Ampera
EF804S
Pentode · IHT · 9-pin Noval · 1951
“Telefunken diamond. V72 preamp legend.”
Small-signal pentode for low-noise voltage amplification
TRANSCONDUCTANCE0mA/V
Cgk0pF
Cgp0pF
Cpk0pF
GAIN0%
POWER3%
DRIVE50%
LINEARITY75%
EXECUTIVE SUMMARY
The EF804S is a indirectly-heated pentode from Telefunken, introduced around 1951. Commonly used in preamp / microphone applications. Telefunken diamond. V72 preamp legend.
APPLICATIONS
Voltage amplifier
Generic pentode preamp / microphone stage
HISTORY
Introduced1951ManufacturerTelefunkenEquivalentsNone (unique pinout)
Golden AgeSPECIFICATIONS
Heater Voltage6.3V
Heater Current0.2A
Max Plate Voltage250V
Max Power1W
Sensitivity2 mA/V
Gain Factor—
Internal Impedance—
Pinout9-pin Noval
Era1951
RarityCollector
Input Capacitance3.8pF
Miller Capacitance0.005pF
Output Capacitance6pF
SPICE model not yet available. Loadline calculator requires calibrated Koren parameters.