After I went through a DAC upgrade from my Mac DAC2 board (C2700) it took a significant amount $ to beet it in all respects. Few I tried were just side steps for a slight different sound. Your going to have to spend upwards of $3000+ to get any real upgrade, everything else IMO is just a side step for a slightly different sound. I ended up with a Chord Dave (used) but I'd say the same for the TT at much less money then the Dave. you're really going to have to audition DAC's do not buy unheard or you may be surprised how good the DAC2 board is.
Also considering the DAC2 board has an excellent HDMI ARC connection for a TV integration (if needed). No other DAC I've seen at this level has HDMI ARC, for me this was pivotal for movies and TV-apple 4k TV box streaming (2ch). noting I use the apple 4k box for primarily background music and TV.