantilever carries a tiny permanent magnet. As the magnet vibrates in response to the following the record groove. Because the magnet is small and has mass, and is not coupled mechanically to the generator. The MC design is again a tiny electromagnetic generator, but with the magnet and coils reversed, the coils are attached to the stylus, the coils are tiny and made from very fine wire. Since the number of windings that can be supported in such armature is small, the resulting signal is only a few hundred microvolts, and thus more easily swamped by noise, induced hum, etc. Thus it is challenging to design a preamplifier with the extremely low noise inputs needed for moving-coil cartridge
2.
Humbucker
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A humbucking pickup, humbucker, or double coil, is a type of electric guitar pickup that uses two coils to buck the hum picked up by coil pickups. Most pickups use magnets to produce a field around the strings. Humbuckers work by pairing a coil with the poles of its magnets oriented up. By connecting the coils together out of phase, the interference is reduced via phase cancellation. The string signals from both coils add up instead of canceling, because the magnets are placed in opposite polarity. The coils can be connected in series or in parallel in order to achieve this hum-cancellation effect, in addition to electric guitar pickups, humbucking coils are sometimes used to cancel hum in dynamic microphones. Hum is caused by the magnetic fields created by transformers. While playing a guitar without humbuckers, a musician would hear a hum through the pickups during quiet sections of music, sources of studio and stage hum include high-power amps, processors, mixers, motors, power lines, and other equipment. Compared to unshielded single coil pickups, humbuckers dramatically reduce hum, the twin coiled guitar pickup invented by Arnold Lesti in 1935 is arranged as a humbucker, and the patent USRE20070 describes the noise cancelation and current summation principles of such a design. This Electric Translating Device employed the solenoid windings of the pickup to magnetize the steel strings by means of switching on a short D. C. charge before switching over to amplification, in 1938 A. F. Knoblaugh invented a pickup for stringed instruments involving 2 stacked coils. This pickup was to be used in pianos, since he was working for Baldwin Piano at the time, the iron cores of these pickups were magnetized to have their north-south poles at the opposite ends of the core, rather than the now more common top-bottom orientation. To overcome the hum problem for guitars, a humbucking pickup was invented by Seth Lover of Gibson under instruction of then president Ted McCarty, about the same time Ray Butts developed a similar pickup that was taken up by Gretsch guitars. Although Gibsons patent was filed almost 2 years before Gretschs, Gibsons patent was issued 4 weeks after Gretschs, both patents describe a reverse wound and reverse polarity pair of coils. A successful early humbucking pickup was the so-called PAF invented by Seth Lover in 1955, humbuckers are also known as dual-coil, double-coil, or hum-canceling pickups. In any magnetic pickup, a guitar string, magnetized by a fixed magnet within the pickup induces an alternating voltage across its coil. Guitar pickups reproduce this noise, which can be quite audible, the direction of voltage induced across a coil by the moving string depends on both the coil winding direction and the polarity of the fixed magnet. On the other hand, the direction of current induced by external fields is only dependent on the direction of winding, therefore a humbucker has two coils wound in such a way to cancel hum and maximize signal when they are connected. By convention humbucker coils are both wound counterclockwise, however typically the outside ends of the coils are connected together so that the starts are out of phase
3.
Single coil guitar pickup
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A single coil pickup is a type of magnetic transducer, or pickup, for the electric guitar and the electric bass. It electromagnetically converts the vibration of the strings to an electric signal, single coil pickups are one of the two most popular designs, along with dual-coil or humbucking pickups. In the mid-1920s George Beauchamp, a Los Angeles, California guitarist, originally using a phonograph pickup assembly, Beauchamp began testing many different combinations of coils and magnets hoping to create the first electromagnetic guitar pickup. He wound his earliest coils using an out of a washing machine, later on switching to a sewing machine motor. Beauchamp was backed in his efforts by Adolph Rickenbacker, an engineer and wealthy owner of a successful tool, Beauchamp eventually produced the first successful single coil pickup. The pickup consisted of two massive U shaped magnets and one coil and was known as the horseshoe pickup, the two horseshoe-shaped magnets surrounded the strings that passed over a single core plate in the center of the coil. The Gibson Guitar Corporation introduced the bar pickup in 1935 for its new line of Hawaiian lap steel guitars, the pickups basic construction is that of a metal blade inserted through the coil as a shared pole piece for all the strings. A pair of large magnets were fastened below the coil assembly. In 1936 Gibson introduced the ES-150, its first electric Spanish styled guitar, the ES-150 was outfitted with the bar pickup. Jazz guitar innovator, Charlie Christian, began playing an ES-150 in the late 1930s with the Benny Goodman Orchestra and this caused the popularity of the electrified guitar to soar. Due to Christian’s close association with the ES-150 it began being referred to as the “Charlie Christian Model”, the P-90 is a single-coil pickup designed by the Gibson Guitar Corporation. These pickups have a large, flat coil with adjustable steel screws as pole pieces, the adjustable pole pieces pick up the magnetism from the magnets. Moving the screw closer or further away from the magnet determines signal strength, occasionally, they are mistaken for pole pieces, thus, the P-90 is sometimes erroneously said to have eight pole pieces. Dog ear is a type with extensions at both sides of pickup that somewhat resemble dogs ears. These are extensions of the predominantly rectangular cover that encompass the outlying mounting screws, dog-ear P-90 pickups were commonly mounted on Gibsons hollowbody guitars like the ES-330 and occasionally on solid body models like the Les Paul Junior. The same pickups were available on Epiphone models and the design is best remembered for its appearance on the hollow body Epiphone Casino of the mid to late 1960s. Despite its tonal qualities the P-90 fell out of favor with Gibson in the early 1950s as a consequence of guitar players complaining about the amount of hum it put out. Gibson employee Seth Lover solved the hum problem by designing a hum-canceling pickup known as a humbucker, it was supposed to sound like a P-90 and it nevertheless became Gibsons mainstay pickup from that point on
4.
Transducer
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A transducer is a device that converts one form of energy to another. Usually a transducer converts a signal in one form of energy to a signal in another, Transducers are often employed at the boundaries of automation, measurement, and control systems, where electrical signals are converted to and from other physical quantities. The process of converting one form of energy to another is known as transduction, passive sensors require an external power source to operate, which is called an excitation signal. The signal is modulated by the sensor to produce an output signal, active sensors generate electric signals in response to an external stimulus without the need of an additional energy source. Such examples are a photodiode, and a sensor, thermocouple. A sensor is a device that receives and responds to a signal or stimulus, transducer is the other term that is sometimes interchangeably used instead of the term sensor, although there are subtle differences. A transducer is a term that can be used for the definition of many such as sensors, actuators. An actuator is a device that is responsible for moving or controlling a mechanism or system and it is operated by a source of energy, which can be mechanical force, electrical current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion. An actuator is the mechanism by which a system acts upon an environment. The control system can be simple, software-based, a human, bidirectional transducers convert physical phenomena to electrical signals and also convert electrical signals into physical phenomena. Likewise, DC electric motors may be used to generate electrical power if the shaft is turned by an external torque. Radio transmitters converts electrical signals to electromagnetic transmissions, horn analyzer List of sensors Tactile sensor Agarwal, Anant. Foundations of Analog and Digital Electronic Circuits. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology,2005, p.43. Introduction to Closed Loop Hall Effect Current Transducers Federal Standard 1037C, August 7,1996, transducer A sound transducer with a flat flexible diaphragm working with bending waves
5.
Stringed instrument
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String instruments, stringed instruments, or chordophones are musical instruments that produce sound from vibrating strings when the performer plays or sounds the strings in some manner. Musicians play some string instruments by plucking the strings with their fingers or a plectrum—and others by hitting the strings with a wooden hammer or by rubbing the strings with a bow. In some keyboard instruments, such as the harpsichord or piano, with bowed instruments, the player rubs the strings with a horsehair bow, causing them to vibrate. With a hurdy-gurdy, the musician operates a wheel that rubs the strings. Bowed instruments include the string instruments of the Classical music orchestra. All of the string instruments can also be plucked with the fingers. Some types of string instrument are mainly plucked, such as the harp, in the Hornbostel-Sachs scheme of musical instrument classification, used in organology, string instruments are called chordophones. Other examples include the sitar, rebab, banjo, mandolin, ukulele, in most string instruments, the vibrations are transmitted to the body of the instrument, which often incorporates some sort of hollow or enclosed area. The body of the instrument also vibrates, along with the air inside it, the vibration of the body of the instrument and the enclosed hollow or chamber make the vibration of the string more audible to the performer and audience. The body of most string instruments is hollow, some, however—such as electric guitar and other instruments that rely on electronic amplification—may have a solid wood body. Archaeological digs have identified some of the earliest stringed instruments in Ancient Mesopotamian sites, like the lyres of Ur, the development of lyre instruments required the technology to create a tuning mechanism to tighten and loosen the string tension. During the medieval era, instrument development varied from country to country, Middle Eastern rebecs represented breakthroughs in terms of shape and strings, with a half a pear shape using three strings. Early versions of the violin and fiddle, by comparison, emerged in Europe through instruments such as the gittern, a four stringed precursor to the guitar and these instruments typically used catgut and other materials, including silk, for their strings. String instrument design refined during the Renaissance and into the Baroque period of musical history, violins and guitars became more consistent in design, and were roughly similar to what we use in the 2000s. At the same time, the 19th century guitar became more associated with six string models. In big bands of the 1920s, the guitar played backing chords. The development of guitar amplifiers, which contained a power amplifier, the development of the electric guitar provided guitarists with an instrument that was built to connect to guitar amplifiers. Electric guitars have magnetic pickups, volume control knobs and an output jack, in the 1960s, larger, more powerful guitar amplifiers were developed, called stacks
6.
Electric guitar
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The vibrations of the strings are sensed by a pickup, of which the most common type is the magnetic pickup, which uses the principle of direct electromagnetic induction. The signal generated by a guitar is too weak to drive a loudspeaker, so it is plugged into a guitar amplifier before being sent to a loudspeaker. The output of a guitar is an electric signal. Invented in 1931, the electric guitar was adopted by jazz guitarists. Early proponents of the guitar on record included Les Paul, Lonnie Johnson, Sister Rosetta Tharpe, T-Bone Walker. During the 1950s and 1960s, the guitar became the most important instrument in pop music. It has evolved into an instrument that is capable of a multitude of sounds and styles in genres ranging from pop and rock to country music, blues and jazz. It served as a component in the development of electric blues, rock and roll, rock music, heavy metal music. Electric guitar design and construction vary greatly in the shape of the body and the configuration of the neck, bridge, Guitars may have a fixed bridge or a spring-loaded hinged bridge that lets players bend the pitch of notes or chords up or down or perform vibrato effects. The sound of a guitar can be modified by new playing techniques such as string bending, tapping, hammering on, using audio feedback, in a small group, such as a power trio, one guitarist switches between both roles. In larger rock and metal bands, there is often a rhythm guitarist, many experiments at electrically amplifying the vibrations of a string instrument were made dating back to the early part of the 20th century. Patents from the 1910s show telephone transmitters were adapted and placed inside violins, hobbyists in the 1920s used carbon button microphones attached to the bridge, however, these detected vibration from the bridge on top of the instrument, resulting in a weak signal. With numerous people experimenting with electrical instruments in the 1920s and early 1930s, Electric guitars were originally designed by acoustic guitar makers and instrument manufacturers. Some of the earliest electric guitars adapted hollow-bodied acoustic instruments and used tungsten pickups, the first electrically amplified guitar was designed in 1931 by George Beauchamp, the general manager of the National Guitar Corporation, with Paul Barth, who was vice president. The maple body prototype for the one-piece cast aluminum frying pan was built by Harry Watson, commercial production began in late summer of 1932 by the Ro-Pat-In Corporation, in Los Angeles, a partnership of Beauchamp, Adolph Rickenbacker, and Paul Barth. In 1934, the company was renamed the Rickenbacker Electro Stringed Instrument Company, in that year Beauchamp applied for a United States patent for an Electrical Stringed Musical Instrument and the patent was issued in 1937. The Electro-Spanish Ken Roberts provided players a full 25 scale, with 17 frets free of the fretboard and it is estimated that fewer than 50 Electro-Spanish Ken Roberts were constructed between 1933 and 1937, fewer than 10 are known to survive today. The need for the guitar became apparent during the big band era as orchestras increased in size, particularly when acoustic guitars had to compete with large
7.
