Alternatives & variations Download PDF datasheet

Voltage - Dual Triode (similar) ·Triode-Triode

7AU7

Medium-mu twin triode, a heater variant of the 12AU7A family, suitable for Class-A amplification and television oscillator or deflection-related circuitry.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 9A
Socket code: B9A
Base pins: 9
Nominal heater: 7 V / 300 mA

Description

Medium-mu twin triode used as phase inverter, push-pull amplifier, multivibrator, oscillator, and television deflection oscillator/amplifier.

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: 9A
Socket code: B9A
Base pins: 9
Nominal heater voltage: 7 V
Nominal heater current: 300 mA
Parallel heater voltage: 3.5 V
Parallel heater current: 600 mA
Series capable: Yes

9A - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN12P	B	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN22G1	B	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN32K	B	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN4H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN5H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN61P	A	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN71G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN81K	A	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN9HCT	—	HCT — Heater Center Tap EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 6250 Ω
Transconductance: 0.0031 S
Amplification factor: 19.5
Max plate voltage: 330 V
Max plate dissipation: 2.75 W
Max cathode current: 22 mA

Inherited from explicit parent 12AU7A; supplied 7AU7 sheet changes heater characteristics only.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 7700 Ω
Transconductance: 0.0022 S
Amplification factor: 17
Max plate voltage: 330 V
Max plate dissipation: 2.75 W
Max cathode current: 22 mA

Inherited from explicit parent 12AU7A; supplied 7AU7 sheet changes heater characteristics only.

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

Other

Heater voltage
7 V
Nominal
Heater current
600 mA
Nominal
Plate voltage
330330 V
Typical operating conditions
Plate current
1.810.5 mA
Typical operating conditions

Data set 02

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Heater Voltage
7 V
Heater Current
600 mA
Heater Voltage Series
7 V
Heater Current Series
600 mA
Heater Voltage Parallel
3.5 V
Heater Current Parallel
1.2 A
Grid To Plate Capacitance
1.9 pF
Input Capacitance
3 pF
Output Capacitance
0.5 pF
Plate Voltage
250 V
Grid Voltage
-8.5 V
Plate Current
10.5 mA
Plate Resistance
7700 ohm
Transconductance
2200 uS
Amplification Factor
17

Data set 03

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Maximum_both_plate_dissipation
5.5 W
Maximum_heater_cathode_total
200 V
Peak_negative_pulse_grid_voltage
440 V
Peak_cathode_current
66 mA
Plate_voltage
250 V
Section1,Section2,ClassA
Heater_warmup_time
11 s
Section1,Section2,ClassA

Characteristic

Plate_current
10.5 mA
Section1,Section2,ClassA
Amplification_factor
17
Section1,Section2,ClassA
Plate_resistance
7700 ohm
Section1,Section2,ClassA
Transconductance
2200 uS
Section1,Section2,ClassA

Capacitance

Grid-to-plate capacitance
1.5 pF
Section1,Section2
Grid-to-cathode capacitance
1.6 pF
Section1,Section2
Plate-to-cathode capacitance
0.5 pF
Section1,Section2

Data set 04

1971 RCA HB3 Binder 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Heater voltage series
12.6 V
SeriesHeater
Heater current series
150 mA
SeriesHeater
Heater voltage parallel
6.3 V
ParallelHeater
Heater current parallel
300 mA
ParallelHeater
Plate voltage
100 V
ClassA1;PublishedPoint1
Plate voltage
250 V
ClassA1;PublishedPoint2
Grid voltage
0 V
ClassA1;PublishedPoint1
Grid voltage
-8.5 V
ClassA1;PublishedPoint2
Amplification factor
19.5
ClassA1;PublishedPoint1
Amplification factor
17
ClassA1;PublishedPoint2
Plate resistance
6250 ohm
ClassA1;PublishedPoint1
Plate resistance
7700 ohm
ClassA1;PublishedPoint2
Transconductance
3100 µS
ClassA1;PublishedPoint1
Transconductance
2200 µS
ClassA1;PublishedPoint2
Plate current
11.8 mA
ClassA1;PublishedPoint1
Plate current
10.5 mA
ClassA1;PublishedPoint2

Other

Maximum plate voltage
330 V
ClassA1
Maximum cathode current
22 mA
ClassA1
Maximum plate dissipation
2.75 W
ClassA1
Peak heater-cathode voltage
200 V
Peak negative-pulse grid voltage
660 V
HorizontalDeflectionOscillator
Peak cathode current
330 mA
HorizontalDeflectionOscillator
Peak negative-pulse grid voltage
440 V
VerticalDeflectionOscillator
Peak cathode current
66 mA
VerticalDeflectionOscillator
Peak positive-pulse plate voltage
1200 V
VerticalDeflectionAmplifier
Heater voltage nominal
7 V
Heater current nominal
300 mA
Heater voltage series
7 V
Series
Heater current series
300 mA
Series
Heater voltage parallel
3.5 V
Parallel
Heater current parallel
600 mA
Parallel

Capacitance

Grid-to-plate capacitance
1.5 pF
Grid-to-cathode-and-heater capacitance
1.6 pF
Plate-to-cathode-and-heater capacitance
0.5 pF

