What is the 250TL vacuum tube?

The 250TL (250TL / VT-130) is a triode vacuum tube designed for transmitting (set) applications. Eimac transmitting triode. Extreme power SET..

What is a 250TL substitute or equivalent?

Direct equivalents to the 250TL include VT-130. 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 250TL?

Amplification factor μ ≈ 14, transconductance gm ≈ 2.65 mA/V, plate resistance rp ≈ 5.3 kΩ, max plate voltage 4000 V, max plate dissipation 250 W, heater 5 V / 10.5 A.

Is the 250TL still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 250TL 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 250TL sound like?

Eimac transmitting triode. Extreme power SET.. 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

←250TL

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250TL 250TL / VT-130 Triode Vacuum Tube

Triode5V / 10.5AUX-4

SourceEimacReviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Power triode delivering 250W for push-pull and SET designs

Datasheet ↗

250TL / VT-130 — Eimac — triode vacuum tube — (1938)

5.3kΩ

2.6mA/V

3.7pF

3.0pF

0.70pF

GAIN14%

POWER100%

DRIVE95%

LINEARITY93%

SPECIFICATIONS

Heater5 V · 10.5 A

Max Plate Voltage4000 V

Pa max250 W

Gain Factor14

gm2.65 mA/V

rp5.3 kΩ

Inter-electrode capacitances

Cgk3.7 pF

Cgp3 pF

Cpk0.7 pF

PinoutUX-4

Era1938

RarityRare

HEATER5V / 10.5A

MAX PLATE4000V / 250W

BASEux4

Source datasheets

3 manufacturer datasheets cross-checked for 250TL / VT-130

3 verified

EXECUTIVE SUMMARY

The 250TL is a directly-heated triode from Eimac, introduced around 1938. It provides a gain factor (μ) of 14 with 5283Ω plate resistance. Commonly used in transmitting (set) applications. Eimac transmitting triode. Extreme power SET.

APPLICATIONS

SET outputPush-pull output

Generic triode transmitting (set) stage

• PA/public address

HISTORY

Introduced1938ManufacturerEimac

Pre-War

250TL 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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