I'm building a dual rail PSU and for the op amps supply I didn't want to have too much voltage drop, so I decided to design a discrete one. cheap and easy. :
SOLVED] - Rail 12V -- PSU -- Amperage -- DC Jack | Tom's Hardware Forum
Power Supply Splitter circuit using op-amp | ElecCircuit.com
DIN rail PSU with battery charger - output 12/24VDC at up to 7.2Amps