Sensibly equivalent¶ to:
6CA7 CV1741 KT77
The EL34 is a much loved audio power valve with an anode dissipation of 25 Watts. The EL34 was the 1952 successor to the very successful EL37 and both share a high value of mutual conductance 11.0 mA/V. The EL37 was of pinch construction whereas for the EL34 mullard used the pressed glass foot construction employed on the B9A and B7G miniature valves for this IO based device.
When used in push-pull ultra linear configuration is capable of excellent results and low distortion.
The ratings given for this valve are maxima. The Vg figure is pk-pk between both grid 1's. Rl was 11k in that configuration. It is normal to run a pair of these valves to give 20 Watts at 1.6% total distortion.
The definitive circuits for these valves was given by Mullard's own design labs in the publication Circuits for Audio Amplifiers.
Our exhibit is brand new and had never been out of its box prior to taking the photographs.
By clicking the link under the valve name at the top of the page the full Mullard datasheet can be downloaded. Warning this is a large PDF file.
The wide glass tube envelope is 34 mm in diameter and excluding IO base pins the valve is 95 mm high.
References: Datasheet & 1040. Type EL34 was first introduced in 1952.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated February 21, 2014.