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 was found in the October 1994 issue of Electronics Now magazine. The 40446 IC is a...
Found in a 1967 EEE, this circuit generates a constant amplitude signal, stabilized by a zener...
This circuit is from the November 1974 issue of Radio Electronics magazine. The capacitor...