options for high amperage voltage regulation

[bobodioulasso]

Why not to use the Cviller board version using double outputs and cascoding.
And reduce by a few volts only the rails using the zen cap multiplier.
The extra power would be dissipated into the output devices instead of a (doubtfull for class A) regulation.
At the end , at equal dissipation, you will get a more powerfull amp.
In anycase you need bigger heatsinks than standard F5.