You stated your now running it from the original A2000 power supply. If this is true, and the system is operating, then the original supply is adequate in wattage.
There are several voltages and "tick signals" that are not standard with non-Amiga 2000 PS units.
My assumption is that you wanted to lighten the load on the original supply. You also stated "many drives".
My suggestion is this: keep the original supply for all MB and expansion cards. Power hard drives and other devices from another supply source. I did this for many years with an A3000D that had several 5.25" full height hard drives in an external case.
