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E408N

Philips audio power triode for Class A and push-pull Class AB service. Published operation provides about 2.6 W single-ended or roughly 7 W from a push-pull pair, with 12 W maximum plate dissipation.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: B4
Base pins: -
Nominal heater: 4 V / 1 A

Description

E408N is a Triode device in the supplied Philips literature. Philips directly heated power triode with Class-A and Class-AB operating data.

Socket description

European 4-pin base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B4
Base pins: -
Nominal heater voltage: 4 V
Nominal heater current: 1 A
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

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.0027 S
Amplification factor: 38
Max plate dissipation: 12 W

Philips directly heated power triode with Class-A and Class-AB operating data.

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

1938 Philips Miniwatt Vacuum Tube Catalog

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate voltage
400 V
ClassA; OneTube
Quiescent plate current
30 mA
ClassA; OneTube
Grid bias
-36 V
ClassA; OneTube
Optimum load resistance
6000 ohm
ClassA
Power output
2.6 W
ClassA
Distortion
5 %
ClassA
Maximum anode dissipation
12 W
Plate voltage
400 V
ClassAB; PushPull; TwoTubes; FixedBias
Quiescent plate current per tube
20 mA
ClassAB; PushPull; TwoTubes; FixedBias
Plate current at full modulation per tube
28 mA
ClassAB; PushPull; TwoTubes; FixedBias
Grid bias
-40 V
ClassAB; PushPull; TwoTubes; FixedBias
Load resistance plate-to-plate
12000 ohm
ClassAB; PushPull; TwoTubes; FixedBias
Power output
7 W
ClassAB; PushPull; TwoTubes; FixedBias
Plate voltage
400 V
ClassAB; PushPull; TwoTubes; CathodeBias
Quiescent plate current per tube
35 mA
ClassAB; PushPull; TwoTubes; CathodeBias
Plate current at full modulation per tube
32 mA
ClassAB; PushPull; TwoTubes; CathodeBias
Common cathode resistor
600 ohm
ClassAB; PushPull; TwoTubes; CathodeBias
Load resistance plate-to-plate
10000 ohm
ClassAB; PushPull; TwoTubes; CathodeBias
Power output
7 W
ClassAB; PushPull; TwoTubes; CathodeBias

Characteristic

Transconductance
2.7 mA/V
ClassA
Internal resistance
3000 ohm
ClassA

Data set 02

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Normal plate current
30 mA
Va=400V
Grid bias
-34 V
Va=400V