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.

EL36 Tetrode Vacuum Tube

Also known as 6CM5 · 6P31S · EL360 · PL36 · 25E5

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

TetrodeHeater 6.3 V · 1.25 AOctalPhilips 1955

Plate dissipation: 10W
Max plate voltage: 250V
Max screen voltage: 250V
Max cathode current: 200mA
Transconductance: 14mA/V

EL36

Characteristics

Datasheet values, once each. Every value cites its sheet.

HeaterIndirectly heated

Specifications of EL36 — Heater
Heater voltageVh	6.3 V
Heater currentIh	1.25 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of EL36 — Limiting values
Plate voltageVa max	250 V
Screen voltageVg2 max	250 V
Plate dissipationPa max	10 W
Cathode currentIk max	200 mA
Grid resistorRg1 max	500 kΩ
Peak plate voltageVao	550 V
Heater–cathode voltageVhk max	100 V

Mechanical

Specifications of EL36 — Mechanical
Base	Octal
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of EL36 — Small signal
Transconductance	14 mA/V
Plate resistance	5 kΩ
Amplification factor	6

Capacitances

Specifications of EL36 — Capacitances
Input	17.5 pF
Grid–plate	1.1 pF
Output	8 pF

Charactereditorial reading, not a measurement

Specifications of EL36 — Character
Gain	6%
Power	25%
Drive	95%
Linearity	95%

datasheet cited · model or editorial reading · catalogue value, no citation attached yet · nothing invented

Using this tube

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : tubes-store EL36/6P31SActive model : Koren pentode

Manufacturer datasheets

5 manufacturer datasheets cross-checked for EL365 verified

EL36 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: tubes-store EL36/6P31S
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

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

Introduced: 1955
Manufacturer: Philips
Era: Golden Age

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