In electric and electronic instruments, tone is also affected by the amplifiers, effects, and speakers used by the musician.
The instrument's shape, particularly of its resonant cavity, as well as the choice of tonewood for the body, neck, and fingerboard, are all major determinants of its tone.
At minimum, the signal path will consist of the instrument, a preamplifier, a power amplifier, and one or more speakers.
Preamplifiers and signal processing units typically provide multiple controls to allow the user to "dial in" their tone.
Electronic keyboards and synthesizers typically have multiple patches that can be selected to make the instrument produce a different timbre.