Ampera
AD1
Triode · DHT · 8-pin Side Contact · 1937
“Legendary European DHT. Queen of triodes.”
High-power directly-heated triode for single-ended amplification
GAIN FACTOR0
PLATE IMPEDANCE0Ω
TRANSCONDUCTANCE0mA/V
Cgk0pF
Cgp0pF
Cpk0pF
GAIN5%
POWER38%
DRIVE99%
LINEARITY95%
EXECUTIVE SUMMARY
The AD1 is a directly-heated triode from Telefunken, introduced around 1937. It provides a gain factor (μ) of 4.5 with 700Ω plate resistance. Commonly used in power (se) applications. Legendary European DHT. Queen of triodes.
APPLICATIONS
SET outputPush-pull outputHeadphone output
Generic triode power (se) stage
• Hi-Fi stereo• Headphone amp
HISTORY
Introduced1937ManufacturerTelefunkenEquivalentsAD1/350
Pre-WarSPECIFICATIONS
Heater Voltage4V
Heater Current1.1A
Max Plate Voltage250V
Max Power15W
Sensitivity6 mA/V
Gain Factor4.5
Internal Impedance700Ω
Pinout8-pin Side Contact
Era1937
RarityLegendary
Input Capacitance4.5pF
Miller Capacitance6.5pF
Output Capacitance3.5pF
SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.