Vox Guitar Wiring Diagram A electric guitar pickup is essentially much like a powerful microphone coil. For many years, active microphones have already been wired with the voice coil attached to the primary of the microphone's transformer, and maybe not introduced to floor (‘floating'). The microphone's case is normally connected to the cable shield, which is attached to the microphone amplifier's floor (see Rane's site for more discussion).
By and large, active microphones are very calm products consequently of the mixture of transformer isolation and balanced, suspended transmission lines all through, in addition to guarded, humbucking coils.
So why not instruments? Guitars are notoriously plagued by noise. Humbucking pickups are only a partial (though important!) solution. Well-known solution is to move the guitar pickup to a balanced production, being a microphone. The same strategy was printed this 2001 patent application like this Vox Guitar Wiring Diagram?