Where Does Ringo Starr Live A guitar collection is basically much like an energetic mike coil. For many years, energetic microphones have now been wired with the voice coil mounted on the principal of the microphone's transformer, and perhaps not introduced to soil (‘floating'). The microphone's event is typically attached to the wire shield, which will be linked to the microphone amplifier's ground (see Rane's website for more discussion).
By and large, powerful microphones are very quiet units consequently of the combination of transformer isolation and healthy, suspended sign lines throughout, along with shielded, humbucking coils.
So why don't you guitars? Instruments are once affected by noise. Humbucking pickups are only a partial (though essential!) solution. The obvious option is always to move practicing the guitar collection to a balanced output, just like a microphone. A similar idea was published this 2001 patent program like this Where Does Ringo Starr Live?