I suggest don't do it.
I am an electrician, and I would not even contemplate this task.

If you look at this diagram (above) you will see the Brick supplies ARII board creates +12V, +22V, -22V, +5V and -5V

The Power Brick (Above) creates 10V, 36V, 6V and 60Volts ALL AC voltages
Would the brick still be used in your idea? Surely it must?

In this diagram above you will see all the voltages are connected and used.
The ARII board provides sound amplification as well so you would need to take care of that as well to Omit the ARII board completely.
Yes it is do-able, but Why??
There are plenty of them ARII Boards around (Well over there anyway). They are rare over here, but I would still not try and re-invent the wheel.
Is it for reliability, that you propose this?
If you do, be sure to keep us posted
