The electron tube EL34 is a pentode is used in output stages of audio amplifiers such as guitar amps. The American term for this tube is 6CA7. Russian it is called 6P27S (Cyrillic: 6п27C )


In the name of EL34 mean: E - 6.3V filament voltage, L - Leistungspentode; the 3 represents the base type ( octal ), and the 4 is a sequential number ( numbering scheme see electron tube ).

The current consumption of indirect heating is 1.5 A.

With an EL34 is 11 watts of output power as a class A amplifier can be achieved. Two EL34 achieve 34 watts as push-pull AB amplifier and 100 watts as push-pull class B amplifier ( 800 V operating voltage, 5 % THD ).

The maximum anode dissipation of 25 watts, the screen grid dissipation 8 watts.

The tube is often used in stage amplifiers for electric guitars. Here, the single-ended class-A operation is particularly interesting because it leads at full load or light overdrive to characteristic, typical for this music distortion.

The operating parameters of such a class -A amplifier ( 1 tube ) be loud Valvo sheet 1965:

  • Anode voltage / screen voltage: 265 V
  • THD ( 11Watt output power ): 10%
  • Load resistor ( output transformer coupling to the speaker): 2 kOhm

The EL34 is often used also in the final stages of many hi-fi tube amplifier both for bodies under its sonic qualities as for their ability to comparatively high output powers.

The European pavers such as Philips or Telefunken have ceased production of the EL34 years ago. In North America, the EL34 was made ​​under the name of 6CA7 General Electric and RCA. In addition, there were various similar replicas of this pentode such as the KT77, which is currently manufactured in Slovakia again.

The development of the EL34 ranges over various precursor types back to the period before the Second World War - but the first copies with this designation appeared only as of the year 1949 The EL34 was from about 1968 worldwide by the Marshall guitar amplifiers often used in rock music. known and is still produced today in various designs and qualities. So companies such as the Russian Svetlana tubes or the tube manufacturer Slovak JJ Electronic EL34 this pentode under the name also in 2006 from new production in the delivery program.

In addition, there is at least one series with the Siemens brand, which takes the conventional Pentodenbauweise with a suppressor grid sheet beam (so-called Beam -power design) exhibit ( see photo). These are fully interchangeable with the normal braking grid variant.


The EL60 is a term introduced by Philips / Valvo EL34 precursor of which differs from it only by using a 9-pin Loktalsockels instead of Oktalsockels. It is caused ( once ) very rare to find due to the higher production costs and the relatively short-term commercial availability, in practice devices.