This amplifier uses a 1975 integrated circuit, which is uncommon today. The circuit has a gain of 30 dB and uses a transformer-less output with 9 V power.
Found in a 1970 EEE, this circuit uses general-purpose transistors of the time. Transistors support...
This simple source using fixed voltage regulators can supply currents up to 1 A at the voltages...
Originally suggested by Harris in the 1990s, this circuit uses an optical tachometer. The circuit is...