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Three magnetic pickups on a Fender Stratocaster. The left pickup is a humbucker and the right and middle pickups are single coils.
Three magnetic pickups on a Fender Stratocaster. The Fender Stratocaster, often referred to as the Strat, is a model of Electric guitar designed by Leo Fender, George Fullerton and Freddie Tavares The left pickup is a humbucker and the right and middle pickups are single coils. A conventional humbucker (or Humbucking pickup) is a type of Electric guitar pickup that uses two coils both generating string signal A single coil pickup is a type of magnetic Transducer for the Electric guitar and the electric bass.
For phonograph pickup, see Magnetic cartridge. A magnetic cartridge is a Transducer used for the playback of Gramophone records on a turntable or phonograph. For other uses, see Pickup disambiguation page.

A pickup device acts as a transducer that captures mechanical vibrations (usually from suitably equipped stringed instruments such as the electric guitar, electric bass guitar or electric violin) and converts them to an electrical signal, which can be amplified and recorded. A transducer is a device usually electrical, electronic, Electro-mechanical, Electromagnetic, Photonic, or Photovoltaic A string instrument (or stringed instrument) is a Musical instrument that produces Sound by means of Vibrating strings In the Hornbostel-Sachs An electric guitar is a type of Guitar that uses pickups to convert the vibration of its steel-cored strings into an electrical current which is made louder The electric bass guitar (also called electric bass, or simply bass; ˈbeɪs as in "base" is a Stringed instrument played primarily with the An electric violin is a Violin equipped with an electronic output of its sound An instrument amplifier is an Electronic amplifier that converts the inaudible electric or electronic signal from musical instruments such as an Electric guitar

Contents

Magnetic pickups

A magnetic pickup consists of a permanent magnet wrapped with a coil of a few thousand turns of fine enameled copper wire. A magnet (from Greek grc μαγνήτης λίθος " Magnesian stone" is a material or object that produces a Magnetic field. A coil is a series of loops A coiled coil is a structure where the coil itself is in turn also looping Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 The pickup is most often mounted on the body of the instrument, but can be attached to the bridge, neck and/or pickguard, as on many electro-acoustic archtop jazz guitars. A bridge is a device for supporting the strings on a Stringed instrument and transmitting the Vibration of those strings to some other structural component The vibration of the nearby soft-magnetic strings modulates the magnetic flux linking the coil, thereby inducing an alternating voltage through the coil of wire. A magnet (from Greek grc μαγνήτης λίθος " Magnesian stone" is a material or object that produces a Magnetic field. In Telecommunications, modulation is the process of varying a periodic Waveform, i Magnetic flux, represented by the Greek letter Φ ( Phi) is a measure of quantity of Magnetism, taking into account the strength and the extent of a Magnetic Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of Electromotive force ( emf, \mathcal{E} is a term used to characterize electrical devices such as Voltaic cells thermoelectric devices electrical This signal is then carried to amplification or recording equipment via a cable. An instrument amplifier is an Electronic amplifier that converts the inaudible electric or electronic signal from musical instruments such as an Electric guitar A cable is one or more Wires or Optical fibers bound together typically in a common protective jacket or sheath There may also be an internal preamplifier stage between the pickup and cable. A preamplifier (preamp or control amp in some parts of the world is an Electronic amplifier which precedes another amplifier to prepare an electronic More generally, the pickup operation can be described using the concept of a magnetic circuit. A magnetic circuit is a closed path containing a Magnetic flux. In this description, the motion of the string varies the magnetic reluctance in the circuit created by the permanent magnet. Magnetic reluctance or "magnetic resistance" is analogous to resistance in an Electrical Circuit (although it does not dissipate magnetic

