LEAK

LEAK

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 60s, the company produced high-quality amplifiers, radio tuners, loudspeakers (the LEAK Sandwich), pickups, arms 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 position the brand to counter competition from Japanese electronics manufacturers, so by the late 1970s electronics and speaker production ceased under the LEAK name.

Early days

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 invented by Harold Black of Bell Telephone Laboratories in 1934, but it was slow to emerge as popular method for controlling amplifier performance.

Point One

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 60s.

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.

References

* cite book
last = Spicer
first = Stephen
year = 2000
title = Firsts in High Fidelity
publisher = Audio Amateur Press
id = ISBN 1-882580-31-1

External links

* [http://www.44bx.com/leak Unofficial LEAK web site]


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Synonyms:
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Look at other dictionaries:

  • Leak — (l[=e]k), n. [Akin to D. lek leaky, a leak, G. leck, Icel. lekr leaky, Dan. l[ae]k leaky, a leak, Sw. l[ a]ck; cf. AS. hlec full of cracks or leaky. Cf. {Leak}, v.] 1. A crack, crevice, fissure, or hole which admits water or other fluid, or lets… …   The Collaborative International Dictionary of English

  • leak — leak·age; leak·er; leak·i·ness; leak·less; leak·man; leak; …   English syllables

  • leak|y — «LEE kee», adjective, leak|i|er, leak|i|est. having a leak or leaks; full of leaks; leaking: »The ship was leaky and very much disabled (Daniel Defoe). – …   Useful english dictionary

  • Leak — Leak, v. i. [imp. & p. p. {Leaked} (l[=e]kt); p. pr. & vb. n. {Leaking}.] [Akin to D. lekken, G. lecken, lechen, Icel. leka, Dan. l[ae]kke, Sw. l[ a]cka, AS. leccan to wet, moisten. See {Leak}, n.] 1. To let water or other fluid in or out through …   The Collaborative International Dictionary of English

  • leak — Ⅰ. leak UK US /liːk/ verb ► [I or T] if a liquid or gas leaks, or is allowed to leak, from a pipe or container, it escapes through an opening: »Textile chemicals leaking from a container started a fire in a cargo compartment. »The ship leaked an… …   Financial and business terms

  • leak — ► VERB 1) accidentally allow contents to escape or enter through a hole or crack. 2) (of liquid, gas, etc.) escape or enter accidentally through a hole or crack. 3) intentionally disclose (secret information). 4) (of secret information) become… …   English terms dictionary

  • leak — [lēk] vi. [ME leken < ON leka, to drip < IE base * leg , to drip, trickle, LACK, OIr legaim, (I) dissolve, Welsh llaith, damp] 1. to let a fluid substance out or in accidentally [the boats leaks] 2. to enter, or escape accidentally from, an …   English World dictionary

  • Leak — Leak, a. Leaky. [Obs.] Spenser. [1913 Webster] …   The Collaborative International Dictionary of English

  • leak — verb. The transitive meaning ‘to disclose (secret information) intentionally’ is, apart from an isolated example of 1859, a 20c use, although the practice is doubtless a lot older. It is related to, if not a development of, the phrasal verb to… …   Modern English usage

  • leak — [n] opening; seepage through opening aperture, chink, crack, crevice, decrease, destruction, detriment, drip, drop, escape, expenditure, exposure, fissure, flow, hole, leakage, leaking, loss, outgoing, percolation, pit, puncture, short circuit,… …   New thesaurus

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