6SN7
Encyclopedia
6SN7 is a dual triode
vacuum tube
, on an 8 pin octal base. Although the 6S—series tubes are often metal cased, the 6SN7 is generally found only in a glass GT size envelope. The 6SN7 is basically two 6J5 triodes in one glass envelope.
With the advent of television the 6SN7 was well suited for use as a vertical-deflection amplifier. As screen sizes became larger, the tube started to have marginal voltage and power headroom. To address this, upgraded versions GTA (General Electric
, 1950) and GTB (GE, 1954) were made with higher peak voltage and power ratings. The 6SN7GTA has anode
dissipation uprated to 5.0 watts "design center rating". The 6SN7GTB is identical to the 6SN7GTA except for a controlled heater warmup time, for use in Television sets with 600 mA series
heater strings.
The 6SN7 has a 6.3 V 600 mA heater/filament. The 12 volt filament equivalent is the 12SN7GT or 12SN7GTA. (12.6 V 300 mA filament) There was also a comparatively rare 8SN7 (8.4V@450mA filament intended for 450 mA series string TV sets)
Numerous other variations on the 6SN7 type have been offered over the years, including 7N7 (Sylvania 1940, loktal-base version), 5692 (RCA 1948, a super-premium version with guaranteed 10,000 hour lifetime), 12SX7 (RCA 1946, intended for use in 26-volt aircraft electronics), 1633 (RCA 1941, also for 26-V radios), 6042 (1951, another 1633 type), and 6180 (1952). American military designator for the 6SN7GA was VT-231, and the British called it CV1988. European designators include ECC32, 13D2 and B65. Each of the giant SAGE
computer systems used hundreds of 5692s as flip-flop
s.
While often used as an audio amplifier in the 1940-1955 period, usually in the driver stages of power amps, the 6SN7 was also very popular in television vertical sweep applications. The designer of the famous Williamson amplifier
, one of the first true high-fidelity designs, suggested use of the 6SN7 since it was similar to the British triodes that he used in his circuit. In most late-1950s applications it was replaced by the 12AU7
, then by transistor
s in the 1960s.
The 6SN7 was considered to be obsolete by the 1960's and almost impossible to source. However, with the resurgence of interest in vacuum tube amplifiers for audio use, manufacture of 6SN7s (along with its companion higher gain tube the 6SL7) was recommenced. 6SN7s are still manufactured in Russia and China under the old Soviet designator 6N8S, and continue to be used in some modern tube high-fidelity equipment. The 6SN7 is similar, but not identical, in electrical characteristics to the 12AU7.
The 6CG7 is a miniature tube (RCA, 1951) that has very similar ratings. It was also made as an 8.4V 450mA series string type as the 8CG7. The British made a single triode with identical characteristics as one half of a 6SN7, its number is L63.
Triode
A triode is an electronic amplification device having three active electrodes. The term most commonly applies to a vacuum tube with three elements: the filament or cathode, the grid, and the plate or anode. The triode vacuum tube was the first electronic amplification device...
vacuum tube
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...
, on an 8 pin octal base. Although the 6S—series tubes are often metal cased, the 6SN7 is generally found only in a glass GT size envelope. The 6SN7 is basically two 6J5 triodes in one glass envelope.
History
Originally released in 1939 it was officially registered in 1941 as the glass-cased 6SN7GT. During World War II a 6SN7A was developed as a slightly improved version, then also a more rugged 6SN7W for military use.With the advent of television the 6SN7 was well suited for use as a vertical-deflection amplifier. As screen sizes became larger, the tube started to have marginal voltage and power headroom. To address this, upgraded versions GTA (General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
, 1950) and GTB (GE, 1954) were made with higher peak voltage and power ratings. The 6SN7GTA has anode
Anode
An anode is an electrode through which electric current flows into a polarized electrical device. Mnemonic: ACID ....
dissipation uprated to 5.0 watts "design center rating". The 6SN7GTB is identical to the 6SN7GTA except for a controlled heater warmup time, for use in Television sets with 600 mA series
Series and parallel circuits
Components of an electrical circuit or electronic circuit can be connected in many different ways. The two simplest of these are called series and parallel and occur very frequently. Components connected in series are connected along a single path, so the same current flows through all of the...
heater strings.
The 6SN7 has a 6.3 V 600 mA heater/filament. The 12 volt filament equivalent is the 12SN7GT or 12SN7GTA. (12.6 V 300 mA filament) There was also a comparatively rare 8SN7 (8.4V@450mA filament intended for 450 mA series string TV sets)
Numerous other variations on the 6SN7 type have been offered over the years, including 7N7 (Sylvania 1940, loktal-base version), 5692 (RCA 1948, a super-premium version with guaranteed 10,000 hour lifetime), 12SX7 (RCA 1946, intended for use in 26-volt aircraft electronics), 1633 (RCA 1941, also for 26-V radios), 6042 (1951, another 1633 type), and 6180 (1952). American military designator for the 6SN7GA was VT-231, and the British called it CV1988. European designators include ECC32, 13D2 and B65. Each of the giant SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
computer systems used hundreds of 5692s as flip-flop
Flip-flop (electronics)
In electronics, a flip-flop or latch is a circuit that has two stable states and can be used to store state information. The circuit can be made to change state by signals applied to one or more control inputs and will have one or two outputs. It is the basic storage element in sequential logic...
s.
While often used as an audio amplifier in the 1940-1955 period, usually in the driver stages of power amps, the 6SN7 was also very popular in television vertical sweep applications. The designer of the famous Williamson amplifier
Williamson amplifier
A Williamson amplifier refers to a type of vacuum tube amplifier whose circuit design is similar to that originally published by D.T.N. Williamson.- Explanation :...
, one of the first true high-fidelity designs, suggested use of the 6SN7 since it was similar to the British triodes that he used in his circuit. In most late-1950s applications it was replaced by the 12AU7
12AU7
12AU7 is a miniature nine-pin medium-gain dual triode vacuum tube. 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...
, then by 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...
s in the 1960s.
The 6SN7 was considered to be obsolete by the 1960's and almost impossible to source. However, with the resurgence of interest in vacuum tube amplifiers for audio use, manufacture of 6SN7s (along with its companion higher gain tube the 6SL7) was recommenced. 6SN7s are still manufactured in Russia and China under the old Soviet designator 6N8S, and continue to be used in some modern tube high-fidelity equipment. The 6SN7 is similar, but not identical, in electrical characteristics to the 12AU7.
The 6CG7 is a miniature tube (RCA, 1951) that has very similar ratings. It was also made as an 8.4V 450mA series string type as the 8CG7. The British made a single triode with identical characteristics as one half of a 6SN7, its number is L63.
See also
- List of vacuum tubes
- 6SL7
- 12AT712AT712AT7 is a miniature 9-pin medium-gain dual triode vacuum tube popular in guitar amplifiers. It belongs to a large family of dual triode vacuum tubes which share the same pinout and of which 12AX7 is the most prolific type....
- 12AU712AU712AU7 is a miniature nine-pin medium-gain dual triode vacuum tube. 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...
- 12AX712AX712AX7 is a miniature dual triode vacuum tube with high voltage gain. It was developed around 1946 by RCA engineers in Harrison, 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...
- 12BH7
- 6CG7
- L63