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.

ECL80 Pentode Vacuum Tube

Also known as 6AB8

Triode + PentodeHeater 6.3 V · 0.3 A9-pin Noval2 sectionsPhilips 1953

Triode · Plate dissipation: 1W
Triode · Amplification factor: 18
Pentode · Plate dissipation: 3.5W
Pentode · Amplification factor: 14

ECL80

Characteristics

Datasheet values, once each. Every value cites its sheet.

HeaterIndirectly heated

Specifications of ECL80 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.3 A

Mechanical

Specifications of ECL80 — Mechanical
Base	9-pin Noval
Rarity	Common
Pinout

TriodeTriode

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of ECL80-T — Triode — Limiting values
Plate voltageVa max	200 V
Screen voltageVg2 max	250 V
Plate dissipationPa max	1 W
Screen dissipationPg2 max	0.75 W
Cathode currentIk max	25 mA
Grid resistorRg1 max	1 MΩ
Peak plate voltageVao	550 V
Heater–cathode voltageVhk max	150 V

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of ECL80-T — Triode — Small signal
Transconductance	1.4 mA/V
Plate resistance	12.5 kΩ
Amplification factor	18

Capacitances

Specifications of ECL80-T — Triode — Capacitances
Grid–cathode	2.1 pF
Grid–plate	0.9 pF
Plate–cathode	0.8 pF

Charactereditorial reading, not a measurement

Specifications of ECL80-T — Triode — Character
Gain	18%
Power	3%
Drive	88%
Linearity	91%

PentodePentode

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of ECL80-P — Pentode — Limiting values
Plate voltageVa max	400 V
Screen voltageVg2 max	250 V
Plate dissipationPa max	3.5 W
Screen dissipationPg2 max	1.2 W
Cathode currentIk max	25 mA
Grid resistorRg1 max	2 MΩ
Peak plate voltageVao	550 V
Heater–cathode voltageVhk max	150 V

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of ECL80-P — Pentode — Small signal
Transconductance	3.3 mA/V
Plate resistance	150 kΩ
Amplification factor	14

Capacitances

Specifications of ECL80-P — Pentode — Capacitances
Input	4.5 pF
Grid–plate	0.2 pF
Output	4.9 pF

Charactereditorial reading, not a measurement

Specifications of ECL80-P — Pentode — Character
Gain	14%
Power	9%
Drive	0%
Linearity	93%

datasheet cited · model or editorial reading · catalogue value, no citation attached yet · nothing invented

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

Design a stage →

Using this tube

Applications

Phase splitter

Generic pentode power stage

Replace or compare

Sources

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

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

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.

History

Introduced: 1953
Manufacturer: Philips
Era: Golden Age

METRIX TESTER

Characteristics

HeaterIndirectly heated

Mechanical

TriodeTriode

Limiting valuesDatasheet maximum ratings — not to be exceeded

Small signalDatasheet parameters at the reference operating point — not limits

Capacitances

Charactereditorial reading, not a measurement?

PentodePentode

Limiting valuesDatasheet maximum ratings — not to be exceeded

Small signalDatasheet parameters at the reference operating point — not limits

Capacitances

Charactereditorial reading, not a measurement?

Typical operation

Using this tube

Applications

Replace or compare

Versus 12SJ7

Similar tubes

Sources

Manufacturer datasheets

SPICE models

Context

History

Test this tube on a Metrix

Charactereditorial reading, not a measurement

Charactereditorial reading, not a measurement