Pickup (music technology)
The first electrical string instrument with pickups, the "Frying Pan" slide guitar, was created by George Beauchamp and Adolph Rickenbacker around 1931.
[citation needed] A typical magnetic pickup is a transducer (specifically a variable reluctance sensor) that consists of one or more permanent magnets (usually alnico or ferrite) wrapped with a coil of several thousand turns of fine enameled copper coil.
This moving magnetic field induces a voltage in the coil of the pickup as described by Faraday's law of induction.
A pickup is a part of an electric guitar or bass that "hears" the strings and turns their vibrations into sound.
It’s usually attached to the guitar's body, but sometimes it’s placed on other parts like the bridge (where the strings rest) or the neck.
The turns of wire in proximity to each other have an equivalent self-capacitance that, when added to any cable capacitance present, resonates with the inductance of the winding.
The arrangement of parasitic resistances and capacitances in the guitar, cable, and amplifier input, combined with the inductive source impedance inherent in this type of transducer forms a resistively-damped second-order low-pass filter, producing a non-linearity effect not found in piezoelectric or optical transducers.
Pickups are usually designed to feed a high input impedance, typically a megohm or more, and a low-impedance load increases attenuation of higher frequencies.
Single-coil pickups act like a directional antenna and are prone to pick up mains hum—nuisance alternating current electromagnetic interference from electrical power cables, power transformers, fluorescent light ballasts, video monitors or televisions—along with the musical signal.
Mains hum consists of a fundamental signal at a nominal 50 or 60 Hz, depending on local current frequency, and usually some harmonic content.
To overcome this, the humbucking pickup was invented by Joseph Raymond "Ray" Butts (for Gretsch), while Seth Lover also worked on one for Gibson.
An alternative wiring places the coils in buck parallel, which has a more neutral effect on resonant frequency.
These have a very different sound, and also have the advantage of not picking up any other magnetic fields, such as mains hum and feedback from monitoring loops.
In hybrid guitars, this system allows switching between magnetic pickup and piezo sounds, or simultaneously blending the output.
For this reason, the buffer amplifier is often powered from relatively high voltage rails (about ±9 V) to avoid distortion due to clipping.
[14] There are basically four principles used to convert sound into an alternating current, each with their pros and cons: An amplification system with two transducers combines the qualities of both.
A combination of a microphone and a piezoelectric pickup typically produces better sound quality and less sensitivity to feedback, as compared to single transducers.
Examples of a double system amplifier are the Highlander iP-2, the Verweij VAMP or the LR Baggs dual source and the D-TAR Multisource.
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.
The main disadvantage of an active system is requirement of a battery power source to operate the preamp circuitry.
Their proprietary "Ric-O-Sound" circuitry has two separate output jacks, allowing the musician to send each pickup to its own audio chain (effects device, amplifier, mix console input).
