What is the UCL82-P vacuum tube?

The UCL82-P (UCL82 (Pentode)) is a pentode vacuum tube designed for power applications. Pentode section. 100mA series heater..

What is a UCL82-P substitute or equivalent?

Direct equivalents to the UCL82-P 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-P?

Amplification factor μ ≈ 10, transconductance gm ≈ 7.5 mA/V, plate resistance rp ≈ 16.0 kΩ, max plate voltage 250 V, max plate dissipation 7 W, heater 50 V / 0.1 A.

Is the UCL82-P still in production?

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

Pentode section. 100mA series heater.. 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-P UCL82 (Pentode) Pentode Vacuum Tube

Pentode50V / 0.1A9-pin Noval

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

Small-signal pentode for low-noise voltage amplification

Datasheet ↗

UCL82 (Pentode) — Philips·Mullard — pentode vacuum tube — (1955)

16.0kΩ

7.5mA/V

9.3pF

0.3pF

8.00pF

GAIN10%

POWER18%

DRIVE84%

LINEARITY95%

SPECIFICATIONS

Heater50 V · 0.1 A

Max Plate Voltage250 V

Pa max7 W

Gain Factor10

gm7.5 mA/V

rp16.0 kΩ

Inter-electrode capacitances

Cgk9.3 pF

Cgp0.3 pF

Cpk8 pF

Pinout9-pin Noval

Era1955

RarityCommon

HEATER50V / 0.1A

MAX PLATE250V / 7W

BASEnoval

Source datasheets

4 manufacturer datasheets cross-checked for UCL82 (Pentode)

4 verified

Triode-connectedPhilips1969 (Dec 1969 / Jan 1969)

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) (1969 (Dec 1969 / Jan 1969)): « en triode »

EXECUTIVE SUMMARY

The UCL82-P is a indirectly-heated pentode from Philips·Mullard, introduced around 1955. It provides a gain factor (μ) of 10 with 16.0kΩ plate resistance. Commonly used in power applications. Pentode section. 100mA series heater.

HISTORY

Introduced1955ManufacturerPhilips·Mullard

Golden Age

UCL82-P 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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