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

What is the budget?  There is a 2K price differential between the Topping and and Yggdrasil.
  Transports make a difference—they don’t all sound the same—but the DAC is more important.  If the system as a whole is low on resolution, then the NAK CD tray, if it has a digital out, can suffice.  Same with cables-one step above standard interconnects is probably all that is required before diminishing returns sets in.
  If otoh, the system can detect subtle differences between components, get back to us with a budget

@holmz,
If playing from your spinning disc is the requirement, you'll need a transport or DVD player with a digital output(USB, BNC, dig coax, etc).  All DACs don't have the same complement of inputs, so be sure of compatibility.

SQ of DACs can vary quite widely from input-to-input. Some designers focus their design energy and invest in better parts for one or the other; it's worth considering user's experiences for the particular DAC you're getting. e.g. USB a decade ago was almost always noisier vs. coax & AES/EBU, but with much focus on improving USB due to it's popularity, newer designs have often overcome the concern.  

While Monoprice and other bargain cables can do the job, the impact of cable choice varies widely from system-to-system and is more distinguishable on more resolving gear. Advice from posters with no system posted or other similar context and explanation as to what they've heard for comparison, should be discounted accordingly. 

One huge question for you, is how tied in are you to your silver discs? Many of us have reported improved SQ playing ripped files from a NAS that sends the files to your dac through a network player/streamer. This is a whole convo in itself, but I would suggest considering using any computer drive to rip discs to a NAS.

If your new  "Home Theatre pre, which is Roon capable" means it's a Roon Ready endpoint device, then it can be your network streamer/player. Just connect it via ethernet cable to your network. Run Roon Core(the main Roon software) on 1) An Intel NUC if you're into some DIY-ish assembly 2) Small Green Computer/Sonore Sonic Orbiter 3) Roon Nucleus or 4) Mac or PC. Use any phone or tablet as a remote.
Roon is a game changing experience. I'd suggest this for a good visual on using Roon https://www.youtube.com/watch?v=Qe61rmLKc1E
and this if you're unclear on the 3 elements of Roon(Core/Endpoint/Remote) https://www.youtube.com/watch?v=qgoXpMFxi5g
Cheers,
Spencer 

@jasonbourne52
This forum is generally assumed to be for those who want to intelligently discuss making their audio systems better. Certainly the OP is of that mindset.  The information you shared just isn’t remotely true in any modestly high performing system.

Of course, everything is budget and system dependent. However, I could swap digital cables for you in my system (and you could even pick which cables) and you would very clearly and immediately understand that they sound different - even in a blind A/B test.

I could also swap out my good streamer for a Bluesound node and you would clearly and immediately hear that they sound different - even though my DAC is supposedly “immune” to jitter. I get that your experience may not support what I’ve stated above - in which case, you’re missing out.  But, you’re also misleading others who are in search for something better.  Unless you’re intentionally trolling - certainly a possibility - but then you’re a busy troll here.  

To the OP - lots of other information on these forums (in this thread and others) to help you.

Peace,