Understanding Guitar Wiring


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60-cycle hum Interference and noise that is emitted by most electric devices. The humbucking pickup was designed to eliminate this RF interference.

Alnico An acronym for an expensive and powerful permanent-magnet alloy containing iron, Aluminum, Nickel, and one or more of the elements Cobalt, copper, and titanium (Al-Ni-Co). There are several different formulations of Alnico and they are designated using roman numerals. The most common are Alnico II (two) and Alnico 5 (five) for guitar and bass pickups. Alnico is often preferred over other permanent-magnet materials (such as ceramic) for its tonality and response.

Antenna A usually metallic device (as a rod or wire) for radiating or receiving radio waves. A pickup coil is a very long wire antenna. One complete wrap of a traditional single-coil averages around 4-1/2" long. Therefore, a pickup with an average 6,000 turns has 3000 feet of wire—over half a mile!

Alternating Current (AC) An electric current that reverses its direction at regularly recurring intervals or cycles.

Amplifier Boosts an electrical signal from the pickups to a much greater signal that can power the amplifiers speakers.

Attenuate To reduce or cut.

Backplate A plastic cover that conceals the tremolos block, springs, and claw, or covers the electronics cavity.

Bobbin The part of the pickup that the coil-wire is wrapped around.

Cable Often referred to as a cord or guitar cable, it carries the electrical signal produced by the pickups to the amplifier.

Capacitor An electrical component, which has many uses (storing electricity, acting as a filter and more). Typically, guitar wiring uses a cap as a filter for certain frequencies, in conjunction with a pot to affect the tone of the guitar.

Capacitor (2) A device giving capacitance and usually consisting of conducting plates or foils separated by thin layers of dielectric (as air or mica) with the plates on opposite sides of the dielectric layers oppositely charged by a source of voltage and the electrical energy of the charged system stored in the polarized dielectric

Ceramic-Magnet A powerful permanent magnet material, which is made by combining a nonmetallic mineral (such as clay) with other materials, and by firing them at a high temperature. This material can then be magnetically charged using a capacitance discharge devise, or another magnet.

Coil The bobbin, magnet, and coil of magnet-wire assembly.

Coil-wire See magnet-wire.

Conductive A material with the ability to transmit or convey energy (electrical, magnetic, heat, etc.). Some materials are better than others for transmitting, while act as resistors to the transmission of energy.

Cycle An interval of time during which a sequence of a recurring succession of events (i.e. Alternating Currents reversal in direction) is completed. Standard US wall voltage is 60-cycle AC. This translates into 60 "reversals" per second.

Direct Current (DC) An electric current flowing in one direction only and substantially constant in value.

Electrical Current A flow of electric charge; also the rate of such flow. See alternating current and direct current.

Electromagnet A core of magnetic material surrounded by a coil of wire through which an electric current is passed to magnetize the core.

Electromotive Force a) Something that moves or tends to move electricity. b) The potential difference derived from an electrical source per unit quantity of electricity passing through the source (as a cell or generator).

Farad The unit of measurement used for capacitors. Caps used in guitar wiring are typically measured in microfarads (a unit of capacitance equal to one millionth of a farad) and picofarads (one trillionth of a farad).

Farad (2) The unit of capacitance equal to the capacitance of a capacitor between whose plates there appears a potential of one volt when it is charged by one coulomb of electricity. Etymology: Michael Faraday, 1873

Flatwork The two stamped pieces of vulcanized-fiber material traditional Fender-style single-coil pickups used in the construction of the pickup bobbin. The six magnets were pressed into two pieces of flatwork (one for the top of the coil and the other for the bottom).

Ferrous Of, relating to, or containing iron.

Finish The end of a coil.

Gauge Referring to wire. The higher the gauge number of the wire, the thinner its diameter. The thinner the diameter (the higher the gauge), the higher its DC resistance per linear foot.

