Amplifier stage with the T411E (T411E)

The pentode tube used in this circuit has 1.5 V filament. The circuit is a voltage amplifier with the 1U5 tube.

Millivoltmeter with the 709 IC (CB24208E)
This circuit was found in the September 1972 issue of Radio Electronics magazine. The circuit uses...
62 mW Stereo Amplifier Handset (CB15569E)
The circuit shown in the figure consists of an amplifier for stereo sources with Maxim's MAX9723...
Microphone Booster (CB923E)
This circuit was obtained in a 1980 edition of Elementary Electronics a magazine that no longer...