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Movements, leaders, victories and the continuing fight for equality.
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Meet the people whose lives, choices and achievements shaped the journey.
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Moments that changed communities, movements, institutions and the nation.
Katherine Johnson’s mathematical calculations helped guide some of America’s most important early space missions while she confronted the racial and gender barriers faced by Black women in twentieth-century America.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
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LEAK is the brand name for high-fidelity audio equipment made by H. J. Leak & Co. Ltd, of London, England. The company was founded in 1934 by Harold Joseph Leak and was sold to the Rank Organisation in January 1969. During the 1950s and 1960s, the company produced high-quality amplifiers, radio tuners, loudspeakers (the LEAK Sandwich), pickups, tonearms and a turntable. The sale of the business to Rank saw an expanded range of models, and considerable further development of loudspeakers, but Rank was not able to position the brand to counter competition from Japanese electronics manufacturers, so by the late 1970s, electronics and speaker production ceased under the LEAK name.
The company initially focussed on provision of amplifiers for public address systems and theatres, with only a few staff. Typical designs used were similar to those found in the Partridge Public Address Manuals of the time, which used Osram's DA30 power triodes in push-pull for 45 watts output.
During the latter part of the Second World War, the company started developing amplifiers that made extensive use of negative feedback to achieve very high performance. This approach had been patented by Harold Black of Bell Telephone Laboratories in 1934, and already used before that by Alan Blumlein of EMI, but it was slow to emerge as popular method for controlling amplifier performance.
In September 1945, the company released the first of the "Point One" series of amplifiers, so named because the total harmonic distortion was 0.1% at rated output. This represented a major leap forward in accepted standards for high-performance amplifiers (with 2% distortion generally considered acceptable at the time). This first "Point One" amplifier was known as the Type 15, and produced 15 watts output, at 0.1% distortion, using push-pull KT66 valves connected as triodes, with 26 dB feedback applied over four stages. The amplifier has a similar topology to the Williamson amplifier published in Wireless World in 1947.
In 1948, the original four-stage circuit was replaced with a three-stage design that was designated the TL/12. This amplifier had the same high performance at reduced cost, and it was responsible for establishing and securing the future of the company as a dominant player in the "hi-fi" boom of the 1950s and 1960s.
Subsequent amplifiers from the company all used the same circuit topology as the TL/12, but took advantage of newer more efficient power valves and the so-called "ultra-linear" connection of the output stage to obtain higher power output with triode-like characteristics. These amplifiers included the TL/10, TL/25, TL/12-Plus, TL/25-Plus, TL/50-Plus, and the Stereo 20, Stereo 50 and Stereo 60.
Firsts in High-Fidelity- SPICER Stephen- Firsts in High-Fidelity- 2000-
LEAK Audio Hi-Fi- FERRARI Pier Paolo- 2014- LEAK Audio Hi-Fi- SANDIT Editor, Bergamo, ITALY- ISBN 978-88-97599-92-0
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
LEAK is the brand name for high-fidelity audio equipment made by H. J. Leak & Co. Ltd, of London, England. The company was founded in 1934 by Harold Joseph Leak and was sold to the Rank Organisation in January 1969. During the 1950s and 1960s, the company produced high-quality amplifiers, radio tuners, loudspeakers (the LEAK Sandwich), pickups, tonearms and a turntable. The sale of the business to Rank saw an expanded range of models, and considerable further development of loudspeakers, but Rank was not able to position the brand to counter competition from Japanese electronics manufacturers, so by the late 1970s, electronics and speaker production ceased under the LEAK name.
A leak is a way (usually an opening) for fluid to escape a container or fluid-containing system, such as a tank or a ship's hull, through which the contents of the container can escape or outside matter can enter the container. Leaks are usually unintended and therefore undesired. The word leak usually refers to a gradual loss; a sudden loss is usually called a spill. The matter leaking in or out can be gas, liquid, a highly viscous paste, or even a fluidized solid such as a powdered or granular solid or other solid particles.
Leak or Leaks is the surname of: Leak: Bill Leak (1956–2017), Australian cartoonist and painter, father of Johannes Leak Bill Leak (sportsman) (1917–2007), Australian rules footballer and cricketer Bruce Leak, American inventor and entrepreneur Chris Leak (born 1985), American former football quarterback Hector Leak (1887–1976), British statistician James Leak, 19th century English bare-knuckle prize fighter Johannes Leak (born 1980), Australian cartoonist and painter, son of Bill Leak John Leak (1892–1972), Australian First World War recipient of the Victoria Cross Maysa Leak (born 1966), American jazz singer better known simply as Maysa Leaks: Manny Leaks (born 1945), American Basketball Association and National Basketball Association player Roosevelt Leaks (born 1953), African-American college football and National Football League player, member of the College Football Hall of Fame
Christopher Patrick Leak (born May 3, 1985) is an American former professional football quarterback who played in the National Football League (NFL) for a season with the Chicago Bears. He played college football for the University of Florida, and led the Florida Gators to victory in the 2007 BCS National Championship Game. Leak also played professionally for the Hamilton Tiger-Cats and Montreal Alouettes of the Canadian Football League (CFL) and the Jacksonville Sharks and Orlando Predators of the Arena Football League (AFL).
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →The Greenwood District.