Instrument amplifier
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An instrument amplifier is an electronic device which converts the often barely audible or purely electronic signal of a musical instrument into an audible sound. Combination amplifiers include a preamplifier, an amplifier, tone controls, and one or more speakers in a cabinet. Instrument amplifiers are available for specific instruments, including the guitar, electric bass, electric/electronic keyboards. A guitar amplifier is designed to amplify the signal of an electric so that it will produce a sound through a loudspeaker that is loud enough for the performer. Most guitar amplifiers can also modify the tone by emphasizing or de-emphasizing certain frequencies. Vibrations of the strings are picked up by a microphone or pickup. For electric guitars, strings are almost always made of metal, acoustic guitars do not usually have a built-in pickup or microphone, at least with entry-level and beginner instruments. Acoustic guitars may also use a pickup, which converts the vibrations of the instrument into an electronic signal. Standard amplifiers, such as the Fender tweed-style amps and Gibson amps, are used by traditional rock, blues. They are used by guitarists, pedal steel guitar players. Combo amplifiers such as the Fender Super Reverb have powerful, loud tube amplifiers, four 10 speakers, smaller guitar amps are also available, which have fewer speakers and lighter, less powerful amplifier units. Smaller guitar amps are easier to transport to gigs and sound recording sessions, smaller amps are widely used in small venue shows and in recordings, because players can obtain the tone they want without having to have an excessively loud volume. One of the challenge with the large, powerful 4x10 Fender Bassman-type amps is that to get the tone a player wants, she has to turn up the amp to too loud a volume. These amps are designed to produce a variety of sounds ranging from a clean, warm sound to a growling, natural overdrive, when the volume is set near its maximum. These amplifiers usually have a sharp treble roll-off at 5 kHz to reduce the high frequencies. The nickname tweed refers to the lacquered beige-light brown fabric covering used on these amplifiers, the smallest combo amplifiers, which are mainly used for individual practice and warm-up purposes, may have only a single 8 or 10 speaker. Some harmonica players use these small combo amplifiers for concert performances, though, larger combo amplifiers, with one 12 inch speaker or two or four 10 or 12 inch speakers are used for club performances and larger venues. For large concert venues such as stadiums, performers may use an amplifier head with several separate speaker cabinets
8.
Loudspeaker
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A loudspeaker is an electroacoustic transducer, which converts an electrical audio signal into a corresponding sound. The most widely used type of speaker in the 2010s is the speaker, invented in 1925 by Edward W. Kellogg. The dynamic speaker operates on the basic principle as a dynamic microphone. Besides this most common method, there are several technologies that can be used to convert an electrical signal into sound. The sound source must be amplified or strengthened with a power amplifier before the signal is sent to the speaker. Speakers are typically housed in an enclosure or speaker cabinet which is often a rectangular or square box made of wood or sometimes plastic. The enclosures materials and design play an important role in the quality of the sound, where high fidelity reproduction of sound is required, multiple loudspeaker transducers are often mounted in the same enclosure, each reproducing a part of the audible frequency range. In this case the individual speakers are referred to as drivers, drivers made for reproducing high audio frequencies are called tweeters, those for middle frequencies are called mid-range drivers, and those for low frequencies are called woofers. Smaller loudspeakers are found in such as radios, televisions, portable audio players, computers. Larger loudspeaker systems are used for music, sound reinforcement in theatres and concerts, the term loudspeaker may refer to individual transducers or to complete speaker systems consisting of an enclosure including one or more drivers. To adequately reproduce a range of frequencies with even coverage, most loudspeaker systems employ more than one driver. Individual drivers are used to different frequency ranges. The drivers are named subwoofers, woofers, mid-range speakers, tweeters, the terms for different speaker drivers differ, depending on the application. In two-way systems there is no mid-range driver, so the task of reproducing the mid-range sounds falls upon the woofer and tweeter, home stereos use the designation tweeter for the high frequency driver, while professional concert systems may designate them as HF or highs. When multiple drivers are used in a system, a network, called a crossover. Loudspeaker driver of the type pictured are termed dynamic to distinguish them from earlier drivers, or speakers using piezoelectric or electrostatic systems, or any of several other sorts. Johann Philipp Reis installed an electric loudspeaker in his telephone in 1861, it was capable of reproducing clear tones, alexander Graham Bell patented his first electric loudspeaker as part of his telephone in 1876, which was followed in 1877 by an improved version from Ernst Siemens. In 1898, Horace Short patented a design for a loudspeaker driven by compressed air, he sold the rights to Charles Parsons
9.
Loudspeaker enclosure
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As such, a loudspeaker cannot be used without installing it in a cabinet of some type, or mounting it into a wall or ceiling. The enclosure also plays a role in managing vibration induced by the frame and moving airmass within the enclosure, as well as heat generated by driver voice coils. Sometimes considered part of the enclosure, the base, may include specially designed feet to decouple the speaker from the floor, enclosures designed for use in PA systems, sound reinforcement systems and for use by electric musical instrument players. Speaker enclosures are used in homes in stereo systems, home cinema systems, televisions, boom boxes, small speaker enclosures are used in car stereo systems. Speaker cabinets are key components of a number of applications, including sound reinforcement systems, movie theatre sound systems. Electric musical instruments invented in the 20th century, such as the guitar, electric bass and synthesizer, among others, are amplified using instrument amplifiers. Early on, radio loudspeakers consisted of horns, often separately from the radio itself. When paper cone loudspeaker drivers were introduced in the mid 1920s and these cabinets were made largely for the sake of appearance, with the loudspeaker simply mounted behind a round hole in the cabinet. It was observed that the enclosure had an effect on the bass response of the speaker. This results in a loss of bass and comb filtering, before the 1950s many manufacturers did not fully enclose their loudspeaker cabinets, the back of the cabinet was typically left open. This was done for reasons, not least because electronics could be placed inside. In some respects, the mounting for a low-frequency loudspeaker driver would be a rigid flat panel of infinite size with infinite space behind it. This would entirely prevent the sound waves from interfering with the sound waves from the front. An open baffle loudspeaker is an approximation of this, since the driver is mounted on a panel, a speaker driver mounted on a finite baffle will display a physical phenomenon known as interference which can result in a perceivable frequency-dependent sound attenuation. This phenomenon is particularly noticeable at low frequencies where the wavelengths are large enough that interference will affect the entire listening area, the box is typically made of wood, wood composite, or more recently plastic, for reasons of ease of construction and appearance. Stone, concrete, plaster, and even building structures have also been used, wharfedale, in some designs, reduced panel resonance by using two wooden cabinets with the space between filled with sand. Home experimenters have even designed speakers built from concrete, granite, many diffraction problems, above the lower frequencies, can be alleviated by the shape of the enclosure, such as by avoiding sharp corners on the front of the enclosure. Research experiments from the 1930s by Dr. Harry F. Olson showed that curved loudspeaker baffles reduce some response deviations due to sound wave diffraction and it was discovered later that careful placement of a speaker on a sharp-edged baffle can reduce diffraction-caused response problems
10.
Sound recording and reproduction
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Sound recording and reproduction is an electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording, prior to the development of analog recording, there were mechanical systems for reproducing instrumental music, such as wind-up music boxes and later, in the late 19th century, player pianos. Analog sound reproduction is the process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Digital recording and reproduction converts the sound signal picked up by the microphone to a digital form by the process of digitization. This lets the audio data be stored and transmitted by a variety of media. Whereas successive copies of an analog recording tend to degrade in quality, as noise is added. A digital audio signal must be reconverted to analog form during playback before it is amplified and connected to a loudspeaker to produce sound, long before sound was first recorded on cylinders or records, music was recorded—first by written music notation, then also by mechanical devices. Fowler, this. cylinder with raised pins on the surface remained the device to produce and reproduce music mechanically until the second half of the nineteenth century. The Banu Musa brothers also invented an automatic flute player, which appears to have been the first programmable machine, according to Fowler, the automata were a robot band that performed. more than fifty facial and body actions during each musical selection. In the 14th century, Flanders introduced a mechanical bell-ringer controlled by a rotating cylinder, similar designs appeared in barrel organs, musical clocks, barrel pianos, and musical boxes. A music box is a musical instrument that produces sounds by the use of a set of pins placed on a revolving cylinder or disc so as to pluck the tuned teeth of a steel comb. They were developed from musical snuff boxes of the 18th century, some of the more complex boxes also have a tiny drum and/or bells, in addition to the metal comb. The fairground organ, developed in 1892, used a system of accordion-folded punched cardboard books, the player piano, first demonstrated in 1876, used a punched paper scroll that could store an long piece of music. The most sophisticated of the rolls were hand-played, meaning that the roll represented the actual performance of an individual. This technology to record a live performance onto a piano roll was not developed until 1904, piano rolls were in continuous mass production from 1896 to 2008. A1908 U. S. Supreme Court copyright case noted that, in 1902 alone, the use of piano rolls began to decline in the 1920s although one type is still being made today. The first device that could record actual sounds as they passed through the air was the phonautograph, the earliest known recordings of the human voice are phonautograph recordings, called phonautograms, made in 1857. They consist of sheets of paper with sound-wave-modulated white lines created by a stylus that cut through a coating of soot as the paper was passed under it
11.
Acoustic guitar
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An acoustic guitar is a guitar that produces sound acoustically—by transmitting the vibration of the strings to the air—as opposed to relying on electronic amplification. The sound waves from the strings of an acoustic guitar resonate through the guitars body and this typically involves the use of a sound board and a sound box to strengthen the vibrations of the strings. The main source of sound in a guitar is the string. The string vibrates at a frequency and also creates many harmonics at various different frequencies. The frequencies produced can depend on string length, mass, gitterns, a small plucked guitar were the first small guitar-like instruments created during the Middle Ages with a round back like that of a lute. Modern guitar shaped instruments were not seen until the Renaissance era where the body, the earliest string instruments that related to the guitar and its structure where broadly known as the vihuelas within Spanish musical culture. Vihuelas where string instruments that were seen in the 16th century during the Renaissance. Later, Spanish writers distinguished these instruments into 2 categories of vihuelas, the vihuela de arco was an instrument that mimicked the violin, and the vihuela de penola was played with a plectrum or by hand. When it was played by hand it was known as the vihuela de mano, vihuela de mano shared extreme similarities with the Renaissance guitar as it used hand movement at the sound hole or sound chamber of the instrument to create music. The real production of guitars kicked off in France where the popularity, the production became so large that early famous creators such as Gaspard Duyffooprucgars instruments were being sold as copies by other guitar makers in Lyon. Benoist Lejeune, a maker, offered and sold guitar copies of Duyffoprucgars instruments and was later imprisoned for using his mark and work. During this time, the production was increasing tremendously but it was not until Robert and Claude Denis appeared overproducing the early Renaissance guitar in Paris, as father and son, Robert and Claude produced hundreds of guitars that increased the popularity of the instrument greatly. Because of them and the great many guitar inventors of this time, by 1790 only six-course vihuela guitars were being created and had become the main type and model of guitar used in Spain. Most of the older 5-course guitars where still in use but were also being modified to a six-coursed acoustical guitar, by the 19th century, coursed strings where evolved into 6 single-stringed instruments much like that of the guitar today. It had evolved into the modern look except for size, retaining a smaller frame, the acoustic guitars soundboard, or top, also has a strong effect on the loudness of the guitar. No amplification actually occurs in this process, because no energy is added to increase the loudness of the sound. All the energy is provided by the plucking of the string, but without a soundboard, the string would just cut through the air without actually moving it much. The soundboard increases the surface of the area in a process called mechanical impedance matching
12.
