What is the 6AS7G vacuum tube?

The 6AS7G is a triode vacuum tube designed for otl / regulator applications. Classic OTL output..

What is a 6AS7G substitute or equivalent?

Direct equivalents to the 6AS7G include 6080 / 6AS7 / 6AS7G family — verify operating point and dissipation before substitution. 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 6AS7G?

Amplification factor μ ≈ 2, transconductance gm ≈ 7 mA/V, plate resistance rp ≈ 280 Ω, max plate voltage 250 V, max plate dissipation 13 W, heater 6.3 V / 2.5 A.

Is the 6AS7G still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6AS7G 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 6AS7G sound like?

Classic OTL output.. 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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6AS7G Triode Vacuum Tube

Dual triode6.3V / 2.5AOctalSPICE

SourceRCA 6AS7G datasheet — dual power triode; corrected sections=2Reviewed2026-05-29StatusDataModelCalcModelNorman KorenPDF

High-power directly-heated triode for single-ended amplification

Datasheet ↗SPICE

6AS7G — RCA — triode vacuum tube — (1945)

280Ω

7.0mA/V

6.2pF

8.4pF

2.20pF

GAIN2%

POWER33%

DRIVE100%

LINEARITY95%

SPECIFICATIONS

Heater6.3 V · 2.5 A

Max Plate Voltage250 V

Pa max13 W

Gain Factor2

gm7 mA/V

rp280 Ω

Inter-electrode capacitances

Cgk6.2 pF

Cgp8.4 pF

Cpk2.2 pF

PinoutOctal

Era1945

RarityCommon

HEATER6.3V / 2.5A

MAX PLATE250V / 13W

BASEoctal

SECTIONS2 (dual)

Source datasheets

2 manufacturer datasheets cross-checked for 6AS7G

2 verified

TYPICAL OPERATING POINT

Va250V

Ia27.14mA

Vg-138.09084857572398V

Pd6.78W

RL1kΩ

Av0.9dB

EXECUTIVE SUMMARY

The 6AS7G is a dual indirectly-heated triode from RCA, introduced around 1945. It provides a gain factor (μ) of 2 with 280Ω plate resistance. Commonly used in otl / regulator applications. Classic OTL output.

APPLICATIONS

SET outputPush-pull outputHeadphone outputPhase splitter

OTL headphone ampAtma-Sphere MA-1

• Headphone amp

HISTORY

Introduced1945ManufacturerRCA

Golden Age

6AS7G Datasheet

Local mirror · PDF

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METRIX TESTER

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