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Voltage - Dual Triode (similar) ·Triode-Triode

12SX7GT

Premium twin triode derived from the 12SN7 family for applications requiring dependable, stable operation, combining medium gain with useful current capability in two similar sections.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
8BD
Socket code
IO
Base pins
8
Nominal heater
12.6 V / 300 mA

Description

The 12SX7GT combines two electrically independent medium-mu triodes, apart from a common heater, for audio-amplifier, oscillator, converter, and multivibrator applications.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8BD
Socket code
IO
Base pins
8
Nominal heater voltage
12.6 V
Nominal heater current
300 mA
Parallel heater voltage
6.3 V
Parallel heater current
600 mA
Series capable
Yes

8BD - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN12G1BG1 — Control Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN22PBP — Plate (Anode)

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN32KBK — Cathode

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN41G1AG1 — Control Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN51PAP — Plate (Anode)

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN61KAK — Cathode

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN7H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

PIN8H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8BD

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
7700 Ω
Transconductance
0.0026 S
Amplification factor
20
Max plate voltage
300 V
Max plate dissipation
2.75 W
Max cathode current
20 mA

Published promoted fields populated semantically; identical repeated sections compressed.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
7700 Ω
Transconductance
0.0026 S
Amplification factor
20
Max plate voltage
300 V
Max plate dissipation
2.75 W
Max cathode current
20 mA

Second identical physical triode section; added to align rows with SectionCount.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Control-grid bias

    8 V

    ClassA

  • Plate current

    9 mA

    ClassA

Characteristic

  • Plate resistance

    7700 ohm

    Published handbook characteristic

  • Transconductance

    2600 µS

    Published handbook characteristic

  • Amplification factor

    20

    Published handbook characteristic

  • Heater voltage

    12.6 V

    Published heater rating

  • Heater current

    300 mA

    Published heater rating

Data set 02

1960 RCA Industrial and Communications Types

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • HeaterOrFilamentVoltage

    12.6 V

  • HeaterOrFilamentCurrent

    300 mA

Data set 03

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Typical plate supply voltage

    180 V

    ResistanceCoupledAmplifier

  • Typical load resistance

    0.1 MOhm

    ResistanceCoupledAmplifier

  • Typical cathode resistor

    2830 ohm

    ResistanceCoupledAmplifier

  • Typical voltage gain

    14

    ResistanceCoupledAmplifier

  • Maximum plate voltage

    330 V

    PromotedValue

  • Maximum plate dissipation

    2.75 W

    PromotedValue

  • Maximum cathode current

    20 mA

    PromotedValue

Capacitance

  • Grid-to-plate capacitance

    3 pF

    EachSection

  • Input capacitance

    2.9 pF

    EachSection

  • Output capacitance

    0.8 pF

    EachSection