Rule 6: Insist on Quiet Electronics.

The pick-ups on guitars and basses must be shielded as well as possible from extraneous sound such as humming and buzzing and encapsulated to prevent microphonic feedback. Sometimes in rock, feedback is desirable, but when it is unintentional, it's a nuisance. Hum and buzz are always objectionable.

The quietest pick-ups are Humbuckers, invented at Gibson by Seth Lover in the fifties.

Humbuckers have two coils with reverse polarities wired out of phase for virtually no extraneous noise. The signal, however, is actually "beefed-up" for a fatter tone.

Some players prefer the single-coil-sound because pick-ups have different resonant frequencies. Generally speaking, single coil pick-ups peak in the high midrange and are bright sounding. Double coil Humbuckers peak in the low midrange and have a richer sound. Single coil pick-ups may also be preferable in applications where a very quick attack is needed.

The Nighthawk with coiltapped humbucker switch

Split coil pick-ups are a more recent development. With the flip of a switch, the pick-ups is either single or double coil. With up to three split coil pick-ups, Gibson's new Nighthawk guitar is capable of a whole range of distinctive sounds.

When an amplified acoustic sound is applicable, piezo pick-ups are the answer. Piezos work on a completely different principle to capture a broad range of frequencies. The piezo signal is produced directly from the strings' vibration without using a magnetic field. The full harmonic content of strings is reproduced for the most acoustic tone that can be attained with a solid body guitar.

Whatever the type of pick-up, steps can be taken to isolate them from unwanted, extraneous noise. Gibson's piezo pick-ups are encapsulated in a marine-grade epoxy. Other Gibson pick-up types are double saturated in paraffin.

An active circuit is achieved with a battery operated pre-amplifier which gives active treble and bass controls instead of passive potentiometers. An active circuit has the advantage of more responsive tone controls and a lower output impedance than traditional passive circuitry.