This circuit uses a power component that is not common today, being recommended by Motorola in the 90's. Note the need for symmetrical power supply.
The configuration shown was found in an old Poptronics but can be easily assembled using a common...
This circuit is from an old American publication. The indicated transistor is oversized as the 15 V...
Found in a 90’s Radio Electronics magazine, this circuit uses a component from the time, difficult...