Weak link?


Hi all. I am new to the forum and wondering if I can ask for some opinions. Although I'm pleased with my current system's performance, like most, I am always in search of improvement. What would members consider as the weakest link in my system, or rather, the one item, if changed, to most likely to influence overall quality. Current system: I use a Microsoft surface pro with thousands of files ranging in quality from 256 mp3 to 96/24 flac, output through USB converted to coax in on a McIntosh 132 processor, (48/24 internal dac only but I do have a dragonfly red as well, usually for headphone use), Mc 300 amp, B&W 804 D2's. Audioquest interconnects. My musical taste is all over the place but usually rock, both classic and indie/alternative. 
(My gut tells me to search for a dedicated high quality dac, and if so, where do I start, considering the overall level of my existing components?)
Many thanks!
harry333
Your post begs the question - "Why do you think your sound is lacking?" What is it about the sound signature that needs improvement? You've got great components, so I would focus on these in the following order:

1. Room treatments (panels, positioning)
2. The best quality source files you can get (lossy files are painful on high-end systems)
3. Power components and accessories (you didn't mention any, and they make a world of difference in high-end systems)
4. Interconnects and speaker cables (Audioquest is good only if you spend for their way-too-expensive cables)
5. A better DAC (the dragonfly red is decent, but the rest of your system needs to be in top shape to really hear the benefits of a > $1.5K DAC).
I very much appreciate your input. 
I suppose that there isn't a specific disappointment in my overall sonic signature, but rather, is there something I'm overlooking that would create that "wow" moment. I will certainly experiment with room treatments and altering speaker position.
By power components, do you mean a power line conditioner/voltage regulator? 
I too agree you have some decent components here. I also owned B&W 800 Series speakers. Liked them very much. About the only thing I can see as to what you have is go to the D3 800 Series? That to me would make the most logical difference, in my opinion. Albeit, an expensive one.....
Yes, that’s what I mean. I ended up getting a PS Audio PowerPlant P3, upgrading all of my power cables, upgraded all my fuses in my components, and even replaced the wall wart with a cryo treated hospital grade one. All that, and I once thought it power would never wouldn’t make a difference, but it all did. It all started with upgrading a single power cord. Again, the higher grade my components became, the more these types of upgrades made a difference. This is a very expensive route, though.

Also what interconnects and speaker cables are you using?
SVS speaker cable, biwired.  
Audioquest Evergreen interconnects, 
And just a basic power surge protector at the moment. 
These are great ideas and I appreciate your input as I'm not quite  a newbie to the world of audio perfection, but have much to learn. 
The D3 series sounds fantastic, just demoed  800 D3 with mono McIntosh 601 at local dealer and was floored but even 804 D3 are out of my current budget, and I just purchased the D2s from an acquaintance at a great price.