The A1200 at least will actually function without -12V, but the audio will be bad. I had crackly audio problems. I swapped the A1200 motherboard (a few years b

The A1200 at least will actually function without -12V, but the audio will be bad. I had crackly audio problems. I swapped the A1200 motherboard (a few years back when they were still fairly cheap on eBay), and still had the same audio problem. Only then did I investigate+repair the PSU issue. Recently built a replacement Amiga PSU from a MeanWell PT-65B board in a 3D printed case. This USB-C option would have been neater and easier (so long as it puts out enough power for a PiStorm as well as the Amiga)