Storing DSD/PCM files and playing through a DAC

A Renderer would interface between the local source Server and the DAC or in place of a computer.
An example would be the Roon Nucleus (Roon Based) instead of a computer.
White Paper here: https://docs.google.com/document/d/1pUj-yFsAHPgTuV1TbcESA4va1_mxv1M_VQPJV___nuQ/edit
The Nucleus is a good example of a dedicated digital transport with no
redundant features.
A Local Server will add flexibility and utility and not be dependent upon the differences between PCs and Macs (Files and Format) as well as being able to physically handle storage drives.
A two bay Server starting at $500 +/- including drives (4-6TB) will be powerful enough and redundant Back Up with Mirrored drives.
All components would be Plug N Play apart from setting up a Server.
A portable HDD would be more compatibility dependent and more vulnerable to damage.
Oppo states Roon Ready for the 203-205 series.
Look here for Oppo info: http://help.nativedsd.com/en/articles/94445-playing-dsd-on-oppo-machines-explained
It seems that a network device is accessible with Roon.
If you would output to a separate DAC then the Oppo is a Digital Transport / Renderer (as a Roon Endpoint). 
My 203 is typically used for BluRay and CD playback  >>> Coax >>> Integrated for Audio.

How do you like the Roon's sound quality?

I like it a great deal.  I'm particularly happy being able to do digital domain equalization with it. :)

Thank You for the info @rego and @er

@ milpai,

what ever drive type you use, make sure you make a  back up copy of your files on another drive. The first time I did a digital library, it was great until the drive crashed.....without a backup,. you will have to re-rip everything....tons of work.....

Agreed @johnss . My DSD files are currently on one HDD and a laptop. The new HDD/SSD would be exclusively for music.