Using an operational amplifier, this circuit from a 90s Popular Electronics, is characterized by its high sensitivity. R5 can be added to control the gain.
An interesting option is the one that makes use of the MC3373 integrated circuit and which is...
We found this circuit in a Radio Electronics from February 1970. The frequency of 1,400 kHz in the...
This power step drains just 3.5 mA from the battery and can provide good playback on a 4-ohm...