Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Voltage - Dual Triode (similar) ·Triode-Triode

6EU7

High-mu twin triode designed for low-noise, low-level audio voltage amplification, providing two similar sections for preamplifier and other sensitive AF circuits.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9L5
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 300 mA

Description

High-mu twin triode designed for low-hum, low-microphonic, low-level audio preamplifier and microphone-amplifier service.

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
9L5
Socket code
B9A
Base pins
9
Nominal heater voltage
6.3 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

9L5 - 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
330 V
Max plate dissipation
1.2 W
Max cathode current
10 mA
Rectifier max heater-cathode voltage
200 V

Representative row for two electrically identical high-mu triode sections; promoted characteristics use the published 250-V operating point.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
62500 Ω
Transconductance
0.0016 S
Amplification factor
100
Max plate voltage
330 V
Max plate dissipation
1.2 W
Max cathode current
10 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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Plate Resistance

    62500 ohm

    EachUnit

  • Transconductance

    1600 uS

    EachUnit

Data set 02

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage maximum

    330 V

  • Typical plate voltage

    250 V

    ClassA

Characteristics

  • Amplification factor

    100

  • Plate resistance

    62500 ohm

  • Transconductance

    1600 uS

Application

  • Application

    Low-noise audio preamplifier

Data set 03

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate_voltage

    250 V

    Section1,Section2,ClassA

  • Grid_voltage

    -2 V

    Section1,Section2,ClassA

Characteristic

  • Plate_current

    1.2 mA

    Section1,Section2,ClassA

  • Equivalent_noise_and_hum_voltage

    1.8 uV

    Section1,Section2,ClassA

Capacitance

  • Grid-to-plate capacitance

    1.5 pF

    Section1,Section2

  • Grid-to-cathode-and-heater capacitance

    1.6 pF

    Section1,Section2

  • Plate-to-cathode-and-heater capacitance

    0.2 pF

    Section1,Section2

Data set 04

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Plate Voltage

    250 V

    AverageCharacteristics EachSection

  • Grid Voltage

    -2 V

    AverageCharacteristics EachSection

  • Plate Current

    1.2 mA

    AverageCharacteristics EachSection

  • Equivalent Noise and Hum Voltage

    1.8 uV

    Average TrueRMS EachSection

Data set 05

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    250 V

    ClassA

  • Maximum plate voltage

    330 V

  • PLATE VOLTAGE

    330 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Negative-bias value

    55 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Positive-bias value

    0 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • PLATE DISSIPATION

    1.2 mA

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Heater negative with respect to cathode

    200 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Heater positive with respect to cathode

    200 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

Characteristics

  • Amplification factor

    100

    ClassA

  • Voltage (AC or DC) — published value 1

    6.3 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Voltage (AC or DC) — published value 2

    10 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Current at 6.3 volts — published value 1

    6.3 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Current at 6.3 volts — published value 2

    0.3 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Grid to plate

    1.5

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • and heater

    1.6

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • and heater

    0.2

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • tions: Heater volts (AC)= 6.3; center-tap of heater

    6.3 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • 250; plate load resistor (megohms)= 0.1; cathode resistor — published value 1

    250 Mohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • 250; plate load resistor (megohms)= 0.1; cathode resistor — published value 2

    0.1 Mohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • (ohms)= 2700; cathode bypass capacitor (µf)= 100; grid — published value 1

    2700 ohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • (ohms)= 2700; cathode bypass capacitor (µf)= 100; grid — published value 2

    100 ohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • resistor (ohms)= 0; ampl ifierfrequency range 25 to 10000 cps — published value 1

    0 mA

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • resistor (ohms)= 0; ampl ifierfrequency range 25 to 10000 cps — published value 2

    25 A

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • resistor (ohms)= 0; ampl ifierfrequency range 25 to 10000 cps — published value 3

    10000 A

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Voltage — published value 1

    100 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Voltage — published value 2

    250 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Grid Voltage — published value 1

    -1 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Grid Voltage — published value 2

    -2 V

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Amplification Factor — published value 1

    100 A

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Amplification Factor — published value 2

    100 A

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Resistance (Approx ) — published value 1

    80000 ohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Resistance (Approx ) — published value 2

    62500 ohm

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Transconductance — published value 1

    1250

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Transconductance — published value 2

    1600

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Current — published value 1

    0.5 mA

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Plate Current — published value 2

    1.2 mA

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 1 -Heater — published value 1

    1

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 1 -Heater — published value 2

    6

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 2 -Heater

    2

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • P i n 3 - No Connec — published value 1

    3

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • P i n 3 - No Connec — published value 2

    7

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 4 -Cathode of — published value 1

    4

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 4 -Cathode of — published value 2

    8

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 5 -Grid of — published value 1

    5

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

  • Pin 5 -Grid of — published value 2

    9

    Published datasheet value; multiple numbers on one source row represent separate limits or operating conditions.

Data set 06

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved 6EU7 target entry; Section1

  • Heater Current

    300 mA

    Published in approved 6EU7 target entry; Section1

  • Grid to Plate

    1.5 pF

    Published in approved 6EU7 target entry; Section1

  • Grid to Cathode and Heater

    1.6 pF

    Published in approved 6EU7 target entry; Section1

  • Negative-bias value

    55 V

    Published in approved 6EU7 target entry; Section1

  • Positive-bias value

    0 W

    Published in approved 6EU7 target entry; Section1

  • Plate Dissipation

    1.2 W

    Published in approved 6EU7 target entry; Section1

  • Plate Voltage 100

    250 V

    Published in approved 6EU7 target entry; Section1

  • Plate Resistance (Approx.) 80000

    62500 Ω

    Published in approved 6EU7 target entry; Section1

Capacitance

  • Plate to Cathode and Heater

    0.2 pF

    Published in approved 6EU7 target entry; Section1

  • Average Value*

    1.8 microvolts rms

    Published in approved 6EU7 target entry; Section1

  • 100000 ohms cathode resistor,

    2700 Ω

    Published in approved 6EU7 target entry; Section1

Characteristic

  • Transconductance 1250

    1600 µS

    Published in approved 6EU7 target entry; Section1

  • Plate Current 0.5

    1.2 mA

    Published in approved 6EU7 target entry; Section1