NOTE: There are tonal differences between two coils with the same number of turns of two different gauges. The thinner-wire pickup will have a higher DC resistance, and therefore a different response than a pickup utilizing a thicker gauge coil-wire. If a pickup is wound to a specific DC resistance, a higher gauge (thinner) wire will achieve that resistance quicker than a thicker gauge wire.

Gauss The unit of measurement for a magnetic field and its strength.

Generator A machine by which mechanical energy is changed into electrical energy.

Ground The base or zero reference point that electrical potential or voltage is measured. Guitar circuits have a common ground and are connected to earth ground through the amplifier.

Hand-Wound Using a simple winding machine, the operator guides the coil-wire onto the spinning bobbin by hand. This gives the operator complete control of the tension of the winding, the traverse, and the concentration of the windings. This is how many single-coil pickups are wound, which allows the operator to have some control over the pickup's output and tone.

Hollow Body Electric Guitars that can be heard un-amplified as well as amplified because of their soundboard. They produce softer, warmer tones preferred by jazz and blues musicians.

Humbucker Two coils of opposite magnetic polarity and opposite electrical phase, which effectively cancel 60-cycle hum. Humbuckers typically have a warm tone with an increased upper-midrange, and attenuated lows and highs. Seth Lover of the Gibson Guitar Company designed the humbucker in 1956.

Since the two coils of a humbucker work with one another to cancel hum, then both coils must be as close to identical as possible. This is why humbuckers are almost always machine-wound. If the coils had varying inner-coil tensions, inconsistent numbers of wraps, and an uneven traverse (all indicative of a hand-wound pickup), then they would not sound smooth and they wouldn't effectively cancel hum.

Inductance a) A property of an electric circuit by which an electromotive force is induced in it by a variation of current either in the circuit itself or in a neighboring circuit. b) The measure of this property that is equal to the ratio of the induced electromotive force to the rate of change of the inducing current.

Impedance The measurement of the overall resistance of an electrical circuit.

Impedance (2) The apparent opposition in an electrical circuit to the flow of an alternating current that is analogous to the actual electrical resistance to a direct current and that is the ratio of effective electromotive force to the effective current.

In-Phase The linking of two signals so they are working identically, in a synchronized or correlated manner. The opposite of out-of-phase.

Intonation The process of adjusting a string's length (using the individual saddles of the bridge) so that each string plays in tune at every fret relative to all of the other strings.

Jack Plate A mounting apparatus for the output jack.

Machine-wound Pickup coils that have been wound using a completely autonomous winding machine. Most humbucking and many single-coil pickups are machine-wound rather than hand-wound.

Magnet A ferrous (containing iron) material or certain other material which can be magnetically charged and therefore will attract other ferrous or similar materials. Pickups are often manufactured first, then the magnets are charged. Magnetism is measured in Gauss.

There are two common methods for charging the magnets of a pickup. One method is to simply introduce the pickup to the field of another, larger magnet and let it charge the magnet(s) of the pickup. The orientation, proximity, and exposure time of the pickup relative to the large magnet will determine the polarity and intensity of the pickup's magnet(s). Therefore, this method can give varied results. The other, more precise method utilizes a capacitor discharged into a coil of wire (similar to a large solenoid). The pickup is placed within the coil of wire, the capacitor is charged with a preset amount of voltage and current, and then the capacitor is allowed to discharge into the coil. The coil will become a very stable, but short-lived magnetic field surrounding the pickup. This short burst of magnetism can be repeated as many times as necessary to produce a consistent product.

Magnetic Polarity see polarity.

Magnet-Wire Very thin (generally 43-42 gauge, .0022-.0025"; human hair is .0025"), flexible copper wire which is coated with a non-conductive "insulation"—usually a thin plastic finish such as lacquer or polyurethane.

Millivolt One thousandth of a volt.

Ohm The unit of measurement for resistance. The higher the value, the greater the resistance.

