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.

6AS7G Triode Vacuum Tube

Also known as 6080 · 6AS7 · 6AS7G family — verify operating point and dissipation before substitution

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

Dual triodeHeater 6.3 V · 2.5 AOctal2 sectionsRCA 1945

Plate dissipation: 13W
Max plate voltage: 250V
Transconductance: 7mA/V

6AS7G

Pd check: failDissipation check failed — the Koren model exceeds this tube's Pa-max at the audit probe point. Calculator results for this tube are under review.

Characteristics

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

HeaterIndirectly heated

Specifications of 6AS7G — Heater
Heater voltageVh	6.3 V
Heater currentIh	2.5 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6AS7G — Limiting values
Plate voltageVa max	250 V
Plate dissipationPa max	13 W

Mechanical

Specifications of 6AS7G — Mechanical
Base	Octal
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 6AS7G — Small signal
Transconductance	7 mA/V
Plate resistance	280 Ω
Amplification factor	2

Capacitances

Specifications of 6AS7G — Capacitances
Grid–cathode	6.2 pF
Grid–plate	8.4 pF
Plate–cathode	2.2 pF

Charactereditorial reading, not a measurement

Specifications of 6AS7G — Character
Gain	2%
Power	33%
Drive	100%
Linearity	95%

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

Using this tube

Applications

SET output
Push-pull output
Headphone output
Phase splitter

OTL headphone ampAtma-Sphere MA-1

Headphone amp

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : RCA 6AS7G datasheet — dual power triode; corrected sections=2Active model : Norman Koren

Manufacturer datasheets

2 manufacturer datasheets cross-checked for 6AS7G2 verified

6AS7G DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: RCA 6AS7G datasheet — dual power triode; corrected sections=2
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Norman Koren

Context

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.

History

Introduced: 1945
Manufacturer: RCA
Era: Golden Age

METRIX TESTER