Quad Electroacoustics
Encyclopedia
Quad Electroacoustics is a British manufacturer of hi-fi equipment, based in Huntingdon
, England
.
, 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 Amplifier 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 all production to Shenzhen China, managed in the UK by an accountant with little interest in Hi-Fi or engineering. However, the company's design ethos of "the closest approach to the original sound" was nominally preserved.,
In September 1997 the company changed ownership again as Verity Group sold off businesses to finance its development of flat panel loudspeakers. With Wharfedale it became part of the International Audio Group under the management of Bernard and Michael Chang. Its products continue to be made entirely in China and it is now debatable whether or not Quad can any longer be considered a truly British hi-fi producer.
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.
The company made the transition to transistor-powered models in 1966 with the "professional" QUAD 50 monoblock which had a tapped transformer output and then the commercial 33/303 preamplifier and stereo power amplifier combination and later with the 44/405 and subsequent 66/606 and 909 models. They also made a range of AM and FM tuners.
Up until 1995 (the end of the British QUAD era) the number of the power amplifier indicated the total power output i.e.
the 303 was 30x3=90W or 45w per channel 8Ω load
the 405 was 40x5=200W or 100W per channel 8Ω load
Even the 606 was 60x6=360W or 180W per channel but this time into 4Ω load
The 500 series was a slight variation
Product Range
Control Unit - Pre Amplifiers
QUAD 33 - 1967 to 1982 - 120,000 units
QUAD 44 - 1979 to 1989 - 40,000 units
QUAD 34 - 1982 to 1995 - 41,000 units
QUAD 66 - 1989 to 1996 - 12,000 units
QUAD 77
QUAD 99
Current Dumping Power Amplifiers
QUAD 405 - 1975 to 1982 - 64,000 units
Quad 405-2 1982 to 1993 - 100,000 units
Quad 306 - 1986 to 1995 - 25,000 units
Quad 606 - 1986 to 1997 - 27,700 units
Quad 707
Quad 909
Other (Conventional) Power Amplifiers
Quad 303 - 1967 to 1985 - 94,000
Quad 77 Integrated
In 1957, the company made history when they released the world's first production full frequency range electrostatic loudspeaker
. This unit is now referred to by enthusiasts as the ESL-57, although the company did not refer to it by that name. It used ultra-thin stretched PET film
as the main component of its drive units. The PET film is coated with a mildly electrically conductive paste and is sandwiched between 2 stators. A very high voltage is applied to the PET film and to the stator
s. Sound is produced by varying the charge on the stators to set the PET film in motion. Two bass panels flank one treble panel to provide full range sound.
The ESL-57 was quickly adopted by the BBC for monitoring the sound quality of their broadcasts. The BBC eventually replaced them with moving coil based monitor speakers developed by several manufacturers to meet BBC specifications, such as the highly successful LS3/5a, that were more easily transported and stored, and were more representative of typical contemporary hi-fi speakers.
Renowned as they were (and still are) for sonic transparency and very low distortion, a well set up stereo pair has a very small 'sweet spot' where the sound stage snaps into focus, moderate power handling, the need for a large room, and moderate bass extension. Although they are sometimes criticised for their directionality, this is rarely a problem and has the benefit of reducing room resonances.
Quad addressed the ESL-57's limitations to some degree with the ESL-63, introduced in 1981. The newer design featured larger panels and a groundbreaking stator design, made up of eight concentric rings fed from the center outwards through analogue delay lines, so that the audio signal radiated out as though coming from a single point. Subsequent electrostatic models, the 988/989 and then the 2805/2905 were successive refinements of the ESL-63 design, featuring increased power handling and output levels, more sophisticated overload protection, and greater structural rigidity.
Following the Verity acquisition, Quad developed and market a range of conventional electrodynamic loudspeakers alongside its electrostatic line, available in both passive and active (i.e. featuring in-box amplification) configurations.
Remarkably, customer demand resulted in manufacture of the ESL-57 continuing in the UK until 1996. The tooling was then bought by QUAD's representative in Germany, QUAD Musikwiedergabe; who continue to manufacture complete speakers and spare parts, and overhaul customers' speakers. In fact this speaker was so in demand that when Quad stopped servicing it, all around the world small companies emerged dedicated to servicing this speaker. Most notably: Gary Jacobson (AU), Wayne Picquet (USA), Sheldon Stokes (USA), One Thing Audio (UK) and ESL Labs (NL) offer full restoration, parts and service for the Quad ESL.
Bass extension of the ESL-57s can be improved by means of one or two sub-woofers, or, if space and appearance permit, by stacking them in pairs, one above the other.
