We found this circuit in a Japanese publication in 1967. The circuit consists of a 15 W audio amplifier with germanium transistors including a voltage indicator power supply.
This circuit is from a 2005 Linear Technology manual. The circuit is powered by 3.3 V but can...
This circuit uses two operational amplifiers, which can be of the type 741, in a full wave...
This simple circuit for an audio link uses a lamp, which has a very poor frequency response, but...