What is the 75TL vacuum tube?

The 75TL is a triode vacuum tube designed for transmitting (set) applications. Building block of the 304TL. Low mu power..

What is a 75TL substitute or equivalent?

Direct equivalents to the 75TL include None standard. 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 75TL?

Amplification factor μ ≈ 12, transconductance gm ≈ 3.35 mA/V, plate resistance rp ≈ 3.6 kΩ, max plate voltage 3000 V, max plate dissipation 75 W, heater 5 V / 6.25 A.

Is the 75TL still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 75TL 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 75TL sound like?

Building block of the 304TL. Low mu power.. 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

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75TL Triode Vacuum Tube

Triode5V / 6.25AUX-4

SourceEimacReviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

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

Datasheet ↗

75TL — Eimac — triode vacuum tube — (1936)

3.6kΩ

3.4mA/V

2.6pF

2.4pF

0.40pF

GAIN12%

POWER100%

DRIVE96%

LINEARITY94%

SPECIFICATIONS

Heater5 V · 6.25 A

Max Plate Voltage3000 V

Pa max75 W

Gain Factor12

gm3.35 mA/V

rp3.6 kΩ

Inter-electrode capacitances

Cgk2.6 pF

Cgp2.4 pF

Cpk0.4 pF

PinoutUX-4

Era1936

RarityRare

HEATER5V / 6.25A

MAX PLATE3000V / 75W

BASEux4

Source datasheets

3 manufacturer datasheets cross-checked for 75TL

3 verified

EXECUTIVE SUMMARY

The 75TL is a directly-heated triode from Eimac, introduced around 1936. It provides a gain factor (μ) of 12 with 3582Ω plate resistance. Commonly used in transmitting (set) applications. Building block of the 304TL. Low mu power.

APPLICATIONS

SET outputPush-pull output

Generic triode transmitting (set) stage

• PA/public address

HISTORY

Introduced1936ManufacturerEimac

Pre-War

75TL 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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