Isn't so bad. Needs an 5V, could be produced by a step-down DC/DC converter, needs 14V, could produced by a step-up DC/DC converter, we can keep the U101 to make 8V supply, the inlet (pin1) of U307 could be wired to outlet of U101. The AC outlet ("AC/DC DET") is rectified, too, so the circuity will accept some DC voltage there as the AC, too.
So it could be modify to 12V DC by adding two cheap, chinesee made DC/DC converters.
Isn't so bad. Needs an 5V, could be produced by a step-down DC/DC converter, needs 14V, could produced by a step-up DC/DC converter, we can keep the U101 to make 8V supply, the inlet (pin1) of U307 could be wired to outlet of U101. The AC outlet ("AC/DC DET") is rectified, too, so the circuity will accept some DC voltage there as the AC, too.
So it could be modify to 12V DC by adding two cheap, chinesee made DC/DC converters.