This circuit uses an amplifier from National Semiconductor, uncommon nowadays. The numbers in parentheses are for the second channel. The circuit is suitable for old tape recorders.
This circuit was found in an Argentine publication from 1973. It uses a common AM coil (50 + 50...
Hughes suggests this circuit in a 1968 documentation. The circuit uses old transistors that can be...
We found this circuit in an English publication from 1982. The transistors can be the BC548. We...