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Pultec EQP-1
The Pultec EQP-1 Program Equalizer is an audio equalizer produced by Pulse Techniques (Pultec) beginning in 1956 with variants produced until 1981, and put back into production in 2000. The EQP-1 and its variants were widely used in professional recording studios and established as a studio standard. It was inducted into the TECnology Hall of Fame in 2005. History Electronic engineers and former RCA Institute classmates Eugene Shenk and Ollie Summerlin founded Pulse Techniques, Incorporated (Pultec) on February 1, 1953. The company, based in Teaneck, New Jersey, initially manufactured specialized equipment for professional audio engineers, such as adjustable power supplies for tube equipment and audio oscillators used for testing. Clair D. Krepps, who had previously worked with Summerlin, both in the Navy, and at Capitol Records, building the labels' first New York mastering studio, had since become the chief engineer at MGM Studios in New York and was renting bench spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equalization (audio)
Equalization, or simply EQ, in sound recording and reproduction is the process of adjusting the volume of different frequency bands within an audio signal. The circuit or equipment used to achieve this is called an equalizer. Most hi-fi equipment uses relatively simple Electronic filter, filters to make Bass (sound), bass and Treble (sound), treble adjustments. Graphic and parametric equalizers have much more flexibility in tailoring the frequency content of an audio signal. Broadcast and recording studios use sophisticated equalizers capable of much more detailed adjustments, such as eliminating unwanted sounds or making certain instruments or voices more prominent. Because of this ability, they can be aptly described as "frequency-specific volume knobs." Equalizers are used in recording studio, recording and radio studios, production control rooms, and live sound reinforcement and in instrument amplifiers, such as guitar amplifiers, to correct or adjust the response of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gain (electronics)
In electronics, gain is a measure of the ability of a two-port circuit (often an amplifier) to increase the power or amplitude of a signal from the input to the output port by adding energy converted from some power supply to the signal. It is usually defined as the mean ratio of the signal amplitude or power at the output port to the amplitude or power at the input port. It is often expressed using the logarithmic decibel (dB) units ("dB gain"). A gain greater than one (greater than zero dB), that is, amplification, is the defining property of an active device or circuit, while a passive circuit will have a gain of less than one. The term ''gain'' alone is ambiguous, and can refer to the ratio of output to input voltage (''voltage gain''), current (''current gain'') or electric power (''power gain''). In the field of audio and general purpose amplifiers, especially operational amplifiers, the term usually refers to voltage gain, but in radio frequency amplifiers it usua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RCA Records
RCA Records is an American record label owned by Sony Music Entertainment, a subsidiary of Sony Group Corporation. It is one of Sony Music's four flagship labels, alongside Columbia Records (its former longtime rival), Arista Records and Epic Records. The label has released multiple genres of music, including pop music, pop, classical music, classical, rock music, rock, hip hop, afrobeat, electronic music, electronic, Contemporary R&B, R&B, blues, jazz, and country music, country. The label's name is derived from the initials of its now defunct parent company, the Radio Corporation of America (RCA). After the RCA Corporation was purchased by General Electric in 1986, RCA Records was fully acquired by Bertelsmann in 1987, making it a part of Bertelsmann Music Group (BMG); following the merger of BMG and Sony in 2004, RCA Records became a label of Sony BMG Music Entertainment. In 2008, after the dissolution of Sony/BMG and the restructuring of Sony Music, RCA Records became fully ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capitol Studios
Capitol Studios is a recording studio located at the landmark Capitol Records Building in Hollywood, California, United States. The studios, which opened in 1956, were initially the primary recording studios for the American record label Capitol Records. While they are still regularly used by Capitol recording artists, the facilities began to be made available to artists outside the label during the late 1960s to the early 1970s. The studios are owned by Universal Music Group, the parent company of Capitol Music Group. Since Capitol Studios' founding, the studio has hosted many well-known artists such as: Frank Sinatra, Nat King Cole, Michael Jackson, Dean Martin, Barbra Streisand, Paul McCartney, The Beach Boys, John Mayer, Green Day, Billie Eilish, and Daft Punk. Along with traditional recording sessions, the studio has been the location of numerous events that include iTunes, Sirius/XM sessions, CMG Productions, such as the Top of the Tower concerts and the 1 Mic 1 Tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Recording Corporation
Universal Recording Corporation was a recording studio in Chicago founded by Bill Putnam, Sr. for the purpose of investigating new recording techniques and the development of specialized recording equipment. Universal Recording was seminal in the development of experimental studio techniques. It was the location of the first use of tape repeat in a recording, the first isolated vocal booth, the first recording with multiple overdubs of a single voice, early 8-track recording trials and the first experiments with half speed disc mastering. History Early history Putnam established Universal Recording Corp. north of Downtown Chicago in Evanston, Illinois in 1946. His partners were Bernie Clapper (a former Valparaiso Technical Institute roommate) and Bob Weber (who Putnam had met while working with the U.S. Army). The initial investment, most of which Putnam had borrowed from his family, was $20,000. The Evanston facility consisted of one small studio with a Western Elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rackmount
