Hohner 1896 Marine Band Harmonica A best guitar pickup is actually just like an energetic microphone coil. For decades, active microphones have been wired with the voice coil mounted on the principal of the microphone's transformer, and not introduced to surface (‘floating'). The microphone's event is typically connected to the cable guard, which can be connected to the microphone amplifier's surface (see Rane's web site for more discussion).
By and big, dynamic microphones are extremely calm units as a result of the mixture of transformer solitude and healthy, flying indication lines through the duration of, in addition to protected, humbucking coils.
Therefore why not instruments? Instruments are notoriously plagued by noise. Humbucking pickups are only an incomplete (though essential!) solution. Well-known answer is to float the guitar collection to a balanced production, just like a microphone. An identical strategy was printed that 2001 patent application such as Hohner 1896 Marine Band Harmonica?