Quad

About Quad

Quad (Quality Unit Amplifier Domestic) is a British hi-fi manufacturer founded by Peter Walker in 1936 in Huntingdon, England, and now part of the IAG Group. The company is celebrated for two landmark innovations: the ESL-57 electrostatic loudspeaker (1957), widely regarded as a defining achievement in speaker design, and the current-dumping amplifier topology introduced in the Quad 405 (1975). Quad's product range spans electrostatic and ribbon loudspeakers, valve and solid-state power amplifiers, preamplifiers, and integrated electronics, all designed around the engineering principle of producing sound that is as close as possible to the original performance.