What is the RE604 vacuum tube?

The RE604 is a triode vacuum tube designed for power (se) applications. Legendary German DHT. Cinema heritage..

What is a RE604 substitute or equivalent?

Direct equivalents to the RE604 include AD1. 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 RE604?

Amplification factor μ ≈ 4, transconductance gm ≈ 3.5 mA/V, plate resistance rp ≈ 1.5 kΩ, max plate voltage 200 V, max plate dissipation 12 W, heater 4 V / 0.65 A.

Is the RE604 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the RE604 as Legendary 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 RE604 sound like?

Legendary German DHT. Cinema heritage.. 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

←RE604

← RCA-6146b RO4404 →Compare → AD1

RE604 Triode Vacuum Tube

Triode4V / 0.65A4-pin European

SourceTelefunken RE604 (radiomuseum.org)Reviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

High-power directly-heated triode for single-ended amplification

Datasheet ↗

RE604 — Telefunken — triode vacuum tube — (1929)

1.5kΩ

3.5mA/V

4.0pF

5.5pF

3.00pF

GAIN4%

POWER30%

DRIVE99%

LINEARITY95%

SPECIFICATIONS

Heater4 V · 0.65 A

Max Plate Voltage200 V

Pa max12 W

Gain Factor4

gm3.5 mA/V

rp1.5 kΩ

Inter-electrode capacitances

Cgk4 pF

Cgp5.5 pF

Cpk3 pF

Pinout4-pin European

Era1929

RarityLegendary

HEATER4V / 0.65A

MAX PLATE200V / 12W

BASEb4-eu

Source datasheets

2 manufacturer datasheets cross-checked for RE604

2 verified

EXECUTIVE SUMMARY

The RE604 is a directly-heated triode from Telefunken, introduced around 1929. It provides a gain factor (μ) of 4 with 1500Ω plate resistance. Commonly used in power (se) applications. Legendary German DHT. Cinema heritage.

APPLICATIONS

SET outputPush-pull outputHeadphone output

Generic triode power (se) stage

• Hi-Fi stereo• Headphone amp

VS AD1

μ 0%Rp +124%Pd -20%Full comparison →

HISTORY

Introduced1929ManufacturerTelefunken

Pre-War

RE604 Datasheet

Local mirror · PDF

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METRIX TESTER

Test this tube on a Metrix

SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.

SIMILAR TRIODES

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