Fender Standard Stratocaster Electric Guitar A guitar pickup is basically similar to an energetic microphone coil. For many years, energetic microphones have already been sent with the voice coil mounted on the primary of the microphone's transformer, and perhaps not recommended to floor (‘floating'). The microphone's situation is normally attached to the wire shield, that is attached to the microphone amplifier's ground (see Rane's internet site for more discussion).
By and big, active microphones are very calm units consequently of the mix of transformer isolation and balanced, suspended transmission lines throughout, as well as shielded, humbucking coils.
So why not instruments? Instruments are notoriously affected by noise. Humbucking pickups are merely an incomplete (though important!) solution. Well-known answer is always to float your guitar collection to a healthy result, being a microphone. An identical thought was published that 2001 patent application such as Fender Standard Stratocaster Electric Guitar?