This Glossary gathers definitions from diverse historical references, in the fields of audio, acoustics, musical composition, and engineering. These terms describe how musical instrument pickups or electronics, sound, behave, are used, or are measured. Where no description can be found, un-sourced definitions are listed, marked with asterisk, *. Definitions clarifying industry jargon are marked double asterisk, **.
Active Pickup ** - Pickups designated as "active," are passive pickups in series with active electronics. Active electronics is defined as a device or circuit (e.g., a transistor or op-amp) that requires the addition of electric voltage or current to function. Permanent magnet pickups operate without external voltage or current, i.e., they are in the same category as resistors, passive devices.
Alnico - Magnet material primarily composed of Aluminum, Nickel, and Cobalt.
Aperture * - The height of the bobbin opening.
String Spacing * - center of one string to the center of the adjacent string over the centerline of the pickup, and not at the physical bridge. For pole piece pickups, is specified at the time of purchase.
Restoration faithfully returns a pickup to its "original" condition. These images of a Pro 8 lapsteel bobbin show, how it arrived at Aero, and then how it looked after a complete restoration.
Minor repair can be as simple as lead dressing or replacement, re-potting, re-attaching broken magnet wire, cleaning, or refinishing. Major repairs include addressing bobbin delamination or warping, and bobbin or magnet or component replacement.
Z - see Impedance