Ohm (2) The practical meter-kilogram-second unit of electric resistance equal to the resistance of a circuit in which a potential difference of one volt produces a current of one ampere.

Out-of-Phase The combination of two signals or waves so they are unsynchronized, or not in correlation—they are 180-degrees out-of-synch. The opposite of in-phase.

Output The power or energy produced or delivered by a machine or system, in our case, the pickup(s). It is virtually impossible to measure a pickup's output (not the DC Resistance, but its actual output voltage) since the forces that induce a current into a pickup's coil(s) vary considerably. This is due to the fact that string-gauges, the string's proximity to the pickup and polepieces, the vibrating length of the string, and the force at which the string is plucked can vary considerably.

DiMarzio is the only company I'm aware of that even advertises their pickup's voltage output. They went to great lengths to ensure that the variables listed were maintained at a constant so they could quantitatively compare their pickups and give a specific DC Volt output for each model.

Output Jack This is a receptacle that accepts the cable, which is then connected to the guitar amplifier.

Parallel When two or more electrical components are combined so that their inputs are connected and their outputs are connected.

Parallel (2) An arrangement of electrical devices in a circuit in which the same potential difference is applied to two or more resistance's with each resistance being on a different branch of the circuit—compare to series.

Phase The relationship of positive and negative waveforms. See in-phase and out-of-phase.

Pickguard Generally made of some type of plastic, it is used to suspend the pickups, pots and switch. The pickguard is held in place by pickguard screws.

Pickup The component of an electric guitar that transmits the vibration of the strings into an electrical signal. The pickup has three primary parts: 1) magnet(s); 2) copper wire; 3) bobbin.

Permanent-Magnet Any material that will retain a magnetic charge much longer than a simple ferrous alloy. The original permanent magnet material was the mineral lodestone (Magnetite), which was known to the ancient Greeks, Romans, and Chinese. They found that when a piece of iron is stroked with lodestone, the iron acquires the ability to attract other pieces of iron.

Polarity The particular state, either positive or negative, with reference to the two poles or to electrification.

Polarity (2) The particular state, either north or south, with reference to the two poles or to a magnetic charge or field.

Pole Referring to a switch; a distinct circuit that will not interact in any way with any other pole.

Polepiece Part of a pickup which senses string vibration. Depending upon the design of the pickup, the polepieces may not be actual magnets, but they must be magnetically conductive.

Potentiometer Often referred to as a "pot," it's an electrical device consisting of a resistive strip and a variable sweeper. The resistance strip is equal to the pot's value (250K, 500K, 1Meg, etc.) and its ends are the two outer lugs (1 and 3). The middle lug (2) is connected to the "sweeper" which travels along the resistance strip as the pot shaft is rotated. The location of the sweeper determines the amount of resistance between lugs 2 and 3, and 2 and 1. The pots used in guitar electronics are generally "audio taper." This means that the resistive strip has a special logarithmic taper to compensate for how the human ear perceives changes in volume. This allows the musician to vary the volume and/or tone of an electric guitar in a smooth, gradual manner.

Preamp An electrical device which is designed to boost and/or buffer a signal's strength and/or impedance.

Resistance The restriction or impedance of electrical flow.

Resistance (2) The opposition offered by a body or substance to the passage through it of a steady electric current.

Resistor An electrical component designed to apply a predetermined amount of resistance to an electrical circuit.

Resistor (2) A device that has electrical resistance and that is used in an electric circuit for protection, operation, or current control.

RF Interference The ever present Radio Frequencies that bounce around the world. It is the source of 60-cycle hum and is emitted by virtually any electrical device. The humbucking pickup is designed to eliminate or cancel-out RF Interference.

Scatter Winding See hand-wound.

Selector Switch Determines which pickup or pickups are connected to the amp.

Series When two or more electrical components are connected so that the output of one component feeds into the input of the next component.

Series (2) An arrangement of the parts of or elements in an electric circuit whereby the whole current passes through each part or element without branching—compare parallel.

