The 6DJ8 is a miniature nine-pin medium gain dual triode vacuum tube. It is distinguished by its very high transconductance, mostly the result of its frame grid construction. Versions of the tube are named ECC88, E88CC, 6922, E188CC, CV4108, 7308, 6N1P and 6N23P.
The tube was developed by Philips in the Netherlands under European designation ECC88. The series-string version 7DJ8 / PCC88 was also introduced at the same time. The 6DJ8 was designed for use as a low-noise amplifier in VHF and UHF TV tuners, an improved successor to the usual 6BK7, but due to its high gain it was heavily used in high-end test equipment, for example, most high-quality oscilloscopes from the 1950s to the 1960s utilize a number of 6DJ8 tubes.
Although not originally designed for the purpose, it became popular in hi-fi audio amplifiers. European-produced version of the tube is designated ECC88. An industrial (improved/higher ratings) version of the tube was designated 6922 / E88CC between 1959 and 1961. Siemens introduced their own super ECC88 / 6DJ8 at the same time under CCa type. New Old Stock (NOS) 6DJ8s and ECC88s produced in the past by major American or West European vacuum tube manufacturers (such as Philips or Amperex) remain extremely popular with and highly sought by audiophiles. A version (direct equivalent) of this tube was also produced in the Soviet Union as 6N23P (Russian: 6Н23П).
As of 2015 [update] the tube was being produced in three versions in Eastern Europe - Slovakia by JJ Electronic (ex-Tesla), and in Russia: 6DJ8 for Sovtek and 6922 for Electro-Harmonix.
A vacuum tube, electron tube, valve, or tube, is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied.
12AX7 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.
6SN7 is a dual triode vacuum tube with an eight-pin octal base. It provides a medium gain. The 6SN7 is basically two 6J5 triodes in one envelope.
KT66 is the designator for a beam power tube introduced by Marconi-Osram Valve Co. Ltd. (M-OV) of Britain in 1937 and marketed for application as a power amplifier for audio frequencies and driver for radio frequencies. The KT66 is a beam tetrode that utilizes partially collimated electron beams to form a low potential space charge region between the anode and screen grid to return anode secondary emission electrons to the anode and offers significant performance improvements over comparable power pentodes. In the 21st century, the KT66 is manufactured and used in some high fidelity audio amplifiers and musical instrument amplifiers.
The EL34 is a thermionic vacuum tube of the power pentode type, first made in 1949. It has an international octal base 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.
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.
In Europe, the principal method of numbering vacuum tubes was the nomenclature used by the Philips company and its subsidiaries Mullard in the UK, Valvo(de, it) in Germany, Radiotechnique (Miniwatt-Dario brand) in France, and Amperex in the United States, from 1934 on. Adhering manufacturers include AEG (de), CdL (1921, French Mazda brand), CIFTE (fr, Mazda-Belvu brand), EdiSwan (British Mazda brand), Lorenz (de), MBLE(fr, nl), RCA (us), RFT(de, sv) (de), Siemens (de), Telefunken (de), Tesla (cz), Toshiba (ja), Tungsram (hu), and Unitra. This system allocated meaningful codes to tubes based on their function and became the starting point for the Pro Electron naming scheme for active devices.
12AT7 is a miniature 9-pin medium-gain (60) dual-triode vacuum tube popular in guitar amplifiers. It belongs to a large family of dual triode vacuum tubes which share the same pinout, including in particular the very commonly used low-mu 12AU7 and high-mu 12AX7.
The 12AU7 and its variants are miniature nine-pin medium-gain dual triode vacuum tubes. It belongs to a large family of dual triode vacuum tubes which share the same pinout. 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 ECC82 and E182CC.
The 6N2P,, also sometimes spelled in English "6H2Pi", is a miniature 9-pin dual triode vacuum tube manufactured in USSR, Russia and China with characteristics similar to the 12AX7. The most significant difference between the two is that 6N2P has its two filament elements connected in parallel, unlike the series filament connection of the 12AX7, and it is thus only possible to operate it from a 6.3 volt, 340 mA filament supply
The 6N3P is a Russian-made direct equivalent of the 2C51 medium gain dual triode vacuum tube. It may be used as an amplifier, mixer, oscillator or multivibrator over a frequency range AF through VHF. The Russian tube is slightly larger in size than the American tube.
The 6N1P is a Russian-made miniature 9-pin medium gain double triode vacuum tube intended for use as a line audio amplifier and cathode driver.
Vacuum tubes produced in the former Soviet Union and in present-day Russia carry their own unique designations. Some confusion has been created in "translating" these designations, as they use Cyrillic rather than Latin characters.
The Vox AC30 is a guitar amplifier manufactured by Vox. It was introduced in 1958 to meet the growing demand for louder amplifiers. Characterised by its "jangly" high-end sound it has become widely recognized by British musicians and others, such as George Harrison and John Lennon of the Beatles, Bill Wyman of the Rolling Stones, Brian May of Queen, Dave Davies of the Kinks and Hank Marvin.
The 6AQ5 is a miniature 7-pin (B7G) audio power output beam tetrode vacuum tube with ratings virtually identical to the 6V6 at 250 V. It was commonly used as an output audio amplifier in tube TVs and radios. There are versions of this tube with extended ratings for industrial application which are designated as 6AQ5A, and 6AQ5W/6005 or 6005W.
The 6N14P is a miniature Russian-made medium gain dual triode vacuum tube, intended for service as a low-noise cascode amplifier at HF through VHF frequencies. It is a direct equivalent of ECC84 and 6CW7 vacuum tubes.
The 6N24P is a miniature Russian-made medium gain dual, frame grid triode vacuum tube, intended for service as a cascode amplifier at HF through VHF frequencies. The construction of the tube is asymmetrical, with the control grid of the first triode section being internally connected to the internal RF shielding plate, thereby making the first section more suitable for common grid operation.
JJ Electronic, s.r.o is a Slovak electronic component manufacturer, and one of the world's remaining producers of vacuum tubes. They are based in Čadca, in the Kysuce region of Slovakia. Most of the products that JJ offers are audio receiving tubes. These vacuum tubes are mainly used for guitar and hi-fi amplifiers. In technical terms, JJ produces triodes, beam tetrodes and power pentodes. Double diode vacuum tubes for full wave AC-to-DC rectifiers are also produced. JJ also produces electrolytic capacitors for higher-voltage purposes, generally for use in audio amplifiers. JJ also manufactures their own line of high-end audio amplifiers and guitar amplifiers. In 2015, the company sales amounted to EUR 8.5 million and net income came to EUR 3.8 million. Most production is exported to the United States.