Voltage amplifier with the 37 tube (T392E)

Found in a modern design book with tubes, this stage with the triode 37 has a plate current of 3.7 mA.

62 mW Stereo Amplifier Handset (CB15569E)
The circuit shown in the figure consists of an amplifier for stereo sources with Maxim's MAX9723...
Power supply with zener regulation (CB23688E)
This simple low current circuit was found in a Radio Electronics magazine from August 1960. The...
Power amplifier (CB23607E)
This small 2-transistor amplifier was found in the Radio Electronics magazine of May 1959. The...