Akai Advance 49 A guitar collection is actually much like a powerful mike coil. For many years, dynamic microphones have now been sent with the voice coil attached to the principal of the microphone's transformer, and perhaps not referenced to ground (‘floating'). The microphone's event is usually connected to the cable shield, that is attached to the mike amplifier's soil (see Rane's web site for more discussion).
By and big, active microphones are extremely quiet devices consequently of the mixture of transformer isolation and balanced, hanging indication lines through the duration of, in addition to shielded, humbucking coils.
So why not instruments? Instruments are once plagued by noise. Humbucking pickups are only an incomplete (though important!) solution. The most obvious alternative is always to move your guitar pickup to a healthy production, just like a microphone. The same idea was printed that 2001 patent request such as Akai Advance 49?