Pentode amplifier stage (T404E)

This voltage amplifier stage circuit using a pentode was found in American documentation on modern tube designs. The gain is 60 times.

Overtone Oscillator II (CB4585E)
In the figure we show a configuration for a crystal controlled overtone oscillator using a...
Microphone Preamplifier (CB837E)
This two transistor preamplifier is intended for the use with three terminals electret...
Gated Oscillator 4093 (CIR094E)
The circuit shown bellow is gated by an external signal. A high logic level applied to the input...