EL156 — Power Pentode | Tubeofile

EL156

Power Pentode

Telefunken

Known Equivalents & Substitutes

EL156A

Electrical Specifications

Section 1 — Pentode

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)800V

Screen Voltage (max)Screen Voltage (max)450V

Anode Dissipation (max)Anode Dissipation (max, cathode bias)50W

Screen Dissipation (max)Screen Dissipation (max, music)12W

Cathode Current (max)Cathode Current (max)180mA

Heater-to-Cathode Voltage (max)Heater-Cathode Voltage (max)50V

Max Grid ResistorMax Grid Resistor0.1MΩ

Typical Operating

Anode Voltage (typical)Anode Voltage450V

Screen Voltage (typical)Screen Voltage280V

Grid 1 Bias VoltageGrid 1 Bias Voltage-11.6V

Anode CurrentAnode Current112mA

Screen CurrentScreen Current

Output

Output PowerOutput Power24W

Load ImpedanceLoad Impedance3,800Ω

Capacitances

Grid-to-Plate CapacitanceGrid-to-Plate Capacitance0.5pF

Input CapacitanceInput Capacitance19pF

Output CapacitanceOutput Capacitance7.5pF

Section 2 — Triode Strapped

Absolute Maximum

Anode Voltage (max)Anode Voltage (max)800V

Anode Dissipation (max)Anode Dissipation (max, cathode bias)50W

Typical Operating

Anode Voltage (typical)Anode Voltage500V

Grid 1 Bias VoltageGrid 1 Bias Voltage-27.5V

Heater

Heater VoltageHeater Voltage6.3V

Heater CurrentHeater Current1.9A

Notes

Uses German Steel 10-pin (Y10A / Stahl 10 / G10A) base, which is not a standard octal, noval, or magnoval socket. Requires a dedicated Y10 socket.
A Magnoval-based variant also exists (EL156 Magnoval) but is not pin-compatible with the original Y10A version.
Max anode dissipation differs by bias type: 50W with cathode (auto) bias, 40W with fixed bias.
Screen grid dissipation limit depends on drive level: 8W at Ug1eff=0, but 12W permissible with speech and music signals.
In triode connection, max combined screen voltage is 500V (vs 450V in pentode mode). Telefunken recommends keeping combined anode+screen dissipation below 35W in triode mode.
A 100 Ohm screen stopper resistor is required before the screen grid in push-pull AB operation.
Pins 3 and 4 are internal connections (beam plates) and must not be connected externally.
Predecessor: EL151. Production period: 1952-1973.

Pin Layout

1Heater

2Heater

References