What is the VT-4C vacuum tube?

The VT-4C (VT-4C / 211) is a triode vacuum tube designed for transmitting (set) applications. Military 211 variant. Same mighty bass..

What is a VT-4C substitute or equivalent?

Direct equivalents to the VT-4C include 211, 242C. 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 VT-4C?

Amplification factor μ ≈ 12, transconductance gm ≈ 3.3 mA/V, plate resistance rp ≈ 3.6 kΩ, max plate voltage 1250 V, max plate dissipation 75 W, heater 10 V / 3.25 A.

Is the VT-4C still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the VT-4C as Moderate 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 VT-4C sound like?

Military 211 variant. Same mighty bass.. 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

←VT-4C

← VT-168A VT-91 →Compare → 211

VT-4C VT-4C / 211 Triode Vacuum Tube

Triode10V / 3.25AUX-4

Sourcecap audit 2026-05-09Reviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Power triode delivering 75W for push-pull and SET designs

Datasheet ↗

VT-4C / 211 — GE·RCA — triode vacuum tube — (1938)

3.6kΩ

3.3mA/V

5.4pF

14.0pF

4.80pF

GAIN12%

POWER100%

DRIVE96%

LINEARITY94%

SPECIFICATIONS

Heater10 V · 3.25 A

Max Plate Voltage1250 V

Pa max75 W

Gain Factor12

gm3.3 mA/V

rp3.6 kΩ

Inter-electrode capacitances

Cgk5.4 pF

Cgp14 pF

Cpk4.8 pF

PinoutUX-4

Era1938

RarityModerate

HEATER10V / 3.25A

MAX PLATE1250V / 75W

BASEux4

Source datasheets

1 manufacturer datasheets cross-checked for VT-4C / 211

1 verified

EXECUTIVE SUMMARY

The VT-4C is a directly-heated triode from GE·RCA, introduced around 1938. It provides a gain factor (μ) of 12 with 3600Ω plate resistance. Commonly used in transmitting (set) applications. Military 211 variant. Same mighty bass.

APPLICATIONS

SET outputPush-pull output

Generic triode transmitting (set) stage

• PA/public address

VS 211

μ 0%Rp +0%Pd -25%Full comparison →

HISTORY

Introduced1938ManufacturerGE·RCA

Pre-War

VT-4C Datasheet

Local mirror · PDF

↗

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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