This circuit uses an unusual operational amplifier nowadays and has a very low consumption. The number in parentheses corresponds to the second channel, for a stereo version.
I found this circuit in a 1978 publication. The circuit can be assembled with a BD136 transistor to...
This sensitive 4-transistor signal follower can be used in both audio and RF circuits. P1 is a...
This is a commercial circuit from the year 1958. Transistors are germanium types and transformers...