Power - Triode ·Triode
PA40
Directly heated Mazda mains-output power triode for higher-power audio stages. Rated around 450 V and 40 W dissipation, its low amplification factor and high transconductance provide strong output-stage current drive.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- -
- Base pins
- -
- Nominal heater
- 4 V / 2 A
Description
Directly heated mains output triode.
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- -
- Base pins
- -
- Nominal heater voltage
- 4 V
- Nominal heater current
- 2 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
- Plate resistance
- 425 Ω
- Transconductance
- 0.01 S
- Amplification factor
- 4.25
- Max plate voltage
- 450 V
- Max plate dissipation
- 40 W
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.