adam18, don't you love it? This is the joy that audio is all about! :)
The best part is, if you want to keep exploring there is no end to it. All systems have characteristics/personalities and you can take it as far as you wish. This is truly a hobby for a lifetime. :)
Yup, digital can be contoured every bit as much as analogue, though with less "moving parts", obviously. But, every piece of a digital system has capacity to render significant improvements. Pursue those improvements with abandon and you will have a marvelous experience!
I spent two years on an experiment whereby I took a stock Mac Mini and iTunes as a server. I used approx. one dozen USB cables and one dozen DACs to see how much improvement could be had in letting the DAC do the "heavy lifting". The results were startling, and like you the sound went from OK to splendid. Now I am moving into examination of the dedicated server territory and I presume it will be ripe with potential as well. I am excited about it because the sound I have is already very gratifying. However, after decades at this I have learned to never say, "I'm there, it can't get any better." There are limitless improvements, experiences in this hobby there for the adventurous. :)
Looking at your system I have some suggestions, if you don't mind. I strongly recommend you move to file playback vs. disc. Put your discs on file playback and you will hear your collection better than ever. I have found file playback consistently better than CD or streaming audio and the convenience is fabulous. Check out software for up conversion of PCM files (native 16bit/44.1Khz) and you will have a grand time. To date one of the "best $100 I ever spent," for me has been HQPlayer software. A bit ragged in terms of functionality but powerful to contour the sound.
You may wish to elevate your speakers a bit more; raising the soundstage a couple inches by placing speakers on inert pedestals of a couple inches is an easy way to alter the experience and often it is more enjoyable. Keep exploring cables for power, speaker, etc. You can tune a rig quite well that way. You don't need to spend more, just rotate them with cables of comparable cost but quite different build/geometry and you will be shocked at the variety of performance.
Explore power cords if you have not. It doesn't have to be expensive, but even affordable power cords will render similar changes as the digital cable has. Trust me, well worth the effort. (Maybe you will believe me considering the "wow" experience you had with a digital cable.) Tuning rigs with power cords is a regular event for me. Also, try different speaker cables if you have not. Compare the sound of speaker cables with heavier gauge to the Anticables. You may be surprised at that, too.
Plenty of fun things to do for not too much cost. That's one of the wonderful aspects of audio.