Art Headphone Amp A guitar collection is actually much like an energetic microphone coil. For decades, energetic microphones have been wired with the voice coil attached with the primary of the microphone's transformer, and perhaps not called to soil (‘floating'). The microphone's situation is typically linked to the wire shield, that is linked to the microphone amplifier's floor (see Rane's web site for more discussion).
By and big, vibrant microphones are extremely quiet units consequently of the mix of transformer isolation and balanced, floating transmission lines throughout, along with shielded, humbucking coils.
Therefore why don't you instruments? Instruments are once affected by noise. Humbucking pickups are only an incomplete (though crucial!) solution. Well-known alternative would be to float your guitar collection to a balanced result, being a microphone. The same thought was printed this 2001 patent program like this Art Headphone Amp?