Heavy Metal Movies A guitar pickup is actually much like a powerful mike coil. For many years, dynamic microphones have already been sent with the style coil mounted on the principal of the microphone's transformer, and not introduced to ground (‘floating'). The microphone's situation is typically attached to the cable guard, which will be connected to the microphone amplifier's soil (see Rane's web site for more discussion).
By and large, dynamic microphones are very quiet devices consequently of the mix of transformer isolation and balanced, suspended indication lines all through, as well as protected, humbucking coils.
Therefore why not instruments? Instruments are once plagued by noise. Humbucking pickups are just an incomplete (though important!) solution. The obvious alternative is to float the guitar pickup to a healthy output, being a microphone. A similar idea was printed this 2001 patent program such as Heavy Metal Movies?