With only 1% distortion, this Motorola amplifier found in a 1968 documentation makes use of period components. The frequency response ranges from 10 Hz to 100 kHz.
Sine signals are converted into square signals by this simple circuit. The maximum frequency is...
This circuit was published in an English magazine from 1981, but it can be easily assembled today,...
Found in Radio Electronics from the 90's, this circuit employs a 3140 operational amplifier, still...