The invention provides a plug for an electronic plucked string instrument having a structure for fixing with a set screw by inserting a cable into a sleeve in a plug side. A biting convex portion biting into an insulated outer sheath while receiving a screwing compression force of a set screw via a cable is formed integrally on an inner peripheral surface of an attachment sleeve in a plug side along a peripheral direction of a sleeve inner peripheral surface. The biting convex portion formed on the inner peripheral surface of the attachment sleeve in the plug bites into the insulated outer sheath of the cable. Thus, a slip displacement against a sleeve inner surface of the cable is inhibited by the biting convex portion and a slack of the set screw can be effectively suppressed even in a case where a stronger tensile force is applied to the cable.

A humbucker pickup device for active and passive guitars including a matched pair of elongated coil assemblies with two sets of ferrous pole pieces also includes two elongated, transversely polarized permanent magnets positioned between and parallel to the coils. The magnets are beside each other with opposite poles facing each other. The magnets and said two sets of pole pieces create two narrow magnetic fields under each string to interact with it at two points. The humbucker device includes an improved differential amplifier built from two or three operational amplifiers. Alternatively, the device may include a steel plate positioned between the magnets and extending to the strings for weakening a wide magnetic field between pole pieces of the different sets. Both embodiments, with and without the plate, are described.

An operation detection device for a key operation of a keyboard device includes a conductive unit configured to be disposed on each of keys, a substrate configured to be disposed facing each of the keys in a pressing direction of the keys. The substrate is provided with a sensor including at least first and second coils, the sensor being configured to be disposed spaced from one key so that at least one of the first or second coil outputs a signal corresponding to a distance between the one key and the respective sensor. The operation detection device includes a detection unit configured to detect a displacement of the one key in at least one of a yaw direction or a roll direction based on signals output from the first and second coils during a key pressing stroke of the one key.

This invention discloses a hollow-body guitar with a large rectangular sound hole between the neck and bridge, with two pickup mounting slots on each side of the sound hole in removable top plates, including a system of top plates and mounting adapters for 7 different single-coil and dual-coil pickup types. The invention has a system humbucking pickup circuit mixing modules that can be cascaded in linear or tree form to mix all the types of pickups in the output, providing a much wider range of tones than current 3-way and 5-way switching systems. For example, three matched single-coil pickups and one humbucker can be mixed to provide 19 humbucking circuits and 18 circuits with hum. Mixed a different way, using switchless analog circuits, they can produce the tones of all 19 switched humbucking circuits, plus all the continuous variations in between.

An operation detection device for a key operation of a keyboard device includes a conductive unit configured to be disposed on each of keys, a substrate configured to be disposed facing each of the keys in a pressing direction of the keys. The substrate is provided with a sensor including at least first and second coils, the sensor being configured to be disposed spaced from one key so that at least one of the first or second coil outputs a signal corresponding to a distance between the one key and the respective sensor. The operation detection device includes a detection unit configured to detect a displacement of the one key in at least one of a yaw direction or a roll direction based on signals output from the first and second coils during a key pressing stroke of the one key.

A musical keyboard instrument includes a key displaceable in response to a playing operation, a detection system including a magnetic body disposed on or in the key, and a coil facing and spaced from the magnetic body and configured to generate a magnetic field in response to receiving a supply of current, wherein the detection system is configured to generate a detection signal with a level that depends on a distance between the magnetic body and the coil, and an electromagnetic shield configured to block electromagnetic waves emitted from the detection system.

A hum-cancelling system includes two or more hum-cancelling coils configured in a distributed manner, connected in series with each other. The hum-cancelling coils form a series circuit that is electrically connected to at least one pickup. Each hum-cancelling coil includes a top plate, a bottom plate, and a coil of wire wrapped between the top plate and the bottom plate.

A modular single-coil electromagnetic stringed-instrument pickup, made to mount in replacement of a standard single-coil pickup, using the similar mounting screws and springs, has a replaceable base, core, blade pole and cover. The core unit has two flat coil forms glued to a bar magnet, which together form a trough for the coil. The outsides of the coil forms have printed circuits which form the coil end contacts and an integral electrostatic shield, with interconnect fixed after the coil is wound, so that the core unit can be flipped to change the magnetic polarity of the pickup, and thus the string vibration signal, while maintaining a humbucking pair circuit with equivalent pickup. The base, which can be either non-magnetic or ferro-magnetic material in different shapes and configurations to shape the magnetic field, contains three conductive index pins, which both make contact with the core unit contacts, and transmit string signals to any circuit or electrical contacts on the bottom of the base. The bottom of the base can be endowed with printed circuits, either on the base itself, or in flexible printed circuit soldered to the index pins. An elastomer shim sits between the core unit and base to give support to the core and microphonic damping. The vertical blade pole sits on top of the core unit, embedded in a non-conductive, non-magnetic horizontal support plate, is held in place by the cover, and separate elastomer shims. The shim between the blade and core unit has a section directly under the blade filled with magnetic material to transmit the magnetic field from the magnet to the blade. The blade pole can be formed, ground or filed to different heights and shapes under the strings, so as to correct for signal strength or to affect the harmonic content of the string signal directly. By trading out the core, base and blade for different types, a wide variety of tonal characters can result, imitating several other types of pickups, as well as providing upgrades from passive pickups to those with active circuits on the base.

This invention discloses a pickup based upon the core of a common lipstick pickup for an electric stringed musical instrument with a core and housing, the core comprised of a magnet, coil form, and a wire coil connected to electrical contacts on the coil form, and a separate housing providing mounting to the body of the instrument and mating electrical contacts for that core, such that the core can be removed from the housing, flipped so as to reverse the magnetic field towards the strings, and reinserted into the housing, such that any humbucking circuit constructed with other matching pickups will remain humbucking.

This invention discloses a pickup based upon the core of a common lipstick pickup for an electric stringed musical instrument with a core and housing, the core comprised of a magnet, coil form, and a wire coil connected to electrical contacts on the coil form, and a separate housing providing mounting to the body of the instrument and mating electrical contacts for that core, such that the core can be removed from the housing, flipped so as to reverse the magnetic field towards the strings, and reinserted into the housing, such that any humbucking circuit constructed with other matching pickups will remain humbucking.