Keyboard Amp Vs Powered Speaker A best guitar pickup is essentially just like a powerful mike coil. For decades, powerful microphones have already been wired with the voice coil mounted on the primary of the microphone's transformer, and perhaps not referenced to ground (‘floating'). The microphone's situation is normally connected to the cable shield, which is attached to the mike amplifier's soil (see Rane's website for more discussion).
By and large, powerful microphones are very calm products consequently of the combination of transformer isolation and balanced, flying sign lines throughout, along with shielded, humbucking coils.
So why don't you instruments? Instruments are notoriously plagued by noise. Humbucking pickups are only an incomplete (though important!) solution. The most obvious alternative would be to float your guitar pickup to a balanced output, being a microphone. The same idea was published that 2001 patent program such as Keyboard Amp Vs Powered Speaker?