This is my first fully homemade device i ever built and i built it before having enough knowledges on electronics. I found the circuit on the internet here. It is a very stable power supply with current limiting 0-30V adjustable and 0-3A adjustable which is enough for most of the electronic circuits. I also made a modification and added an Operational Amplifier for inverting the output Voltage in order to have symmetric voltages for powering Op Amps. The only disadvantage is that the negative voltage is 1 Voltage less than the positive (eg. if you have a +6V positive output then the negative output will be -5V) and starts working after +1V of positive voltage.
The front panel is a printed cardboard.
Here you see the backside with the 2N3055 screwed on a heat sink