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Voltage - Dual Triode (similar) ·Triode-Triode

ECC83S

High-mu twin triode of the ECC83 family for audio-frequency voltage amplification, intended for preamplifier and other high-gain small-signal circuits.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B9A
Base pins
9
Nominal heater
12.6 V / 150 mA

Description

High-mu audio-frequency double triode; also designated ECC83S and 7025. Printed co-designation record duplicated from 12AX7.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B9A
Base pins
9
Nominal heater voltage
12.6 V
Nominal heater current
150 mA
Parallel heater voltage
6.3 V
Parallel heater current
300 mA
Series capable
Yes

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
62500 Ω
Transconductance
0.0016 S
Amplification factor
100
Max plate voltage
300 V
Max plate dissipation
1 W
Max cathode current
8 mA

R.F. double triode; source header also names ECC83, 12AX7 and 7025 without proving exact sameness for alias expansion.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
62500 Ω
Transconductance
0.0016 S
Amplification factor
100
Max plate voltage
300 V
Max plate dissipation
1 W
Max cathode current
8 mA

Second physical triode restored.

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

199X JJ

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Typical Plate Voltage

    250 V

  • TypicalGridVoltage

    -2 V

  • Typical Plate Current

    1.2 mA

Characteristic

  • Grid Cathode Capacitance

    1.6 pF

  • Plate Capacitance

    0.33 pF

  • GridPlateCapacitance

    1.7 pF

Data set 02

2026 JJ Electronic

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Ik

    8 mA

    Published value

  • Ub

    250

    Published value

  • Ra

    47

    Published value

  • Rg

    150

    Published value

  • Rk

    1.2

    Published value

Characteristics

  • Ua

    250 V

    Published value

  • Ug

    -2 V

    Published value

  • Ia

    1.2 mA

    Published value

  • S

    1600 µS

    Published value

  • Ri

    62.5 kΩ

    Published value

  • µ

    100

    Published value

Capacitance

  • cg/k

    1.6

    Published value

  • ca

    0.33

    Published value

  • cg/a

    1.7

    Published value