Hi Sonia123,
First: I haven't seen many OpAmps capable of a supply voltage of 55V. There are high voltage OpAmps on the market but they cost $$$.
Second: At 15A current flow both, positive and negative supply (smoothed using 220µ F) will produce an extremely high ripple voltage, usable to charge lead-acid-batteries, but not supply electronic circuits.
For low ripple voltage I normally select 4.700µF of filter capacitance per Ampere of current (70,500µF total).
For medium to good the value should not be worse than 2.200µF per Ampere. (still very high at 33,000µ
F).
The absolute minimum should not be below 1.000µF per Ampere. (15,000µF)
I wonder why you're planning for such a high output voltage.
It is normally not required for any circuit supply.
A safe output voltage of 24V (max 30V) should suffice in any case.
Using bipolar transistors for the power stages was yesterday (and some more days).
I suggest to redesign the circuit for ±24V and maximum currents of 5A and use MosFet transistors for the power stages. Bipolar transistors dissipate a lot of power at high current which requires a huge heat sink.
With a power supply as suggested you'll be able to cover 99% requirements for all circuits.
Just think about the problems involved as I pointed out.
Boncuk