What is the 30A-EmissionLabs vacuum tube?

The 30A-EmissionLabs (30A EML) is a triode vacuum tube designed for power (set) applications. EML DHT in the Type 30 family; higher μ than 2A3 and not a 2A3 equivalent..

What is a 30A-EmissionLabs substitute or equivalent?

Direct equivalents to the 30A-EmissionLabs include Type 30 family (μ=8); NOT a 2A3 equivalent (2A3 has μ≈4). 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 30A-EmissionLabs?

Amplification factor μ ≈ 8, transconductance gm ≈ 4.5 mA/V, plate resistance rp ≈ 1.8 kΩ, max plate voltage 450 V, max plate dissipation 11 W, heater 5 V / 1.5 A.

Is the 30A-EmissionLabs still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 30A-EmissionLabs as Sought-after 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 30A-EmissionLabs sound like?

EML DHT in the Type 30 family; higher μ than 2A3 and not a 2A3 equivalent.. 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.

30A-EmissionLabs 30A EML Triode Vacuum Tube

Also known as Type 30 family (μ=8) · NOT a 2A3 equivalent (2A3 has μ≈4)

Power triode delivering 11W for push-pull and SET designs

TriodeHeater 5 V · 1.5 AUX-4Emission Labs 2005

Plate dissipation: 11W
Max plate voltage: 450V
Transconductance: 4.5mA/V

30A-EmissionLabs

Characteristics

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

HeaterDirectly heated

Specifications of 30A-EmissionLabs — Heater
Heater voltageVh	5 V
Heater currentIh	1.5 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 30A-EmissionLabs — Limiting values
Plate voltageVa max	450 V
Plate dissipationPa max	11 W

Mechanical

Specifications of 30A-EmissionLabs — Mechanical
Base	UX-4
Rarity	Sought-after
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 30A-EmissionLabs — Small signal
Transconductance	4.5 mA/V
Plate resistance	1.8 kΩ
Amplification factor	8

Capacitances

Specifications of 30A-EmissionLabs — Capacitances
Grid–cathode	10 pF
Grid–plate	16 pF
Plate–cathode	8 pF

Charactereditorial reading, not a measurement

Specifications of 30A-EmissionLabs — Character
Gain	8%
Power	28%
Drive	98%
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

Generic triode power (set) stage

Hi-Fi stereoHeadphone amp

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 10, 2026Source : Emission Labs design notes (EML-12B-20A-20B-30A) · external audit feedback · wording corrected: not 2A3 equivalentActive model : Norman Koren

Manufacturer datasheets

30A-EmissionLabs DatasheetFrank's Electron Tube Pages · PDF

SPICE models

Revision and verification status

Source: Emission Labs design notes (EML-12B-20A-20B-30A) · external audit feedback · wording corrected: not 2A3 equivalent
Reviewed: 2026-05-10
Status: DataModelCalc
Model: Norman Koren

Context

The 30A-EmissionLabs is a directly-heated triode from Emission Labs, introduced around 2005. It provides a gain factor (μ) of 8 with 1780Ω plate resistance. Commonly used in power (set) applications. EML DHT in the Type 30 family; higher μ than 2A3 and not a 2A3 equivalent.

History

Introduced: 2005
Manufacturer: Emission Labs
Era: Modern

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