Two-input amplifier (CB21661E)

The critical component of this 1967 amplifier is the driver transformer. The circuit has both high and low impedance input.

Decade Counter with Nixie Tube (CB20141E)
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
Two-Transistor Oscillator (CB1387E )
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
Tone Control Preamplifier (CB18561E)
This preamp with several inputs using germanium transistors from the time was found in Japanese...