This variable frequency circuit was found in a Popular Electronics from the 90s. The circuit outputs to a small speaker and can be powered by voltages as low as 3 V.
Found in National Semiconductor documentation from the 1990s, this circuit employs basic...
This circuit should be placed between a turntable and recorder or playback media from the input to...
Found in a 1964 Electronic Design, this circuit uses transistors from that time. Equivalent...