What is the WE437A vacuum tube?

The WE437A is a triode vacuum tube designed for power (se) applications. Holy grail small triode. ~2W SE. Legendary..

What is a WE437A substitute or equivalent?

Direct equivalents to the WE437A include 6S45P-E, 6C45Pi. 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 WE437A?

Amplification factor μ ≈ 40, transconductance gm ≈ 46 mA/V, plate resistance rp ≈ 870 Ω, max plate voltage 160 V, max plate dissipation 7 W, heater 6.3 V / 0.4 A.

Is the WE437A still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the WE437A as Collector 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 WE437A sound like?

Holy grail small triode. ~2W SE. Legendary.. 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

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WE437A Triode Vacuum Tube

Triode6.3V / 0.4A9-pin Magnoval

SourceWestern ElectricReviewed—StatusDataModelCalcModelunder reviewPDF

Medium-gain triode for driver and line stage applications

Datasheet ↗

WE437A — Western Electric — triode vacuum tube — (1956)

870Ω

46.0mA/V

4.5pF

0.1pF

2.80pF

GAIN40%

POWER18%

DRIVE99%

LINEARITY80%

SPECIFICATIONS

Heater6.3 V · 0.4 A

Max Plate Voltage160 V

Pa max7 W

Gain Factor40

gm46 mA/V

rp870 Ω

Inter-electrode capacitances

Cgk4.5 pF

Cgp0.07 pF

Cpk2.8 pF

Pinout9-pin Magnoval

Era1956

RarityCollector

HEATER6.3V / 0.4A

MAX PLATE160V / 7W

BASEmagnoval

EXECUTIVE SUMMARY

The WE437A is a indirectly-heated triode from Western Electric, introduced around 1956. It provides a gain factor (μ) of 40 with 870Ω plate resistance. Commonly used in power (se) applications. Holy grail small triode. ~2W SE. Legendary.

APPLICATIONS

Push-pull outputHeadphone output

Generic triode power (se) stage

• Hi-Fi stereo• Headphone amp

HISTORY

Introduced1956ManufacturerWestern Electric

Golden Age

WE437A 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.

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