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Voltage - Dual Triode (similar) ·Triode-Triode

B759

High-gain miniature twin triode for low-frequency voltage amplification, co-designated 12AX7 and ECC83, providing two high-mu small-signal amplifier sections.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 370 mA

Description

High-gain miniature twin triode for low-frequency voltage amplification; co-designated 12AX7 and ECC83.

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
6.3 V
Nominal heater current
370 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

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
Transconductance
0.0014 S
Amplification factor
83
Max plate voltage
330 V
Max plate dissipation
1.2 W
Max cathode current
9 mA

Representative section for two electrically identical sections.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Transconductance
0.0014 S
Amplification factor
83
Max plate voltage
330 V
Max plate dissipation
1.2 W
Max cathode current
9 mA

Second physical triode restored under current one-row-per-physical-section policy.

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

2026 Genalex Rebrand

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Plate Current

    1.05 to 2 mA

    Plate 250 V; grid -2 V