The ECLL800 is a double audio output pentode with a voltage amplifier triode also in the envelope. The pentodes operate in Class AB push-pull with a common screen grid. The output is 9.2 W at 5% distortion.
Thanks to Michael for sending in the photograph. Michael says that this valve was used in his Normande Tannhaeuser stereo radio that dates from the 1960's.
The thin glass tube envelope is 22 mm in diameter, and excluding the B9A base pins is 71 mm tall.
Reference: Datasheet. Type ECLL800 was first introduced in 1963.
Absolute Maximum Operating Conditions¶
Updated February 20, 2013. shape:thin.glass.tube construction:all.glass type:triode.double.pentode age:1960.1975 base:b9a heater:6.3v pins:9 pin:1.a(t) pin:2.g1(t).g1(p1) pin:3.a(p1) pin:4.h pin:5.h pin:6.g1(p2) pin:7.k.g3.s pin:8.a(p2) pin:9.g2