Acoustic Guitar Tuner A best guitar collection is basically much like an energetic mike coil. For decades, powerful microphones have been wired with the voice coil mounted on the primary of the microphone's transformer, and perhaps not referenced to soil (‘floating'). The microphone's case is usually linked to the cable guard, that will be connected to the mike amplifier's ground (see Rane's web site for more discussion).
By and big, active microphones are extremely quiet units consequently of the mix of transformer isolation and balanced, suspended sign lines for the duration of, in addition to protected, humbucking coils.
So why don't you guitars? Instruments are notoriously affected by noise. Humbucking pickups are only a partial (though important!) solution. The most obvious alternative would be to move your guitar collection to a balanced result, being a microphone. A similar thought was printed that 2001 patent request like this Acoustic Guitar Tuner?