What is a 6EM7 substitute or equivalent?

Direct equivalents to the 6EM7 include 6EA7, 6GL7. 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 6EM7?

Amplification factor μ ≈ 68, transconductance gm ≈ 1.6 mA/V, plate resistance rp ≈ 40.0 kΩ, max plate voltage 330 V, max plate dissipation 10 W, heater 6.3 V / 0.925 A.

Is the 6EM7 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 6EM7 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 6EM7 sound like?

Asymmetric noval dual: one high-μ driver + one low-μ output section. Allows a complete one-tube SE amplifier (driver + output) per channel.. 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.

6EM7 6EA7 Triode Vacuum Tube

Q: What is the 6EM7 vacuum tube?

The 6EM7 (6EM7 / 6EA7) is a triode vacuum tube designed for driver + power applications. Asymmetric noval dual: one high-μ driver + one low-μ output section. Allows a complete one-tube SE amplifier (driver + output) per channel..

Also known as 6EA7 · 6GL7

Power triode delivering 10W for push-pull and SET designs

Dual triodeHeater 6.3 V · 0.925 AOctal2 sectionsRCA·Sylvania·GE 1957

Plate dissipation: 10W
Max plate voltage: 330V
Transconductance: 1.6mA/V

6EM7

Characteristics

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

Asymmetric sections — each unit has its own characteristics

Unit 1 — High-μ (driver)

40.0kΩ

1.6mA/V

Pd max2.5W

2.2pF

4.8pF

0.60pF

Unit 2 — Low-μ (output)

5.4

750Ω

7.2mA/V

Pd max7.5W

7.0pF

10.0pF

1.80pF

HeaterIndirectly heated

Specifications of 6EM7 — Heater
Heater voltageVh	6.3 V
Heater currentIh	0.925 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 6EM7 — Limiting values
Plate voltageVa max	330 V
Plate dissipationPa max	10 W

Mechanical

Specifications of 6EM7 — Mechanical
Base	Octal
Rarity	Common
Pinout

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

Typical operation

Conditions published by the manufacturers, one row per condition. Nothing is computed.

Typical operation
Setup	Va	Vg1 / Rk	Ia	gm	rp	Source
Class A, single-endedtriode connection · fixed bias	250 V	-3 V	1.4 mA	1.6 mA/V	40 kΩ	OCR, to be checked RCA · 8-60 (pages 1-6) + 5-61 reprint (pages 7-13) · p. 1 · transcript

Using this tube

No interactive loadline model for this tube yet — download a SPICE model below to simulate it in LTspice or ngspice.

Applications

SET output
Push-pull output
High-gain preamp
Phase splitter

Generic triode driver + power stage

Hi-Fi stereoStudio/recording

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : RCA 6EM7 datasheet

Manufacturer datasheets

2 manufacturer datasheets cross-checked for 6EM7 / 6EA72 verified

6EM7 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: RCA 6EM7 datasheet
Reviewed: 2026-05-29
Status: DataModelCalc
Model: under review

Context

The 6EM7 is a dual indirectly-heated triode from RCA·Sylvania·GE, introduced around 1957. It provides a gain factor (μ) of 68 with 40.0kΩ plate resistance. Commonly used in driver + power applications. Asymmetric noval dual: one high-μ driver + one low-μ output section. Allows a complete one-tube SE amplifier (driver + output) per channel.

History

Introduced: 1957
Manufacturer: RCA·Sylvania·GE
Era: Golden Age

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