Bass Guitar Preamplifier Circuit Diagram A best guitar pickup is actually similar to an energetic mike coil. For decades, dynamic microphones have been wired with the style coil mounted on the primary of the microphone's transformer, and not introduced to surface (‘floating'). The microphone's case is usually connected to the cable shield, that will be connected to the mike amplifier's soil (see Rane's website for more discussion).
By and large, dynamic microphones are very quiet units as a result of the mixture of transformer isolation and balanced, suspended indication lines during, in addition to guarded, humbucking coils.
So why don't you instruments? Instruments are notoriously affected by noise. Humbucking pickups are just an incomplete (though important!) solution. The most obvious option is to move practicing the guitar pickup to a balanced output, being a microphone. The same strategy was printed that 2001 patent application like this Bass Guitar Preamplifier Circuit Diagram?