What is the PL504 vacuum tube?

The PL504 is a pentode vacuum tube designed for power applications. Enhanced PL500..

What is a PL504 substitute or equivalent?

Direct equivalents to the PL504 include None. 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 PL504?

Transconductance gm ≈ 14 mA/V, max plate voltage 250 V, max plate dissipation 16 W, heater 27 V / 0.3 A.

Is the PL504 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the PL504 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 PL504 sound like?

Enhanced PL500.. 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

←PL504

← PL36 PP5/400 →Compare…

PL504 Pentode Vacuum Tube

Pentode27V / 0.3AMagnovalSPICE

SourcePL504 datasheet (beam power tube)Reviewed2026-05-29StatusDataModelCalcModelKoren pentodePDF

Power pentode delivering up to 16W in pentode, UL, or triode mode

Datasheet ↗SPICE

PL504 — Philips — pentode vacuum tube — (1963)

14.0mA/V

15.0pF

1.8pF

7.50pF

GAIN0%

POWER40%

DRIVE50%

LINEARITY75%

SPECIFICATIONS

Heater27 V · 0.3 A

Max Plate Voltage250 V

Pa max16 W

Gain Factor—

gm14 mA/V

rp—

Inter-electrode capacitances

Cgk15 pF

Cgp1.75 pF

Cpk7.5 pF

PinoutMagnoval

Era1963

RarityCommon

HEATER27V / 0.3A

MAX PLATE250V / 16W

BASEmagnoval

Source datasheets

2 manufacturer datasheets cross-checked for PL504

2 verified

EXECUTIVE SUMMARY

The PL504 is a indirectly-heated pentode from Philips, introduced around 1963. Commonly used in power applications. Enhanced PL500.

APPLICATIONS

Power output

Generic pentode power stage

HISTORY

Introduced1963ManufacturerPhilips

Late Production

PL504 Datasheet

Local mirror · PDF

↗

METRIX TESTER

Test this tube on a Metrix

SIMILAR PENTODES

View all →

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