Output

The output voltage of pickups varies between 100 mV rms to over 1 V rms for some of the higher output types. In Mathematics, the root mean square (abbreviated RMS or rms) also known as the quadratic mean, is a statistical measure of the Some high-output pickups achieve this by employing very strong magnets, thus creating more flux and thereby more output. These can be detrimental to the final sound because the magnets can tend to attract the strings and damp them, thus, greatly reducing sustain. Damping is any effect either deliberately engendered or inherent to a system that tends to reduce the amplitude of Oscillations of an oscillatory system Other high-output pickups have more turns of wire to increase the voltage generated by the string's movement. However, this also increases the pickup's output resistance/impedance, which can affect high frequencies if the pickup is not isolated by a buffer amplifier. A buffer amplifier (sometimes simply called a buffer) is one that provides Electrical impedance transformation from one circuit to another

Pickup sound

The turns of wire in proximity to each other have an equivalent self-capacitance which, when added to any cable capacitance present, resonates with the inductance of the winding. Capacitance is a measure of the amount of Electric charge stored (or separated for a given Electric potential. In Electrical circuits, any Electric current i produces a Magnetic field and hence generates a total Magnetic flux \Phi acting This resonance can accentuate certain frequencies, giving the pickup a characteristic tonal quality. In Physics, resonance is the tendency of a system to Oscillate at maximum Amplitude at certain frequencies, known as the system's The more turns of wire in the winding, the higher the output voltage but the lower this resonance frequency. In Physics, resonance is the tendency of a system to Oscillate at maximum Amplitude at certain frequencies, known as the system's The inductive source impedance inherent in this type of transducer makes it less linear than other forms of pickups, such as piezo-electric or optical. Any linear electronic circuit or device which supplies a current may be modelled as an Ideal voltage source in series with an impedance. A transducer is a device usually electrical, electronic, Electro-mechanical, Electromagnetic, Photonic, or Photovoltaic The tonal quality produced by this nonlinearity is, however, subject to taste, and may therefore also be considered by some to be aesthetically superior to that of a more linear transducer.

The external load usually consists of resistance (the volume and tone potentiometer in the guitar, and any resistance to ground at the amplifier input) and capacitance between the hot lead and shield in the guitar cable. The cable capacitance has a large effect and must not be neglected. This arrangement of passive components forms a resistively-damped second-order low-pass filter. A low-pass filter is a filter that passes low- Frequency signals but Attenuates (reduces the Amplitude of signals with frequencies Electronic filters are Electronic circuits which perform Signal processing functions specifically intended to remove unwanted signal components and/or enhance wanted Electromagnetic pickups are usually designed to feed a high input impedance, typically a megohm or more, and a low impedance load will reduce the high-frequency response of the pickup because of the filtering effect of the inductance. The Input impedance, Load impedance, or external impedance of a circuit or electronic device is the Thévenin The ohm (symbol Ω) is the SI unit of Electrical impedance or in the Direct current case Electrical resistance,

Humbuckers

Main article: Humbucker
PRS's Dragon humbucker
PRS's Dragon humbucker

One problem with electromagnetic pickups is that — along with the musical signal — they also pick up mains hum. A conventional humbucker (or Humbucking pickup) is a type of Electric guitar pickup that uses two coils both generating string signal PRS Guitars is an American guitar manufacturer based in Stevensville Maryland. Electric hum, Mains hum, or power line hum is an audible oscillation at the frequency of the Mains Alternating current Mains hum consists of a fundamental signal at a nominal 50 or 60 Hz, depending on local alternating current frequency, and usually some harmonic content. An alternating current ( AC) is an Electric current whose direction reverses cyclically as opposed to Direct current, whose direction remains constant The changing magnetic flux caused by the mains current links with the windings of the pickup, inducing a voltage by transformer action. A transformer is a device that transfers Electrical energy from one circuit to another through inductively coupled Electrical conductors

To overcome this effect, the humbucking pickup was developed, concurrently and independently by Seth Lover of Gibson and Ray Butts, working for Gretsch. A conventional humbucker (or Humbucking pickup) is a type of Electric guitar pickup that uses two coils both generating string signal Seth Lover ( January 1 1910 in Kalamazoo Michigan &ndash January 31 1997 in Garden Grove California) is most famous for The Gibson Guitar Corporation of Nashville Tennessee, USA is a manufacturer of acoustic and Electric guitars The company's most popular guitar Gretsch is a US Musical instrument manufacturer currently being distributed by Guitar company Fender and Drum craft company Who developed it first is a matter of some debate, but Seth Lover was awarded the first patent (U.S. Patent 2,896,491 ). Ultimately, both men developed essentially the same concept.

