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

• 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 loudspeaker, 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.

1907, January 8

Harold Joseph Leak born.

1922 At his school in Middlesex, he formed a Wireless Society

1920′s Worked in the Wine trade, but subsequently joined Gaumont British cinemas where he learnt much about electronics and audio amplifiers.

1926 Commenced his own business as a “Wireless Doctor” Constructed a portable wireless model.

1927 Constructed a pickup for 78 rpm records; an amplifier of two-stage design, and a speaker along the lines of the new Rice & Kellog moving coil design.

Late 1920′s Established himself in new premises at 124a Dalling Road, Hammersmith, West London. Continued primarily in the design of amplifiers.

1931 Harold Leak conducts a test transmission of stereo sound with D.W. Turpin.

1934, September 14 Founded H.J.Leak & Co- and promotes the company with his own name, adversting himself as “Sound Engineer – Technician”.

1936 H.J.Leak & Co. release a P.A.Amplifier, with exhibits at Olympia Exhibition. 13 Watts output using push-pull PX25 power triodes. 40Hz to 12kHz +/- 1dB. Cost was 13 guineas. (H.J. Leak does not appear in listings of exhibitors for Olympia, so the company may have used another company’s stand for the exhibit). This amplifer was supposedly advertised in Wireless World around 1938, although a search has failed to locate the advertisement.)

Late 1930′s Ted Ashley joins H.J.Leak, and was later to become Chief Engineer, and remain with the company until the late 1960′s.

1942 Harold Leak marries Muriel.

circa 1940 The Leak 124 Dalling Road premises at Hammersmith were destroyed by German bombs. Leak moves to 470 Uxbidge Road, Shepherd Bush, and continues to make amplifiers under contract.

Late 1945 The first low distortion amplifier was released as a result of war-time research. This was the original “Point One Amplifier – the “Type 15″, a four-stage circuit, with substantial negative feedback, and push-pull triode-connected KT66 valves for 15 Watts output.

Late 1940′s Leak moves to the Westway Trading Estate at Acton, in London. This was a new factory estate (with factories styled with hints of art-deco) in Brunel Road, named after the famous engineer.

1948

The Leak TL/12 was released, heralding a move toward domestic high-fidelity sound reproduction for the company. Leak release a pickup arm and moving coil pickup with diamond or sapphire stylus, and matching transformer. A 25 Watt version, the TL/25 was also available (using tetrode connect KT66′s).

1949 Harold Leak travels Britain doing live – versus – reproduced sound comparisons with his new TL/12 and RC/PA amplifier set. The live sound is reproduced via the Leak system using an STC4033 microphone (also known as the WE639A in the USA).

During 1949 he travels at short notice, and attends the Audio Engineering Society exhibition that was held in New York. He demonstrates the TL/12 to amazed Americans. This trip establishes highly succesful American distribution of Leak products via the British Industries Incorporation.

In Australia “Simon Gray Pty Ltd” were later signed as agents. Leak also exported to other world-wide destinations such as Asia, South Africa and New Zealand.

In 1949 the company has grown to a team of around twenty staff.

1949/1950 The Leak “550″ two-way moving coil loudspeaker was released. This loudspeaker was used in the many live-versus reproduced sound demonstrations Harold Leak conducted.

1951 The BBC place large orders for the TL/12 power amplifier (specially modified with input attenuator and balancing transformer).

1954 New moving coil pickup and arm released.

1955 Troughline FM tuner released. Leak undertakes research into suitable transducer for a high quality loudspeaker, and settles on a moving coil 15 inch bass unit, and electrostatic high frequency unit, but the prototypes never make it to mass-production.

1956 The new range of TL/12Plus, TL/25Plus and TL/50Plus mono power amps is released, with revised mono preamps featuring the stylish diakron plastic front panel.

1958 The Stereo 20 and Stereo 50 amplifiers, with new stereo pre-amps are released. Troughline II FM Tuner is released.

1959 Leak engages Dr. Don.A. Barlow to develop a new “piston action” loudspeaker.

1960 A new stereo pickup is released, this time using the variable reluctance principle.

1961 The highly successful Leak Sandwich loudspeaker was released.

1963 The “Stereo 30″ transistor amp using a quasi-complementary germanium transistor output stage is released (after H.C.Lin). Valve amplifier production continued into the mid 60′s, and higher power models such as the TL/50Plus were still available in the late 1960′s.

