How to get into high end digital? (Feeding a DAC)

The only explanation I can offer that will be from a subjective viewpoint, is that when experiencing certain cable types within the System there were presentations that were immediately recognized as being able to be a detractor and not an attractor.
From recollection the most short lived cable used in a trial was a Silver Wired Cable.
In contrast a Silver Wired Din > RCA Phono Cable has been in use for more than Three Years, and has only very recently been changed, this cable has been compared to approx' Six cables over this period, that have been made up of varying purchase values.
The retained Silver Wire Cable proved to be a satisfactory cable throughout the usage period.
Its replacement is a PC Triple C Wire Cable.  

Just to add to what others have said, streamers/digital sources all sound different. I am on my third streamer, the other two are okay, this one is better, all through the same DAC. I will keep looking. I have one of those Nakamichi 5 CD changers and put it in my main rig once. It has no digital out, so you get the digital source and DAC in one. Almost unlistenable compared to streamed versions of of the same ripped CD's through a streamer. Anything you do will be an upgrade there. I have gone completely digital with all my CD's ripped on a NAS, no plans to go back to a CD player, however I understand why some folks like/want them. But understand, even if you are using an external DAC, the digital stream coming out of the CD player can affect the sound like any streamer can. Everything matters if you have the ears to hear it.

The Ygg is a good choice, I have a Gumby and am very happy with it.

Disregarding for the moment the issue of transport and cable, there's quite a price differential between the two DACs you mention in the original post.  I'd recommend you take a hard look at the Gustard X26 Pro.