James Jamerson's double bass was a German upright acoustic bass that he bought as a teenager and later used on such Motown hits as "My Guy" by Mary Wells and "(Love Is Like a) Heat Wave" by Martha and the Vandellas.
The electric bass Jamerson played was a stock 1962 Fender Precision Bass which was dubbed "The Funk Machine." Jamerson bought it after his first Precision (a gift from fellow bassist Horace "Chili" Ruth) was stolen. It had a three-tone sunburst finish, a tortoise-shell pickguard, and chrome pickup and bridge covers (the latter containing a piece of foam used to dampen sustain). He typically set its volume and tone knobs on full. This instrument was also stolen, just days before Jamerson's death in 1983. To date, it has not been found.
James Jamerson used La Bella heavy-gauge (.052-.110) flatwound strings that he never changed. He never took care of the instrument, and it is possible that the neck eventually warped, as many claimed it impossible to play. While this made it more difficult to fret, Jamerson believed it improved the quality of the tone. Early in the '70s, a producer attempted to modernize James Jamerson's sound by asking the bassist to switch to brighter-sounding roundwound bass strings. Jamerson politely declined.
One aspect of James Jamerson's upright playing that carried over to the electric bass guitar was the fact that he generally used only his right index finger to pluck the strings while resting his 3rd and 4th fingers on the chrome pickup cover. Jamerson's index finger even earned its own nickname: "The Hook".
Jamerson's amplifier of choice at club performances was an Ampeg B-15; in larger venues, he used a blue Naugahyde Kustom with twin 15" speakers. On both, the bass was typically turned up full and the treble turned halfway up. On most of his studio recordings, his bass was plugged directly into the mixing console.