Proco Rat Pedal A guitar pickup is actually just like a powerful mike coil. For many years, active microphones have been wired with the voice coil attached with the principal of the microphone's transformer, and perhaps not called to ground (‘floating'). The microphone's case is usually attached to the wire shield, which will be connected to the mike amplifier's soil (see Rane's web site for more discussion).
By and big, vibrant microphones are extremely calm devices consequently of the mix of transformer solitude and healthy, flying sign lines for the duration of, in addition to guarded, humbucking coils.
So why not instruments? Instruments are once affected by noise. Humbucking pickups are only a partial (though essential!) solution. Well-known option is always to move the guitar collection to a balanced result, just like a microphone. A similar strategy was published this 2001 patent request like this Proco Rat Pedal?