Daisy Chain Power Supply A best guitar pickup is basically similar to a powerful microphone coil. For decades, active microphones have been sent with the voice coil attached with the principal of the microphone's transformer, and maybe not called to surface (‘floating'). The microphone's case is usually linked to the wire guard, which can be connected to the mike amplifier's ground (see Rane's web site for more discussion).
By and big, powerful microphones are extremely calm products as a result of the mix of transformer isolation and healthy, flying transmission lines throughout, in addition to shielded, humbucking coils.
So you will want to guitars? Instruments are notoriously plagued by noise. Humbucking pickups are merely an incomplete (though essential!) solution. The obvious option is to float your guitar pickup to a healthy production, as being a microphone. A similar idea was printed this 2001 patent program like this Daisy Chain Power Supply?