This stereo meter-indicator was found in the August 1971 issue of Radio Electronics magazine. The transistors are known types and BC548 equivalents can be used.
This circuit converts BCD inputs to analog voltages. The operational amplifier must be powered...
This circuit is suitable for the calibration of old analog oscilloscopes. It was found in...
This is the circuit of a hearing aid amplifier manufactured by Sony in the 1960s. The circuit was...