What is the EL50 vacuum tube?

The EL50 (EL50 / 4654) is a pentode vacuum tube designed for power (se) applications. Philips cinema pentode. EL34 predecessor..

What is a EL50 substitute or equivalent?

Direct equivalents to the EL50 include 4654. 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 EL50?

Transconductance gm ≈ 6 mA/V, plate resistance rp ≈ 30.0 kΩ, max plate voltage 800 V, max plate dissipation 18 W, heater 6.3 V / 1.35 A.

Is the EL50 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the EL50 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 EL50 sound like?

Philips cinema pentode. EL34 predecessor.. 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.

EL50 4654 Pentode Vacuum Tube

Also known as 4654

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

PentodeHeater 6.3 V · 1.35 A8-pin Side Contact P8APhilips 1938

Plate dissipation: 18W
Max plate voltage: 800V
Max screen voltage: 425V
Max cathode current: 120mA
Transconductance: 6mA/V

EL50

Characteristics

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

HeaterIndirectly heated

Specifications of EL50 — Heater
Heater voltageVh	6.3 V
Heater currentIh	1.35 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of EL50 — Limiting values
Plate voltageVa max	800 V
Screen voltageVg2 max	425 V
Plate dissipationPa max	18 W
Cathode currentIk max	120 mA
Peak plate voltageVao	1600 V
Heater–cathode voltageVhk max	100 V

Mechanical

Specifications of EL50 — Mechanical
Base	8-pin Side Contact P8A
Rarity	Rare
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of EL50 — Small signal
Transconductance	6 mA/V
Plate resistance	30 kΩ

Capacitances

Specifications of EL50 — Capacitances
Input	10 pF
Grid–plate	0.8 pF
Output	7.5 pF

Charactereditorial reading, not a measurement

Specifications of EL50 — Character
Gain	0%
Power	45%
Drive	70%
Linearity	75%

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

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) stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026

Manufacturer datasheets

5 manufacturer datasheets cross-checked for EL50 / 46545 verified

EL50 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

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

Context

The EL50 is a indirectly-heated pentode from Philips, introduced around 1938. Commonly used in power (se) applications. Philips cinema pentode. EL34 predecessor.

History

Introduced: 1938
Manufacturer: Philips
Era: Pre-War

METRIX TESTER