i made a power amp using opa549 chips , bridged stereo
now the chips max voltage is -+ 30V my traffo makes more , so i need to regulate it , now i need 20amp and i dont know what device(s) to use , any help will be appriciated
can you alter the transformer? Remove turns to reduce it's output.
How about adding a capacitance multplier? You can adjust the output voltage by varying the dropper resistors feeding the base of the pass transistor. Some contributors don't like this as a solution.
if you want the reg to survive a short you will need to put at least 600watts of (maybe 1000w after temp derating) of output Trs in parallel and enormous heatsinks or use fold back current limiting or a slow blow fuse <= to max output current.