Upright bass
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The double bass, or simply the bass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra. It is an instrument and is typically notated one octave higher than sounding to avoid excessive ledger lines below the staff. The double bass is the modern bowed string instrument that is tuned in fourths, rather than fifths, with strings usually tuned to E1, A1, D2. The instruments exact lineage is still a matter of some debate, the double bass is a standard member of the orchestras string section, as well as the concert band, and is featured in concertos, solo and chamber music in Western classical music. The bass is used in a range of genres, such as jazz, 1950s-style blues and rock and roll, rockabilly, psychobilly, traditional country music, bluegrass, tango. The double bass is played either with a bow or by plucking the strings, in orchestral repertoire and tango music, both arco and pizzicato are employed. In jazz, blues, and rockabilly, pizzicato is the norm, Classical music uses just the natural sound produced acoustically by the instrument, so does traditional bluegrass. In jazz, blues, and related genres, the bass is typically amplified with an amplifier and speaker, the double bass stands around 180 cm from scroll to endpin. However, other sizes are available, such as a 1⁄2 or 3⁄4 and these sizes do not reflect the size relative to a full size, or 4⁄4 bass, a 1⁄2 bass is not half the size of a bass but is only slightly smaller. It is typically constructed from several types of wood, including maple for the back, spruce for the top and it is uncertain whether the instrument is a descendant of the viola da gamba or of the violin, but it is traditionally aligned with the violin family. While the double bass is nearly identical in construction to other violin family instruments, like other violin and viol-family string instruments, the double bass is played either with a bow or by plucking the strings. In orchestral repertoire and tango music, both arco and pizzicato are employed, in jazz, blues, and rockabilly, pizzicato is the norm, except for some solos and also occasional written parts in modern jazz that call for bowing. In classical pedagogy, almost all of the focus is on performing with the bow and producing a good bowed tone, some of these articulations can be combined, for example, the combination of sul ponticello and tremolo can produce eerie, ghostly sounds. Classical bass players do play pizzicato parts in orchestra, but these parts generally require simple notes, vibrato is used to add expression to string playing. In general, very loud, low-register passages are played with little or no vibrato, mid- and higher-register melodies are typically played with more vibrato. The speed and intensity of the vibrato is varied by the performer for an emotional and musical effect, in jazz, rockabilly and other related genres, much or all of the focus is on playing pizzicato. In jazz and jump blues, bassists are required to play extremely rapid pizzicato walking basslines for extended periods, as well, jazz and rockabilly bassists develop virtuoso pizzicato techniques that enable them to play rapid solos that incorporate fast-moving triplet and sixteenth note figures. In jazz and related styles, bassists often add semi-percussive ghost notes into basslines, to add to the rhythmic feel and to add fills to a bassline
13.
Fiddle
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Fiddle is another name for the bowed string musical instrument more often called a violin. It is also a term for the instrument used by players in all genres. Fiddle playing, or fiddling, refers to various styles of music, Fiddle is also a common term among musicians who play folk music on the violin. The fiddle is part of traditional styles of music which are aural traditions. There are few distinctions between violins and fiddles, though more primitively constructed and smaller violins are more likely to be considered fiddles. In order to produce a tone, compared to the deeper tones of gut or synthetic core strings. Among musical styles, fiddling tends to produce rhythms focused on dancing, with associated quick note changes, whereas classical music tends to contain more vibrato and it is less common for a classically trained violinist to play folk music, but today, many fiddlers have classical training. The medieval fiddle emerged in 10th-century Europe, deriving from the Byzantine lira, lira spread widely westward to Europe, in the 11th and 12th centuries European writers use the terms fiddle and lira interchangeably when referring to bowed instruments. During the Renaissance the gambas were important and elegant instruments, they eventually lost ground to the viola da braccio family. The etymology of fiddle is uncertain, the Germanic fiddle may derive from the same early Romance word as does violin, the name seems however to be related to Icelandic Fiðla and also Old English fiðele. A native Germanic ancestor of fiddle may even be the ancestor of the early Romance form of violin, historically, fiddle also referred to a predecessor of todays violin. Like the violin, it tended to have four strings, another family of instruments that contributed to the development of the modern fiddle are the viols, which are held between the legs and played vertically, and have fretted fingerboards. Violins, on the hand, are commonly grouped in sections. The difference was likely compounded by the different sounds expected of violin music, historically, the majority of fiddle music was dance music, while violin music had either grown out of dance music or was something else entirely. Violin music came to value a smoothness that fiddling, with its dance-driven clear beat, in situations that required greater volume, a fiddler could push their instrument harder than could a violinist. In the very late 20th century, a few artists have attempted a reconstruction of the Scottish tradition of violin and big fiddle. Notable recorded examples include Iain Fraser and Christine Hanson, Amelia Kaminski and Christine Hansons Bonnie Lasses and Alasdair Fraser and Natalie Haas Fire and Grace. In Hungary, a three stringed viola variant with a bridge, called the kontra or háromhúros brácsa makes up part of a traditional rhythm section in Hungarian folk music
14.
Piezoelectricity
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Piezoelectricity /piˌeɪzoʊˌilɛkˈtrɪsɪti/ is the electric charge that accumulates in certain solid materials in response to applied mechanical stress. The word piezoelectricity means electricity resulting from pressure and it is derived from the Greek piezō or piezein, which means to squeeze or press, and ēlektron, which means amber, an ancient source of electric charge. Piezoelectricity was discovered in 1880 by French physicists Jacques and Pierre Curie, the piezoelectric effect is understood as the linear electromechanical interaction between the mechanical and the electrical state in crystalline materials with no inversion symmetry. The piezoelectric effect is a process in that materials exhibiting the direct piezoelectric effect also exhibit the reverse piezoelectric effect. For example, lead zirconate titanate crystals will generate measurable piezoelectricity when their structure is deformed by about 0. 1% of the original dimension. Conversely, those same crystals will change about 0. 1% of their static dimension when an electric field is applied to the material. The inverse piezoelectric effect is used in the production of sound waves. The pyroelectric effect, by which a material generates a potential in response to a temperature change, was studied by Carl Linnaeus. Drawing on this knowledge, both René Just Haüy and Antoine César Becquerel posited a relationship between stress and electric charge, however, experiments by both proved inconclusive. The first demonstration of the piezoelectric effect was in 1880 by the brothers Pierre Curie. Quartz and Rochelle salt exhibited the most piezoelectricity, the Curies, however, did not predict the converse piezoelectric effect. The converse effect was mathematically deduced from fundamental principles by Gabriel Lippmann in 1881. For the next few decades, piezoelectricity remained something of a laboratory curiosity, more work was done to explore and define the crystal structures that exhibited piezoelectricity. The first practical application for piezoelectric devices was sonar, first developed during World War I, in France in 1917, Paul Langevin and his coworkers developed an ultrasonic submarine detector. The detector consisted of a transducer, made of quartz crystals carefully glued between two steel plates, and a hydrophone to detect the returned echo. The use of piezoelectricity in sonar, and the success of that project, over the next few decades, new piezoelectric materials and new applications for those materials were explored and developed. Piezoelectric devices found homes in many fields, ceramic phonograph cartridges simplified player design, were cheap and accurate, and made record players cheaper to maintain and easier to build. The development of the ultrasonic transducer allowed for easy measurement of viscosity and elasticity in fluids and solids, ultrasonic time-domain reflectometers could find flaws inside cast metal and stone objects, improving structural safety
15.
Magnet
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A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet, a force that pulls on other materials, such as iron. A permanent magnet is a made from a material that is magnetized. An everyday example is a refrigerator used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are attracted to a magnet, are called ferromagnetic. These include iron, nickel, cobalt, some alloys of rare-earth metals, ferromagnetic materials can be divided into magnetically soft materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically hard materials, which do. To demagnetize a saturated magnet, a magnetic field must be applied. Hard materials have high coercivity, whereas soft materials have low coercivity, an electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of soft material such as steel. The overall strength of a magnet is measured by its magnetic moment or, alternatively, the local strength of magnetism in a material is measured by its magnetization. Ancient people learned about magnetism from lodestones, which are naturally magnetized pieces of iron ore, the word magnet in Greek meant stone from Magnesia, a part of ancient Greece where lodestones were found. Lodestones, suspended so they could turn, were the first magnetic compasses, the earliest known surviving descriptions of magnets and their properties are from Greece, India, and China around 2500 years ago. The properties of lodestones and their affinity for iron were written of by Pliny the Elder in his encyclopedia Naturalis Historia, by the 12th to 13th centuries AD, magnetic compasses were used in navigation in China, Europe, the Arabian Peninsula and elsewhere. The magnetic flux density is a vector field, the magnetic B field vector at a given point in space is specified by two properties, Its direction, which is along the orientation of a compass needle. Its magnitude, which is proportional to how strongly the compass needle orients along that direction, in SI units, the strength of the magnetic B field is given in teslas. A magnets magnetic moment is a vector that characterizes the overall magnetic properties. For a bar magnet, the direction of the moment points from the magnets south pole to its north pole. In SI units, the moment is specified in terms of A·m2
16.
Alnico
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Alnico is an acronym referring to a family of iron alloys which in addition to iron are composed primarily of aluminium, nickel and cobalt, hence al-ni-co. They also include copper, and sometimes titanium, Alnico alloys are ferromagnetic, with a high coercivity and are used to make permanent magnets. Before the development of rare-earth magnets in the 1970s, they were the strongest type of permanent magnet, other trade names for alloys in this family are, Alni, Alcomax, Hycomax, Columax, and Ticonal. The composition of alnico alloys is typically 8–12% Al, 15–26% Ni, 5–24% Co, up to 6% Cu, up to 1% Ti, Alnico alloys can be magnetised to produce strong magnetic fields and have a high coercivity, thus making strong permanent magnets. Of the more commonly available magnets, only rare-earth magnets such as neodymium, Alnico magnets produce magnetic field strength at their poles as high as 1500 gausses, or about 3000 times the strength of Earths magnetic field. Some brands of alnico are isotropic and can be magnetized in any direction. Other types, such as alnico 5 and alnico 8, are anisotropic, with each having a direction of magnetization. Anisotropic alloys generally have greater capacity in a preferred orientation than isotropic types. Alnicos remanence may exceed 12,000 G, its coercivity can be up to 1000 oersteds and this means that alnico can produce a strong magnetic flux in closed magnetic circuits, but has relatively small resistance against demagnetization. The field strength at the poles of any permanent magnet depends very much on the shape and is well below the remanence strength of the material. Alnico alloys have some of the highest Curie temperatures of any material, around 800 °C. They are the only magnets that have useful magnetism even when heated red-hot and this property, as well as its brittleness and high melting point, is the result of the strong tendency toward order due to intermetallic bonding between aluminium and other constituents. They are also one of the most stable if they are handled properly. Alnico magnets are electrically conductive, unlike ceramic magnets, as of 2008, Alnico magnets cost about 44 USD/kg or 4.30 USD/BHmax. Alnico magnets are traditionally classified using numbers assigned by the Magnetic Materials Producers Association, for example and these classifications indicate chemical composition and magnetic properties. Alnico magnets are produced by casting or sintering processes, anisotropic alnico magnets are oriented by heating above a critical temperature and cooling in the presence of a magnetic field. After the heat treatment alnico becomes a material, named precipitation material—it consists of iron-. Without an external field there are local anisotropies of different orientations due to spontaneous magnetization, the precipitate structure is a barrier against magnetization changes, as it prefers few magnetization states requiring much energy to get the material into any intermediate state
17.
Ferrite (magnet)
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A ferrite is a type of ceramic compound composed of iron oxide combined chemically with one or more additional metallic elements. They are both electrically nonconductive and ferrimagnetic, meaning they can be magnetized or attracted to a magnet, ferrites can be divided into two families based on their magnetic coercivity, their resistance to being demagnetized. Hard ferrites have high coercivity, hence they are difficult to demagnetize and they are used to make magnets, for devices such as refrigerator magnets, loudspeakers and small electric motors. They are used in the industry to make ferrite cores for inductors and transformers. Yogoro Kato and Takeshi Takei of the Tokyo Institute of Technology synthesized the first ferrite compounds in 1930, ferrites are usually non-conductive ferrimagnetic ceramic compounds derived from iron oxides such as hematite or magnetite as well as oxides of other metals. Ferrites are, like most of the ceramics, hard. Many ferrites are spinels with the formula AB2O4, where A and B represent various metal cations and it is also possible to have mixed structure spinel ferrites with formula O4 where δ is the degree of inversion. The magnetic material known as ZnFe has the formula ZnFe2O4, with Fe3+ occupying the sites and Zn2+ occupy the tetrahedral sites. Some ferrites have hexagonal structure, like barium and strontium ferrites BaFe12O19 and SrFe12O19. In terms of their properties, the different ferrites are often classified as soft or hard. Ferrites that are used in transformer or electromagnetic cores contain nickel, zinc and they have a low coercivity and are called soft ferrites. The most common soft ferrites are, Manganese-zinc ferrite, MnZn have higher permeability and saturation induction than NiZn. NiZn ferrites exhibit higher resistivity than MnZn, and are more suitable for frequencies above 1 MHz. For applications below 5 MHz, MnZn ferrites are used, above that, the exception is with common mode inductors, where the threshold of choice is at 70 MHz. In contrast, permanent ferrite magnets are made of hard ferrites, iron oxide and barium or strontium carbonate are used in manufacturing of hard ferrite magnets. The high coercivity means the materials are very resistant to becoming demagnetized and they also have high magnetic permeability. These so-called ceramic magnets are cheap, and are used in household products such as refrigerator magnets. The maximum magnetic field B is about 0.35 tesla, the density of ferrite magnets is about 5 g/cm3
18.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
19.
