Things are supposed to get hot at maximum output.

The emitter resistor should be rated at 2 watts so your five resistors should be atleast 1/2 watt each.

The emitter voltage should a little less than 1 volt more positive than the base voltage, so maybe no
Problem there.

What is the voltage from pin 2 to ground?

What is the voltage across the 100 ohm resistor?

What is the voltage across the 15 ohm resistor?

What is the control voltage referenced to ground?

 

Things are supposed to get hot at maximum output.

The emitter resistor should be rated at 2 watts so your five resistors should be atleast 1/2 watt each.

The emitter voltage should a little less than 1 volt more positive than the base voltage, so maybe no
Problem there.

What is the voltage from pin 2 to ground?

What is the voltage across the 100 ohm resistor?

What is the voltage across the 15 ohm resistor?

What is the control voltage referenced to ground?

Hi sir,
We are applying input control signal with function generator - 3 volt offset and 600 mV peak-to-peak sinusoidal signal.
Answer 1. the voltage from pin 2 to ground is almost same as our input signal i.e. 2.89 V.
2. Across the 100 ohm resistor, we are getting 11V w.r.t grnd.
3. Across the 15 ohm resistor, we are getting 10.2 V w.r.t grnd.

 

Hi sir,
We are applying input control signal with function generator - 3 volt offset and 600 mV peak-to-peak sinusoidal signal.
Answer 1. the voltage from pin 2 to ground is almost same as our input signal i.e. 2.89 V.
2. Across the 100 ohm resistor, we are getting 11V w.r.t grnd.
3. Across the 15 ohm resistor, we are getting 10.2 V w.r.t grnd.

Yep, something is broken,, the wrong part or wired incorrectly, but it is puzzling because the transistor seems to be working but the opamp is acting like there is not feedback through the 10 resistor.

New questions:
4. How many volts do you measure between the two ends of the 100 ohm resistor?
5. Is the voltage on pin 6 positive with respect to ground of negative with respect to ground?
6. Is the voltage on the 15 ohm resitor positive with respect to ground of negative with respect to ground?
7. Confirm -one end of the 15 ohms is grounded (not connected to +12).

Please confirm that the base and emitter are not swapped. Notice in the drawing below that the emitter and base leads are reversed from many other transistors in similar packages.