Exactly what are you wanting to do here?
You Must Heatsink the components for 5 amps each if not they will only handle 1 amp each.
There is another way to make a high current power supply.
That circuit will have very poor regulation because the base-emitter saturation voltage of the 2N3055 will vary depending on the current drawn and the 0.47R resistors will have a significant voltage accross them.
Suppose the current draw is 0A and you set the voltage to 12V.
Then you increase the current to 5A.
@0A the VBE
of the transistors will be near 0.6V.
Each transistor will have 5/6 = 833mA through it, the same for the emitter resistor.
The voltage will drop by the 0.47R resistor will be 5/6