What is the 274B vacuum tube?

The 274B is a rectifier vacuum tube designed for rectifier applications. Designed for the WE 300B amp. Premier WE rectifier..

What is a 274B substitute or equivalent?

Direct equivalents to the 274B include WE274B, 5U4G, WE274A. 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.

Is the 274B still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 274B 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 274B sound like?

Designed for the WE 300B amp. Premier WE rectifier.. 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.

274B Rectifier Vacuum Tube

Also known as WE274B

Full-wave rectifier for vacuum tube power supply designs

RectifierHeater 5 V · 2 AOctalWestern Electric 1935

Max plate voltage: 550V

274B

Characteristics

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

HeaterDirectly heated

Specifications of 274B — Heater
Heater voltageVh	5 V
Heater currentIh	2 A

Rectifier limitsDatasheet maximum ratings — not to be exceeded

Specifications of 274B — Rectifier limits
Max Plate V	550 V

Mechanical

Specifications of 274B — Mechanical
Base	Octal
Rarity	Legendary
Pinout

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 supply rectification

Generic rectifier rectifier stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026

Manufacturer datasheets

274B DatasheetFrank's Electron Tube Pages · PDF

SPICE models

Revision and verification status

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

Context

The 274B is a directly-heated rectifier from Western Electric, introduced around 1935. Commonly used in rectifier applications. Designed for the WE 300B amp. Premier WE rectifier.

History

Introduced: 1935
Manufacturer: Western Electric
Era: Pre-War

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