M Audio Uno A electric guitar pickup is actually much like a dynamic microphone coil. For many years, active microphones have been sent with the style coil attached to the primary of the microphone's transformer, and maybe not introduced to ground (‘floating'). The microphone's case is usually linked to the cable shield, that is attached to the microphone amplifier's ground (see Rane's internet site for more discussion).
By and large, dynamic microphones are very quiet products consequently of the mix of transformer isolation and balanced, flying sign lines throughout, along with protected, humbucking coils.
So why don't you instruments? Guitars are notoriously plagued by noise. Humbucking pickups are only a partial (though essential!) solution. The most obvious answer is always to move practicing the guitar collection to a balanced result, as being a microphone. The same strategy was published this 2001 patent software such as M Audio Uno?