hello there .
you can use one transformer with +/- 12v ac, wich you can connect the leads without center tap, rectify it and get 33v dc, then you can use adjustable regulator lm338k or lm317 to regulate it down to 1.25v
also you will need to rectify the +-12v and you will get around 16vdc.
if you want a constant +-12vdc you need to regulate both rails , using lm337negative voltage regulator and lm317 positive regulator, both are adjustable so you will be having a range of +-14v but will have to have a dual taper adjustment potentiometer
i cannot draw you circuit at the moment but it is not difficult. would you like to operate both voltages the same time?