A humbucking pickup, shown in the image on the right, generally comprises two standard pickups wired together with identical coils bathed in fields of opposite magnetic polarity. Ambient hum from power-supply transformers, radio frequencies, or electrical devices reaches the coils as common-mode noise, inducing an electrical current of equal magnitude in each coil. In Telecommunication, the term common-mode interference has the following meanings Interference that appears on both signal leads (signal and circuit With the coils wired together in "buck" series, the induced currents sum and cancel each other out. However, the signal present from the vibrations of the guitar strings sums and adds together, doubling output.

One side-effect of this technique is that, when wired in series, as is most common, the overall inductance of the pickup is increased, which lowers its resonance frequency and attenuates the higher frequencies, giving a fatter and less trebly tone than either of the two component single-coil pickups would give alone. In Electrical circuits, any Electric current i produces a Magnetic field and hence generates a total Magnetic flux \Phi acting A second side-effect of the technique is that, because the two coils are wired in series, the resulting signal that is output by the pickup is larger in amplitude, thus more able to overdrive the early stages of the amplifier. This is the essence of the "humbucker tone. In Music, timbre (ˈtæm-bər' like timber, or, from Fr timbre tɛ̃bʁ is the quality of a Musical note or sound that distinguishes different "

An alternative wiring places the coils in buck parallel. The equal common-mode mains hum interference cancels, while the string variation signal sums. This method has a more neutral effect on resonant frequency: mutual capacitance is doubled (which if inductance were constant would result in a lowering of resonant frequency), and inductance is halved (which would raise the resonant frequency without the capacitance change). The net is NO change in resonant frequency. This pickup wiring is rare, as guitarists have come to expect that humbucking 'has a sound', and is not neutral. On fine jazz guitars, the parallel wiring will produce significantly cleaner sound however, as the lowered source impedance will drive capacitive cable with lower high frequency attenuation.

Construction

With a notable exception of rail pickups, pickups have magnetic polepieces — one or two for each string. These polepiece centers should be perfectly aligned with strings, or else sound will be suboptimal as pickup would capture only a part of vibrational energy.

String spacing is not even on most guitars: it starts with minimal spacing at nut and ends with maximal at bridge. So, bridge, neck and middle pickups should have a different polepiece spacing on the same guitar.

There are several standards on pickup sizes and string spacing between the poles. Spacing is measured either as a distance between 1st to 6th polepieces' centers (this is also called "E-to-E" spacing), or as a distance between adjacent polepieces' centers.

1st-to-6th Adjacent
Standard spacing
(Vintage Gibson guitars)		 1. 90"
48 mm		 0. 380"
9. 6 mm
F-spacing
(Most Fender guitars, modern Gibson, Floyd Rose bridges)		 2. Floyd Rose is the organization that licenses distributes and manufactures the Floyd Rose Locking Tremolo invented by Floyd D 01"
51 mm		 0. 402"
10. 2 mm
Very close to bridge, extra pickup
(Roland guitar synth hex pickups)		 2. 060"
52. 3 mm		 0. 412"
10. 5 mm
Telecaster spacing
(Fender Telecaster guitars)		 2. 165"
55 mm		 0. 433"
11 mm

Notation

Usually an electric guitar has more than one magnetic pickup. A combination of pickups is called a pickup configuration. It is usually notated by just writing out the pickup types, using "S" for single-coil and "H" for humbucker, in order from neck pickup to bridge pickup. This order matches left to right enumeration from a perspective of right-handed guitarist playing the guitar, although reverse order (right to left) could be rarely used too. Someone who is right-handed will prefer to use this hand for everyday activities such as writing, maintaining personal hygiene, Cooking and so forth Popular pickup configurations include:

