Days Of Future Passed A guitar pickup is essentially much like a vibrant mike coil. For decades, powerful microphones have now been wired with the style coil attached to the primary of the microphone's transformer, and perhaps not introduced to surface (‘floating'). The microphone's case is typically linked to the cable guard, which will be linked to the microphone amplifier's ground (see Rane's site for more discussion).
By and big, active microphones are extremely calm devices as a result of the mix of transformer isolation and balanced, flying indication lines during, in addition to protected, humbucking coils.
Therefore why not instruments? Instruments are notoriously overwhelmed by noise. Humbucking pickups are merely an incomplete (though essential!) solution. The obvious option would be to move practicing the guitar pickup to a healthy result, just like a microphone. A similar strategy was published that 2001 patent request like this Days Of Future Passed?