What is the ECL85-T vacuum tube?

The ECL85-T (ECL85 (Triode)) is a triode vacuum tube designed for preamp applications. Triode section..

What is a ECL85-T substitute or equivalent?

Direct equivalents to the ECL85-T include 6GV8. 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 ECL85-T?

Amplification factor μ ≈ 50, transconductance gm ≈ 5.5 mA/V, plate resistance rp ≈ 9.0 kΩ, max plate voltage 250 V, max plate dissipation 0.5 W, heater 6.3 V / 0.9 A.

Is the ECL85-T still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the ECL85-T 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 ECL85-T sound like?

Triode section.. 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

←ECL85-T

← ECL85-P ECL86-P →Compare…

ECL85-T ECL85 (Triode) Triode Vacuum Tube

Triode6.3V / 0.9A9-pin NovalSPICE

Sourcer-type.org ECL85/6GV8Reviewed2026-05-29StatusDataModelCalcModelNorman KorenPDF

Medium-gain triode for driver and line stage applications

Datasheet ↗SPICE

ECL85 (Triode) — Philips — triode vacuum tube — (1960)

9.0kΩ

5.5mA/V

2.5pF

1.5pF

0.50pF

GAIN50%

POWER1%

DRIVE91%

LINEARITY75%

SPECIFICATIONS

Heater6.3 V · 0.9 A

Max Plate Voltage250 V

Pa max0.5 W

Gain Factor50

gm5.5 mA/V

rp9.0 kΩ

Inter-electrode capacitances

Cgk2.5 pF

Cgp1.5 pF

Cpk0.5 pF

Pinout9-pin Noval

Era1960

RarityCommon

HEATER6.3V / 0.9A

MAX PLATE250V / 0.5W

BASEnoval

Source datasheets

4 manufacturer datasheets cross-checked for ECL85 (Triode)

4 verified

TYPICAL OPERATING POINT

Va135V

Ia2.79mA

Vg-2V

Pd0.38W

RL18kΩ

Av29.6dB

EXECUTIVE SUMMARY

The ECL85-T is a indirectly-heated triode from Philips, introduced around 1960. It provides a gain factor (μ) of 50 with 9000Ω plate resistance. Commonly used in preamp applications. Triode section.

APPLICATIONS

Voltage amplifier

Generic triode preamp stage

• Hi-Fi stereo

HISTORY

Introduced1960ManufacturerPhilips

Late Production

ECL85-T Datasheet

Local mirror · PDF

↗

METRIX TESTER

Test this tube on a Metrix

SIMILAR TRIODES

View all →

01APreamp 100THTransmitting (SET)101DPower (SET)10YPower (SET)12AT7Driver 12AU7Line / Headphone 12AX7Preamp 12AY7Preamp