Pat Quilter began building amplifiers in 1967 as the Quilter Sound Company (QSC). Along with Barry Andrews and later John Andrews, Quilter produced a line of solid-state amplifiers and speaker cabinets that were similar to the large applications that were popular during this era (i.e. Kustom, Earth Sound Research, EBS, etc.). After building guitar amplifiers proved to be unsuccessful in the 1970s, they began focusing on power amps and speaker cabinets (QSC). In the 2010's, Pat Quilter began building Quilter Sound amps again near the QSC factory.
Amplifiers currently produced in the U.S. since the 2010s. Previously produced between the late 1960s and early 1970s in Costa Mesa, CA. Distributed by the Quilter Sound Company.