I'm working with an audio board (company project) that is powered by a external 9V power supply. Actually an ordinary AC adapter, like this one: http://www.sweetwater.com/store/detail/MAud9v500. The power supply project of our board seems to me kind of an overkill. I say that because of this lot of capacitors, also I not sure about the inductors. Are they really doing any work there? Since the external power supply is - supposed to be - linear, I guess all those capacitors are necessary.
Apart that, those caps are taking extra money and extra space in PCB board.
What do you think?