@user193661 Then I think the main reason to keep it close to 48 V is for safety certification. If all the voltages on the secondary side of your transformer are less than 48 V (rms?) you will have an easier time with safety rules. But you'll want to do some research on this. 48 V rms should be enough to drive a 48 V buck converter, but I don't have enough experience to tell you the true best circuit, etc.