What is the 6J7 vacuum tube?

The 6J7 is a pentode vacuum tube designed for preamp applications. Octal preamp pentode..

What are the key specifications of the 6J7?

Transconductance gm ≈ 1.225 mA/V, plate resistance rp ≈ 1500.0 kΩ, max plate voltage 300 V, max plate dissipation 0.75 W, heater 6.3 V / 0.3 A.

Is the 6J7 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6J7 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 6J7 sound like?

Octal preamp pentode.. 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.

6J7 Pentode Vacuum Tube

Small-signal pentode for low-noise voltage amplification

PentodeHeater 6.3 V · 0.3 AOctalRCA 1935

Plate dissipation: 0.75W
Max plate voltage: 300V
Transconductance: 1.225mA/V
Plate resistance: 1.5MΩ

6J7

Characteristics

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

HeaterIndirectly heated

Specifications of 6J7 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.3 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6J7 — Limiting values
Plate voltageVa max	300 V
Plate dissipationPa max	0.75 W

Mechanical

Specifications of 6J7 — Mechanical
Base	Octal
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 6J7 — Small signal
Transconductance	1.225 mA/V
Plate resistance	1.5 MΩ

Capacitances

Specifications of 6J7 — Capacitances
Input	7 pF
Grid–plate	0.005 pF
Output	12 pF

Charactereditorial reading, not a measurement

Specifications of 6J7 — Character
Gain	0%
Power	2%
Drive	0%
Linearity	75%

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

Using this tube

Applications

Voltage amplifier

Generic pentode preamp stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : Frank/pocnet 6J7 datasheetActive model : Koren pentode

Manufacturer datasheets

5 manufacturer datasheets cross-checked for 6J75 verified

6J7 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Frank/pocnet 6J7 datasheet
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The 6J7 is a indirectly-heated pentode from RCA, introduced around 1935. Commonly used in preamp applications. Octal preamp pentode.

History

Introduced: 1935
Manufacturer: RCA
Era: Pre-War

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