1960′s Downnham Market factory established (in Norwich, some distance north of London) to cater for demand for the Sandwich speaker.

1968 Stereo 70 transistor amplifier released, using the classic 2N3055 transistors for the output stage, in quasi-complementery configuration.

1969 H.J. Leak & Co. sold to the Rank Organization, and Harold retires.

1996 The Leak premises at the Westway Factory Estate, Acton, are demolished.

August 27 1989

Harold Leak dies.

Saul B. Marantz, a pioneer in the development of high-fidelity audio components, died last Thursday at Somerset Medical Center in Somerville, N.J. He was 85 and lived in Bridgewater, N.J.

A man of many parts — photographer, classical guitarist, graphics designer, collector of Chinese and Japanese art — Mr. Marantz was fascinated by electronics from his boyhood days in Brooklyn. His passion for music led to his first attempts at building audio components.

In the 1950′s and 60′s, the Marantz name became synonymous with audio products that were pleasing to look at, easy to use, durable and sonically first rate. Working with audio engineers like Sidney Smith and Richard Sequerra, Mr. Marantz created a series of vacuum-tube components that became touchstones for the fledgling hi-fi industry. Several of those products, like the Model 9 amplifier and the Model 10B tuner, have become still-working classics that today command as much as $20,000.

With the advent of transistor technology in the early 1960′s, Mr. Marantz and his colleagues soon brought forth another benchmark product, the Model 18 receiver. It was an early, high-quality example of what a receiver, which combines the preamplifier, power amplifier and tuner in one box, could be.

• 1952 Saul Marantz sells his first audio product, the “Consolette” pre-amp
• 1964 Marantz acquired by Superscope
• 1966 Beginning with the Model 25, and then 22 and 28, Marantz started manufacturing their products in Japan through a partnership with Standard Radio Corp.
• 1975 Standard Radio Corp. changes its name to Marantz Japan Inc.
• 1980 Superscope sold the Marantz brand, dealer network, and all overseas assets (except U.S. and Canada) to Philips Electronics
• 1992 Philips acquires U.S. and Canada trademarks and dealer network
• 1997 Saul Marantz passes away aged 86.
• 2001 Marantz Japan Inc. acquired the brand and all overseas sales subsidiaries
• 2002 Marantz Japan and Denon merge to form D&M Holdings, to later be joined by other elite audio equipment brands, most famously McIntosh Labs and Boston Acoustics
• 2008 Philips sells its remaining stake in D&M Holdings, ending a 28-year relationship between Philips and Marantz.

 

KEF was founded in 1961 by Raymond Cooke OBE – a deeply practical man keen to experiment with new materials and technologies in order to create products with superior acoustic quality. He built the company on a foundation of quality engineering with a vision that has ensured its continued success to the present day.

Following his time as a radio operator in the Royal Navy, he obtained a BSc in Electrical Engineering from the University of London and went on to join the Engineering Designs Department at the BBC where he was exposed to the pioneering loudspeaker development work of a talented group of engineers that included Dudley Harwood and D.E.L. Shorter.

After five years at Wharfedale, working alongside Gilbert Briggs, he decided to set up his own company to develop loudspeakers using the latest in materials technology. KEF soon found success with products such as the K1 Monitor and the bookshelf ‘Celeste’ and, with Cooke’s commitment to strong engineering principles, developed into one of the leading loudspeaker companies in the world.

KEF became famous for the quality of its drive units, which were used in countless systems around the world, and later for significant developments in loudspeaker measurement technology. The investment required to achieve this level of technical expertise was considerable but Raymond Cooke correctly judged the logical route forward that KEF needed to take.

Cooke was a great communicator and made sure that not just the engineering but the marketing of KEF products was up to his high standards. His commitment to the audio industry was visible from his support of the Audio Engineering Society, of which he was president in 1984, and from which he was awarded the Silver Medal in 1993 for outstanding contributions to transducer measurements. His contributions on a wider scale were recognised in 1979 when he was awarded the OBE by HM Queen Elizabeth II.