Bridge (instrument)
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Most stringed instruments produce their sound through the application of energy to the strings, which sets them into vibratory motion. The strings alone, however, produce only a faint sound because they displace only a volume of air as they vibrate. Consequently, the sound of the strings alone requires impedance matching to the air by transmitting their vibrations to a larger surface area capable of displacing larger volumes of air. This calls for an arrangement that allows for the strings to vibrate freely, a bridge is the customary means by which this is accomplished. Typically, the bridge is perpendicular to the strings and larger surface with the tension of the strings pressing down on the bridge and thus on the larger surface beneath it. That larger, more acoustically responsive surface may be coupled to a sound chamber—an enclosure such as the body of a guitar or violin—that provides resonance that helps amplify the sound, alternatively, a bridge may consist of multiple parts. One common form is a bridge that incorporates a separate bearing surface on which the strings rest and this is often of a material harder than the bridge itself, such as bone, ivory, high-density plastic, or metal. A classical guitar saddle sits loosely in the bridge and is kept there by string tension. The saddle has shallow grooves in it, at least for the treble strings, yet another type of multi-part bridge is common on instruments whose sound plate is curved rather than flat. Instruments of this type, such as guitars and mandolins, often have a bridge with a base. On classical and flat-top guitars the bridge is glued to the top, a bridge held on to the top by string tension, as in archtop guitars, is known as a floating bridge, and requires a separate tailpiece to anchor the strings. The bridge must transfer vibration to the board or other amplifying surface. As the strings are set in motion, it does this by bending to and this causes the sounding board to vibrate at the same frequency as the string producing a wave-like motion and an audible sound. Bridges are designed to hold the strings at a height above the fingerboard of the instrument. Bridge height may be fixed or alterable, in addition to supporting the strings and transmitting their vibrations, the bridge also controls the spacing between strings with shallow grooves cut in the bridge or its saddle. The strings sit in grooves, thus are held in their proper lateral position. The nut, at the end of the instrument from the bridge or tailpiece. Bridges for electric guitars can be divided into two groups, vibrato and non-vibrato
20.
Jazz guitar
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The term jazz guitar may refer to either a type of guitar or to the variety of guitar playing styles used in the various genres which are commonly termed jazz. The jazz-type guitar was born as a result of using electric amplification to increase the volume of acoustic guitars. Conceived in the early 1930s, the guitar became a necessity as jazz musicians sought to amplify their sound to be heard over loud big bands. When guitarists in big bands only had acoustic guitars, all they could do was play chords, once guitarists switched from acoustic guitar to electric guitar and began using guitar amplifiers, it made the guitar much easier to hear, which enabled guitarists to play guitar solos. Arguably, no musical instrument had greater influence on how jazz evolved since the beginning of the twentieth century. Traditionally, jazz guitarists use an archtop with a relatively broad hollow sound-box, violin-style f-holes, a floating bridge. Solid body guitars, mass-produced since the early 1950s, are also used, Jazz guitar playing styles include comping with jazz chord voicings and blowing over jazz chord progressions with jazz-style phrasing and ornaments. Comping refers to playing chords underneath a melody or another musicians solo improvisations. When jazz guitar players improvise, they may use the scales, modes, the stringed, chord-playing rhythm can be heard in groups which included military band-style instruments such as brass, saxes, clarinets, and drums, such as early jazz groups. As the acoustic guitar became a popular instrument in the early 20th century. The Gibson L5, an acoustic guitar which was first produced in 1923, was an early “jazz”-style guitar which was used by early jazz guitarists such as Eddie Lang. During the late 1930s and through the 1940s—the heyday of big band jazz, some guitarists, such as Freddie Green of Count Basie’s band, developed a guitar-specific style of accompaniment. Few of the big bands, however, featured amplified guitar solos, improved electric guitars such as Gibson’s ES-175, gave players a larger variety of tonal options. In the 1940s through the 1960s, players such as Wes Montgomery, Joe Pass, as jazz-rock fusion emerged in the early 1970s, many players switched to the more rock-oriented solid body guitars. Other jazz guitarists, like Grant Green and Wes Montgomery, turned to applying their skills to pop-oriented styles that fused jazz with soul and R&B, younger jazz musicians rode the surge of electric popular genres such as blues, rock, and funk to reach new audiences. Fusion players such as John McLaughlin adopted the fluid, powerful sound of guitarists such as Clapton. McLaughlin was an innovator, incorporating hard jazz with the new sounds of Clapton, Hendrix, Beck. Guitarists such as Pat Martino, Al Di Meola, Larry Coryell, John Abercrombie, John Scofield, in addition, they also simply turned up to full volume in order to create natural overdrive such as the blues rock players
21.
Double bass
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The double bass, or simply the bass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra. It is an instrument and is typically notated one octave higher than sounding to avoid excessive ledger lines below the staff. The double bass is the modern bowed string instrument that is tuned in fourths, rather than fifths, with strings usually tuned to E1, A1, D2. The instruments exact lineage is still a matter of some debate, the double bass is a standard member of the orchestras string section, as well as the concert band, and is featured in concertos, solo and chamber music in Western classical music. The bass is used in a range of genres, such as jazz, 1950s-style blues and rock and roll, rockabilly, psychobilly, traditional country music, bluegrass, tango. The double bass is played either with a bow or by plucking the strings, in orchestral repertoire and tango music, both arco and pizzicato are employed. In jazz, blues, and rockabilly, pizzicato is the norm, Classical music uses just the natural sound produced acoustically by the instrument, so does traditional bluegrass. In jazz, blues, and related genres, the bass is typically amplified with an amplifier and speaker, the double bass stands around 180 cm from scroll to endpin. However, other sizes are available, such as a 1⁄2 or 3⁄4 and these sizes do not reflect the size relative to a full size, or 4⁄4 bass, a 1⁄2 bass is not half the size of a bass but is only slightly smaller. It is typically constructed from several types of wood, including maple for the back, spruce for the top and it is uncertain whether the instrument is a descendant of the viola da gamba or of the violin, but it is traditionally aligned with the violin family. While the double bass is nearly identical in construction to other violin family instruments, like other violin and viol-family string instruments, the double bass is played either with a bow or by plucking the strings. In orchestral repertoire and tango music, both arco and pizzicato are employed, in jazz, blues, and rockabilly, pizzicato is the norm, except for some solos and also occasional written parts in modern jazz that call for bowing. In classical pedagogy, almost all of the focus is on performing with the bow and producing a good bowed tone, some of these articulations can be combined, for example, the combination of sul ponticello and tremolo can produce eerie, ghostly sounds. Classical bass players do play pizzicato parts in orchestra, but these parts generally require simple notes, vibrato is used to add expression to string playing. In general, very loud, low-register passages are played with little or no vibrato, mid- and higher-register melodies are typically played with more vibrato. The speed and intensity of the vibrato is varied by the performer for an emotional and musical effect, in jazz, rockabilly and other related genres, much or all of the focus is on playing pizzicato. In jazz and jump blues, bassists are required to play extremely rapid pizzicato walking basslines for extended periods, as well, jazz and rockabilly bassists develop virtuoso pizzicato techniques that enable them to play rapid solos that incorporate fast-moving triplet and sixteenth note figures. In jazz and related styles, bassists often add semi-percussive ghost notes into basslines, to add to the rhythmic feel and to add fills to a bassline
22.
Magnetic field
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A magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any point is specified by both a direction and a magnitude, as such it is represented by a vector field. The term is used for two distinct but closely related fields denoted by the symbols B and H, where H is measured in units of amperes per meter in the SI, B is measured in teslas and newtons per meter per ampere in the SI. B is most commonly defined in terms of the Lorentz force it exerts on moving electric charges, Magnetic fields can be produced by moving electric charges and the intrinsic magnetic moments of elementary particles associated with a fundamental quantum property, their spin. In quantum physics, the field is quantized and electromagnetic interactions result from the exchange of photons. Magnetic fields are used throughout modern technology, particularly in electrical engineering. The Earth produces its own field, which is important in navigation. Rotating magnetic fields are used in electric motors and generators. Magnetic forces give information about the carriers in a material through the Hall effect. The interaction of magnetic fields in electric devices such as transformers is studied in the discipline of magnetic circuits, noting that the resulting field lines crossed at two points he named those points poles in analogy to Earths poles. He also clearly articulated the principle that magnets always have both a north and south pole, no matter how finely one slices them, almost three centuries later, William Gilbert of Colchester replicated Petrus Peregrinus work and was the first to state explicitly that Earth is a magnet. Published in 1600, Gilberts work, De Magnete, helped to establish magnetism as a science, in 1750, John Michell stated that magnetic poles attract and repel in accordance with an inverse square law. Charles-Augustin de Coulomb experimentally verified this in 1785 and stated explicitly that the north and south poles cannot be separated, building on this force between poles, Siméon Denis Poisson created the first successful model of the magnetic field, which he presented in 1824. In this model, a magnetic H-field is produced by magnetic poles, three discoveries challenged this foundation of magnetism, though. First, in 1819, Hans Christian Ørsted discovered that an electric current generates a magnetic field encircling it, then in 1820, André-Marie Ampère showed that parallel wires having currents in the same direction attract one another. Finally, Jean-Baptiste Biot and Félix Savart discovered the Biot–Savart law in 1820, extending these experiments, Ampère published his own successful model of magnetism in 1825. This has the benefit of explaining why magnetic charge can not be isolated. Also in this work, Ampère introduced the term electrodynamics to describe the relationship between electricity and magnetism, in 1831, Michael Faraday discovered electromagnetic induction when he found that a changing magnetic field generates an encircling electric field
23.
Magnetic flux
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In physics, specifically electromagnetism, the magnetic flux through a surface is the surface integral of the normal component of the magnetic field B passing through that surface. The SI unit of flux is the weber, and the CGS unit is the maxwell. Magnetic flux is measured with a fluxmeter, which contains measuring coils and electronics. The magnetic interaction is described in terms of a vector field, since a vector field is quite difficult to visualize at first, in elementary physics one may instead visualize this field with field lines. The magnetic flux through some surface, in this picture, is proportional to the number of field lines passing through that surface. In more advanced physics, the field line analogy is dropped, for a varying magnetic field, we first consider the magnetic flux through an infinitesimal area element dS, where we may consider the field to be constant, d Φ B = B ⋅ d S. This law is a consequence of the observation that magnetic monopoles have never been found. In other words, Gausss law for magnetism is the statement, while the magnetic flux through a closed surface is always zero, the magnetic flux through an open surface need not be zero and is an important quantity in electromagnetism. For example, a change in the flux passing through a loop of conductive wire will cause an electromotive force. The electromotive force is induced along this boundary, dℓ is an infinitesimal vector element of the contour ∂Σ, v is the velocity of the boundary ∂Σ, E is the electric field, B is the magnetic field. This equation is the principle behind an electrical generator, note that the flux of E through a closed surface is not always zero, this indicates the presence of electric monopoles, that is, free positive or negative charges. Gausss law gives the relation between the electric flux flowing out a surface and the electric charge enclosed in the surface. Magnetic circuit is a method using an analogy with electric circuits to calculate the flux of complex systems of magnetic components, Magnetic monopole is a hypothetical particle that may loosely be described as a magnet with only 1 pole. Magnetic flux quantum is the quantum of magnetic flux passing through a superconductor, carl Friedrich Gauss developed a fruitful collaboration with the physics professor Wilhelm Weber, it led to new knowledge in the field of magnetism. James Clerk Maxwell demonstrated that electric and magnetic forces are two aspects of electromagnetism. Patent 6,720,855, Magnetic-flux conduits Magnetic Flux through a Loop of Wire by Ernest Lee, conversion Magnetic flux Φ in nWb per meter track width to flux level in dB - Tape Operating Levels and Tape Alignment Levels
24.
