This is a 1960s amplifier setup found in a period publication. The circuit uses a special driver transformer that inverts the phases of the signal to excite the output transistors.
This circuit offers excellent sound quality for headphones of 150 ohms or more. The circuit was...
This ultra-simple FM tuner can pick up local stations with good sound quality and was found in a...
This interesting comparator circuit was found in an old Motorola documentation. The integrated circuit...