Active Pickup - A pickup using an electronic preamp to achieve gain enhancement, tonal shaping and/or output impedance reduction. Some advantages include less susceptibility to noise, greater flexibility in creating new tones and the elimination of high frequency losses caused by driving long cables. Active pickups can be particularly useful for producing the strong noise free signal needed to drive multi-effects racks. (For comparison, see "Passive Pickup").

Calibrate - The winding of each pickup in a set differently in order to produce a balanced output level when switching from pickup to pickup.

DC Resistance - The resistance to the flow of Direct Current. For most pickups, it is a very general indicator of the output and tonality with higher DC Resistance tending to be higher in output and less bright.

Distributed Capacitance - The capacitance which exists turn-to-turn and layer-to-layer between the wires of a coil. This property combines with the coil's inductance to produce a resonant peak. Post resonance, distributed capacitance acts like a built-in tone pot and rolls off high frequency response. (See "Resonant Peak").

Epoxy Potting - A method of sealing a pickup in epoxy to reduce microphonic feedback and protect the pickup from damages due to handling, exposure to the elements and normal use. (See also "Wax Potting").

Four Conductor Wiring - The practice of independent termination of the beginning and ending leads from each coil of a humbucking pickup to a cable with a common shield. This approach allows much versatility in wiring and switching configurations, i.e., series/split/parallel, splitting with coil selection, in/out of phase with itself, in/out of phase with another pickup, etc.

Gauss - The CGS unit of magnetic flux density used to describe the field strength of a magnet.

Ground - A common reference point in an electrical circuit.

Hum Canceling, Humbucking - A pickup design consisting of two coils which are summed electrically out of phase and with magnetic polarities reversed. The effect of the configuration is to cancel hum and other extraneous noise and leave the string signal perfectly intact.

Impedance - The resistance to the flow of Alternating Current. In passive pickups this figure is variable with frequency.

Inductance - The property of a coil to oppose changes of current through itself.

Milli Volt - One thousandth of a volt.

Ohms - The standard unit of electrical resistance.

Out Of Phase - The electrical linking of two coils or two pickups in either series or parallel but with the signal polarities summed in such a way as to provide at least partial cancellation of the signal. Usually the low frequencies are canceled so the resulting sound is thin, lacking in warmth and often quite brittle.

Parallel - The electrical linking of two coils in a parallel or side by side fashion. The sonic effect compared to a series configuration is approximately 30% lower output but with additional brilliance and clarity on the high end. (See "Series").

Parallel Axisô - A patented pole piece system that utilizes four separate small blades per string. The blades are arranged in a configuration that decentralizes and softens the magnetic field providing smoother highs and greater sustain while minimizing distortions induced by string pull.

Passive Pickup - A type of pickup which uses no internal active electronic circuitry. (See "Active Pickup".)

Phase - The relationship of two wave forms with respect to time.

Polarity - The relationship of positive and negative electric currents (or North and South magnetic poles) to each other.

Pole Piece, Non-Magnetic - A ferrous (containing iron, magnetically conductive) metal piece used to control, concentrate and/or shape a magnetic field. Although many styles have been used, pole pieces fall into two broad categories of adjustable and non-adjustable.
At Seymour Duncan, we currently use many different types of adjustable and non-adjustable pole pieces. The physical configuration of the pole piece will vary the magnetic field intensity of the pickup. Generally a more massive pole piece, such as the button head cap screw used in the SH-8 Invaderô, will produce a stronger field. This gives higher output and a more aggressive attack. Smaller or thinner pole pieces tend to produce a lower field intensity giving reduced output and a smoother attack. It is possible to combine two or more types of pole pieces in one pickup in order to achieve a subtle balance between attack, definition, and fullness.

Pole Piece, Magnetic - Refers to a pickup in which the axis of the magnet is aimed directly at the strings and the magnet itself is serving as the pole piece. This design approach is most commonly used on vintage single coil pickups where cylindrical rod magnets serve as pole pieces, however, bar magnets have also been used in this application.

Resonant Peak - The frequency at which the impedance of a pickup is at its highest. Within a given category of pickups. a higher resonant peak usually indicates a brighter, clearer sound.

RW/RP - Stands for Reverse Wind/Reverse Polarity. Refers to the practice (originated at Seymour Duncan in the late '70s) of reversing the winding direction and magnetic polarity of one single coil pickup from a two or three pickup guitar. When this is done, hum cancellation can be achieved when using two pickups together.

Series - The electrical linking of two coils in a serial fashion producing a higher output, fuller and more powerful sound. This is the standard hookup for humbucking pickups. (See "Parallel").

Splitting, Split Pickup - The process of grounding out one of the two coils of a humbucking pickup thereby producing a single coil sound. (See, for comparison, "Tapped Pickup").

Stack® - Our patented technique of stacking two coils, one above the other, in order to cancel hum and noise but retain a single coil tonality.

Tapped Pickup - A coil which has two or more hot leads exiting at different percentages of the total wind in order to provide multiple output levels and tones. (See "Split Pickup").

Transducer - A device that converts energy from one form to another (i.e. a pickup converts kinetic motion into an electrical signal, a speaker converts an electrical signal into kinetic motion).

Trembuckerô - A humbucking pickup designed with wider pole-to-pole spacing in order to accommodate guitars with vibrato systems or wider string spacing.

Volt - The practical unit of electromotive force, the pressure which causes a current of one ampere to flow through a resistance of one ohm.

Wax Potting - A method of saturating a pickup in wax to hold the coil and any mechanical parts absolutely rigid. This is done to prevent undesirable microphonic feedback. At Seymour Duncan we use a custom made vacuum encapsulation system to insure thorough wax penetration.