What is the 6J1 vacuum tube?

The 6J1 is a pentode vacuum tube designed for rf / preamp applications. Russian RF pentode..

What is a 6J1 substitute or equivalent?

Direct equivalents to the 6J1 include 6AK5 / EF95 (US/EU equivalent — same B7G pinout). 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 6J1?

Transconductance gm ≈ 5.1 mA/V, plate resistance rp ≈ 600.0 kΩ, max plate voltage 200 V, max plate dissipation 1.8 W, heater 6.3 V / 0.17 A.

Is the 6J1 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6J1 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 6J1 sound like?

Russian RF 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.

6J1 Pentode Vacuum Tube

Also known as 6AK5 · EF95 (US · EU equivalent — same B7G pinout)

Small-signal pentode for low-noise voltage amplification

PentodeHeater 6.3 V · 0.17 A7-pin MiniatureRussian 1960

Plate dissipation: 1.8W
Max plate voltage: 200V
Transconductance: 5.1mA/V
Plate resistance: 600kΩ

6J1

Characteristics

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

HeaterIndirectly heated

Specifications of 6J1 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.17 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6J1 — Limiting values
Plate voltageVa max	200 V
Screen voltageVg2 max	120 V
Plate dissipationPa max	1.8 W

Mechanical

Specifications of 6J1 — Mechanical
Base	7-pin Miniature
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 6J1 — Small signal
Transconductance	5.1 mA/V
Plate resistance	600 kΩ

Capacitances

Specifications of 6J1 — Capacitances
Input	4.3 pF
Grid–plate	0.02 pF
Output	2.35 pF

Charactereditorial reading, not a measurement

Specifications of 6J1 — Character
Gain	0%
Power	5%
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 rf / preamp stage

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : Russian 6Ж1П datasheet · 6AK5 familyActive model : Koren pentode

Manufacturer datasheets

1 manufacturer datasheets cross-checked for 6J11 verified

6J1 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: Russian 6Ж1П datasheet · 6AK5 family
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Koren pentode

Context

The 6J1 is a indirectly-heated pentode from Russian, introduced around 1960. Commonly used in rf / preamp applications. Russian RF pentode.

History

Introduced: 1960
Manufacturer: Russian
Era: Late Production

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