Powered by an old laptop power supply - the laptop stopped working long ago but the power supply still works and its 19v output is just right to power my CD player. The CDROM takes 5v and 12v so I needed to reduce the input 19v from my power supply using voltage regulars. Of course you can use an old PC power supply but these are big, heavy and noisy. On the case of my CDROM it says that it draws 1.5 amps of both voltages. Each 78xx can supply 1 amp so I tried just connecting two in parallel for both the 5v and 12v supply. This worked fine for the 12v circuit but for the 5volts one 7805 got much hotter than the other and then one day it just went BANG. So for the final version I used a circuit I copied from here
for the 5v circuit. I stayed with the 2 parallel 7812 ICs for the 12volts.
For my first version I soldered the 78xx's directly onto the board. This proved to be a bad idea when I needed to change things, so I used sockets from then on.
Just for fun I added LEDs on the 5v and 12v rails.