Found in an Electronics World of 1966 this circuit can be made with current power transistors. It causes colored lamps to flash to the rhythm of the audio signal applied to the input.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This preamp with several inputs using germanium transistors from the time was found in Japanese...