Dynamic Microphones Are A electric guitar collection is basically just like a powerful microphone coil. For many years, energetic microphones have been wired with the voice coil attached with the primary of the microphone's transformer, and maybe not called to ground (‘floating'). The microphone's case is typically attached to the cable shield, which can be linked to the microphone amplifier's soil (see Rane's site for more discussion).
By and big, vibrant microphones are extremely quiet devices as a result of the mix of transformer solitude and balanced, hanging sign lines during, along with guarded, humbucking coils.
So why not instruments? Guitars are once affected by noise. Humbucking pickups are only an incomplete (though crucial!) solution. The obvious option is to float practicing the guitar collection to a balanced output, being a microphone. A similar thought was printed this 2001 patent request like this Dynamic Microphones Are?