Quad Electroacoustics

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Quad Electroacoustics is a British manufacturer of hi-fi equipment, based in Huntingdon, England.

Corporate history

The company was founded by Peter J. Walker in 1936 in London, and was initially called S.P. Fidelity Sound Systems. In 1936 the name was changed to the Acoustical Manufacturing Co. Ltd. The company moved from London to Huntingdon in 1941 after being bombed out of London in World War II.

The company initially produced only Public Address equipment but after the war they began to produce equipment designed for use in the home as a result of the rising demand for high quality domestic sound reproduction. Within a few years the company had transitioned almost entirely to manufacturing models for the home audio market.

The name "QUAD" is an acronym for "Quality Unit Amplified Domestic", used to describe the QUAD I amplifier. In 1983, when having become known for their QUAD range of products, the Acoustical Manufacturing Co. Ltd changed its name to QUAD Electroacoustics Ltd.

In 1995, QUAD Electroacoustics Ltd was bought by Verity Group plc, joining its existing brands of Wharfedale and Mission. A few changes were made, including shifting some loudspeaker production to East China, but the company essentially stayed the same, and still tries to adhere to its ethos of "the closest approach to the original sound".

Pioneering Audio Products

The company’s first products were released in 1948. The QA12 and QA12/P were low-powered mono vacuum tube designs. This unit’s sound quality reproduction was high compared with other products on the market at the time, and was thus adopted for use by the BBC.

Following the development of stereo records in 1958, the QC 22 control unit was developed and released in 1959. This was a stereo control unit that was designed to be used with a pair of QUAD II mono amplifiers. To complement the QUAD II, the company also produced AM and FM tuners for use with the QC II & 22 control units.

In 1957, the company made history when they released the world's first production electrostatic loudspeaker - the ESL-57. It used ultra-thin stretched mylar as the main component of its drive units. The mylar sheet is coated with a mildly electrically conductive paste and is sandwiched between 2 stators. A very high voltage is applied to the mylar and to the stators. Sound is produced by varying the charge on the stators to set the mylar in motion. Two bass panels flank one treble panel to provide full range sound.

The critical and popular success of the ESL-57, and later the ESL-63, means that the QUAD name is almost synonymous today with the electrostatic loudspeaker design.

Quad have always had a very straight forward engineering view of their products. Peter Walker insisted that all amplifiers sounded the same when used within their capabilities and that speaker cable had no sound at all unless ludicrously long and thin.

Peter J. Walker died in 2003 at the age of 87.


  • 1936, S.P. Fidelity Sound Systems founded by Peter J. Walker.
  • 1936, The company name changed to the Acoustical Manufacturing Co. Ltd.
  • 1941, The company moved to Huntingdon.
  • 1948, The QA12/ QA12/P amplifiers - the first product for domestic (consumer) market
  • 1950, QUAD I, (15 watt mono amplifier) released. Discontinued 1953.
  • 1953, launched the QUAD II amplifier, made until 1970.
  • 1957, released the ESL-57, the world's first production electrostatic loudspeaker.
  • 1959, the QC 22 stereo control unit released along with separate AM and FM tuners.
  • 1966, launched the first mono transistor amplifier, the 50 and 50/E, for the professional market.
  • 1967, launched 303 stereo amplifier for domestic use, accompanied by the all-transistor QUAD 33 control unit. Discontinued around 1985.
  • 1975, The QUAD 405 power amplifier released. replaced by the 405-2 in 1982. The 405-2 was discontinued 1993.
  • late 1970’s , released two new control units - the QUAD 34 and 44.
  • 1983, changed its name to QUAD Electroacoustics Ltd.
  • 1983, new electrostatic loudspeaker, the ESL-63.
  • mid-80s , released the QUAD 66/606 system, the first QUAD CD player.
  • 1993, launched the 77 series.
  • 1993, launched the L series conventional loudspeakers.
  • 1995, QUAD Electroacoustics Ltd acquired by Verity Group plc, joining its existing brands, Wharfedale and Mission
  • 1999, QUAD released the QUAD 99 system; resurrected the legendary QUAD II as the QUAD II-Forty
  • 2006, QUAD released the ESL-2805 and ESL-2905 electrostatic loudspeakers

External links