307A
Pentode · DHT · Special · 1938
“WE pentode. Triode-strapped yields 2A3-like tone.”
Power pentode delivering up to 15W in pentode, UL, or triode mode
PLATE IMPEDANCE0kΩ
TRANSCONDUCTANCE0mA/V
GAIN0%
POWER38%
DRIVE99%
LINEARITY75%
EXECUTIVE SUMMARY
The 307A is a directly-heated pentode from Western Electric, introduced around 1938. Commonly used in power/output applications. WE pentode. Triode-strapped yields 2A3-like tone.
APPLICATIONS
Power output
Generic pentode power/output stage
• Headphone amp
HISTORY
Introduced1938ManufacturerWestern ElectricEquivalentsVT-225, RK-75
Pre-WarSPECIFICATIONS
Heater Voltage5.5V
Heater Current1A
Max Plate Voltage350V
Max Power15W
Sensitivity4 mA/V
Gain Factor—
Internal Impedance1.5kΩ
PinoutSpecial
Era1938
RarityCollector
SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.