Black Sabbath Live A guitar collection is essentially just like a dynamic microphone coil. For many years, active microphones have been wired with the voice coil attached to the primary of the microphone's transformer, and not referenced to soil (‘floating'). The microphone's case is normally attached to the wire shield, that will be connected to the microphone amplifier's ground (see Rane's site for more discussion).
By and large, vibrant microphones are extremely quiet products consequently of the mixture of transformer isolation and healthy, flying sign lines throughout, along with shielded, humbucking coils.
So why don't you instruments? Guitars are once overwhelmed by noise. Humbucking pickups are just an incomplete (though crucial!) solution. The most obvious answer would be to move your guitar pickup to a balanced result, being a microphone. A similar thought was published that 2001 patent software like this Black Sabbath Live?