Quad manufactures or has manufactured the following equipment (click to expand models list):Cables
Articles on Quad amplifiers
Current dumping audio amplifier (PDF article) (by P.J. Walker, Wireless World, December 1975) (Provided by Willy Lefebvre)
Amplifiers and superlatives (PDF article) (by P.J. Walker, Wireless World, September 1952)
Articles on Quad speakers
Wide Range Electrostatic Loudspeakers by P.D. Walker - version 1. (PDF article) (Provided by Willy Lefebvre)
Wide Range Electrostatic Loudspeakers by P.D. Walker - version 2. (PDF article) (Provided by Rolv-Karsten Roenningstad)
These articles contain the following articles that appeared in Wireless World from May 1955 to August 1955.
- Principles of Design for Operation at Low as well as High Frequencies with Negligible Distortion
- Problems of Air Loading : Different Requirements of Moving-coil and Electrostatic Drive Units
- Complete Systems Loudspeaker/Room Relationships
Huntingdon on the Quad website (December 12, 2003): It is with great sadness that we announce the death of Peter Walker. Although he had not been actively involved in running the company for several years, his work and philosophy remain an inspiration to everyone at QUAD.
Geoffrey Horn, an industry professional, one time colleague and lifelong friend of Peter Walker has written the following passage:
"Peter J Walker OBE DSc founder of the Acoustical Manufacturing Company, later better known as QUAD, died peacefully at the age of 87 on Wednesday December 10th, 2003. Formed in 1936 as a one man business specialising in amplification for Public Address, he was bombed out of his London works early in WW II and settled in Huntingdon. After the war, with a burgeoning public regard for music, he decided the time was right to diversify into what became known as High-Fidelity. Designing and producing a series of amplifiers and loudspeakers he soon established his company as a leader in its field; his products were always notable for novelty of approach and economy of design.
A long held belief in the possibility of making a different type of loudspeaker based on electrostatic principles became his most important life's work and he spent many periods of intensive research, spread over the years, fighting the many hurdles the project threw up. This work lead to the world's first full range electrostatic loudspeaker, which reached the market in 1957. Its successors are still very highly regarded to this day. Alongside, work on amplifiers was not neglected and his company secured the rare Queen's Award for Technological Achievement in 1978.
Throughout his life he was also highly regarded as a man, greatly treasured by his staff and admired by the industry in general. In his early days he had played saxophone in a dance band and later in life took up the flute, performing in local orchestras. Music has always been his inspiration. Peter James Walker had been married twice, both his wives had predeceased him. He is succeeded by a daughter Victoria and a son Ross, but perhaps his real successors are the products of his brilliant mind, spread all over the world, which continue to give great joy to their owners."
Audio Amateur interviews Peter Walker at the Quad Factory in 1978 (Edward T. Dell, Jr. graciously granted permission to reprint this article)(article provided by Christian Steingruber, February 2001)
Hifi-review interviews Ross Walker at the Quad Factory in 1989 (article provided by Christian Steingruber, January 2002)
Quad web site (January 2001): The history of Quad is one of audio excellence. The early products were all firsts of their particular type and cast the mould for the products which would follow for many years afterwards. Quad products are renowned for their longevity, and a journalist recently commented that new Quad products come along slightly less frequently than leap years.
You might think that this would leave us trailing behind other manufacturers, but quite the opposite applies. Instead, every product Quad releases is a landmark, building on the successes of the predecessors, refining and innovating to bring you closer to the original sound.
The company was founded in 1936 by audio master Peter Walker, under the tiltle, the "Acoustical manufacturing company". The company produced "Public Address" systems and compact amplifiers (relatively speaking). In 1949, the company produced the "Corner Ribbon Loudspeaker", producing higher frequencies than had ever previously been achieved. In the same year, the QA12/P was launched and the brand "Quad" was born from an acronym "Quality Unit Amplified Domestic".
Shortly after the QA12/P, the now legendary Quad II was launched, a control unit with two monoblock valve amplifiers. It was around this time, that a series of concerts were given at both the Royal Festival Hall in London and "Carnegie Hall" in New York. Gilbert Briggs, founder of Wharfedale was trying to prove that recorded music could compete with live music. A capacity audience of 3000, filling the Royal Festival Hall, listened to Peter and Gilbert demonstrate the undeniable clarity and quality of well designed, and well-built hi-fi.
In the period from 1957 to 1966, innovation was fast. Improved broadcasting meant a high demand for quality reproduction equipment. During this time, Quad developed the world's first ever full range electrostatic loudspeaker, nicknamed "Walkers little wonder" and later called the ESL-57. Many have tried to emulate the Quad electrostatic principles, but none have ever managed to produce a speaker with quite such transparency and clarity.
In 1955 Quad introduced the first electrostatic loudspeaker for home use, the Quad ESL . Later this ESL is called ESL-57 (also ESL 55) to distinguish it from its younger brother, the ESL-63. In 1985 production of the ESL-57 stopped, there were about 60.000 produced. There are still thousands around, playing very well and giving their owners a lot of audio pleasure. In 1981 Quad introduced a new ESL, the Quad ESL-63. Later Gradient introduced a subwoofer system, the SW-63.
Refurbishing & modifications
Peter Hickman (March 15, 2005): Fidele Audio offer a full refurbishment and upgrade service for Quad Amplifiers including 33, 34, 44, 66, 405, 306, 606 plus 66 and 67 CD players. Visit them at www.fidele.co.uk.
Arend-Jan Wijtzes (June 15, 2011): ESL Labs offers full refurbishment, parts and restoration service for the Quad ESL 55/57 electrostatic loudspeakers
Andy's HiFi and Music Website Refurbishing the Quad ESL 57Â
Audio Nirvana Site with a section on the Quad ESL 57 by Ernest Ruiz
Contrapunt the active dipole sub woofer
Doctor Quad-Hifi Very nice German site on Quad.
Japan Quad Fan Club
Net Audio Various upgrades for the Quad 33 and 303 Stacking, ESL 57
One Thing Audio Servicing/refurbishing electrostatic loudspeakers replacement panels for both the Quad ESL
Quad Electrostatic Speaker Unoffical page Technical Pages
Quad ESL Gary Jacobson The creator of the
Quad Francophone site
Quad Hi-Fi Din Leads If you've been searching in vain for DIN leads for your vintage QUAD Hi-Fi equipment, then you need look no further
Quad Musikwiedergabe GmbH Refurbishers of Quad equipment Koblenz, Germany
Quadatelier Speaker repair service for dynamic Speakers of nearly all brands
SDS Labs Page Excellent page on rebuilding the Quad ESL 57
Sheldon Stokes Quad ESL pages.
Tritet Audio Lots of technical knowledge on vintage Quad equipment.
Forum topics on Quad
The following topics regarding Quad in general can be found in the forums. Topics about specific models can be found on the model pages. If you want to start a new topic, click here.