Metallica Iron Maiden A guitar pickup is basically just like a powerful mike coil. For decades, energetic microphones have been wired with the voice coil mounted on the primary of the microphone's transformer, and not referenced to ground (‘floating'). The microphone's event is typically connected to the cable shield, that will be attached to the microphone amplifier's surface (see Rane's internet site for more discussion).
By and big, energetic microphones are extremely calm devices consequently of the combination of transformer isolation and healthy, suspended transmission lines for the duration of, along with shielded, humbucking coils.
Therefore why not guitars? Guitars are notoriously plagued by noise. Humbucking pickups are just a partial (though crucial!) solution. Well-known alternative would be to move your guitar collection to a balanced production, as being a microphone. A similar strategy was printed that 2001 patent application such as Metallica Iron Maiden?