This simple tone control using two transistors was found in an Electronics Today International of the 90s. Transistors are general purpose NPN types, like the BC549 for greater gain.
This circuit came out in an American magazine that no longer exists. It's the Electronic...
This circuit originally came out in a Budget Electronics from 1981. The American magazine no...
This is the traditional audio preamp configuration with the National Semiconductor LM382. The...