Speaker Aux Cable A guitar pickup is essentially just like a dynamic microphone coil. For decades, powerful microphones have now been sent with the voice coil mounted on the principal of the microphone's transformer, and maybe not recommended to floor (‘floating'). The microphone's situation is normally attached to the wire guard, which will be connected to the microphone amplifier's ground (see Rane's site for more discussion).
By and big, energetic microphones are very calm products as a result of the mix of transformer isolation and healthy, floating indication lines through the duration of, along with shielded, humbucking coils.
So why not instruments? Instruments are notoriously plagued by noise. Humbucking pickups are only a partial (though crucial!) solution. The obvious solution is to float the guitar pickup to a balanced output, as being a microphone. A similar strategy was printed this 2001 patent program like this Speaker Aux Cable?