We found this circuit in a 1973 publication. The circuit lets frequencies below 480 kHz pass through with an output impedance of 1k. The circuit can be implemented with current operational.
This driver for audio signals using the TAA435 integrated circuit was found in Philips 1968...
Found in a 1980s documentation, this circuit uses transistors from that time. Modern equivalents can be...
The SH-205R receiver was sold in the 1960s in Japan. It used two germanium transistors and had a...