Epiphone Ultra 339 A electric guitar collection is actually much like a dynamic mike coil. For decades, active microphones have already been wired with the style coil mounted on the principal of the microphone's transformer, and not recommended to ground (‘floating'). The microphone's case is typically attached to the cable guard, which is linked to the mike amplifier's surface (see Rane's site for more discussion).
By and big, dynamic microphones are extremely calm units as a result of the mix of transformer isolation and healthy, suspended sign lines for the duration of, in addition to guarded, humbucking coils.
So why not guitars? Guitars are notoriously plagued by noise. Humbucking pickups are merely an incomplete (though important!) solution. Well-known option is to float practicing the guitar pickup to a healthy production, being a microphone. An identical strategy was published that 2001 patent software such as Epiphone Ultra 339?