EL84
Encyclopedia
The EL84 is a vacuum tube
(a.k.a. valve) of the power pentode
type. It has a 9 pin Noval base and is found mainly in the final output stages of amplification circuits, most commonly now in guitar amplifier
s, but originally in radios and many other devices of the pre-transistor
era.
It was developed to eliminate the need for a driver tube in radios, and has rather more gain than is usual in a power pentode, producing full output from a relatively small drive signal. This eliminated the need for a preamplifier
triode in radios, making them cheaper to produce. As the EL84 itself is a 9 pin Noval, it was also cheap to produce and manufacturers were quick to adopt it in general use, and they are found in many old European valve radios.
In common with all 'E' prefix tubes, using the Mullard-Philips tube designation
, it has a heater voltage of 6.3V. It is capable, when used at its plate rating of 300 volts maximum, of producing 17 watts output in Class AB1
in push-pull
configuration. Many guitar amplifiers routinely run EL84 tubes in excess of 400VDC, with the Traynor Guitarmate reportedly putting out 25w RMS with 2 EL84's in a push pull configuration and a B+ between 400-420VDC.
Developed by Philips
in 1953 for use in the British Mullard 5-10
amplifier, the EL84 came to prominence when used in Watkins (and later the Vox
) amplifiers preferred by many British invasion
bands of the 1960s. When overdriven, the EL84 power tubes in these amplifiers produce a distinctive chiming, articulate, treble-heavy sound when compared to 6L6
tubes more commonly used in American amplifiers of the era such as those from Fender.
Other equivalent tubes are the 7189, an extended-ratings version of the tube for industrial applications and the 6P14P (Cyrillic: 6П14П) produced in the USSR by the Reflektor plant, which is a direct equivalent of EL84/6BQ5. A slightly modified version of the 6P14P is currently being manufactured in Russia for Sovtek
. An extended-ratings version of the 6P14P is also available - 6P14P-EV (Cyrillic: 6П14П-ЕВ) and is known among US guitar players as "EL84M" or the "Russian military EL84". While not necessarily a true "military version" of the tube (in fact it is more comparable to the 7189), 6P14P-EV are known for their low noise and durability. Large NOS (New Old Stock) supplies of the tube are available.
The 6GK6 is a nearly equivalent tube as far as operating characteristics are concerned, with a different tube pinout though.
Current production of the tube takes place in Russia
(Sovtek
and Electro-Harmonix
brands), Slovakia
- Čadca
(JJ Electronics), and Serbia
- Niš
(Ei). The Sovtek EL84 is often sold under their own brand name by other well-known electric guitar
and guitar amplifier
manufacturers - such as Fender or Mesa Boogie
.
Also see 6P1P
.
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
(a.k.a. valve) of the power pentode
Pentode
A pentode is an electronic device having five active electrodes. The term most commonly applies to a three-grid vacuum tube , which was invented by the Dutchman Bernhard D.H. Tellegen in 1926...
type. It has a 9 pin Noval base and is found mainly in the final output stages of amplification circuits, most commonly now in guitar amplifier
Guitar amplifier
A guitar amplifier is an electronic amplifier designed to make the signal of an electric or acoustic guitar louder so that it will produce sound through a loudspeaker...
s, but originally in radios and many other devices of the pre-transistor
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
era.
It was developed to eliminate the need for a driver tube in radios, and has rather more gain than is usual in a power pentode, producing full output from a relatively small drive signal. This eliminated the need for a preamplifier
Preamplifier
A preamplifier is an electronic amplifier that prepares a small electrical signal for further amplification or processing. A preamplifier is often placed close to the sensor to reduce the effects of noise and interference. It is used to boost the signal strength to drive the cable to the main...
triode in radios, making them cheaper to produce. As the EL84 itself is a 9 pin Noval, it was also cheap to produce and manufacturers were quick to adopt it in general use, and they are found in many old European valve radios.
In common with all 'E' prefix tubes, using the Mullard-Philips tube designation
Mullard-Philips tube designation
In Europe, the principal method of numbering vacuum tubes was the nomenclature developed and used by Mullard in the UK and applied Europe-wide thanks to their parentage by Philips who had subsidiaries in Germany and France , plus the support of Telefunken, from 1934...
, it has a heater voltage of 6.3V. It is capable, when used at its plate rating of 300 volts maximum, of producing 17 watts output in Class AB1
Electronic amplifier
An electronic amplifier is a device for increasing the power of a signal.It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude...
in push-pull
Electronic amplifier
An electronic amplifier is a device for increasing the power of a signal.It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude...
configuration. Many guitar amplifiers routinely run EL84 tubes in excess of 400VDC, with the Traynor Guitarmate reportedly putting out 25w RMS with 2 EL84's in a push pull configuration and a B+ between 400-420VDC.
