This low power bass booster is from the 1977 National Semiconductor Audio Handbook. The circuit is powered by 6 to 9 V voltages and the feedback determines the enhanced bass range.
This small audio amplifier circuit in complementary symmetry was found in the 1974 Mullard...
This is an experimental crystal radio that uses no power source. The antenna must be very long (at...
This brightness control for incandescent lamps or engine speed has been found in a 1970 English...