The company's founder, Peter J. Walker, died in 2003 at the age of 87. He had retired in the late 1980s, then turning management over to his son.
Huntingdon
Huntingdon is a market town in Cambridgeshire, England. The town was chartered by King John in 1205. It is the traditional county town of Huntingdonshire, and is currently the seat of the Huntingdonshire district council. It is known as the birthplace in 1599 of Oliver Cromwell.-History:Huntingdon...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
.
Corporate history
The company was founded by Peter J. Walker in 1936 in LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, 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
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
to Huntingdon in 1941 after being bombed out of London in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
The company initially produced only public address
Public address
A public address system is an electronic amplification system with a mixer, amplifier and loudspeakers, used to reinforce a sound source, e.g., a person giving a speech, a DJ playing prerecorded music, and distributing the sound throughout a venue or building.Simple PA systems are often used in...
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 Amplifier 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
Public limited company
A public limited company is a limited liability company that sells shares to the public in United Kingdom company law, in the Republic of Ireland and Commonwealth jurisdictions....
, joining its existing brands of Wharfedale
Wharfedale (company)
Wharfedale is the name of a prominent audio equipment manufacturer in the UK, best known for its loudspeakers. It is currently part of the International Audio Group.Wharfedale also used to manufacture televisions, DVD players, set-top boxes and Hi-Fi players...
and Mission. A few changes were made, including shifting all production to Shenzhen China, managed in the UK by an accountant with little interest in Hi-Fi or engineering. However, the company's design ethos of "the closest approach to the original sound" was nominally preserved.,
In September 1997 the company changed ownership again as Verity Group sold off businesses to finance its development of flat panel loudspeakers. With Wharfedale it became part of the International Audio Group under the management of Bernard and Michael Chang. Its products continue to be made entirely in China and it is now debatable whether or not Quad can any longer be considered a truly British hi-fi producer.
Audio products
The company’s first products were released in 1948. The QA12 and QA12/P were low-powered mono valveVacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
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
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
.
Amplification
AM broadcasting
AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. Commercial and public AM broadcasting is carried out in the medium wave band world wide, and on long wave and short wave...
and FM
FM broadcasting
FM broadcasting is a broadcasting technology pioneered by Edwin Howard Armstrong which uses frequency modulation to provide high-fidelity sound over broadcast radio. The term "FM band" describes the "frequency band in which FM is used for broadcasting"...
tuners
Tuner (radio)
A radio tuner is a subsystem that receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, Digital Audio Broadcasting DAB tuner, etc. are types of radio tuner dealing with transmissions using different...
for use with the QC II & 22 control units.
The company made the transition to transistor-powered models in 1966 with the "professional" QUAD 50 monoblock which had a tapped transformer output and then the commercial 33/303 preamplifier and stereo power amplifier combination and later with the 44/405 and subsequent 66/606 and 909 models. They also made a range of AM and FM tuners.
Up until 1995 (the end of the British QUAD era) the number of the power amplifier indicated the total power output i.e.
the 303 was 30x3=90W or 45w per channel 8Ω load
the 405 was 40x5=200W or 100W per channel 8Ω load
Even the 606 was 60x6=360W or 180W per channel but this time into 4Ω load
The 500 series was a slight variation
Product Range
Control Unit - Pre Amplifiers
QUAD 33 - 1967 to 1982 - 120,000 units
QUAD 44 - 1979 to 1989 - 40,000 units
QUAD 34 - 1982 to 1995 - 41,000 units
QUAD 66 - 1989 to 1996 - 12,000 units
QUAD 77
QUAD 99
Current Dumping Power Amplifiers
QUAD 405 - 1975 to 1982 - 64,000 units
Quad 405-2 1982 to 1993 - 100,000 units
Quad 306 - 1986 to 1995 - 25,000 units
Quad 606 - 1986 to 1997 - 27,700 units
Quad 707
Quad 909
Other (Conventional) Power Amplifiers
Quad 303 - 1967 to 1985 - 94,000
Quad 77 Integrated
Loudspeakers
In late 1949 (or early 1950), the company launched the CR corner ribbon loudspeaker. This used a Goodmans Axiom 150 cone loudspeaker for the lower frequencies and an electromagnetic ribbon loudspeaker, designed by Acoustical, for the higher frequencies. Fewer than one thousand units were sold.In 1957, the company made history when they released the world's first production full frequency range electrostatic loudspeaker
Electrostatic loudspeaker
An electrostatic loudspeaker is a loudspeaker design in which sound is generated by the force exerted on a membrane suspended in an electrostatic field.-Design and functionality:...
