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Dynaco
Dynaco was an American hi-fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components.Dunn, Greg, Dynaco Company History', retrieved 8 August 2011 Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, its best known product was the ST-70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd. Early company history In 1950 David Hafler and Herb Keroes started a Philadelphia-based company called Acrosound to build and sell audio-quality output transformers, primarily for home electronics hobbyists. The two men refined and developed the ultra-linear audio circuit pioneered by British audio electronics engineer Alan Blumlein, using taps from the output transformer to feed signal back into the output stage screen grid c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynaco A-25
Dynaco was an American hi-fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components.Dunn, Greg, Dynaco Company History', retrieved 8 August 2011 Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, its best known product was the ST-70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd. Early company history In 1950 David Hafler and Herb Keroes started a Philadelphia-based company called Acrosound to build and sell audio-quality output transformers, primarily for home electronics hobbyists. The two men refined and developed the ultra-linear audio circuit pioneered by British audio electronics engineer Alan Blumlein, using taps from the output transformer to feed signal back into the output stage screen grid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynaco SCA-80
Dynaco was an American hi-fi audio system manufacturer popular in the 1960s and 1970s for its wide range of affordable, yet high quality audio components.Dunn, Greg, Dynaco Company History', retrieved 8 August 2011 Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, its best known product was the ST-70 tube stereo amplifier. They also manufactured other tube and solid state amplifiers, preamplifiers, radio tuners and bookshelf loudspeakers. Dynaco was liquidated in 1980, and the trademark is now owned by Radial Engineering Ltd. Early company history In 1950 David Hafler and Herb Keroes started a Philadelphia-based company called Acrosound to build and sell audio-quality output transformers, primarily for home electronics hobbyists. The two men refined and developed the ultra-linear audio circuit pioneered by British audio electronics engineer Alan Blumlein, using taps from the output transformer to feed signal back into the output stage screen grid ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynaquad
Dynaquad, or DY, was a matrix decoder 4-channel quadraphonic sound system developed by Dynaco in 1969. The system originally had four speakers that were arranged in a diamond shape (centre-front, centre-left, centre-rear, centre-right). Initially (first available in 1969 with th ''Dynaco SCA-80Q'' amplifier ), it was introduced as a derived (2:2:4) four channel "decoding" system based on the Hafler circuit, where the back channels played ambient sounds recovered from standard stereo sounds. As such it wasn't used initially used as an encoding method (a similar approach was used on the Electrovoice Stereo-4 system). Commercial usage A simpler form of Dynaquad was adopted, allowing an easy adaptation of existing home setups. The two forward speakers remain in their normal positions, with the user only needing to add two similarly positioned back speakers, forming a square (front-left, front-right, back-left, back-right). Four channel record pioneers Vanguard Records started to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Hafler
David Hafler (February 7, 1919 – May 25, 2003) was an American audio engineer. He was best known for his work on an improved version of the Williamson amplifier using the ultra-linear circuit of Alan Blumlein. Biography In 1950, Hafler founded Acrosound with his colleague Herbert Keroes. This company was primarily in the business of designing and manufacturing transformers for tube amplifiers. Around this time Hafler and Keroes popularized the ultra-linear output-stage for audio amplifiers. However, the partnership did not last. In 1954 Hafler founded Dynaco with Ed Laurent. Hafler was instrumental in bringing affordable, high-quality audio kits to hobbyists, making his name a household word in the US audio community for many years. In the 1970s Hafler promoted "passive pseudo-quadraphonics", an inexpensive method of recreating ambient sounds at the rear from ordinary stereophonic recordings. Known as the "Hafler hookup" or " Hafler circuit", this consisted of two simila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williamson Amplifier
The Williamson amplifier is a four-stage, Push–pull output, push-pull, Power amplifier classes#Class A, Class A triode-output Valve amplifier, valve audio power amplifier designed by David Theodore Nelson Williamson during World War II. The original circuit, published in 1947 and addressed to the worldwide do it yourself community, set the standard of high fidelity sound reproduction and served as a benchmark or reference design, reference amplifier design throughout the 1950s. The original circuit was copied by hundreds of thousands amateurs worldwide. It was an absolute favourite on the DIY scene of the 1950s, and in the beginning of the decade also dominated British and North American markets for factory-assembled amplifiers. The Williamson circuit was based on the 1934 ''Wireless World Quality Amplifier'' by Walter Cocking, with an additional Error amplifier (electronics), error amplifier stage and a global negative feedback loop. Deep feedback, triode-connected KT66 power te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
7199
The 7199 is a vacuum tube, combining a pentode and triode. Typically, the pentode was used for the input stage, and the triode as a phase inverter. The tube was used in a number of American guitar amplifiers; the Gibson Guitar Corporation, for instance, used the 7199 in 1961's Falcon for the reverb circuit. Ampeg Ampeg ("amplified peg") is a manufacturer best known for its bass amplifiers. Originally established in 1946 in Linden, New Jersey by Everett Hull and Stanley Michaels as "Michael-Hull Electronic Labs," today Ampeg is part of the Yamaha Guit ... also used the 7199 extensively. Notable is the Dynaco ST-70 stereo amplifier introduced in 1959 which used a 7199 tube in the driver section of each channel. Over the next decade, more than 350,000 of these amplifiers were produced. American 7199 production ended sometime in the 1980s, while the Soviet tube company Sovtek produced one until roughly 2007. As a result, the tube is becoming increasingly scarce. Another tube of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
