Focal Solo 6 Be A best guitar pickup is essentially similar to a vibrant mike coil. For many years, energetic microphones have been wired with the voice coil mounted on the principal of the microphone's transformer, and not recommended to soil (‘floating'). The microphone's case is normally connected to the cable shield, which is connected to the mike amplifier's floor (see Rane's web site for more discussion).
By and big, powerful microphones are very calm devices consequently of the combination of transformer isolation and healthy, hanging sign lines during, as well as guarded, humbucking coils.
So why not instruments? Instruments are once plagued by noise. Humbucking pickups are merely an incomplete (though crucial!) solution. Well-known solution is always to move practicing the guitar pickup to a balanced productivity, just like a microphone. A similar idea was published this 2001 patent request like this Focal Solo 6 Be?