What is the EL39 vacuum tube?

The EL39 (EL39 / 4654K) is a pentode vacuum tube designed for power (se/pp) applications. Cinema power pentode. Pedigreed Philips sound..

What is a EL39 substitute or equivalent?

Direct equivalents to the EL39 include 4654K. 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 EL39?

Transconductance gm ≈ 6 mA/V, max plate voltage 400 V, max plate dissipation 18 W, heater 6.3 V / 0.9 A.

Is the EL39 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the EL39 as Rare 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 EL39 sound like?

Cinema power pentode. Pedigreed Philips sound.. 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.

EL39 4654K Pentode Vacuum Tube

Also known as 4654K

Power pentode delivering up to 18W in pentode, UL, or triode mode

PentodeHeater 6.3 V · 0.9 AOctalPhilips 1952

Plate dissipation: 18W
Max plate voltage: 400V
Max screen voltage: 200V
Transconductance: 6mA/V

EL39

Characteristics

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

HeaterIndirectly heated

Specifications of EL39 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.9 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of EL39 — Limiting values
Plate voltageVa max	400 V
Screen voltageVg2 max	200 V
Plate dissipationPa max	18 W

Mechanical

Specifications of EL39 — Mechanical
Base	Octal
Rarity	Rare
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of EL39 — Small signal
Transconductance	6 mA/V

Capacitances

Specifications of EL39 — Capacitances
Input	12 pF
Grid–plate	0.4 pF
Output	7.5 pF

Charactereditorial reading, not a measurement

Specifications of EL39 — Character
Gain	0%
Power	45%
Drive	50%
Linearity	75%

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

Typical operation

Conditions published by the manufacturers, one row per condition. Nothing is computed.

Typical operation
Setup	Va	Vg2	Vg1 / Rk	Ia	Ig2	Load	THD	gm	rp	Source
pentode connection, single-endedclass not stated	200 V	200 V	-8.5 V	45 mA	6 mA	4.5 kΩ	10%	8 mA/V	35 kΩ	OCR, to be checked Mullard · ISSUE 3 (CL33 1546) · p. 1 · transcript

Using this tube

Interactive loadline calculator not available for this tube yet — it needs calibrated Koren or Ayumi parameters.

Applications

Power output

Generic pentode power (se/pp) stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026

Manufacturer datasheets

1 manufacturer datasheets cross-checked for EL39 / 4654K1 verified

EL39 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Philips
Reviewed: 2026-05-29
Status: DataModelCalc
Model: under review

Context

The EL39 is a indirectly-heated pentode from Philips, introduced around 1952. Commonly used in power (se/pp) applications. Cinema power pentode. Pedigreed Philips sound.

History

Introduced: 1952
Manufacturer: Philips
Era: Golden Age

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