Obtained from a 1980s Signetics documentation, this circuit uses a common integrated circuit at the time. The performance curves are given next to the diagram.
This 80's circuit uses an audio amplifier to obtain a symmetrical source from a single source. The...
I found this circuit in a 1986 English magazine. It can still be easily assembled, exchanging Q1...
Found in a 1970s documentation, this circuit has a flat response from 15 Hz to 130 kHz. Modern...