This circuit with RIAA equalization is from 1985 US documentation. The circuit has a flat response of 150 Hz to 40 kHz. The power supply must be symmetrical.
This is basically the same circuit as the previous one, but using PNP transistors. In the original...
This TTL traffic light circuit was found in an English magazine from 1977. The magazine no longer...
This old oscillator using germanium transistors has a high impedance headphone as inductor to...