Mullard Circuits for Audio Amplifiers

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Mullard Circuits for Audio Amplifiers is a famous book by the Technical Services Department of Mullard Ltd, a British valve manufacturing company. First published in 1959 and then reprinted several times it contained a number of designs by Mullard engineers for high quality audio amplifiers, which were to be used by amateur constructors as well as by manufacturers as the basis for many products that formed part of the high fidelity audio movement in Britain in the 1960s.

Particularly iconic designs were the Mullard 5-10 and the Mullard 5-20, ten and twenty watt power amplifiers. [1] Circuits for preamplifiers with tone controls and tape recorder amplifiers were also included, along with information regarding record and tape equalisation standards.

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Valve amplifier

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Pentagrid converter

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12AX7 Miniature high-gain dual triode vacuum tube

12AX7 is a vacuum tube that is a miniature dual-triode 6AV6 with high voltage gain. Developed around 1946 by RCA engineers in Camden, New Jersey, under developmental number A-4522, it was released for public sale under the 12AX7 identifier on September 15, 1947.

The Williamson amplifier is a four-stage, push-pull, Class A triode-output valve audio power amplifier designed by D. T. N. 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 a benchmark or 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.

Beam tetrode

A beam tetrode, sometimes called a "beam power tube", is a type of tetrode vacuum tube with auxiliary beam-focusing plates designed to augment power-handling capability and help reduce unwanted emission effects. These tubes are usually used for power amplification, especially at audio-frequency.

Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania in 1955, 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.. 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.

Hiwatt

Hiwatt is a British company that manufactures amplifiers for electric guitars and electric basses. Starting in the late 1960s, together with Marshall and Vox, Hiwatt contributed to the sonic image popularly termed "British sound".

Single-ended triode

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Mullard 5-10

The Mullard 5-10 was a circuit for a valve amplifier designed by the British valve company, Mullard in 1954 at the Mullard Applications Research Laboratory (ARL) in Mitcham Surrey UK, part of the New Road factory complex, to take advantage of their particular products. The circuit was first published in Practical Wireless magazine.

EL84

The EL84 is a thermionic valve of the power pentode type. It is used in the power output stages of audio amplifiers, most commonly now in guitar amplifiers, but originally in radios. The EL84 is smaller and more sensitive than the octal 6V6 that was widely used around the world until the 1960s. An interchangeable North American type is the 6BQ5.

A valve audio amplifier (UK) or vacuum tube audio amplifier is a valve amplifier used for sound reinforcement, sound recording and reproduction.

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Valve RF amplifier

A valve RF amplifier or tube amplifier (U.S.), is a device for electrically amplifying the power of an electrical radio frequency signal.

Technical specifications and detailed information on the valve audio amplifier, including its development history.

Magic eye tube

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EF86

The EF86 is a high transconductance sharp cutoff pentode vacuum tube with Noval (B9A) base for audio-frequency applications.

Tube sound

Tube sound is the characteristic sound associated with a vacuum tube amplifier, a vacuum tube-based audio amplifier. At first, the concept of tube sound did not exist, because practically all electronic amplification of audio signals was done with vacuum tubes and other comparable methods were not known or used. After introduction of solid state amplifiers, tube sound appeared as the logical complement of transistor sound, which had some negative connotations due to crossover distortion in early transistor amplifiers. The audible significance of tube amplification on audio signals is a subject of continuing debate among audio enthusiasts.

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