Does Anyone Offer Audio Mods For A Mac Mini?

Wondering why a high end power supply makes any difference assuming one is using a USB-SPDIF converter which runs on a dedicated power supply or battery like some high end models do these days. I always thought the only thing that benefits from clean power is the digital output circuitry and clock but maybe I'm wrong??

Just started using a 2009 mini as a music transport and would like to tweak it a bit.

Thanks Steve. This does not answer my question. Already installed a SSD but still running on 2 GB of RAM.
Using Auidirvana which supposedly does all the audio optimation of OSX. Do I still need this ibook?

Alfe,

what kind of USB converter are you using?
Anyone has tried the audio optimation guide mentioned by Steve who is using Audirvana?

Steve, tried to download the guide but it runs on IPAD only and not on my IPOD touch or mini...

Alfe,
got all my music on an external HD and everything else on internal SSD.