I'm working on a dual rail power supply that will provide DC current for 4 power amplifiers.
Two of them require 20V and the other two 25 - 50V. All 4 draw a maximum of 2.5A of current, hence my transformer is 24+24V, 10A. Currently I have the output of the transformer to a rectifier bridge and on each rail 10.000µf capacitors, resulting in 35V.
My question is: how I drop this voltage to 20V, allowing a maximum of 5A of current to flow through? I've read about shunt regulators but it seems I would need a very large resistor and zener for this amount of current.
Are there other options? Which is the most suited for this case?