Upgrading power supply?

I've read quite a few forums about upgrading DC power supplies for various equipment and am curious about upgrading the power supply for my soundcard M-Audio Delta 1010. I'm really new to this subject and have no clue where to begin but from what I understand it makes a huge difference. All I know is the specs of the power supply I have:
OEM AC Adaptor
Model: AA-093A5DT
Input: 120 VAC 60hz 39W
Output: 9 VAC 3.5A

If anybody can help in this subject it would be greatly appreciated... Thanks in advance, JohnnyP.
The DC supply is a very important part of determining the performance of a piece, but it appears your outboard supply is simply a transformer; 120VAC in with 9VAC out. It is not a DC supply, which would therefore be inside the main chassis and probably very difficult to modify.