Seth Lover An incredible "renaissance-man" in the history of Gibson's electric guitars, and the inventor of the humbucking pickup design.

Short Circuit (a.k.a. short) A connection of comparatively low resistance accidentally or intentionally made between points on a circuit between which the resistance is normally much greater.

Single-Coil A pickup comprised of a single bobbin. Most single-coil designs use polepieces that are made of a magnetic material (typically Alnico II or Alnico 5) that are pressed into the flatwork. Single-coil pickups typically have a wider frequency response when compared to humbuckers, and they also have a tighter low-end response as well as more high-end. Due to a single-coils high-end or "bright" sound, manufacturers will often use 250K volume controls to attenuate some of the high-end frequencies. This gives them a warmer, smoother response.

Most tone aficionados prefer hand-wound single-coil pickups to machine-wound varieties. There are many reasons for this, many of which are subjective. Some of the best sounding single-coil pickups were made in the 50's and 60's at the Fender factory. Several elderly women wound thousands of pickups by hand feeding the wire onto the bobbins. These pickups, which don't look nearly as neat and clean as a machine-wound pickup (the coils were lop-sided, uneven, and often warped) sound and respond better than any other single-coils produced. Leo preferred elderly females for the pickup winding, since they had experience in winding sewing string and yarn, and seemed to have the right "touch."

Solidbody Electric A guitar body made of a solid piece or pieces of wood without any soundboard.

Soundboard The top or face of an acoustic or hollow-bodied guitar which vibrates along with the strings and projects the sound of the guitar.

Start The beginning of a coil.

Throw Referring to a switch; the number of distinct stopping points or terminals of a given pole of a switch.

Tone Control A potentiometer and capacitor wired to control certain frequencies of the pickup's output.

Traverse A zigzag course of consecutive lateral movements, which will disperse the windings onto the bobbin.

Variable Resistor See Potentiometer

Volt The practical meter-kilogram-second unit of electrical potential difference and electromotive force equal to the difference of potential between two points in a conducting wire carrying a constant current of one ampere when the power dissipated between these two points is equal to one watt and equivalent to the potential difference across a resistance of one ohm when one ampere is flowing through it.

Volume Control A potentiometer wired to determine the volume, output, or loudness of the instrument, or a portion of an instrument's electronics (say one pickup relative to another). A "master" determines the level of the signal sent on to the amp.

Wax Potting The process of immersing a pickup's coil(s) into hot wax. This allows the wax to penetrate into the windings and components of the pickup so that they will not vibrate, thus eliminating microphonic feedback.

Winding Machines A mechanical means to assist in the winding of the coil-wire around a bobbin to make a pickup coil. The machines are often very simple; with an arbor for the bobbin, a motor to drive the arbor, and a variable speed control for the motor. More advanced winding machines have methods for guiding the coil-wire onto the bobbin, controlling the traverse (number of wraps per layer and the wires spacing), winding counters, tensioning for the coil-wire, and more. If you wish to make your own pickups, a simple winding machine could be made from an old sewing machine motor and controller, and a simple arbor made of wood.

Windings The wraps of copper wire around the bobbin of a pickup. Coils generally have anywhere from 6,000 to 8,500 turns of wire. The number of turns is often used as a rough indicator of a pickups potential output and tone. The higher the number, the higher the output, but not always. As the number of windings increase, the pickup will also lose some clarity, and high and low-end response. Generally, high-output pickups have increased upper midrange response, but high and low frequencies are compromised.

Typical single-coils are wound from 4 - 6.5K ohms, while typical humbuckers wired in series (this means that each coil of the humbucker is half the DC resistance reading) measure 7 - 9K Ohms. The gauge of wire and the number of windings will determine the actual size of the pickup coil. Smaller wire (43-gauge for example) will give a greater DC resistance with less windings, compared to larger (42-gauge) wire.