What is the 6N7S vacuum tube?

The 6N7S is a triode vacuum tube designed for driver applications. Russian 6N7 variant..

What is a 6N7S substitute or equivalent?

Direct equivalents to the 6N7S include 6N7. 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 6N7S?

Amplification factor μ ≈ 35, transconductance gm ≈ 3.4 mA/V, plate resistance rp ≈ 11.0 kΩ, max plate voltage 300 V, max plate dissipation 5.5 W, heater 6.3 V / 0.81 A.

Is the 6N7S still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6N7S 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 6N7S sound like?

Russian 6N7 variant.. 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

←6N7S

← 6N7P 6P1P-EV →Compare → 6N7

6N7S Triode Vacuum Tube

Dual triode6.3V / 0.81AOctalSPICE

SourceRCA RC-15 6N7 datasheet · Norman Koren SPICE modelReviewed2026-05-29StatusDataModelCalcModelNorman KorenPDF

Medium-gain triode for voltage amplification applications

Datasheet ↗SPICE

6N7S — Russian — triode vacuum tube — (1955)

11.0kΩ

3.4mA/V

3.6pF

2.6pF

4.60pF

GAIN35%

POWER14%

DRIVE89%

LINEARITY83%

SPECIFICATIONS

Heater6.3 V · 0.81 A

Max Plate Voltage300 V

Pa max5.5 W

Gain Factor35

gm3.4 mA/V

rp11.0 kΩ

Inter-electrode capacitances

Cgk3.6 pF

Cgp2.6 pF

Cpk4.6 pF

PinoutOctal

Era1955

RarityCommon

HEATER6.3V / 0.81A

MAX PLATE300V / 5.5W

BASEoctal

SECTIONS2 (dual)

Source datasheets

1 manufacturer datasheets cross-checked for 6N7S

1 verified

TYPICAL OPERATING POINT

Va250V

Ia6.86mA

Vg-3V

Pd1.72W

RL22kΩ

Av26.7dB

EXECUTIVE SUMMARY

The 6N7S is a dual indirectly-heated triode from Russian, introduced around 1955. It provides a gain factor (μ) of 35 with 11.0kΩ plate resistance. Commonly used in driver applications. Russian 6N7 variant.

APPLICATIONS

Push-pull outputPhase splitter

Generic triode driver stage

VS 6N7

μ 0%Rp -3%Pd 0%Full comparison →

HISTORY

Introduced1955ManufacturerRussian

Golden Age