Voltage - Triode (single) ·Triode
Early directly heated audio-output triode for loudspeaker receivers; source data establish the output role but not the project’s 5-watt power threshold.
Philips B403 is an early directly heated power triode intended as a loudspeaker output valve. Its datasheet emphasizes low internal resistance and strong audio output from a 4 V filament supply.
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
Published ratings and characteristics promoted where semantically applicable; additional published values retained as section parameters.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Anode voltage range
50 to 150 V
Published datasheet value
Normal anode current
15 mA
Published datasheet value
Grid bias
-30 V
Published datasheet value
Saturation current
50 mA
Published datasheet value
Transconductance
1.5 mA/V
Published datasheet value
Internal resistance
2000 Ω
Published datasheet value
Amplification factor
3
Published datasheet value