What is the ECC81 vacuum tube?

The ECC81 is a triode vacuum tube designed for driver applications. European 12AT7..

What is a ECC81 substitute or equivalent?

Direct equivalents to the ECC81 include 12AT7. 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 ECC81?

Amplification factor μ ≈ 60, transconductance gm ≈ 5.5 mA/V, plate resistance rp ≈ 11.0 kΩ, max plate voltage 300 V, max plate dissipation 2.5 W, heater 6.3 V / 0.3 A.

Is the ECC81 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the ECC81 as Common 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 ECC81 sound like?

European 12AT7.. 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

←ECC81

← ECC40 ECC82 →Compare → 12AT7

ECC81 Triode Vacuum Tube

Dual triode6.3V / 0.3A9-pin NovalSPICE

SourceMullard datasheetReviewed2026-05-29StatusDataModelCalcModelKoren v1PDF

Medium-gain triode for voltage amplification applications

Datasheet ↗SPICE

ECC81 — Mullard — triode vacuum tube — (1947)

11.0kΩ

5.5mA/V

2.3pF

1.6pF

0.45pF

GAIN60%

POWER6%

DRIVE89%

LINEARITY70%

SPECIFICATIONS

Heater6.3 V · 0.3 A

Max Plate Voltage300 V

Pa max2.5 W

Gain Factor60

gm5.5 mA/V

rp11.0 kΩ

Inter-electrode capacitances

Cgk2.3 pF

Cgp1.6 pF

Cpk0.45 pF

Pinout9-pin Noval

Era1947

RarityCommon

HEATER6.3V / 0.3A

MAX PLATE300V / 2.5W

BASEnoval

SECTIONS2 (dual)

Source datasheets

5 manufacturer datasheets cross-checked for ECC81

5 verified

TYPICAL OPERATING POINT

SPICE model(2 available)2 .subckt available ↓

Va180V

Ia3.73mA

Vg-2.17V

Pd0.67W

RL10kΩ

Av28dB

EXECUTIVE SUMMARY

The ECC81 is a dual indirectly-heated triode from Mullard, introduced around 1947. It provides a gain factor (μ) of 60 with 11.0kΩ plate resistance. Commonly used in driver applications. European 12AT7.

APPLICATIONS

High-gain preampPhase splitter

Marshall JCM800 PIFender reverb driver

• Guitar amp• Headphone amp• Studio/recording

VS 12AT7

μ 0%Rp +1%Pd 0%Full comparison →

HISTORY

Introduced1947ManufacturerMullard

Golden Age

ECC81 Datasheet

Local mirror · PDF

↗

METRIX TESTER

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SIMILAR TRIODES

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ECC81 Triode Vacuum Tube

Source datasheets

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