Patch cable
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A patch cable or patch cord or patch lead is an electrical or optical cable used to connect one electronic or optical device to another for signal routing. Devices of different types are connected with patch cords, patch cords are usually produced in many different colors so as to be easily distinguishable, and are relatively short, perhaps no longer than two metres. However, patch cords typically refer only to short cords used with patch panels, patch cord cable differs from standard structured cabling cable in that patch cable is stranded for flexibility, whereas standard cable is solid copper. Because the patch cord is stranded copper construction the attenuation is higher on patch cords than solid cable so short lengths should be adhered to. Patch cords can be as short as 3 inches, to connect stacked components or route signals through a patch bay, as length increases, the cables are usually thicker and/or made with more shielding, to prevent signal loss and the introduction of unwanted radio frequencies and hum. Patch cords are made of coaxial cables, with the signal carried through a shielded core. Each end of the cable is attached to a connector so that the cord may be plugged in, connector types may vary widely, particularly with adapting cables. A pigtail is similar to a cord and is the informal name given to a cable fitted with a connector at one end. In the context of copper cabling, these cables are sometimes referred to as blunt patch cords, optical fiber pigtails, in contrast to copper pigtails, can be more accurately described as a connector than a cable or cord. A fiber pigtail is a single, short, usually tight-buffered, optical fiber that has an optical connector pre-installed on one end, the end of the fiber pigtail is stripped and fusion spliced to a single fiber of a multi-fiber trunk. Splicing of pigtails to each fiber in the trunk breaks out the cable into its component fibers for connection to the end equipment. A variety of cables are used to carry electrical signals in sound recording studios, microphones are typically connected to mixing boards or PA systems with XLR microphone cables which use three-pin XLR connectors. DJs using record players connect their turntables to mixers or PA systems with stereo RCA connectors, to resolve this problem, DJs can either use adapters or special cables. Heavier-gauge cables are used for carrying amplified signals from amplifiers to speakers, ¼ TRS phone connector cables can carry stereo signals, so they are used for stereo headphones and for some patching purposes. The patch bay is a panel of audio connectors where XLR cables. The cables could get tangled or mixed up, and it would be hard to know, when faced with 20 connectors at the end of the cable run, which cable was associated with which microphone or instrument. The patch bay is numbered, so that the engineer can note which microphone or instrument is plugged into each numbered connection, Cable management Crossover cable White Papers - Cable Anatomy
25.
Preamplifier
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Without this, the final signal would be noisy or distorted. They are typically used to amplify signals from analog sensors such as microphones, because of this, the preamplifier is often placed close to the sensor to reduce the effects of noise and interference. An ideal preamp will be linear, have input impedance. It is used to boost the strength to drive the cable to the main instrument without significantly degrading the signal-to-noise ratio. The noise performance of a preamplifier is critical, according to Friiss formula, when the gain of the preamplifier is high, the SNR of the final signal is determined by the SNR of the input signal and the noise figure of the preamplifier. Three basic types of preamplifiers are available, current-sensitive preamplifier parasitic-capacitance preamplifier charge-sensitive preamplifier, in an audio system, they are typically used to amplify signals from analog sensors to line level. The second amplifier is typically a power amplifier, the preamplifier provides voltage gain but no significant current gain. The power amplifier provides the current necessary to drive loudspeakers. For these systems some common sensors are microphones, instrument pickups, preamplifiers are often integrated into the audio inputs on mixing consoles, DJ mixers, and sound cards. They can also be stand-alone devices, the integrated pre-amplifier in a foil electret microphone. The first stages of an instrument amplifier, which is sent to the power amplifier. With instrument amplifiers, the preamp is often designed to produce overdrive or distortion effects, a stand-alone unit for use in live music and recording studio applications. As part of a stand-alone channel strip or channel strip built into a mixing desk. A masthead amplifier used with television receiver antenna or a satellite receiver dish, the circuit inside of a hard drive connected to the magnetic heads or the circuit inside of CD/DVD drive which connects to the photodiodes
26.
Root mean square
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In statistics and its applications, the root mean square is defined as the square root of mean square. The RMS is also known as the mean and is a particular case of the generalized mean with exponent 2. RMS can also be defined for a continuously varying function in terms of an integral of the squares of the values during a cycle. For a cyclically alternating electric current, RMS is equal to the value of the current that would produce the same average power dissipation in a resistive load. In Estimation theory the mean square error of an estimator is a measure of the imperfection of the fit of the estimator to the data. The RMS value of a set of values is the root of the arithmetic mean of the squares of the values. In Physics, the RMS current is the value of the current that dissipates power in a resistor. In the case of a set of n values, the RMS x r m s =1 n, the RMS over all time of a periodic function is equal to the RMS of one period of the function. The RMS value of a function or signal can be approximated by taking the RMS of a sequence of equally spaced samples. Additionally, the RMS value of various waveforms can also be determined without calculus, in the case of the RMS statistic of a random process, the expected value is used instead of the mean. If the waveform is a sine wave, the relationships between amplitudes and RMS are fixed and known, as they are for any continuous periodic wave. However, this is not true for a waveform which may or may not be periodic or continuous. For a zero-mean sine wave, the relationship between RMS and peak-to-peak amplitude is, Peak-to-peak =22 × R M S ≈2.8 × R M S, for other waveforms the relationships are not the same as they are for sine waves. Waveforms made by summing known simple waveforms have an RMS that is the root of the sum of squares of the component RMS values, if the component waveforms are orthogonal. R M S Total = R M S12 + R M S22 + ⋯ + R M S n 2 A special case of this, another special case, useful in statistics, is given in #Relationship to other statistics. Electrical engineers often need to know the power, P, dissipated by an electrical resistance and it is easy to do the calculation when there is a constant current, I, through the resistance. Average power can also be using the same method that in the case of a time-varying voltage, V, with RMS value VRMS. This equation can be used for any waveform, such as a sinusoidal or sawtooth waveform
27.
Damping
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If a frictional force proportional to the velocity is also present, the harmonic oscillator is described as a damped oscillator. Depending on the coefficient, the system can, Oscillate with a frequency lower than in the non-damped case. Decay to the position, without oscillations. The boundary solution between an underdamped oscillator and an overdamped oscillator occurs at a value of the friction coefficient and is called critically damped. If an external time dependent force is present, the oscillator is described as a driven oscillator. Mechanical examples include pendulums, masses connected to springs, and acoustical systems, other analogous systems include electrical harmonic oscillators such as RLC circuits. The harmonic oscillator model is important in physics, because any mass subject to a force in stable equilibrium acts as a harmonic oscillator for small vibrations. Harmonic oscillators occur widely in nature and are exploited in many devices, such as clocks. They are the source of virtually all sinusoidal vibrations and waves, a simple harmonic oscillator is an oscillator that is neither driven nor damped. It consists of a m, which experiences a single force, F, which pulls the mass in the direction of the point x=0 and depends only on the masss position x. Balance of forces for the system is F = m a = m d 2 x d t 2 = m x ¨ = − k x. Solving this differential equation, we find that the motion is described by the function x = A cos , the motion is periodic, repeating itself in a sinusoidal fashion with constant amplitude, A. The position at a time t also depends on the phase, φ. The period and frequency are determined by the size of the mass m, the velocity and acceleration of a simple harmonic oscillator oscillate with the same frequency as the position but with shifted phases. The velocity is maximum for zero displacement, while the acceleration is in the direction as the displacement. The potential energy stored in a harmonic oscillator at position x is U =12 k x 2. In real oscillators, friction, or damping, slows the motion of the system, due to frictional force, the velocity decreases in proportion to the acting frictional force. While simple harmonic motion oscillates with only the force acting on the system
28.
Buffer amplifier
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Two main types of buffer exist, the voltage buffer and the current buffer. A voltage buffer amplifier is used to transfer a voltage from a first circuit, having an output impedance level. The interposed buffer amplifier prevents the circuit from loading the first circuit unacceptably. In the ideal voltage buffer in the diagram, the resistance is infinite. Other properties of the buffer are, perfect linearity, regardless of signal amplitudes. If the voltage is transferred unchanged, the amplifier is a unity gain buffer, although the voltage gain of a voltage buffer amplifier may be unity, it usually provides considerable current gain and thus power gain. However, it is commonplace to say that it has a gain of 1, as an example, consider a Thévenin source driving a resistor load RL. Because of voltage division the voltage across the load is only VA RL /, at the output the dependent voltage source delivers voltage Av VA = VA to the load, again without voltage division because the output resistance of the buffer is zero. A Thévenin equivalent circuit of the combined original Thévenin source and the buffer is a voltage source VA with zero Thévenin resistance. Typically a current buffer amplifier is used to transfer a current from a first circuit, having a low output impedance level, the interposed buffer amplifier prevents the second circuit from loading the first circuits current unacceptably and interfering with its desired operation. In the ideal current buffer in the diagram, the impedance is infinite. Again, other properties of the buffer are, perfect linearity, regardless of signal amplitudes. As an example, consider a Norton source driving a resistor load RL, because of current division the current delivered to the load is only IA RA /. However, if the Norton source drives a unity gain buffer such as that in Figure 1, at the output the dependent current source delivers current βi IA = IA to the load, again without current division because the output resistance of the buffer is infinite. A Norton equivalent circuit of the combined original Norton source and the buffer is a current source IA with infinite Norton resistance. Unity gain here implies a voltage gain of one, but significant current gain is expected, in this configuration, the entire output voltage is fed back into the inverting input. The difference between the input voltage and the inverting input voltage is amplified by the op-amp. This connection forces the op-amp to adjust its output voltage equal to the input voltage
29.
DI unit
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DIs are frequently used to connect an electric guitar or electric bass to a mixing consoles microphone input jack. The DI performs level matching, balancing, and either active buffering or passive impedance matching/impedance bridging to minimize unwanted noise, distortion, DI boxes are extensively used with professional and semi-professional PA systems, professional sound reinforcement systems and in sound recording studios. DI units are referred to as a DI box, direct box. The term is claimed to stand for direct input, direct injection. These boxes typically contained an audio transformer with a ratio from approximately 8,1 to 12,1. With this kind of transformer, the voltage of the instrument is stepped down to a range compatible with the typical mixing consoles microphone preamp. The typical console preamp input impedance of 1,500 ohms would appear to the instrument as a high input impedance of 216,000 ohms. To accommodate these instruments, active direct boxes were designed containing powered electronic circuitry which increased the input impedance from about 200,000 to above 1,000,000 ohms. In 1975, a 48-volt phantom powered active direct box was designed for Leon Russells recording studio, its published in dB. The direct box takes a high impedance, unbalanced signal and converts it to a low impedance, furthermore, the lower impedance allows an insignificant load to the input of a mixing console or preamp which is also designed to accept input from low impedance microphones. Because all cables using in live sound and recording are capacitive, using a DI box provides a balanced cable, which reduces radio frequency noise and electromagnetic problems coming from lighting systems. Mic cables are typically XLR cables, which are balanced cables, on the other hand, another advantage of DI units is that the DI contains a. balancing transformer that reduces ground‑loop problems and potential electrical safety issues under fault conditions. A passive DI unit typically consists of a transformer used as a balun. The term passive indicates that the unit does not require a battery or other source to operate. This makes passive DIs less expensive, but it means that they cannot include preamplifier features which enable the user to boost the gain. The turns ratio on a passive DI is typically chosen to convert a nominal 50 kΩ signal source to the 100–200 Ω expected by the mic input of an audio mixer, typical turns ratios are in the range of 10,1 to 20,1. Less commonly, a passive DI unit may consist of a resistive load, such units are best suited to outputs designed for headphones or loudspeakers. The less expensive passive DI units are more susceptible to hum, however, they require no batteries, are simpler to use, and the better units are extremely reliable when used as designed
30.
