Ryan Adams Carnegie Hall A guitar pickup is basically just like an energetic microphone coil. For decades, energetic microphones have been sent with the voice coil attached to the principal of the microphone's transformer, and perhaps not recommended to ground (‘floating'). The microphone's case is usually attached to the cable shield, which is connected to the microphone amplifier's floor (see Rane's website for more discussion).
By and big, active microphones are very calm units as a result of the mix of transformer solitude and balanced, flying transmission lines during, along with protected, humbucking coils.
So why not instruments? Guitars are once overwhelmed by noise. Humbucking pickups are just an incomplete (though important!) solution. The obvious option is always to float your guitar collection to a balanced production, being a microphone. The same idea was published that 2001 patent request such as Ryan Adams Carnegie Hall?