SECTION 2

Triode

Characteristics

Heater voltage series
12.6 V
SeriesHeater
Heater current series
150 mA
SeriesHeater
Heater voltage parallel
6.3 V
ParallelHeater
Heater current parallel
300 mA
ParallelHeater
Plate voltage
100 V
ClassA1;PublishedPoint1
Plate voltage
250 V
ClassA1;PublishedPoint2
Grid voltage
0 V
ClassA1;PublishedPoint1
Grid voltage
-8.5 V
ClassA1;PublishedPoint2
Amplification factor
19.5
ClassA1;PublishedPoint1
Amplification factor
17
ClassA1;PublishedPoint2
Plate resistance
6250 ohm
ClassA1;PublishedPoint1
Plate resistance
7700 ohm
ClassA1;PublishedPoint2
Transconductance
3100 µS
ClassA1;PublishedPoint1
Transconductance
2200 µS
ClassA1;PublishedPoint2
Plate current
11.8 mA
ClassA1;PublishedPoint1
Plate current
10.5 mA
ClassA1;PublishedPoint2

Other

Maximum plate voltage
330 V
ClassA1
Maximum cathode current
22 mA
ClassA1
Maximum plate dissipation
2.75 W
ClassA1
Peak heater-cathode voltage
200 V
Peak negative-pulse grid voltage
660 V
HorizontalDeflectionOscillator
Peak cathode current
330 mA
HorizontalDeflectionOscillator
Peak negative-pulse grid voltage
440 V
VerticalDeflectionOscillator
Peak cathode current
66 mA
VerticalDeflectionOscillator
Peak positive-pulse plate voltage
1200 V
VerticalDeflectionAmplifier
Heater voltage nominal
7 V
Heater current nominal
300 mA
Heater voltage series
7 V
Series
Heater current series
300 mA
Series
Heater voltage parallel
3.5 V
Parallel
Heater current parallel
600 mA
Parallel

Capacitance

Grid-to-plate capacitance
1.5 pF
Grid-to-cathode-and-heater capacitance
1.6 pF
Plate-to-cathode-and-heater capacitance
0.35 pF

Data set 05

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate Supply Voltage 100
250 V
Published in approved ECC82 target datasheet entry; Section1
Cathode-Bias Resistor 270
200 Ω
Published in approved ECC82 target datasheet entry; Section1
Plate Resistance (Approx.) 15000
10900 Ω
Published in approved ECC82 target datasheet entry; Section1
Transconductance 4000
5500 µS
Published in approved ECC82 target datasheet entry; Section1
Grid Voltage (Approx.) for plate current of 10 /iA —5
12 V
Published in approved ECC82 target datasheet entry; Section1
Plate Current 3.7
10 mA
Published in approved ECC82 target datasheet entry; Section1
Series 7 9.4
12.6 V
Published in approved ECC82 target datasheet entry; Section1
Parallel 3.5 4.7
6.3 V
Published in approved ECC82 target datasheet entry; Section1
Series 0.3 0.225
150 mA
Published in approved ECC82 target datasheet entry; Section1
Parallel 0.6 0.45
300 mA
Published in approved ECC82 target datasheet entry; Section1
Heater Warm-up Time (Parallel, Average) 11
11 seconds
Published in approved ECC82 target datasheet entry; Section1
Plate Voltage
330 V
Published in approved ECC82 target datasheet entry; Section1
Cathode Current
22 mA
Published in approved ECC82 target datasheet entry; Section1
Each Plate
2.75 W
Published in approved ECC82 target datasheet entry; Section1
Both Plates (Both units operating)
5.5 W
Published in approved ECC82 target datasheet entry; Section1
Plate Resistance (Approx.) 6250
7700 Ω
Published in approved ECC82 target datasheet entry; Section1
Transconductance 3100
2200 µS
Published in approved ECC82 target datasheet entry; Section1
For fixed-bias operation
0.25 MΩ
Published in approved ECC82 target datasheet entry; Section1
For cathode-bias operation
1 MΩ
Published in approved ECC82 target datasheet entry; Section1
DC Plate Voltage 330
330 V
Published in approved ECC82 target datasheet entry; Section1
Peak Negative-Pulse Grid Voltage 440
660 V
Published in approved ECC82 target datasheet entry; Section1
Peak Cathode Current 66
330 mA
Published in approved ECC82 target datasheet entry; Section1
Average Cathode Current 22
22 mA
Published in approved ECC82 target datasheet entry; Section1
Each Plate 2.75
2.75 W
Published in approved ECC82 target datasheet entry; Section1
Both Plates (Both units operating) 5.5
5.5 W
Published in approved ECC82 target datasheet entry; Section1
Grid-Circuit Resistance 2.2
2.2 MΩ
Published in approved ECC82 target datasheet entry; Section1
DC Plate Voltage
330 V
Published in approved ECC82 target datasheet entry; Section1
Peak Positive-Pulse Plate Voltage#
1200 V
Published in approved ECC82 target datasheet entry; Section1
Peak Negative-Pulse Grid Voltage
275 V
Published in approved ECC82 target datasheet entry; Section1
Peak Cathode Current
66 mA
Published in approved ECC82 target datasheet entry; Section1

Capacitance

Grid to Plate 1.5
1.5 pF
Published in approved ECC82 target datasheet entry; Section1
Grid to Cathode and Heater 1.6
1.6 pF
Published in approved ECC82 target datasheet entry; Section1
Plate to Cathode and Heater 0.5
0.35 pF
Published in approved ECC82 target datasheet entry; Section1

Characteristic

Plate Current 11.8
10.5 mA
Published in approved ECC82 target datasheet entry; Section1