What is the 6LQ6 vacuum tube?

The 6LQ6 is a tetrode vacuum tube designed for power applications. High-current compactron..

What is a 6LQ6 substitute or equivalent?

Direct equivalents to the 6LQ6 include 6JE6. 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 6LQ6?

Amplification factor μ ≈ 3, transconductance gm ≈ 9.6 mA/V, plate resistance rp ≈ 5.8 kΩ, max plate voltage 990 V, max plate dissipation 30 W, heater 6.3 V / 2.5 A.

Is the 6LQ6 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6LQ6 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 6LQ6 sound like?

High-current compactron.. 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.

6LQ6 Tetrode Vacuum Tube

Also known as 6JE6

Beam power tetrode rated at 30W for high-power output stages

TetrodeHeater 6.3 V · 2.5 A12-pin CompactronRCA 1962

Plate dissipation: 30W
Max plate voltage: 990V
Transconductance: 9.6mA/V

6LQ6

Characteristics

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

HeaterIndirectly heated

Specifications of 6LQ6 — Heater
Heater voltageVh	6.3 V
Heater currentIh	2.5 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6LQ6 — Limiting values
Plate voltageVa max	990 V
Plate dissipationPa max	30 W

Mechanical

Specifications of 6LQ6 — Mechanical
Base	12-pin Compactron
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 6LQ6 — Small signal
Transconductance	9.6 mA/V
Plate resistance	5.8 kΩ
Amplification factor	3

Capacitances

Specifications of 6LQ6 — Capacitances
Input	22 pF
Grid–plate	0.56 pF
Output	11 pF

Charactereditorial reading, not a measurement

Specifications of 6LQ6 — Character
Gain	3%
Power	75%
Drive	94%
Linearity	95%

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

Using this tube

Applications

High-power output

Generic tetrode power stage

PA/public address

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : amplifiedparts 6JE6C/6LQ6 beam powerActive model : Koren pentode

Manufacturer datasheets

2 manufacturer datasheets cross-checked for 6LQ62 verified

Triode-connectedGeneral Electric1973 (3-73; curves FEBRUARY 4, 1970)

µ: 1

6LQ6 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: amplifiedparts 6JE6C/6LQ6 beam power
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The 6LQ6 is a indirectly-heated beam tetrode from RCA, introduced around 1962. It provides a gain factor (μ) of 3 with 5800Ω plate resistance. Commonly used in power applications. High-current compactron.

History

Introduced: 1962
Manufacturer: RCA
Era: Late Production

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