At2020 Usb Plus A electric guitar pickup is essentially much like a powerful mike coil. For decades, active microphones have now been wired with the style coil mounted on the principal of the microphone's transformer, and not called to floor (‘floating'). The microphone's case is typically connected to the cable guard, which is linked to the mike amplifier's soil (see Rane's site for more discussion).
By and large, dynamic microphones are very quiet products consequently of the combination of transformer isolation and healthy, suspended transmission lines during, as well as protected, humbucking coils.
So why not guitars? Guitars are once plagued by noise. Humbucking pickups are just an incomplete (though important!) solution. The obvious alternative is always to float practicing the guitar collection to a healthy output, being a microphone. A similar thought was published that 2001 patent request like this At2020 Usb Plus?