Charlie Christian pickup
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The "Charlie Christian" pickup was an early electric guitar pickup. It was first used on the Gibson ES-150, which entered the market in 1936. The ES-150 was the first electric "Spanish-style" guitar; previous electric guitars had been designed to be played lap, or "Hawaiian" style. Jazz musician Charlie Christian's pioneering use of the ES-150 demonstrated to the world that the electric guitar was a viable instrument. The association between Christian and the ES-150 was so strong that it became known as the "Charlie Christian Guitar" (even though no formal association between Christian and Gibson ever existed), and the pickup that gave the instrument its voice was referred to as the "Charlie Christian pickup."
Although the principle of the magnetic induction coil had been applied to musical instruments for years, the Charlie Christian pickup represented a departure from previous ideas. Earlier pickups featured either a horseshoe magnet that arched over the strings (as found on the Rickenbacker A-22 "Frying Pan"), or a static coil through which a magnet passed, the magnet being vibrated by the guitar's bridge (a design used by former Gibson employee Lloyd Loar on his Vivitone guitar). The Charlie Christian pickup has an appearance immediately familiar to modern guitarists, although it is constructed quite differently from pickups today.
[edit] Physical Properties
The Charlie Christian pickup consists of a coil of wire wound around a bobbin to about 7 kΩ resistance. The coil has a rectangular hole in its center, and the coil and bobbin fit around a chrome-plated steel blade polepiece. Attached at right angles to the bottom of the polepiece are a pair of five-inch-long steel bar magnets, which remain out of sight inside the instrument. These magnets are secured to the top of the ES-150 by the three bolts visible on the guitar's top. The entire assembly is about six inches long, and weighs nearly two pounds.
There were three different varieties of Charlie Christian pickup produced by Gibson, and all three are distinguished by the polepiece. The first of these was produced from 1936 until mid-1938 and had a plain blade polepiece. The second type was introduced on ES-150s built from mid-1938 onward, and featured a polepiece that had a notch cut out below the second (B) string. This modification was made to lower the volume of the B string, which sounded significantly louder than the other strings. The third pickup was available on Gibson's ES-250, which was available beginning in 1939. The blade on this pickup had five notches, each located between the strings.
[edit] Sound
The sound this pickup produced is clear—thanks to the narrow string-sensing blade—and powerful because of the relatively high resistance of the coil. Uneven magnetic flux within the steel magnets could cause some distortion in the signal. Electrostatic hum was a big problem with these pickups because of their large surface area and utter lack of shielding.
After guitar production resumed following World War II, the invention of ceramic and alnico magnets made it possible to build a smaller, lighter guitar pickup. The Charlie Christian pickup has fallen into the realm of legend, as it has been available on only one guitar produced since 1942. The 1978 Gibson ES-175CC shipped 489 units with "recreated" Charlie Christian pickups.
