Acoustic Upright Bass A guitar collection is basically much like a dynamic mike coil. For many years, vibrant microphones have already been wired with the style coil attached to the principal of the microphone's transformer, and perhaps not introduced to ground (‘floating'). The microphone's situation is typically linked to the cable shield, that will be connected to the microphone amplifier's ground (see Rane's site for more discussion).
By and big, vibrant microphones are very quiet units consequently of the mix of transformer isolation and healthy, hanging sign lines through the duration of, as well as shielded, humbucking coils.
Therefore why not guitars? Instruments are notoriously affected by noise. Humbucking pickups are only an incomplete (though important!) solution. The most obvious answer is to float practicing the guitar pickup to a balanced result, just like a microphone. A similar thought was published that 2001 patent application like this Acoustic Upright Bass?