Less frequently found configurations are:

Examples of rare configurations that only a few particular models use include:

Piezoelectric pickups

A piezoelectric pickup on a classical guitar.
A piezoelectric pickup on a classical guitar. The Fender Telecaster, also known as the Tele (pronounced Telly is typically a dual-pickup solid-body Electric guitar made by Fender. The Fender Stratocaster, often referred to as the Strat, is a model of Electric guitar designed by Leo Fender, George Fullerton and Freddie Tavares The Gibson Les Paul is a solidbody Electric guitar originally developed in the early 1950s Superstrat (sometimes spelled as super strat or super-strat) is a name for an Electric guitar design that resembles a Fender Stratocaster but The Squier '51 is an Electric guitar made by Squier, a subsidiary of Fender. Steven J Morse (born July 28, 1954 in Hamilton Ohio) is an American Guitarist, best known as the founder for the Dixie

More recently, many semi-acoustic and acoustic guitars, and some electric guitars and basses, have been fitted with piezoelectric pickups instead of, or in addition to, magnetic pickups. Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to These have a very different sound which some prefer, and also have the advantage of not picking up unwanted magnetic fields, such as mains hum and feedback from monitoring loops. Feedback is a circular causal Process whereby some proportion of a system's output is returned (fed back to the Input. The advantage of such systems allow for switching between magnetic pickup and piezo sounds, or simultaneously blending the output.

Preamps

Piezoelectric pickups have a very high output impedance and appear as a capacitance in series with a voltage source. Any linear electronic circuit or device which supplies a current may be modelled as an Ideal voltage source in series with an impedance. Capacitance is a measure of the amount of Electric charge stored (or separated for a given Electric potential. A voltage source is any device or system that produces an Electromotive force between its terminals OR derives a secondary voltage from a primary They must therefore have an instrument-mounted buffer amplifier fitted if the sound is to retain its full frequency response. A buffer amplifier (sometimes simply called a buffer) is one that provides Electrical impedance transformation from one circuit to another Piezo pickups are usually mounted under the bridge and sometimes form part of the bridge assembly itself. A bridge is a device for supporting the strings on a Stringed instrument and transmitting the Vibration of those strings to some other structural component

The piezo pickup gives a very wide frequency range output compared to the magnetic types and can give large amplitude signals from the strings. Amplitude is the magnitude of change in the oscillating variable with each Oscillation, within an oscillating system For this reason, it is usually necessary to run the buffer amplifier from relatively high voltage rails (about ±9 V) to avoid distortion due to clipping. A distortion is the alteration of the original shape (or other characteristic of an object image sound waveform or other form of information or representation Clipping is a form of Waveform distortion that occurs when an Amplifier is overdriven which happens through attempts to increase the voltage or current Some musicians prefer a preamp that isn't as linear (like a single-FET amplifier) so that the clipping is "softer", although such an amplifier starts to distort sooner, this makes the distortion less "buzzy" and less audible than a more linear, but less forgiving op-amp [1]. A preamplifier (preamp or control amp in some parts of the world is an Electronic amplifier which precedes another amplifier to prepare an electronic The field-effect transistor (FET is a type of Transistor that relies on an Electric field to control the shape and hence the conductivity of a 'channel' An operational amplifier, often called an op-amp, is a DC - coupled high- Gain electronic voltage amplifier with differential However, at least one study [2] indicates that most people can't tell the difference between FET and op-amp circuits in blind listening comparisons of electric instrument preamps, a finding which correlates with results of formal studies done in other types of audio devices. Sometimes, piezoelectric pickups are used in conjunction with magnetic types to give a wider range of available sounds.