Developed by Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....
in 1953 for use in the British Mullard 5-10
Mullard 5-10
The Mullard 5-10 was a circuit for a valve amplifier designed by the British vacuum tube company, Mullard in 1954 at the Mullard Applications Research Laboratory in Mitcham Surrey UK, part of the New Road factory complex, to take advantage of their particular products...
amplifier, the EL84 came to prominence when used in Watkins (and later the Vox
Vox (musical equipment)
Vox is a musical equipment manufacturer which is most famous for making the Vox AC30 guitar amplifier, the Vox Continental electric organ, and a series of innovative but commercially unsuccessful electric guitars and bass guitars...
) amplifiers preferred by many British invasion
British Invasion
The British Invasion is a term used to describe the large number of rock and roll, beat, rock, and pop performers from the United Kingdom who became popular in the United States during the time period from 1964 through 1966.- Background :...
bands of the 1960s. When overdriven, the EL84 power tubes in these amplifiers produce a distinctive chiming, articulate, treble-heavy sound when compared to 6L6
6L6
6L6 is the designator for a vacuum tube introduced by Radio Corporation of America in July 1936. At the time Philips had already developed and patented power pentode designs, which were fast replacing power triodes due to their greater efficiency...
tubes more commonly used in American amplifiers of the era such as those from Fender.
Other equivalent tubes are the 7189, an extended-ratings version of the tube for industrial applications and the 6P14P (Cyrillic: 6П14П) produced in the USSR by the Reflektor plant, which is a direct equivalent of EL84/6BQ5. A slightly modified version of the 6P14P is currently being manufactured in Russia for Sovtek
Sovtek
Sovtek is a brand of vacuum tube owned by Mike Matthews's New Sensor Corporation and manufactured in Saratov, Russia. They are often used in guitar amplification and include the popular variants of the 12AX7, EL84, EL34, and 6L6 models...
. An extended-ratings version of the 6P14P is also available - 6P14P-EV (Cyrillic: 6П14П-ЕВ) and is known among US guitar players as "EL84M" or the "Russian military EL84". While not necessarily a true "military version" of the tube (in fact it is more comparable to the 7189), 6P14P-EV are known for their low noise and durability. Large NOS (New Old Stock) supplies of the tube are available.
The 6GK6 is a nearly equivalent tube as far as operating characteristics are concerned, with a different tube pinout though.
Current production of the tube takes place in Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
(Sovtek
Sovtek
Sovtek is a brand of vacuum tube owned by Mike Matthews's New Sensor Corporation and manufactured in Saratov, Russia. They are often used in guitar amplification and include the popular variants of the 12AX7, EL84, EL34, and 6L6 models...
and Electro-Harmonix
Electro-Harmonix
Electro-Harmonix is a New York-based company that makes high-end electronic audio processors. The company was founded by Mike Matthews in 1968. They are most famous for a series of popular guitar effects pedals introduced in the 1970s and 1990s....
brands), Slovakia
Slovakia
The Slovak Republic is a landlocked state in Central Europe. It has a population of over five million and an area of about . Slovakia is bordered by the Czech Republic and Austria to the west, Poland to the north, Ukraine to the east and Hungary to the south...
- Čadca
Cadca
Čadca is a district town in northern Slovakia, near the border with Poland and the Czech Republic.-Geography:It is located south of the Jablunkov Pass, surrounded by the Javorníky, Kysucké Beskydy and Turzovská vrchovina mountain ranges. It lies in the valley of the Kysuca river, around 30 km...
(JJ Electronics), and Serbia
Serbia
Serbia , officially the Republic of Serbia , is a landlocked country located at the crossroads of Central and Southeast Europe, covering the southern part of the Carpathian basin and the central part of the Balkans...
- Niš
Niš
Niš is the largest city of southern Serbia and third-largest city in Serbia . According to the data from 2011, the city of Niš has a population of 177,972 inhabitants, while the city municipality has a population of 257,867. The city covers an area of about 597 km2, including the urban area,...
(Ei). The Sovtek EL84 is often sold under their own brand name by other well-known electric guitar
Electric guitar
An electric guitar is a guitar that uses the principle of direct electromagnetic induction to convert vibrations of its metal strings into electric audio signals. The signal generated by an electric guitar is too weak to drive a loudspeaker, so it is amplified before sending it to a loudspeaker...
and guitar amplifier
Guitar amplifier
A guitar amplifier is an electronic amplifier designed to make the signal of an electric or acoustic guitar louder so that it will produce sound through a loudspeaker...
manufacturers - such as Fender or Mesa Boogie
Mesa Boogie
Mesa/Boogie is a company in Petaluma, California that makes amplifiers for guitars and basses. It has been in operation since 1969....
.
Also see 6P1P
6P1P
The 6P1P is a Soviet-made miniature 9-pin beam tetrode vacuum tube with ratings similar to the 6AQ5, EL90 and the 6V6. Because of a different pinout than an 6AQ5/EL90, it cannot be used as a plug-in replacement for these types, however, it will work in the same circuit with component values...
.
External links
- http://tdsl.duncanamps.com/show.php?des=EL84 - EL84 data at TDSL.
- Vacuum tube datasheet archive