EL34

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Matched EL34 Vacuum Tubes by Russian manufacturer, Svetlana
Matched EL34 Vacuum Tubes by Russian manufacturer, Svetlana
An EL34 Vacuum Tube manufactured by Mullard
An EL34 Vacuum Tube manufactured by Mullard

The EL34 is a vacuum tube of the pentode type. It has an octal base (indicated by the '3' in the part number) and is found mainly in the final output stages of amplification circuits. The American RETMA tube designation number for this tube is 6CA7. Russian analog is 6p27s (Cyrillic: 6п27с )

[edit] Specifications

In common with all 'E' prefix tubes, using the Mullard-Philips tube designation, the EL34 has a heater voltage of 6.3V. It is capable, when used at its plate rating of 800 volts maximum, of producing 90 watts output in Class AB1 in push-pull configuration.

Unlike the 6L6, (EIA base 7AC) the EL34 has its grid 3 connection brought out to a separate Pin (Pin 1) (EIA base 8ET) and its heater draws 1.5 Amps compared to the 0.9 Amp heater in the 6L6. The EL34 was generally built as a true pentode, while the 6L6 was built as a beam tetrode which RCA often referred to as a beam power tube.

The EL34 is still in production by JJ Electronic, Svetlana and Sovtek, amongst others. Some firms make a related tube called an E34L which is rated to require a higher voltage bias on the grid, but which may be interchangeable in some equipment.

[edit] Application

The EL34 was widely used in higher-powered audio amplifiers of the 1960s and 1970s, such as the very popular Dynaco Stereo 70 and the Leak Stereo 60, and is also widely used in high end guitar amplifiers because it is characterized by a greater amount of distortion at lower power than other octal tubes such as a 6L6, KT88 or 6550. The EL34 is found in many British guitar amps and thus is associated with the "British Tone" (Marshall) as compared to the 6L6 which is generally associated with the "American Tone" (Fender).

[edit] References