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4683

Directly heated Philips audio-output triode designed for Class B and AB push-pull service. Published operating conditions provide roughly 15–20 W from a pair, with a 15 W maximum plate-dissipation rating per tube.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: P35-24
Socket code: P8A
Base pins: 8
Nominal heater: 4 V / 950 mA

Description

Directly heated output triode for Class-B and AB service.

Socket description

European 8-pin side-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: P35-24
Socket code: P8A
Base pins: 8
Nominal heater voltage: 4 V
Nominal heater current: 950 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

P35-24 - 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

Max plate voltage: 350 V
Max plate dissipation: 15 W
Max cathode current: 90 mA

Promoted only from clearly identified published characteristics/limits; additional operating, capacitance, regulator, gas-tube, and push-pull data retained as section parameters.

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
350 V
ClassAB;PushPull;TwoTubes;FixedBias
Quiescent plate current per tube
35 mA
ClassAB;PushPull;TwoTubes;FixedBias
Full-modulation plate current per tube
69.5 mA
ClassAB;PushPull;TwoTubes;FixedBias
Control-grid bias
-75 V
ClassAB;PushPull;TwoTubes;FixedBias
Optimum plate-to-plate load
5000 Ω
ClassAB;PushPull;TwoTubes;FixedBias
Power output
20 W
ClassAB;PushPull;TwoTubes;FixedBias
Total distortion
2.1 %
ClassAB;PushPull;TwoTubes;FixedBias
Grid AC voltage at full modulation
49 V RMS
ClassAB;PushPull;TwoTubes;FixedBias
Maximum plate dissipation per tube
15 W
ClassAB;PushPull;TwoTubes
Plate voltage
350 V
ClassAB;PushPull;TwoTubes;SelfBias
Quiescent plate current per tube
43 mA
ClassAB;PushPull;TwoTubes;SelfBias
Full-modulation plate current per tube
46.5 mA
ClassAB;PushPull;TwoTubes;SelfBias
Common cathode resistor
850 Ω
ClassAB;PushPull;TwoTubes;SelfBias
Optimum plate-to-plate load
8000 Ω
ClassAB;PushPull;TwoTubes;SelfBias
Power output
15.6 W
ClassAB;PushPull;TwoTubes;SelfBias
Total distortion
2.3 %
ClassAB;PushPull;TwoTubes;SelfBias
Grid AC voltage at full modulation
51 V RMS
ClassAB;PushPull;TwoTubes;SelfBias

Data set 02

1957 Philips Receiving and Amplifying Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Application

Application
Audio output

Data set 03

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate-to-plate load resistance
5 kOhm
ClassB; TwoTubes
Power output
20 W
ClassB; TwoTubes
Power output
15.6 W
ClassAB; TwoTubes

Capacitance

Anode-grid capacitance
<20 pF