This circuit is from an Electronics World of 1968. The transistors are of the time and the power is supplied with a voltage of 40 V. The circuit is high fidelity.
This circuit is from a 1965 Electronic Design. The transistors may be general purpose and the...
Also suitable for use as a noisy alarm, this Morse Code or telegraph practice oscillator was found...
This preamplifier is recommended by Sanyo and is based on its LA3160 integrated circuit. The...