| 摘要 |
This invention relates to an electronic pickup system for a stringed musical instrument. The system includes three pickup coils positioned under the instrument strings and oriented one behind the other along the length of the strings. Each of the coils is wound around a coil form in a predetermined direction and has a selectively poled magnet passing through its center. The coils are selectively electrically connected, at least two at a time, to each other and to the system output. The manner in which the coils may be connected include connecting any two of the coils in a maner such that signals induced in the coils as a result of string vibration are in phase, at at least selected frequencies, and thus additive. The coils normally are also connected in a manner such that noise signals induced in the coils are out of phase and therefore cancel. It is also possible to connect both of the outer coils to the center coil so that signals induced in each pair of coils as a result of string vibration are additive and noise signals induced in each pair of coils cancel. When the coils are connected in this manner, the outputs from both of the outer coils may be connected to the same output or, if a stereo output is desired, the outputs from each of the coils may be connected to a separate output channel. The spacing of the coils which are connected together may be selected so that signals induced in the coils as a result of string vibration are in phase and thus additive for selecting frequencies and are out of phase and are thus cancelled for other selected frequencies. The frequencies at which the signals are in phase and the frequencies at which the signals are out of phase may be altered by altering the spacing between the coils. The magnitude of the signal induced in one or more of the coils may also be modified by raising or lowering the coil or by other suitable means.
|
