Some explanations:
The op-amp output (pin 6) is not connected. The signal is output from the compensation pin (pin 5). This can bypass the op amp output stage. To avoid overload, you must use the high magnification of the output transistor. The bc337 - 40 Figure shows, this circuit is more suitable for easy to use.
Enter a 100K resistor is linear. The interaction with the input resistance to provide a practical audio (although not perfect) curve.
The launch of resistance value is 33r. I chose the value according to the red light-emitting diode voltage. It gave me a about 12mA bias current. This is the number of limiting the current in a very short case. Of course, you can go to increase the quiescent current adjustment potentiometer, as long as you do not exceed the power limit of the output transistor current.
Power can be plus or minus 9 volts to plus or minus 15V DC voltage. Some additional decoupling capacitors are not shown, may be appropriately added to the supply pins of the op amp.
Producing simple NE5534 promote transistor amp circuit