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.

4011 Bistable (CB10929E)
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
Full Wave Rectifier with Operational II (CB13214E)
This configuration is from an old Motorola documentation from the 70s. The circuit uses operations that...
Headphone Amplifier (CB24050E)
This simple amplifier was found in a Radio Electronics magazine from July 1970. The transistors are...