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.

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

←EL50

← EL3N EL506 →Compare → 12SJ7

EL50 EL50 / 4654 Pentode Vacuum Tube

Pentode6.3V / 1.35A8-pin Side Contact P8A

SourcePhilipsReviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

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

Datasheet ↗

EL50 / 4654 — Philips — pentode vacuum tube — (1938)

30.0kΩ

6.0mA/V

10.0pF

0.8pF

7.50pF

GAIN0%

POWER45%

DRIVE70%

LINEARITY75%

SPECIFICATIONS

Heater6.3 V · 1.35 A

Max Plate Voltage800 V

Pa max18 W

Gain Factor—

gm6 mA/V

rp30.0 kΩ

Inter-electrode capacitances

Cgk10 pF

Cgp0.8 pF

Cpk7.5 pF

Pinout8-pin Side Contact P8A

Era1938

RarityRare

HEATER6.3V / 1.35A

MAX PLATE800V / 18W

BASEp8a-sc

Source datasheets

5 manufacturer datasheets cross-checked for EL50 / 4654

5 verified

EXECUTIVE SUMMARY

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

APPLICATIONS

Power output

Generic pentode power (se) stage

VS 12SJ7

Rp -97%Pd +620%Full comparison →

HISTORY

Introduced1938ManufacturerPhilips

Pre-War

EL50 Datasheet

Local mirror · PDF

↗

METRIX TESTER

Test this tube on a Metrix

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

SIMILAR PENTODES

View all →

12SJ7Preamp 307APower/Output 310APreamp 35LR6Sweep / Power 47Power/Output 4P1LPower (SET output) — DHT pentode 5639Video / wideband (power)5654RF / Preamp