For early pick-up devices using the piezoelectric effect, see phonograph. The phonograph, or gramophone, was the most common device for playing recorded Sound from the 1870s through the 1980s

Multi-transducer pickups

Hexaphonic pickups (also called divided pickups and polyphonic pickups) have a separate output for each string (Hexaphonic assumes six strings, as on a guitar). Polyphony is the property of an Electronic musical instrument which describes how many notes it can sound at one time This allows for separate processing and amplification for each string. It also allows a converter to sense the pitch coming from individual string signals for producing note commands, typically according to the MIDI (musical instrument digital interface) protocol. MIDI ( Musical Instrument Digital Interface, ˈmɪdi is an industry-standard protocol that enables Electronic musical instruments Computers A hexaphonic pickup and a converter are usually components of a guitar/synthesizer. This is about synthesizers which can be played like guitars for the portable keyboard synthesizers that are held like guitars see Keytar.

Such pickups are relatively uncommon (compared to normal ones), and only a few notable models exists. Hexaphonic pickups can be either electromagnetic or piezoelectric.

Electromagnetic

Piezoelectric

Optical

Optical pickups are a fairly recent development that work by sensing the interruption of a light beam by the string. The light source is usually a LED, and the detector is a photodiode or phototransistor. A photodiode is a type of Photodetector capable of converting Light into either current or Voltage, depending upon the mode of operation A photodiode is a type of Photodetector capable of converting Light into either current or Voltage, depending upon the mode of operation These pickups have complete insensitivity to magnetic or electric interference and also have a very wide and flat frequency response unlike magnetic pickups.

Optical pickup guitars were first shown at the 1969 NAMM in Chicago, by Ron Hoag [13]

Active and passive pickups

Pickups can be either active or passive. Year 1969 ( MCMLXIX) was a Common year starting on Wednesday (link will display full calendar of the Gregorian calendar. The NAMM Show is considered the largest Music products trade show in the world its only major competition being the Musik Messe in Frankfurt Chicago (ʃɪˈkɑːgoʊ is the largest City by population in the state of Illinois and the American Midwest of the United States. Passivity is a property of engineering systems most commonly used in electronic engineering and control systems Pickups, apart from optical types, are inherently passive transducers. So-called active pickups incorporate electronic circuitry to modify the signal. Passive pickups are usually wire wound around a magnet. They can generate electric potential without need for external power, though their output is relatively low, and the harmonic content of output depends greatly on the winding. At a point in space the electric potential is the Potential energy per unit of charge that is associated with a static (time-invariant Electric field

Passive pickups are very convenient as they require no power source to operate. They are the most popular and widely used pickup type on electric guitars, and their frequency response curve is unique to the type and manufacturer. Frequency response is the measure of any system's spectrum response at the output to a signal of varying Frequency (but constant amplitude at its input

EMG 81 & EMG 85 — pair of popular active pickups
EMG 81 & EMG 85 — pair of popular active pickups

Active pickups require an electrical source of energy to operate and include an electronic preamp, active filters, active EQ and other sound-shaping features. EMG 81 is a famous active Humbucker Guitar pickup manufactured by EMG. EMG 85 is a famous active Humbucker Guitar pickup manufactured by EMG. A preamplifier (preamp or control amp in some parts of the world is an Electronic amplifier which precedes another amplifier to prepare an electronic Equalization (or equalisation, EQ) is the process of changing the frequency envelope of a sound in Audio processing. They can sometimes give much higher possible output. They also are less affected in tone by varying lengths of amplifier lead, and amplifier input characteristics. Magnetic pickups used with 'active' circuitry usually feature a lower inductance (and initially lower output) winding that tends to give a flatter frequency response curve.

The disadvantages of active pickups are the power source (usually either a battery or phantom power), cost, and less defined unique tonal signature. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy Phantom power (labeled as +48 V on some audio equipment is a method that sends a DC electrical voltage through microphone cables They are more popular on bass guitars, because of their solid tone; most high-end bass guitars feature an active pickup. Most piezoelectric and all optical pickups are active and include some sort of preamp.

The main advantages of active pickups are that they are hum and noise free, at least compared to their passive single coil counterparts, as they require no ground wiring to connect to ground, which also may isolate the player from being electrocuted, should the wiring elsewhere, in other equipment such as a guitar amp, have become hazardous in any way.

See also

References

External links

[14]

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