Ampera
P27-500
Triode · DHT · UX-4 · 1935
“Philips direct-heated.”
Power triode delivering 25W for push-pull and SET designs
Datasheet ↗SPICE
GAIN FACTOR0
PLATE IMPEDANCE0kΩ
TRANSCONDUCTANCE0mA/V
GAIN5%
POWER63%
DRIVE98%
LINEARITY95%
TYPICAL OPERATING POINT
EXECUTIVE SUMMARY
The P27-500 is a directly-heated triode from Philips, introduced around 1935. It provides a gain factor (μ) of 5 with 1670Ω plate resistance. Commonly used in power (set) applications. Philips direct-heated.
APPLICATIONS
SET outputPush-pull outputHeadphone output
Generic triode power (set) stage
• Hi-Fi stereo• Headphone amp
VS AD1
HISTORY
Introduced1935ManufacturerPhilipsEquivalentsAD1
Pre-WarSPECIFICATIONS
Heater Voltage4V
Heater Current2A
Max Plate Voltage500V
Max Power25W
Sensitivity3 mA/V
Gain Factor5
Internal Impedance1.7kΩ
PinoutUX-4
Era1935
RarityRare