What is the UCL82-T vacuum tube?

The UCL82-T (UCL82 (Triode)) is a triode vacuum tube designed for preamp applications. Triode section..

What is a UCL82-T substitute or equivalent?

Direct equivalents to the UCL82-T include 50BM8. 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 UCL82-T?

Amplification factor μ ≈ 70, transconductance gm ≈ 2.2 mA/V, plate resistance rp ≈ 32.0 kΩ, max plate voltage 250 V, max plate dissipation 1 W, heater 50 V / 0.1 A.

Is the UCL82-T still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the UCL82-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 UCL82-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

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UCL82-T UCL82 (Triode) Triode Vacuum Tube

Triode50V / 0.1A9-pin Noval

Sourceaudit-eu_b (CLEAN — matches canonical datasheet)Reviewed2026-05-29StatusDataModelCalcModelunder reviewPDF

Medium-gain triode for voltage amplification applications

Datasheet ↗

UCL82 (Triode) — Philips·Mullard — triode vacuum tube — (1955)

32.0kΩ

2.2mA/V

2.7pF

4.4pF

4.30pF

GAIN70%

POWER3%

DRIVE68%

LINEARITY65%

SPECIFICATIONS

Heater50 V · 0.1 A

Max Plate Voltage250 V

Pa max1 W

Gain Factor70

gm2.2 mA/V

rp32.0 kΩ

Inter-electrode capacitances

Cgk2.7 pF

Cgp4.4 pF

Cpk4.3 pF

Pinout9-pin Noval

Era1955

RarityCommon

HEATER50V / 0.1A

MAX PLATE250V / 1W

BASEnoval

Source datasheets

4 manufacturer datasheets cross-checked for UCL82 (Triode)

4 verified

Triode-connectedPhilips1969 (pages datées 1969.01 / 1969.12)

Specs when the screen grid (g2) is tied to the anode — the tube acts as a triode.

100 V

Vg1

0 V

3.5 mA

2.2 mA/V

16 Ω

According to Philips (Data handbook, Electronic components and materials) (1969 (pages datées 1969.01 / 1969.12)): « en triode »

EXECUTIVE SUMMARY

The UCL82-T is a indirectly-heated triode from Philips·Mullard, introduced around 1955. It provides a gain factor (μ) of 70 with 32.0kΩ plate resistance. Commonly used in preamp applications. Triode section.

APPLICATIONS

Voltage amplifierHigh-gain preamp

Generic triode preamp stage

• Hi-Fi stereo• Headphone amp• Studio/recording

HISTORY

Introduced1955ManufacturerPhilips·Mullard

Golden Age

UCL82-T 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.

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