What is the EL36 vacuum tube?

The EL36 is a tetrode vacuum tube designed for power applications. European TV sweep..

What is a EL36 substitute or equivalent?

Direct equivalents to the EL36 include 6CM5, 6P31S, EL360. These share the same pinout and operating envelope, so they can usually be swapped without circuit changes — though batch-to-batch variations between manufacturers (NOS vs current production) may shift the sonic character noticeably.

What are the key specifications of the EL36?

Amplification factor μ ≈ 6, transconductance gm ≈ 14 mA/V, plate resistance rp ≈ 5.0 kΩ, max plate voltage 250 V, max plate dissipation 10 W, heater 6.3 V / 1.25 A.

Is the EL36 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the EL36 as Common availability. NOS (new-old-stock) examples from RCA, Mullard, Tung-Sol, GE, Sylvania and Telefunken trade among collectors; modern production where it exists comes mostly from JJ Electronic, Electro-Harmonix, Tung-Sol (New Sensor), Genalex, and a handful of small-batch makers.

What does the EL36 sound like?

European TV sweep.. Sonic character also depends heavily on the circuit operating point, the surrounding tubes in the stage, and the output transformer when present — use the interactive loadline calculator on this page to explore the trade-offs.

By Jean-Michel Falligan Devergne · Reviewed May 29, 2026

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EL36 Tetrode Vacuum Tube

Tetrode6.3V / 1.25AOctalSPICE

Sourcetubes-store EL36/6P31SReviewed2026-05-29StatusDataModelCalcModelKoren pentodePDF

Beam power tetrode rated at 10W for high-power output stages

Datasheet ↗SPICE

EL36 — Philips — tetrode vacuum tube — (1955)

5.0kΩ

14.0mA/V

17.5pF

1.1pF

8.00pF

GAIN6%

POWER25%

DRIVE95%

LINEARITY95%

SPECIFICATIONS

Heater6.3 V · 1.25 A

Max Plate Voltage250 V

Pa max10 W

Gain Factor6

gm14 mA/V

rp5.0 kΩ

Inter-electrode capacitances

Cgk17.5 pF

Cgp1.1 pF

Cpk8 pF

PinoutOctal

Era1955

RarityCommon

HEATER6.3V / 1.25A

MAX PLATE250V / 10W

BASEoctal

Source datasheets

5 manufacturer datasheets cross-checked for EL36

5 verified

EXECUTIVE SUMMARY

The EL36 is a indirectly-heated beam tetrode from Philips, introduced around 1955. It provides a gain factor (μ) of 6 with 5000Ω plate resistance. Commonly used in power applications. European TV sweep.

HISTORY

Introduced1955ManufacturerPhilips

Golden Age