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.

By Jean-Michel Falligan Devergne · Reviewed May 29, 2026

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6J1 Pentode Vacuum Tube

Pentode6.3V / 0.17A7-pin MiniatureSPICE

SourceRussian 6Ж1П datasheet · 6AK5 familyReviewed2026-05-29StatusDataModelCalcModelKoren pentodePDF

Small-signal pentode for low-noise voltage amplification

Datasheet ↗SPICE

6J1 — Russian — pentode vacuum tube — (1960)

600.0kΩ

5.1mA/V

4.3pF

0.0pF

2.35pF

GAIN0%

POWER5%

DRIVE0%

LINEARITY75%

SPECIFICATIONS

Heater6.3 V · 0.17 A

Max Plate Voltage200 V

Pa max1.8 W

Gain Factor—

gm5.1 mA/V

rp600.0 kΩ

Inter-electrode capacitances

Cgk4.3 pF

Cgp0.02 pF

Cpk2.35 pF

Pinout7-pin Miniature

Era1960

RarityCommon

HEATER6.3V / 0.17A

MAX PLATE200V / 1.8W

BASEb7g

Source datasheets

1 manufacturer datasheets cross-checked for 6J1

1 verified

EXECUTIVE SUMMARY

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

APPLICATIONS

Voltage amplifier

Generic pentode rf / preamp stage

HISTORY

Introduced1960ManufacturerRussian

Late Production

6J1 Datasheet

Local mirror · PDF

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METRIX TESTER

Test this tube on a Metrix

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