Fender Stratocaster
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The Fender Stratocaster is a model of electric guitar designed in 1954 by Leo Fender, Bill Carson, George Fullerton, and Freddie Tavares. The Fender Musical Instruments Corporation has continuously manufactured the Stratocaster from 1954 to the present and it is a double-cutaway guitar, with an extended top horn shape for balance. Along with the Gibson Les Paul, it is one of the most often emulated electric guitar shapes, Stratocaster and Strat are trademark terms belonging to Fender. The Fender Stratocaster was the first guitar to feature three pickups and a spring tension tremolo system, as well as being the first Fender with a contoured body, the Stratocasters sleek, contoured body shape differed from the flat, slab-like design of the Telecaster. The Stratocasters double cutaways allowed players access to higher positions on the neck. Starting in 1954, the Stratocaster was offered with a solid, deeply contoured ash body, a 21-fret one-piece maple neck with black dot inlays, the color was originally a two color sunburst pattern, although custom color guitars were produced. In 1956, Fender began using alder for sunburst and most custom color Stratocaster bodies, in 1960, the available custom colors were standardized, many of which were automobile lacquer colors from DuPont available at an additional 5% cost. A unique single-ply, 8-screw hole white pickguard held all electronic components except the recessed jack plate—facilitating easy assembly, in this floating position, players could move the bridge-mounted tremolo arm up or down to modulate the pitch of the notes being played. Hank Marvin, Jeff Beck and Ike Turner used the Strats floating tremolo extensively in their playing, as string gauges have changed, players have experimented with the number of tremolo springs, and modern Stratocasters ship with three springs. Some Strats have a bridge in place of the tremolo assembly. There is considerable debate about the effects on tone and sustain of the used in the tremolo systems inertia bar. The Stratocaster features three single coil pickups, with the originally selected by a 3-way switch. In 1977 Fender introduced a 5-way selector making such pickup combinations more stable, dick Dale is a prominent Stratocaster player who also collaborated with Leo Fender in developing the Fender Showman amplifier. In the early 1960s, the instrument was also championed by Hank Marvin, guitarist for the Shadows, in 1965, George Harrison and John Lennon acquired Stratocasters and used them for Help. Rubber Soul and later recording sessions, the double unison guitar solo on Nowhere Man is played by Harrison and Lennon on their new Stratocasters, after the introduction of the Fender Stratocaster Ultra series in 1989, ebony was officially selected as a fretboard material on some models. In December 1965 the Stratocaster was given a broader headstock with altered decals to match the size of the Jazzmaster, during the CBS era, particularly the 1970s, the perceived quality of Fender instruments fell. During this time, vintage instruments from the era became popular. Dan Smith, with the help of John Page, proceeded to work on a reissue of the most popular guitars of Leo Fenders era
31.
Capacitance
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Capacitance is the ability of a body to store an electric charge. There are two related notions of capacitance--self capacitance and mutual capacitance--that are usually both designated by the same term, capacitance. Any object that can be electrically charged exhibits self capacitance, a material with a large self capacitance holds more electric charge at a given voltage, than one with low capacitance. The notion of mutual capacitance is important for understanding the operations of the capacitor. The capacitance is a function only of the geometry of the design, for many dielectric materials, the permittivity and thus the capacitance, is independent of the potential difference between the conductors and the total charge on them. The SI unit of capacitance is the farad, named after the English physicist Michael Faraday, a 1 farad capacitor, when charged with 1 coulomb of electrical charge, has a potential difference of 1 volt between its plates. In electrical circuits, the capacitance is usually a shorthand for the mutual capacitance between two adjacent conductors, such as the two plates of a capacitor. It is actually mutual capacitance between the turns of the coil and is a form of stray, or parasitic capacitance. This self-capacitance is an important consideration at high frequencies and it changes the impedance of the coil and gives rise to parallel resonance. In many applications this is an effect and sets an upper frequency limit for the correct operation of the circuit. The inverse of capacitance is called elastance, the unit of elastance is the daraf, but is not recognised by SI. A common form is a capacitor, which consists of two conductive plates insulated from each other, usually sandwiching a dielectric material. In a parallel capacitor, capacitance is very nearly proportional to the surface area of the conductor plates. If the charges on the plates are +q and −q, and V gives the voltage between the plates, then the capacitance C is given by C = q V. which gives the voltage/current relationship I = C d V d t. Historically, a farad was regarded as a large unit. Its subdivisions were invariably used, namely the microfarad, nanofarad and picofarad, more recently, technology has advanced such that capacitors of 1 farad and greater can be constructed in a structure little larger than a coin battery. Such capacitors are used for energy storage replacing more traditional batteries. The energy stored in a capacitor is found by integrating the work W, W charging =12 C V2 The discussion above is limited to the case of two conducting plates, although of arbitrary size and shape
32.
Inductance
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According to Lenzs law, a changing electric current through a circuit that contains inductance induces a proportional voltage, which opposes the change in current. The varying field in this circuit may also induce an EMF in neighbouring circuits, the term inductance was coined by Oliver Heaviside in 1886. It is customary to use the symbol L for inductance, in honour of the physicist Heinrich Lenz. In the SI system, the measurement unit for inductance is the henry, with the unit symbol H, named in honor of Joseph Henry, who discovered inductance independently of, an electronic component that is intended to add inductance to a circuit is called an inductor. Inductors are typically manufactured from coils of wire and this design delivers two desired properties, a concentration of the magnetic field into a small physical space and a linking of the magnetic field into the circuit multiple times. The relationship between the self-inductance, L, of a circuit, the voltage, v. A voltage is induced across an inductor, that is equal to the product of the inductors inductance, all circuits have, in practice, some inductance, which may have beneficial or detrimental effects. For a tuned circuit, inductance is used to provide a frequency-selective circuit, practical inductors may be used to provide filtering, or energy storage, in a given network. The inductance of long AC power transmission lines affects the power capacity of the line, sensitive circuits, such as microphone and computer network cables, may utilize special cabling construction, limiting the inductive coupling between circuits. The generalization to the case of K electrical circuits with currents, here, inductance L is a symmetric matrix. The diagonal coefficients Lm, m are called coefficients of self-inductance, the coefficients of inductance are constant, as long as no magnetizable material with nonlinear characteristics is involved. This is a consequence of the linearity of Maxwells equations in the fields. The coefficients of inductance become functions of the currents in the nonlinear case, the inductance equations above are a consequence of Maxwells equations. There is a derivation in the important case of electrical circuits consisting of thin wires. Here Nm denotes the number of turns in loop m, Φm, the flux through loop m. This equation follows from Amperes law - magnetic fields and fluxes are linear functions of the currents and this agrees with the definition of inductance above if the coefficients Lm, n are identified with the coefficients of inductance. Because the total currents Nnin contribute to Φm it also follows that Lm, ∑ n =1 K ∂ W ∂ i n d i n. This must agree with the change of the field energy, W
33.
Resonance
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In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at a specific preferential frequency. Frequencies at which the amplitude is a relative maximum are known as the systems resonant frequencies or resonance frequencies. At resonant frequencies, small periodic driving forces have the ability to produce large amplitude oscillations, Resonance occurs when a system is able to store and easily transfer energy between two or more different storage modes. However, there are some losses from cycle to cycle, called damping, when damping is small, the resonant frequency is approximately equal to the natural frequency of the system, which is a frequency of unforced vibrations. Some systems have multiple, distinct, resonant frequencies, resonant systems can be used to generate vibrations of a specific frequency, or pick out specific frequencies from a complex vibration containing many frequencies. Resonance occurs widely in nature, and is exploited in many manmade devices and it is the mechanism by which virtually all sine waves and vibrations are generated. Many sounds we hear, such as when hard objects of metal, glass, light and other short wavelength electromagnetic radiation is produced by resonance on an atomic scale, such as electrons in atoms. A familiar example is a swing, which acts as a pendulum. Pushing a person in a swing in time with the interval of the swing makes the swing go higher and higher. This is because the energy the swing absorbs is maximized when the match the swings natural oscillations. It may cause violent swaying motions and even catastrophic failure in improperly constructed structures including bridges, buildings, trains, avoiding resonance disasters is a major concern in every building, tower, and bridge construction project. As a countermeasure, shock mounts can be installed to absorb resonant frequencies, the Taipei 101 building relies on a 660-tonne pendulum —a tuned mass damper—to cancel resonance. Furthermore, the structure is designed to resonate at a frequency that does not typically occur, buildings in seismic zones are often constructed to take into account the oscillating frequencies of expected ground motion. Clocks keep time by mechanical resonance in a wheel, pendulum. The cadence of runners has been hypothesized to be energetically favorable due to resonance between the energy stored in the lower limb and the mass of the runner. Acoustic resonance is a branch of mechanical resonance that is concerned with the mechanical vibrations across the range of human hearing. Like mechanical resonance, acoustic resonance can result in failure of the object at resonance. The classic example of this is breaking a glass with sound at the precise resonant frequency of the glass
34.
Output impedance
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The output impedance is a measure of the sources propensity to drop in voltage when the load draws current. The source network being the portion of the network that transmits, because of this the output impedance is sometimes referred to as the source impedance or internal impedance. All devices have some resistance and capacitance, and therefore no device can be a perfect source, the output impedance is often used to model the sources response to current flow. This impedance can be imagined as an impedance in series with a voltage source. Sources are modeled as ideal sources combined with their output impedance, the output impedance is defined as this modeled and/or real impedance in series with an ideal voltage source. Mathematically, current and voltage sources can be converted to each other using Thévenins theorem, the source resistance of a purely resistive device can be experimentally determined by increasingly loading the device until the voltage across the load is one half of the open circuit voltage. At this point, the resistance and internal resistance are equal. It can more accurately be described by keeping track of the voltage vs current curves for various loads, the generalized source impedance for a reactive source device is more complicated to determine, and is usually measured with specialized instruments, rather than taking many measurements by hand. The real output impedance of an amplifier is usually less than 0.1 Ω. This can be calculated from the Zload of the loudspeaker and the value of the damping factor. Generally in audio and hifi, the impedance of components is several times the output impedance of the device connected to them. This is called impedance bridging or voltage bridging, in this case, Zload>> Zsource, DF >10 In video, RF, and other systems, impedances of inputs and outputs are the same. This is called impedance matching or a matched connection, in this case, Zsource = Zload, DF = 1/1 =1. The actual output impedance for most devices is not the same as the output impedance. A power amplifier may have an impedance of 8 ohms. The rated output impedance is the impedance into which the amplifier can deliver its maximum amount of power without failing, internal resistance is a concept that helps model the electrical consequences of the complex chemical reactions inside a battery. It is impossible to measure the internal resistance of a battery. When there is a current through a cell, the measured e. m. f. is lower than when there is no current delivered by the cell
35.
Potentiometer
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A potentiometer, informally a pot, is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a resistor or rheostat. The measuring instrument called a potentiometer is essentially a voltage divider used for measuring electric potential, potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as transducers, for example. Potentiometers are rarely used to control significant power, since the power dissipated in the potentiometer would be comparable to the power in the controlled load. The resistive element can be flat or angled, each end of the resistive element is connected to a terminal on the case. The wiper is connected to a terminal, usually between the other two. On panel potentiometers, the wiper is usually the terminal of three. For single-turn potentiometers, this wiper typically travels just under one revolution around the contact, the only point of ingress for contamination is the narrow space between the shaft and the housing it rotates in. Another type is the slider potentiometer, which has a wiper which slides along a linear element instead of rotating. Contamination can potentially enter anywhere along the slot the slider moves in, making effective sealing more difficult, an advantage of the slider potentiometer is that the slider position gives a visual indication of its setting. The resistive element of inexpensive potentiometers is often made of graphite, other materials used include resistance wire, carbon particles in plastic, and a ceramic/metal mixture called cermet. Others are enclosed within the equipment and are intended to be adjusted to calibrate equipment during manufacture or repair and they are usually physically much smaller than user-accessible potentiometers, and may need to be operated by a screwdriver rather than having a knob. They are usually called preset potentiometers or trim pots, some presets are accessible by a small screwdriver poked through a hole in the case to allow servicing without dismantling. Multiturn potentiometers are also operated by rotating a shaft, but by several turns rather than less than a full turn, a string potentiometer is a multi-turn potentiometer operated by an attached reel of wire turning against a spring, enabling it to convert linear position to a variable resistance. User-accessible rotary potentiometers can be fitted with a switch which operates usually at the extreme of rotation. Multiple resistance elements can be ganged together with their contacts on the same shaft, for example. The relationship between position and resistance, known as the taper or law, is controlled by the manufacturer
36.
