Dean Vendetta 7 String A electric guitar pickup is actually just like a powerful microphone coil. For decades, active microphones have now been wired with the style coil mounted on the primary of the microphone's transformer, and not introduced to ground (‘floating'). The microphone's event is typically linked to the wire shield, that is connected to the microphone amplifier's floor (see Rane's site for more discussion).
By and big, active microphones are extremely quiet units as a result of the mix of transformer isolation and healthy, flying transmission lines for the duration of, in addition to protected, humbucking coils.
Therefore why not instruments? Instruments are once overwhelmed by noise. Humbucking pickups are merely a partial (though important!) solution. Well-known option is always to float practicing the guitar pickup to a balanced production, being a microphone. A similar thought was printed this 2001 patent request like this Dean Vendetta 7 String?