A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is wide. The 19 inch dimension includes the edges or ''ears'' that protrude from each side of the equipment, allowing the module to be fastened to the rack frame with screws or bolts. Common uses include computer servers, telecommunications equipment and networking hardware, audiovisual production gear, professional audio equipment, and scientific equipment. Overview and history Equipment designed to be placed in a rack is typically described as rack-mount, rack-mount instrument, a rack-mounted system, a rack-mount chassis, subrack, rack cabinet, rack-mountable, or occasionally simply shelf. The height of the electronic modules is also standardized as multiples of or one rack unit or U (less commonly RU). The industry-standard rack cabinet is 42U tall; however, many data centers have racks taller than this. The term relay rack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Feedback
Negative feedback (or balancing feedback) occurs when some function (Mathematics), function of the output of a system, process, or mechanism is feedback, fed back in a manner that tends to reduce the fluctuations in the output, whether caused by changes in the input or by other disturbances. Whereas positive feedback tends to instability via exponential growth, oscillation or chaos theory, chaotic behavior, negative feedback generally promotes stability. Negative feedback tends to promote a settling to List of types of equilibrium, equilibrium, and reduces the effects of perturbations. Negative feedback loops in which just the right amount of correction is applied with optimum timing, can be very stable, accurate, and responsive. Negative feedback is widely used in Mechanical engineering, mechanical and electronic engineering, and it is observed in many other fields including biology, chemistry and economics. General negative feedback systems are studied in Control engin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12AU7
The 12AU7 and its variants are miniature nine-pin (B9A base) medium-gain dual-triode vacuum tubes. It belongs to a large family of dual-triode vacuum tubes which share the same pinout (RETMA tube designation, RETMA 9A). 12AU7 is also known in Europe under its Mullard–Philips tube designation ECC82. There are many equivalent tubes with different names, some identical, some designed for ruggedness, long life, or other characteristics; examples are the US military 5814A and the European special-quality ECC802 and E82CC. The tube is popular in hi-fi vacuum tube audio as a low-noise line amplifier, driver (especially for tone stacks), and phase-inverter in vacuum tube push–pull amplifier circuits. It was widely used, in special-quality versions such as 5814A, in pre-semiconductor digital computer circuitry. Use of special-quality versions outside of the purpose they were designed for may not be optimal; for example, a version for digital computers may be designed for long life wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
12AX7
12AX7 (also known as ECC83) is a miniature dual-triode vacuum tube with high voltage gain (electronics), 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 (typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Push–pull Output
A push–pull amplifier is a type of electronic circuit that uses a pair of active devices that alternately supply current to, or absorb current from, a connected load. This kind of amplifier can enhance both the load capacity and switching speed. Push–pull outputs are present in Transistor-transistor logic, TTL and CMOS digital logic circuits and in some types of electronic amplifier, amplifiers, and are usually realized by a complementary pair of transistors, one dissipating or ''sinking'' current from the load to ground or a negative power supply, and the other supplying or ''sourcing'' current to the load from a positive power supply. A push–pull amplifier is more efficient than a single-ended Power amplifier classes#Class A, "class-A" amplifier. The output power that can be achieved is higher than the continuous dissipation rating of either transistor or tube used alone and increases the power available for a given supply voltage. Symmetrical construction of the two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanced Line
In telecommunications and professional audio, a balanced line or balanced signal pair is an electrical circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths, to ground, and to other circuits. The primary advantage of the balanced line format is good rejection of common-mode noise and interference when fed to a differential device such as a transformer or differential amplifier.G. Ballou, ''Handbook for Sound Engineers'', Fifth Edition, Taylor & Francis, 2015, p. 1267–1268. As prevalent in sound recording and reproduction, balanced lines are referred to as balanced audio. A common form of balanced line is twin-lead, used for radio frequency communications. Also common is twisted pair, used for traditional telephone, professional audio, or for data communications. They are to be contrasted to unbalanced lines, such as coaxial cable, which is designed to have its return conductor connected to ground, or circuits w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pass Filter
A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter. In optics, high-pass and low-pass may have different meanings, depending on whether referring to the frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason, it is a good practice to refer to wavelength filters as ''short-pass'' and ''long-pass'' to avoid confusion, which would correspond to ''high-pass'' and ''low-pass'' frequencies. Low-pass filters exist in many different forms, including electronic circuits such as a '' hiss filter'' used in audio, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
