Born in Pitcairn, Pennsylvania to a large musical family, he moved to New York City in 1967 to pursue a career as a jazz guitarist. After working in a guitar shop to supplement his income, he started his own guitar repair business. He made his first instrument in 1974 and quickly gained renown in the craft.
Unusual custom bass guitars made by Carl Thompson are the piccolo bass - a guitar of the same dimensions as a normal bass but tuned an octave higher - and five and six-stringed contra-bass guitars. Carl is attributed with creating both the first electric piccolo bass (commissioned by Stanley Clarke) and the first fretless six string bass.
Carls biggest endorsee is Les Claypool of the band Primus who plays and owns seven Carl Thompson basses, his most famous being "the Rainbow Bass".
Thompson basses are sought after and he maintains a two year waiting list, though some orders can take well over three years to complete. The cost for a basic four string bass made by Thompson is about $4,000. Basses such as the "Rainbow Bass" can cost well over $10,000 although Carl will not make copies of the bass for his clients despite being asked to do so in the past - he maintains that all his basses are "one of a kind".