Vintage 30 Speakers A electric guitar pickup is essentially much like a dynamic mike coil. For decades, active microphones have been wired with the style coil attached to the primary of the microphone's transformer, and maybe not called to soil (‘floating'). The microphone's event is typically connected to the cable shield, which can be attached to the microphone amplifier's soil (see Rane's web site for more discussion).
By and big, energetic microphones are very calm products consequently of the mixture of transformer isolation and balanced, floating sign lines during, in addition to guarded, humbucking coils.
Therefore why not instruments? Guitars are once affected by noise. Humbucking pickups are merely an incomplete (though crucial!) solution. The obvious option would be to move your guitar pickup to a balanced production, being a microphone. The same strategy was published this 2001 patent request like this Vintage 30 Speakers?