Low-pass filter
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A low-pass filter is a filter that passes signals with a frequency lower than a certain cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design, the filter is sometimes called a high-cut filter, or treble cut filter in audio applications. A low-pass filter is the complement of a high-pass filter, Low-pass filters provide a smoother form of a signal, removing the short-term fluctuations, and leaving the longer-term trend. Filter designers will often use the form as a prototype filter. That is, a filter with unity bandwidth and impedance, the desired filter is obtained from the prototype by scaling for the desired bandwidth and impedance and transforming into the desired bandform. Examples of low-pass filters occur in acoustics, optics and electronics, a stiff physical barrier tends to reflect higher sound frequencies, and so acts as a low-pass filter for transmitting sound. When music is playing in another room, the low notes are easily heard, an optical filter with the same function can correctly be called a low-pass filter, but conventionally is called a longpass filter, to avoid confusion. For current signals, a circuit, using a resistor and capacitor in parallel. Electronic low-pass filters are used on inputs to subwoofers and other types of loudspeakers, radio transmitters use low-pass filters to block harmonic emissions that might interfere with other communications. The tone knob on many electric guitars is a filter used to reduce the amount of treble in the sound. An integrator is another time constant low-pass filter, telephone lines fitted with DSL splitters use low-pass and high-pass filters to separate DSL and POTS signals sharing the same pair of wires. Low-pass filters also play a significant role in the sculpting of sound created by analogue, the transition region present in practical filters does not exist in an ideal filter. The filter would therefore need to have infinite delay, or knowledge of the future and past. It is effectively realizable for pre-recorded digital signals by assuming extensions of zero into the past and future, or more typically by making the signal repetitive and this delay is manifested as phase shift. Greater accuracy in approximation requires a longer delay, an ideal low-pass filter results in ringing artifacts via the Gibbs phenomenon. These can be reduced or worsened by choice of windowing function, for example, simple truncation causes severe ringing artifacts, in signal reconstruction, and to reduce these artifacts one uses window functions which drop off more smoothly at the edges. The Whittaker–Shannon interpolation formula describes how to use a perfect low-pass filter to reconstruct a signal from a sampled digital signal. Real digital-to-analog converters use real filter approximations, there are many different types of filter circuits, with different responses to changing frequency
37.
Electronic filter
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Electronic filters are circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both. Electronic filters can be, passive or active analog or digital high-pass, low-pass, band-pass, band-stop, see the article on linear filters for details on their design and analysis. The oldest forms of filters are passive analog linear filters. These are known as RC and RL single-pole filters respectively, more complex multipole LC filters have also existed for many years, and their operation is well understood. Hybrid filters are possible, typically involving a combination of analog amplifiers with mechanical resonators or delay lines. Other devices such as CCD delay lines have also used as discrete-time filters. With the availability of digital processing, active digital filters have become common. Passive implementations of filters are based on combinations of resistors, inductors and capacitors. These types are known as passive filters, because they do not depend upon an external power supply and/or they do not contain active components such as transistors. Inductors block high-frequency signals and conduct low-frequency signals, while capacitors do the reverse, the inductors and capacitors are the reactive elements of the filter. The number of elements determines the order of the filter, in this context, an LC tuned circuit being used in a band-pass or band-stop filter is considered a single element even though it consists of two components. At high frequencies, sometimes the inductors consist of single loops or strips of metal. These inductive or capacitive pieces of metal are called stubs, the simplest passive filters, RC and RL filters, include only one reactive element, except hybrid LC filter which is characterized by inductance and capacitance integrated in one element. An L filter consists of two elements, one in series and one in parallel. Three-element filters can have a T or π topology and in either geometries, the components can be chosen symmetric or not, depending on the required frequency characteristics. The high-pass T filter in the illustration, has a low impedance at high frequencies. That means that it can be inserted in a line, resulting in the high frequencies being passed. Likewise, for the illustrated low-pass π filter, the circuit can be connected to a line, transmitting low frequencies
38.
Input impedance
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The input impedance of an electrical network is the measure of the opposition to current flow, both static and dynamic, into the load network being connected that is external to the electrical source. The input admittance is a measure of the propensity to draw current. The source network is the portion of the network that transmits power, and so the voltage across and current through the input terminals would be identical to the original load network. The Thévenins equivalent circuit of the network uses the concept of input impedance to determine the impedance of the equivalent circuit. To calculate the impedance, short the input terminals together. In this case, Z i n ≫ Z o u t The input impedance of the stage is much larger than the output impedance of the source. In AC circuits carrying power, the due to the reactive component of the impedance can be significant. These losses manifest themselves in a phenomenon called phase imbalance, where the current is out of phase with the voltage, therefore, the product of the current and the voltage is less than what it would be if the current and voltage were in phase. With DC sources, reactive circuits have no impact, therefore power factor correction is not necessary. For a circuit modeled with a source, an output impedance, and an input impedance. In this scenario the reactive component of the input impedance cancels the reactive component of the impedance of the load. From the ideal sources perspective the circuit between the output and input impedance is purely resistive in nature, and there are no losses due to imbalance in the source or the load. Z i n = X − j Im The maximum power will be transferred when the resistance of the source is equal to the resistance of the load, when this occurs the circuit is said to be complex conjugate matched to the signals impedance. Note this only maximizes the transfer, not the efficiency of the circuit. When the power transfer is optimized the circuit runs at 50% efficiency. Also note that equation does not work in reverse, the optimal output impedance of the source is 0 regardless of the input impedance of the load. The formula for complex conjugate matched is Z i n = Z o u t ∗ = | Z o u t | e − Θ o u t j = Re − Im j. When there is no reactive component this equation simplifies to Z i n = Z o u t as the part of Z o u t is zero
39.
Ohm
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The ohm is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm. The definition of the ohm was revised several times, today the definition of the ohm is expressed from the quantum Hall effect. In many cases the resistance of a conductor in ohms is approximately constant within a range of voltages, temperatures. In alternating current circuits, electrical impedance is also measured in ohms, the siemens is the SI derived unit of electric conductance and admittance, also known as the mho, it is the reciprocal of resistance in ohms. The power dissipated by a resistor may be calculated from its resistance, non-linear resistors have a value that may vary depending on the applied voltage. The rapid rise of electrotechnology in the last half of the 19th century created a demand for a rational, coherent, consistent, telegraphers and other early users of electricity in the 19th century needed a practical standard unit of measurement for resistance. Two different methods of establishing a system of units can be chosen. Various artifacts, such as a length of wire or a standard cell, could be specified as producing defined quantities for resistance, voltage. This latter method ensures coherence with the units of energy, defining a unit for resistance that is coherent with units of energy and time in effect also requires defining units for potential and current. Some early definitions of a unit of resistance, for example, the absolute-units system related magnetic and electrostatic quantities to metric base units of mass, time, and length. These units had the advantage of simplifying the equations used in the solution of electromagnetic problems. However, the CGS units turned out to have impractical sizes for practical measurements, various artifact standards were proposed as the definition of the unit of resistance. In 1860 Werner Siemens published a suggestion for a reproducible resistance standard in Poggendorffs Annalen der Physik und Chemie and he proposed a column of pure mercury, of one square millimetre cross section, one metre long, Siemens mercury unit. However, this unit was not coherent with other units, one proposal was to devise a unit based on a mercury column that would be coherent – in effect, adjusting the length to make the resistance one ohm. Not all users of units had the resources to carry out experiments to the required precision. The BAAS in 1861 appointed a committee including Maxwell and Thomson to report upon Standards of Electrical Resistance, in the third report of the committee,1864, the resistance unit is referred to as B. A. unit, or Ohmad. By 1867 the unit is referred to as simply Ohm, the B. A. ohm was intended to be 109 CGS units but owing to an error in calculations the definition was 1. 3% too small. The error was significant for preparation of working standards, on September 21,1881 the Congrès internationale délectriciens defined a practical unit of Ohm for the resistance, based on CGS units, using a mercury column at zero deg
40.
PRS Guitars
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PRS Guitars is an American guitar manufacturer headquartered in Stevensville, Maryland, founded by guitarist and master luthier Paul Reed Smith in 1985. PRS has a reputation as a manufacturer of high end electric guitars made in the US, however, since the 1990s they have expanded production to Asia, where they manufacture the more affordable SE line of instruments. As of 2013 they have begun making more affordable guitars in the US with their S2 line, PRS Guitars also manufactures guitar amplifiers. Two of PRSs most notable endorsers are Carlos Santana and John Mayer, Paul Reed Smith was a guitar player who began building guitars while he was in college in the mid-1970s. Early guitar players to use his guitars were Stanley Whitaker. He used the custom as a prototype to raise orders on the road worth nearly $300,000, Smith set up a limited partnership with his wife Barbara and business man Warren Esanu, and set up a factory in Virginia Avenue, Annapolis. At first there were eight workers taking up one third of the building which they shared with a furniture-stripping shop, after three years PRS had taken over most of the building, with 45 people producing 15 guitars every day, and as time progressed a separate woodshop was added. By 1995 the factory was making 25-30 guitars daily and employed 80 people, in 1996 production moved to a new factory in Stevensville on Kent Island, just across a bridge from Annapolis. By the end of 1998 Prs was producing 700 guitars a month with a staff of 110 people and they often feature highly figured tops, including flame maple, quilt maple and figured maple creating the effect of tiger stripes. A small number of bodies feature white Limba, referred to as Korina by luthiers, PRS necks are usually made from mahogany, although some models feature maple or Indian or Brazilian rosewood necks, fingerboards on production models are normally made of rosewood. PRSs signature fret markers include the standard moon inlays and the optional and sought after birds, the moons appear similar to standard dot inlays, but have a crescent more prominent than the rest of the dot. 20th and 25th anniversary edition production models feature updated and stylized versions of this standard inlay, a very small percentage of maple trees cut in North America are actually figured. According to their website, to make 10-Top status, a PRS top must have clearly defined figure across its top with no dead spots. As such, the term 10 Top refers to specimens of maple with distinctive and notable figure, PRS guitars which feature a 10 Top feature a written or stamped 10 on the upper right headstock. Nuts are synthetic and tuners are of PRSs own design, although some models feature Korean-made Kluson-style tuners, PRS guitars feature three original bridge designs, a one-piece pre-intonated stoptail, vibrato, and wrapover tailpiece. The Vibrato was designed with the help of guitar engineer John Mann. It was an update on the classic Fender vibrato and used cam-locking tuners, the pre-intonated stoptail is unique to PRS, however, this design does not allow intonation to be adjusted to compensate for variations in string thickness or drop tuning. The PRS vibrato resembles a vintage Fender Stratocaster unit, and the more recent compensated wrapover tailpiece allows for minimal intonation adjustment, an adjustable wrapover bridge is available as an extra. Pickups are designed and wound in-house, while most of the pickups are humbuckers, some are actually a pair of single coils wound in opposing directions, one intended for the neck and one for the bridge position
41.
Mains hum
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Mains hum, electric hum, or power line hum is a sound associated with alternating current at the frequency of the mains electricity. The fundamental frequency of sound is usually 50 Hz or 60 Hz. The sound often has heavy harmonic content above 50–60 Hz, mains hum may also be heard coming from powerful electric power grid equipment such as utility transformers, caused by mechanical vibrations induced by the powerful AC current in them. Electric hum around transformers is caused by magnetic fields causing the enclosure. Magnetostriction is a source of vibration, in which the core iron changes shape minutely when exposed to magnetic fields. The intensity of the fields, and thus the hum intensity, is a function of the applied voltage, because the magnetic flux density is strongest twice every electrical cycle, the fundamental hum frequency will be twice the electrical frequency. Additional harmonics above 100 Hz or 120 Hz will be caused by the behavior of most common magnetic materials. Around high-voltage power lines, hum may be produced by corona discharge, in the realm of sound reinforcement, electric hum is often caused by induction. The audible aspect of this sort of electric hum is produced by amplifiers and loudspeakers, the other major source of hum in audio equipment is shared impedances, when a heavy current is flowing through a conductor that a small-signal device is also connected to. This hum is usually at the harmonic of the power line frequency. In vacuum tube equipment, one source of hum is current leakage between the heaters and cathodes of the tubes. Another source is direct emission of electrons from the heater, or magnetic fields produced by the heater, tubes for critical applications may have the heater circuit powered by direct current to prevent this source of hum. Leakage of analogue video signals can give rise to hum sounding very similar to mains hum and it is often the case that electric hum at a venue is picked up via a ground loop. In this situation, an amplifier and a mixing desk are typically at some distance from one another, the chassis of each item is grounded via the mains earth pin, and is also connected along a different pathway via the conductor of a shielded cable. As these two pathways do not run alongside other, an electrical circuit in the shape of a loop is formed. The same situation occurs between musical instrument amplifiers on stage and the mixing desk, to fix this, stage equipment often has a ground lift switch which breaks the loop. Another solution is to connect the source and destination through a 1,1 isolation transformer, another extremely dangerous option is to break contact with the ground wire by using an AC ground lift adapter or by breaking the earth pin off the power plug used at the mixing deck. Depending on the design and layout of the equipment, lethal voltages between the ground at the mixing desk and earth ground can then develop
42.