. This unit is now referred to by enthusiasts as the ESL-57, although the company did not refer to it by that name. It used ultra-thin stretched PET film
PET film (biaxially oriented)
BoPET is a polyester film made from stretched polyethylene terephthalate and is used for its high tensile strength, chemical and dimensional stability, transparency, reflectivity, gas and aroma barrier properties and electrical insulation.A variety of companies manufacture boPET and other...
as the main component of its drive units. The PET film is coated with a mildly electrically conductive paste and is sandwiched between 2 stators. A very high voltage is applied to the PET film and to the stator
Stator
The stator is the stationary part of a rotor system, found in an electric generator, electric motor and biological rotors.Depending on the configuration of a spinning electromotive device the stator may act as the field magnet, interacting with the armature to create motion, or it may act as the...
s. Sound is produced by varying the charge on the stators to set the PET film in motion. Two bass panels flank one treble panel to provide full range sound.
The ESL-57 was quickly adopted by the BBC for monitoring the sound quality of their broadcasts. The BBC eventually replaced them with moving coil based monitor speakers developed by several manufacturers to meet BBC specifications, such as the highly successful LS3/5a, that were more easily transported and stored, and were more representative of typical contemporary hi-fi speakers.
Renowned as they were (and still are) for sonic transparency and very low distortion, a well set up stereo pair has a very small 'sweet spot' where the sound stage snaps into focus, moderate power handling, the need for a large room, and moderate bass extension. Although they are sometimes criticised for their directionality, this is rarely a problem and has the benefit of reducing room resonances.
Quad addressed the ESL-57's limitations to some degree with the ESL-63, introduced in 1981. The newer design featured larger panels and a groundbreaking stator design, made up of eight concentric rings fed from the center outwards through analogue delay lines, so that the audio signal radiated out as though coming from a single point. Subsequent electrostatic models, the 988/989 and then the 2805/2905 were successive refinements of the ESL-63 design, featuring increased power handling and output levels, more sophisticated overload protection, and greater structural rigidity.
Following the Verity acquisition, Quad developed and market a range of conventional electrodynamic loudspeakers alongside its electrostatic line, available in both passive and active (i.e. featuring in-box amplification) configurations.
Remarkably, customer demand resulted in manufacture of the ESL-57 continuing in the UK until 1996. The tooling was then bought by QUAD's representative in Germany, QUAD Musikwiedergabe; who continue to manufacture complete speakers and spare parts, and overhaul customers' speakers. In fact this speaker was so in demand that when Quad stopped servicing it, all around the world small companies emerged dedicated to servicing this speaker. Most notably: Gary Jacobson (AU), Wayne Picquet (USA), Sheldon Stokes (USA), One Thing Audio (UK) and ESL Labs (NL) offer full restoration, parts and service for the Quad ESL.
Bass extension of the ESL-57s can be improved by means of one or two sub-woofers, or, if space and appearance permit, by stacking them in pairs, one above the other.
Principles
Quad have always had a very straightforward engineering view of their products, and 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 wire is used.The company's founder, Peter J. Walker, died in 2003 at the age of 87. He had retired in the late 1980s, then turning management over to his son.
Milestones
- 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, the world's first production full-range electrostatic loudspeakerElectrostatic loudspeakerAn electrostatic loudspeaker is a loudspeaker design in which sound is generated by the force exerted on a membrane suspended in an electrostatic field.-Design and functionality:...
, later referred to as the ESL-57. Technology licensed to Braun company Germany in 1959 (loudspeaker BRAUN LE1) - 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 1970s , released two new control units - the QUAD 34 and 44.
- 1981, new electrostatic loudspeaker, the ESL-63.
- 1983, changed its name to QUAD Electroacoustics Ltd.
- mid-80s , released the QUAD 66/606 system, along with the first QUAD CD player.
- 1993, launched the 77 series.
- 1993, launched the L series dynamic loudspeakers.
- 1995, QUAD Electroacoustics Ltd acquired by Verity Group plc, joining its existing brands, Wharfedale and Mission
- 1996, Manufacture of ESL-57 transferred to QUAD Musikwiedergabe.
- 1999, QUAD released the QUAD 99 system; resurrected the legendary QUAD II and the QUAD II-Forty
- 2000, QUAD released the ESL-988 and ESL-989, based on the legendary ESL-63
- 2006, QUAD released the ESL-2805 and ESL-2905, redesigned versions of the ESL-988 and ESL-989.
- 2006, QUAD released the L2 series loudspeakers.