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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. The amplifier featured five valves and an output of 10 watts - hence '5-10'. Of those valves, one was a full-wave rectifier (an EZ80 or EZ81), one was a pre-amplifier pentode EF86 and one a double-triode ECC83 as phase splitter. The power amplification was handled by a pair of EL84 working in push-pull configuration. The frequency response of the circuit was from 40Hz to 20,000Hz with less than 0.2% THD. In 1959 Mullard published its famous booklet " Mullard Circuits for Audio Amplifiers" covering a range of amplifier and pre-amplifier circuits using valves developed within the Receiving Valve Development Department at the New Road factory. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EL84
The EL84 is a vacuum tube 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'' (the RETMA tube designation name for the EL84). The EL84 was developed to eliminate the need for a driver tube in radios, so it has rather more gain than is usual in a power pentode. Eliminating a preamplifier triode in radios made them cheaper. Manufacturers were quick to adopt it in general use, and they are found in many old European tube-radios and other audio equipment. A single EL84 was used in low-cost equipment, and a push–pull pair for lower distortion and higher power. In common with all 'E' prefix tubes, using the Mullard–Philips tube designation, it has a heater voltage of 6.3V. It can produce 17W output in Class AB1 in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FJ Camm
Frederick James "F.J." Camm (6 October 1895 – 18 February 1959) was an English technical author and magazine editor. He founded several radio and electronics titles, including ''Practical Mechanics'', ''Practical Motorist'', ''Practical Television'', and ''Practical Wireless'', some of which are still in circulation. Biography Camm was born in Windsor, England, the second child of twelve. The eldest, Sydney Camm, became a famous aircraft designer. He shared with Sydney an early interest in building model aeroplanes and this led him to move to London in 1918. Here, he became a technical editor for Benn Brothers in aviation and engineering. From there he worked for Pitmans Publishers and moved eventually, with his friend Molloy, to George Newnes. It was there that he was to produce the ''Hobbies'' journals. In 1932, his supplement to ''Hobbies'' magazine, ''Practical Wireless'' was launched as an independent title, with F.J. as editor. Thus began a highly productive period, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EL34
The EL34 is a thermionic vacuum tube of the power pentode type. The EL34 was introduced in 1955 by Mullard, who were owned by Philips. The EL34 has an octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of audio amplification circuits; it was also designed to be suitable as a series regulator by virtue of its high permissible voltage between heater and cathode and other parameters. The American RETMA tube designation number for this tube is 6CA7. The USSR analog was 6P27S (Cyrillic: 6П27C). Specifications In common with all 'E' prefix tubes, using the Mullard–Philips tube designation, the EL34 has a heater voltage of 6.3 V. According to the data sheets found in old vacuum tube reference manuals, a pair of EL34s with 800 V plate voltage can produce 90 watts output in class AB1 in push–pull configuration. However, this configuration is rarely found. One application of this type was in "Australian Sound" public address amplifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transformer
A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer's core, which induces a varying electromotive force (EMF) across any other coils wound around the same core. Electrical energy can be transferred between separate coils without a metallic (conductive) connection between the two circuits. Faraday's law of induction, discovered in 1831, describes the induced voltage effect in any coil due to a changing magnetic flux encircled by the coil. Transformers are used to change AC voltage levels, such transformers being termed step-up or step-down type to increase or decrease voltage level, respectively. Transformers can also be used to provide galvanic isolation between circuits as well as to couple stages of signal-processing circuits. Since the invention of the first constant-potential transfo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mullard Circuits For Audio Amplifiers
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 The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James ... power amplifiers. Circuits for preamplifiers with tone controls and tape recorder amplifiers were also included, along with information regarding record and tape equalisati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Harmonic Distortion
The total harmonic distortion (THD or THDi) is a measurement of the harmonic distortion present in a signal and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. Distortion factor, a closely related term, is sometimes used as a synonym. In audio systems, lower distortion means the components in a loudspeaker, amplifier or microphone or other equipment produce a more accurate reproduction of an audio recording. In radio communications, devices with lower THD tend to produce less unintentional interference with other electronic devices. Since harmonic distortion tends to widen the frequency spectrum of the output emissions from a device by adding signals at multiples of the input frequency, devices with high THD are less suitable in applications such as spectrum sharing and spectrum sensing. In power systems, lower THD implies lower peak currents, less heating, lower electromagnetic emissions, and less core los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Response
In signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and phase of the output as a function of input frequency. The frequency response is widely used in the design and analysis of systems, such as audio and control systems, where they simplify mathematical analysis by converting governing differential equations into algebraic equations. In an audio system, it may be used to minimize audible distortion by designing components (such as microphones, amplifiers and loudspeakers) so that the overall response is as flat (uniform) as possible across the system's bandwidth. In control systems, such as a vehicle's cruise control, it may be used to assess system stability, often through the use of Bode plots. Systems with a specific frequency response can be designed using analog and digital filters. The frequency response characterizes systems in the frequency domain, just as the impulse response characterizes systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the voltage or current ( power, voltage or current amplifier). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a greater amplitude signal at its output. The ratio of output to input voltage, current, or power is termed gain (voltage, current, or power gain). An amplifier, by definition has gain greater than unity (if the gain is less than unity, the device is an attenuator). An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be cate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase Splitter
A phase splitter is a device that separates a signal into multiple phases (or polarities). The term is most often applied to amplifiers that produce two "balanced" voltage outputs: of equal amplitude but opposite polarity (i.e. 180 degrees phase difference), but sometimes is used to refer to the generation of quadrature signals (i.e. differing by 90 degrees). The term is not used for logic circuits producing complementary outputs, nor applied to differential amplifiers that have balanced inputs ''and'' outputs. Methods * using a unity gain inverting amplifier to provide an inverted copy of its input signal; * a split-load amplifier (also known as a "cathodyne" or "concertina phase splitter", especially in the context of vacuum tube implementations); a transistor implementation is shown in the diagram; * a differential pair amplifier can form a phase splitter in two ways: ** if the shared emitter (or cathode or source, for triodes or FETs) connection is fed from something a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Circuit
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical circuit and to be referred to as ''electronic'', rather than ''electrical'', generally at least one active component must be present. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another. Circuits can be constructed of discrete components connected by individual pieces of wire, but today it is much more common to create interconnections by photolithographic techniques on a laminated substrate (a printed circuit board or PCB) and solder the components to these interconnections to create a finished circuit. In an integrated circuit or IC, the components and interconnections are formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12AX7
12AX7 (also known as ECC83) is a miniature dual-triode 6AV6 vacuum tube 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 12AX7 was originally intended as replacement for the 6SL7 family of dual-triode amplifier tubes for audio applications. As a popular choice for guitar tube amplifiers, its ongoing use in such equipment makes it one of the few small-signal vacuum tubes in continuous production since it was introduced. History The 12AX7 is a twin triode basically composed of two of the triodes from a 6AV6, a double diode triode. The 6AV6 is a miniature repackaging (with just a single cathode) of the triode and twin diodes from the octal 6SQ7 (a double-diode triode used in AM radios), which itself is very similar to the older type 75 triode-diode dating from 1930. Application The 12AX7 is a high-gain (typical amplifica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