Raymond Cooke sadly passed away in 1995 but his legacy lives on in the company that he founded. He spoke of his vision for KEF as follows: ‘I was determined to put into practice the many possibilities I could see for improving loudspeakers through more rigorous engineering’.

Henry Kloss, Dead at 72By David Lander

After entering MIT in 1948, Kloss worked part-time for a contractor and bought woodworking tools to make furniture for his basement apartment. Instead, he used them to turn out enclosures for a speaker system an MIT professor and his student had designed. Henry dropped out of MIT after being drafted. Stationed in New Jersey, he took a New York University night course in high fidelity taught by Edgar Villchur, who had conceived a radically new type of loudspeaker.

In 1954, Villchur and Kloss founded Acoustic Research (Ar) to develop and produce it. Henry provided the facility, a cabinet and speaker-assembly shop he was already operating in a Harvard Square loft. Two other partners, Malcolm Low and J. Anton Hofmann, son of the great pianist Josef Hofmann, supplied $5000 in capital. That led to the AR-1, the world’s first acoustic-suspension loudspeaker system, with its relatively small enclosure and proportionally prodigious bass.

But Villchur remained home in Woodstock, New York, while Kloss ran the Massachusetts factory. That caused friction, leading Kloss, Low and Hofmann to break away and put their initials on a new firm. In 1957, they founded KLH.

In 1967, after producing more landmarks, including the KLH Model Six speaker, the fine-sounding Model Eight radio, and a hi-fi system in a suitcase designated Model Eleven, Henry started Advent to work on projection television. The speakers he built to fund that effort quickly became best-sellers.

Henry Kloss embraced innovation. He was quick to employ the transistor, which was crucial to the KLH Eleven’s portability, and he ingeniously combined previously unrelated concepts with two Advent firsts: a cassette deck featuring Dolby noise reduction (which he had prodded Ray Dolby to adapt for consumers) and chromium dioxide cassettes. That synergy made the medium truly musicworthy.

Yet Kloss was genuinely modest about such achievements. “Some of the particular things I have done…could have and should have been done before,” he once told me.

After leaving Advent, Henry started Kloss Video and, in 1988, co-founded Cambridge SoundWorks, for which he designed some three dozen products. His newest radios, marketed by Tivoli Audio, have the simple, signature look of his KLH models, even down to their planetary dials.

Kloss, informed by his own muse and unimpressed by fashion, created boldly original, straightforward, utilitarian products that lowered the price of performance. Longevity was another criterion, in what he built and what he bought. When he retired his second Checker automobile after 14 years of use, Henry vowed to drive his new Mercedes diesel for 20.

He owned it to the end, 17 years in all. For the many people who so admired Henry Kloss, that wasn’t long enough.

Kloss’s wife, Jacqueline, died last year. A son, two daughters, and seven grandchildren survive him.

helloo world 

J E Sugden & Co Ltd have been designing and manufacturing specialist hi-fi products since the early 1960s.  The company was founded by James Edward Sugden as Research Electronics Ltd and adopted the Sugden name in 1967.

Jim Sugden had designed and developed the first commercial solid state Class ‘A’ amplifier to appear on the market.  Whilst the design was unconventional, the sound performance won wide acclaim and established the company at the forefront of domestic hi-fi.

In the mid 1960s Jim Sugden formed a commercial relationship with Richard Allan a well established manufacturer of quality loudspeakers.  Jim Sugden arranged to market his Class ‘A’ design amplifiers under the Richard Allan brand.  The initial products were the A21 Class ‘A’ Integrated Stereo Amplifier and the C41 Pre-Amplifier and A41 Power Amplifier.

The Richard Allan A21 was rated at 10 watts into 6 Ohms and the A41 20 watts into 15 Ohms. Concurrently Jim Sugden released the Original A21 under the J E Sugden & Co name. Not long afterwards, the Series Two version of the A21 was released.  It could be distinguished by the following inscription on the front panel: J. E. Sugden class A stereo amplifier type A21 series two. The main specification change of the Series Two was the increase of the maximum power output to 12 watts into 8 Ohm. The A21 was further revised to Series Three.  At this stage it was significantly improved and was rated at 20 watts into 8 Ohm.  This version had the same power amplifier circuit as the Sugden P51.

Today the A21 is recognised as one of the classics of specialist consumer hi-fi products.

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