6L6

6L6
A 6L6 tube manufactured by Sylvania
ClassificationBeam power tetrode
ServiceClass-A amplifier, class-B amplifier, class-AB amplifier, (audio amplifiers)
Height4.25 in (108 mm)
Diameter1.438 in (36.5 mm)
Cathode
Cathode typeIndirectly heated
Heater voltage6.3
Heater current900 mA
Anode
Max dissipation Watts30
Max voltage500
Specification listed is for type 6L6-GC
Socket connections
The 6L6 Pinout, metal versions had the shell connected to pin 1

Pin 1 – n.c
Pin 2 – Heater
Pin 3 – Anode (Plate)
Pin 4 – Grid 2 (Screen)
Pin 5 – Grid 1 (control)
Pin 6 – n.c
Pin 7 – Heater

Pin 8 – Cathode & beam-forming plates
Typical class-A amplifier operation
Anode voltage350 V
Anode current54 mA
Screen voltage250 V
Bias voltage−18 V
Anode resistance5 kOhms
Typical class-AB amplifier operation
(Values are for two tubes)
Power output55 W
Anode resistance:
(anode to anode)		5.6 kOhms
Anode voltage450 V
Anode current2*54 mA
Screen voltage400 V
Bias voltage−37 V
References
Essential Characteristics, General Electric, 1973

6L6 is the designator for a beam power tube introduced by Radio Corporation of America in April 1936 and marketed for application as a power amplifier for audio frequencies.[1][2] The 6L6 is a beam tetrode that utilizes formation of a low potential space charge region between the anode and screen grid to return anode secondary emission electrons to the anode and offers significant performance improvements over power pentodes.[1] The 6L6 was the first successful beam power tube marketed. In the 21st century, variants of the 6L6 are manufactured and used in some high fidelity audio amplifiers and musical instrument amplifiers.

  1. ^ a b J. F. Dreyer Jr., "The Beam Power Output Tube", New York: McGraw-Hill, Electronics, April 1936, pp. 18 - 21, 35
  2. ^ RCA Manufacturing Co. Inc., "Here is the New RCA 6L6 Beam Power Amplifier", New York: McGraw-Hill, Electronics, May 1936, back cover