What is the ECL80 vacuum tube?

The ECL80 is a pentode vacuum tube designed for power applications.

What is a ECL80 substitute or equivalent?

Direct equivalents to the ECL80 include 6AB8. 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.

Is the ECL80 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the ECL80 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 ECL80 sound like?

Sonic character depends 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

ECL80 Pentode Vacuum Tube

Triode + Pentode6.3 V · 0.3 A9-pin Noval2 sectionsAlso known as6AB8

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : audit-eu_a (CLEAN — matches canonical datasheet)

ECL80

In brief

TriodeTriode

μ: 18
gm: 1.4 mA/V
rp: 12.5 kΩ
Pa: 1 W

PentodePentode

μ: 14
gm: 3.3 mA/V
rp: 150 kΩ
Pa: 3.5 W

The ECL80-T is a indirectly-heated triode from Philips, introduced around 1953. It provides a gain factor (μ) of 18 with 12.5kΩ plate resistance. Commonly used in preamp applications. Triode section. The ECL80-P is a indirectly-heated pentode from Philips, introduced around 1953. It provides a gain factor (μ) of 14 with 150.0kΩ plate resistance. Commonly used in power applications. Pentode section.

Limits

Specifications of ECL80
Specification	Value	Source
Heater
Heater voltage	6.3 V	Datasheet
Heater current	0.3 A	Datasheet

Specifications of ECL80-T — Triode
Specification	Value	Source
LimitsDatasheet maximum ratings — not to be exceeded
Max Plate V	200 V	Datasheet
Pa max	1 W	Datasheet

Typical operation

Canonical operating pointModel

B+: 175 V
Load: 25 kΩ
Va: 105 V
Ia: 2.09 mA
Vg: -4 V
Pd: 0.22 W
Gain: 21.6 dB

At Q: Norman Koren
μ: 14.9
gm: 0.84 mA/V
rp: 17.6 kΩ

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Using this tube

Open the loadline calculator

APPLICATIONS

Phase splitter

Generic pentode power stage

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Sources

Manufacturer datasheets

Triode

4 manufacturer datasheets cross-checked for ECL80 — Triode4 verified

Triode-connectedPhilips — édition datée 12.12.

Va: 20 V
µ: 1

Pentode

4 manufacturer datasheets cross-checked for ECL80 — Pentode4 verified

Triode-connectedPhilips1951-1952 (12.12.1952; sheets datés 1951/1952; courbes 2.2.1951 / 4-1-51)

µ: 10

ECL80 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: audit-eu_a (CLEAN — matches canonical datasheet)
Reviewed: 2026-05-29
Status: DataModelCalc
Model: SPICE model

Context

HISTORY

Introduced: 1953
Manufacturer: Philips
Era: Golden Age

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