4694

Audio power pentode for moderate push-pull Class AB output, with a pair delivering approximately 12 W.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: P35-31
Socket code: P8A
Base pins: 8
Nominal heater: 6.3 V / 1.2 A

Description

The Philips 4694 is an indirectly heated output pentode for Class AB audio output 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: P35-31
Socket code: P8A
Base pins: 8
Nominal heater voltage: 6.3 V
Nominal heater current: 1.2 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

P35-31 - 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

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 75000 Ω
Transconductance: 0.007 S
Max plate voltage: 400 V
Max screen voltage: 425 V
Max plate dissipation: 9 W
Max screen dissipation: 2.7 W
Max cathode current: 55 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

Pentode

Other

Plate voltage
375 V
ClassAB;PushPull;TwoTubes;SelfBias
Screen voltage
250 V
ClassAB;PushPull;TwoTubes;SelfBias
Quiescent plate current per tube
24 mA
ClassAB;PushPull;TwoTubes;SelfBias
Full-modulation plate current per tube
30 mA
ClassAB;PushPull;TwoTubes;SelfBias
Quiescent screen current per tube
3.2 mA
ClassAB;PushPull;TwoTubes;SelfBias
Full-modulation screen current per tube
5.3 mA
ClassAB;PushPull;TwoTubes;SelfBias
Common cathode resistor
142 Ω
ClassAB;PushPull;TwoTubes;SelfBias
Optimum plate-to-plate load
13000 Ω
ClassAB;PushPull;TwoTubes;SelfBias
Power output
12 W
ClassAB;PushPull;TwoTubes;SelfBias
Total distortion
2.3 %
ClassAB;PushPull;TwoTubes;SelfBias
Grid AC voltage at full modulation
6.9 V RMS
ClassAB;PushPull;TwoTubes;SelfBias
Maximum plate dissipation per tube
9 W
ClassAB;PushPull;TwoTubes

Data set 02

1957 Philips Receiving and Amplifying Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Plate Voltage
400 V
Screen Voltage
425 V
Anode Current
22 mA

Other

Power Output
13 W
ClassAB; PushPull

Data set 03

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Anode-grid capacitance
<0.8 pF

Characteristic

Typical plate current
22 mA
Va=400V; Vg2=425V
Typical screen current
2.8 mA
Va=400V; Vg2=425V

Other

Common cathode resistor
315 Ohm
ClassAB; TwoTubes
Power output
13 W
ClassAB; TwoTubes
Plate-to-plate load resistance
20 kOhm
ClassAB; TwoTubes