Ampeg is primarily a musical instrument amplifier

Instrument amplifier

An instrument amplifier is an electronic amplifier that converts the often barely audible or purely electronic signal from musical instruments such as an electric guitar, an electric bass, or an electric keyboard into an electronic signal capable of driving a loudspeaker that can be heard by the...

 manufacturer headquartered in Woodinville, Washington, though they also manufacture guitars to a small extent. Although the company specializes in the production of bass guitar

Bass guitar

The bass guitar is a stringed instrument played primarily with the fingers or thumb , or by using a pick....

 amplification, Ampeg also manufactures electric guitar

Electric guitar

An electric guitar is a guitar that uses the principle of direct electromagnetic induction to convert vibrations of its metal strings into electric audio signals. The signal generated by an electric guitar is too weak to drive a loudspeaker, so it is amplified before sending it to a loudspeaker...

 and double bass

Double bass

The double bass, also called the string bass, upright bass, standup bass or contrabass, is the largest and lowest-pitched bowed string instrument in the modern symphony orchestra, with strings usually tuned to E1, A1, D2 and G2...

 amplifiers.
Ampeg first existed under the name "Michaels-Hull Electronic Labs" in 1946, as a partnership between Everett Hull, an accomplished pianist and bassist, and Stanley Michaels.