Alternating current
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Alternating current, is an electric current which periodically reverses direction, whereas direct current flows only in one direction. A common source of DC power is a cell in a flashlight. The abbreviations AC and DC are often used to mean simply alternating and direct, the usual waveform of alternating current in most electric power circuits is a sine wave. In certain applications, different waveforms are used, such as triangular or square waves, audio and radio signals carried on electrical wires are also examples of alternating current. These types of alternating current carry information encoded onto the AC signal and these currents typically alternate at higher frequencies than those used in power transmission. Electrical energy is distributed as alternating current because AC voltage may be increased or decreased with a transformer, use of a higher voltage leads to significantly more efficient transmission of power. The power losses in a conductor are a product of the square of the current and this means that when transmitting a fixed power on a given wire, if the current is halved, the power loss will be four times less. Power is often transmitted at hundreds of kilovolts, and transformed to 100–240 volts for domestic use, high voltages have disadvantages, such as the increased insulation required, and generally increased difficulty in their safe handling. In a power plant, energy is generated at a convenient voltage for the design of a generator, near the loads, the transmission voltage is stepped down to the voltages used by equipment. Consumer voltages vary somewhat depending on the country and size of load, the voltage delivered to equipment such as lighting and motor loads is standardized, with an allowable range of voltage over which equipment is expected to operate. Standard power utilization voltages and percentage tolerance vary in the different mains power systems found in the world, high-voltage direct-current electric power transmission systems have become more viable as technology has provided efficient means of changing the voltage of DC power. HVDC systems, however, tend to be expensive and less efficient over shorter distances than transformers. Three-phase electrical generation is very common, the simplest way is to use three separate coils in the generator stator, physically offset by an angle of 120° to each other. Three current waveforms are produced that are equal in magnitude and 120° out of phase to each other, if coils are added opposite to these, they generate the same phases with reverse polarity and so can be simply wired together. In practice, higher pole orders are commonly used, for example, a 12-pole machine would have 36 coils. The advantage is that lower rotational speeds can be used to generate the same frequency, for example, a 2-pole machine running at 3600 rpm and a 12-pole machine running at 600 rpm produce the same frequency, the lower speed is preferable for larger machines. If the load on a system is balanced equally among the phases. Even in the worst-case unbalanced load, the current will not exceed the highest of the phase currents
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Transformer
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A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. A varying current in one coil of the transformer produces a magnetic field. Power can be transferred between the two coils through the field, without a metallic connection between the two circuits. Faradays law of induction discovered in 1831 described this effect, Transformers are used to increase or decrease the alternating voltages in electric power applications. A wide range of designs is encountered in electronic and electric power applications. Transformers range in size from RF transformers less than a centimeter in volume to units interconnecting the power grid weighing hundreds of tons. For simplification or approximation purposes, it is common to analyze the transformer as an ideal transformer model as presented in the two images. An ideal transformer is a theoretical, linear transformer that is lossless and perfectly coupled, perfect coupling implies infinitely high core magnetic permeability and winding inductances and zero net magnetomotive force. A varying current in the primary winding creates a varying magnetic flux in the transformer core. This varying magnetic field at the secondary winding induces a varying EMF or voltage in the secondary winding due to electromagnetic induction. The primary and secondary windings are wrapped around a core of high magnetic permeability so that all of the magnetic flux passes through both the primary and secondary windings. With a voltage source connected to the winding and load impedance connected to the secondary winding. The primary EMF is sometimes termed counter EMF and this is in accordance with Lenzs law, which states that induction of EMF always opposes development of any such change in magnetic field. The transformer winding voltage ratio is shown to be directly proportional to the winding turns ratio according to eq. common usage having evolved over time from turn ratio to turns ratio. However, some use the inverse definition. The ideal transformer model assumes that all flux generated by the primary winding links all the turns of winding, including itself. In practice, some flux traverses paths that take it outside the windings, Such flux is termed leakage flux, and results in leakage inductance in series with the mutually coupled transformer windings. Leakage flux results in energy being alternately stored in and discharged from the fields with each cycle of the power supply
44.
Ray Butts
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Most notably, Butts is the inventor of the EchoSonic, a guitar amplifier with a built-in tape echo, and the FilterTron, the first humbucker guitar pickup. He was active in fields from studio equipment maintenance to sound engineering. As a toddler, Butts moved with his father to Cairo, Illinois, in the early 1940s, he moved to Calumet City, Illinois, where he played at several clubs. His band leader had a chance to join with a tent show billed as a Hillbilly Jamboree featuring the Colorado Cowhands. They played the southern states before ending up in Nashville, Tennessee. He returned to Calumet City, playing nights from 8, 00pm to 5, 00am, but his career as a musician ended abruptly when his father had a heart attack, and he moved back to Cairo. Back in Cairo, Butts worked for a store as a warranty repairman. Soon he started his own business, focusing on musical instruments and amplification and it was a small music store, Butts wife Ann ran the store out front and kept the books, while he tinkered in the back. This tinkering, and his connections with local musicians, led to the development of the EchoSonic, in 1952, a local guitar player named Bill Gwaltney sparked Butts interest in creating the sound-on-sound effect with live guitar. In 1954 Butts went to Nashville where he looked up Chet Atkins in the phone book, buttss tape-loop technology was the basis for the later Echoplex, for which he received a nominal sum from the manufacturers. Though it has represented in error by some authors in later years. In 1954 Gretsch began plans to produce the first Chet Atkins-endorsed guitar model, Atkins recorded much of his music of the 1950s with the Echosonic, and had serious hum problems caused by the single-coil pickups and an unshielded transformer in the amplifier. Butts finally connected two single-coil pickups serially and out of phase, creating the first humbucker, Butts did not receive a patent until later, when it became the Gretsch FilterTron, and Gibson is often credited with developing the first humbucker. Throughout the early years of production, Butts insisted on making all the FilterTron pickups by hand, mass production of the Gretsch FilterTron pickup began in 1957. The Strat in the Attic, Thrilling Stories of Guitar Archaeology, the Electric Guitar Sourcebook, How to Find the Sounds You Like. 365 Guitars, Amps & Effects You Must Play, The Most Sublime, Bizarre and Outrageous Gear Ever
45.
Gibson
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Gibson Brands, Inc. is an American manufacturer of guitars and other instruments, now based in Nashville, Tennessee. The company was known as Gibson Guitar Corp. and renamed Gibson Brands. Orville Gibson founded the company in 1902 as The Gibson Mandolin-Guitar Mfg. Co. Ltd. in Kalamazoo, Gibson invented archtop guitars by constructing the same type of carved, arched tops used on violins. By the 1930s, the company was also making flattop acoustic guitars, as well as one of the first commercially available hollow-body electric guitars, Gibson sells guitars under a variety of brand names and builds one of the worlds most iconic guitars, the Gibson Les Paul. Many Gibson instruments are highly collectible, Gibson was at the forefront of innovation in acoustic guitars, especially in the big band era of the 1930s, the Gibson Super 400 was widely imitated. In 1952, Gibson introduced its first solid-body electric guitar, the Les Paul which became its most popular guitar to date— designed by Ted McCarty, Gibson was owned by the Norlin corporation from 1969 to 1986. In 1986, the company was acquired by its present owners, Gibson is a privately held corporation owned by its chief executive officer Henry Juszkiewicz and its president David H. Berryman. Orville Gibson patented a single-piece mandolin design in 1898 that was more durable than other mandolins, Orville Gibson began to sell his instruments in 1894 out of a one-room workshop in Kalamazoo Michigan. In 1902 Gibson Mandolin-Guitar Mfg. Co, Ltd. was incorporated to market the instruments, initially, the company produced only Orville Gibsons original designs. Orville died in 1918 of endocarditis, the following year the company hired designer Lloyd Loar to create newer instruments. Loar designed the flagship L-5 archtop guitar and the Gibson F5 mandolin that was introduced in 1922, in 1936 Gibson introduced their first Electric Spanish model, the ES-150 followed by other electric instruments like steel guitars, banjos and mandolins. During World War II, instrument manufacturing at Gibson slowed due to shortages of wood and metal, between 1942-1945, Gibson employed women to manufacture guitars. Women produced nearly 25,000 guitars during World War II yet Gibson denied ever building instruments over this period, Gibson folklore has also claimed its guitars were made by seasoned craftsmen who were too old for war. In 1944 Gibson was purchased by Chicago Musical Instruments, the ES-175 was introduced in 1949. Gibson hired Ted McCarty in 1948, who became President in 1950, the Les Paul was offered in Custom, Standard, Special, and Junior models. In the mid-50s, the Thinline series was produced, which included a line of thinner guitars like the Byrdland, the first Byrdlands were slim, custom built, L-5 models for guitarists Billy Byrd and Hank Garland. Later, a neck was added. Other models such as the ES-350T and the ES-225T were introduced as less costly alternatives, in 1958, Gibson introduced the ES-335T model
46.
Gretsch
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Gretsch is an American company that manufactures guitars, basses and drums. The company was founded in 1883 by Friedrich Gretsch, a 27-year-old German immigrant, Friedrich Gretsch manufactured banjos, tambourines, and drums until his death in 1895. In 1916, his son, Fred Gretsch Sr. moved operations to Brooklyn, most modern-era Gretsch guitars are manufactured in the Far East, though American-made Custom Shop models are available. In 2003, Gretsch entered an agreement with Fender Musical Instruments Corporation. Under the terms of that agreement Fred W. Gretsch would retain ownership while FMIC would handle most of the development, distribution, Gretsch was founded in 1883 by Friedrich Gretsch, a young German immigrant. His Brooklyn shop was designed for the manufacture of banjos, tambourines, in 1895, Gretsch died at the age of 39, and the then successful company was taken over by his son Fred Sr. By 1916, Fred had moved the company into a larger 10-story building in the Williamsburg district, chuck Berry also played the Duo Jet when he recorded his first major hit, Maybellene and is pictured on his LP After School Session. Two other models were introduced - the Country Club, and the White Falcon, Guitar production by the Gretsch Company began in the early 1930s, and Gretsch guitars became highly sought after, most notably in the 1950s and 1960s. They lost favor with players during the 1970s and 1980s for various reasons, Gretsch eventually went bankrupt, then was revived in 1989 by Fred W. Gretsch, a great-grandson of Friedrich Gretsch. Fred W. Gretsch remains president of the company, during this time, Chet Atkins became an endorser of Gretsch. Atkins was one of the pre-eminent guitarists of his day, and his endorsement gave Gretsch greater visibility in competition with Gibson and Fender. Gretsch ultimately sold thousands of guitars with Chets name on the pickguard, most notably the 6120 Chet Atkins model, the worldwide success of Eddys twangy instrumental records, television appearances, and extensive touring, helped expose the Gretsch guitar to the teenage rock and roll market. George Harrison, years later, would refer to model as the Eddie Cochran/Duane Eddy guitar. Other Chet Atkins models were the Country Gentleman and the Tennessean, many rockabilly players had followed in the footsteps of Eddie Cochran, who also wielded a 6120 and Gene Vincents guitarist Cliff Gallup, who played a Duo Jet. Elvis Presley later owned a Gretsch Country Gentleman—, playing it briefly both on stage and in the studio, Gretsch quickly became a legitimate competitor to both Gibson and its main rivals, Fender and Rickenbacker. Gretsch fortunes rose yet again in the sixties when George Harrison played a Gretsch Country Gentleman on The Ed Sullivan Show. Despite popular belief, he acquired two Country Gentleman guitars, his first was destroyed when it fell out of the trunk of a car on the roadway. He would later switch to a Gretsch Tennessean and his Country Gentleman made its last appearance in the video of Youre Going to Lose That Girl in the movie Help
