This circuit was obtained in a Popular Electronics from the 90's. The gain depends on R4 and R3. Transistors are general purpose types.
Found in a 90s Elektor, this mixer makes use of integrated circuits of the time. The supply must be...
The input resistance of this circuit is 60k and the pass band from 20 to 20kHz. The circuit is...
This circuit is from a publication on Motorola triacs from 1975. In it we have the way to fire a...