Martin Acoustic Electric A best guitar pickup is actually much like an energetic mike coil. For many years, active microphones have been sent with the style coil attached to the primary of the microphone's transformer, and not recommended to soil (‘floating'). The microphone's case is typically linked to the wire guard, which is connected to the microphone amplifier's soil (see Rane's site for more discussion).
By and big, powerful microphones are very calm devices as a result of the mixture of transformer isolation and balanced, suspended sign lines all through, along with guarded, humbucking coils.
Therefore why don't you guitars? Instruments are notoriously affected by noise. Humbucking pickups are only an incomplete (though important!) solution. The obvious option is always to float the guitar pickup to a balanced output, as being a microphone. An identical thought was published that 2001 patent software like this Martin Acoustic Electric?