What is the 12BH7 vacuum tube?

The 12BH7 (12BH7A) is a triode vacuum tube designed for driver applications. Punchy, dynamic..

What are the key specifications of the 12BH7?

Amplification factor μ ≈ 16, transconductance gm ≈ 3.1 mA/V, plate resistance rp ≈ 5.5 kΩ, max plate voltage 300 V, max plate dissipation 3.5 W, heater 12.6 V / 0.3 A.

Is the 12BH7 still in production?

Production status varies by year and manufacturer. The current Amperatubes catalog classifies the 12BH7 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 12BH7 sound like?

Punchy, dynamic.. 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.

12BH7 A Triode Vacuum Tube

Medium-gain triode for driver and line stage applications

Dual triodeHeater 12.6 V · 0.3 A9-pin Noval2 sectionsRCA·GE 1952

Plate dissipation: 3.5W
Max plate voltage: 300V
Amplification factor: 16
Transconductance: 3.1mA/V
Plate resistance: 5.5kΩ

12BH7

Characteristics

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

HeaterIndirectly heated

Specifications of 12BH7 — Heater
Heater voltageVh	12.6 V
Heater currentIh	0.3 A

Limiting valuesDatasheet maximum ratings — not to be exceeded

Specifications of 12BH7 — Limiting values
Plate voltageVa max	300 V
Plate dissipationPa max	3.5 W

Mechanical

Specifications of 12BH7 — Mechanical
Base	9-pin Noval
Rarity	Common
Pinout

Small signalDatasheet parameters at the reference operating point — not limits

Specifications of 12BH7 — Small signal
Transconductance	3.1 mA/V
Plate resistance	5.5 kΩ
Amplification factor	16

Capacitances

Specifications of 12BH7 — Capacitances
Grid–cathode	3 pF
Grid–plate	2.4 pF
Plate–cathode	0.8 pF

Charactereditorial reading, not a measurement

Specifications of 12BH7 — Character
Gain	16%
Power	9%
Drive	95%
Linearity	92%

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

Typical operation

Canonical operating pointSPICE model2 availableModel

B+: 312 V
Load: 5.5 kΩ
Va: 187 V
Ia: 2.92 mA
Vg: -10.2 V
Pd: 0.55 W
Gain: 18.1 dB

At Q: Ayumi Nakabayashi · 2 engines
μ: 15.1
gm: 1.36 mA/V
rp: 11.1 kΩ

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Using this tube

Applications

Line stage
Phase splitter

Dynaco PAS driverFisher X-100 driver

Headphone amp

Replace or compare

Sources

By Jean-Michel Falligan DevergneReviewed May 29, 2026Source : RCA 12BH7A datasheet (frank/pocnet)Active model : Ayumi Nakabayashi · 2 engines

Manufacturer datasheets

3 manufacturer datasheets cross-checked for 12BH7A3 verified

12BH7 DatasheetLocal mirror · PDF

SPICE models

Revision and verification status

Source: RCA 12BH7A datasheet (frank/pocnet)
Reviewed: 2026-05-29
Status: DataModelCalc
Model: Ayumi Nakabayashi · 2 engines

Context

The 12BH7 is a dual triode originally designed as a vertical deflection amplifier in television sets, with a mu of ~17 and the ability to handle high peak currents relative to its size. Its generous current capability makes it popular as a power amplifier driver and phase inverter, particularly in circuits that need to swing large voltages into capacitive loads. The tube is sometimes used as a low-power headphone amplifier output tube, delivering class A power in the 0.5-1W range. RCA and GE are the primary NOS sources; current production is available from JJ Electronic and Electro-Harmonix.

History

Introduced: 1952
Manufacturer: RCA·GE
Era: Golden Age

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