Sony Uwp D12 Integrated Digital Wireless Handheld Microphone Eng System A guitar pickup is basically similar to an energetic microphone coil. For decades, active microphones have been sent with the voice coil mounted on the principal of the microphone's transformer, and perhaps not introduced to soil (‘floating'). The microphone's case is typically linked to the wire shield, which is connected to the microphone amplifier's soil (see Rane's internet site for more discussion).
By and big, dynamic microphones are very calm devices consequently of the mixture of transformer solitude and healthy, floating transmission lines for the duration of, along with guarded, humbucking coils.
Therefore why not instruments? Instruments are notoriously plagued by noise. Humbucking pickups are only an incomplete (though important!) solution. The obvious option would be to float your guitar pickup to a balanced output, being a microphone. An identical idea was published that 2001 patent program such as Sony Uwp D12 Integrated Digital Wireless Handheld Microphone Eng System?