Line 6 Relay 50 A electric guitar collection is essentially just like a powerful microphone coil. For decades, active microphones have been sent with the voice coil attached to the principal of the microphone's transformer, and maybe not referenced to ground (‘floating'). The microphone's case is normally attached to the wire shield, which will be attached to the microphone amplifier's ground (see Rane's website for more discussion).
By and big, vibrant microphones are extremely quiet units consequently of the combination of transformer isolation and balanced, suspended transmission lines during, in addition to guarded, humbucking coils.
Therefore why not guitars? Instruments are notoriously plagued by noise. Humbucking pickups are just a partial (though essential!) solution. The most obvious answer would be to move practicing the guitar collection to a healthy productivity, as being a microphone. A similar idea was printed this 2001 patent program such as Line 6 Relay 50?