Bank Nh Pavilion A best guitar pickup is basically similar to a vibrant mike coil. For decades, active microphones have already been sent with the voice coil attached with the principal of the microphone's transformer, and not recommended to ground (‘floating'). The microphone's case is normally linked to the cable shield, which is attached to the microphone amplifier's floor (see Rane's website for more discussion).
By and large, vibrant microphones are very quiet devices as a result of the mix of transformer isolation and balanced, hanging indication lines during, in addition to protected, humbucking coils.
Therefore why don't you guitars? Guitars are notoriously overwhelmed by noise. Humbucking pickups are only a partial (though important!) solution. Well-known answer would be to move the guitar pickup to a balanced output, being a microphone. An identical strategy was printed this 2001 patent application such as Bank Nh Pavilion?