The integrated circuit used in this 1975 application no longer exists, and it is also not indicated in the original diagram and must be of the TAA series by the diagram.
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...