Will a new Dac improve the sound?

Another suggestion for the purchase of a MHDT DAC. Excellent products that fit into your budget.  Start with the use of your CD player as a transport. Then consider transport upgrade. Opportunity to experience benefits of each upgrade and consider streaming/server options. Dial in the majority of the frequency range then explore need for better bass. 

I bought an Emotiva ERC 4 CD player. Its $600. It has an excellent DAC. I think you would be surprised with the quality of the sound you get with the built-in DAC. Why not try it. It comes with it for free. I upgraded to an Ares II and it sounds better, not night and day better, but noticeably better. I also noticed an improvement with Audioquest interconnects. My advice is get the ERC 4 and new speakers. If you don't like it add the Ares II. 

I tried a few DACs recently and found the Denafrips ARES II a major improvement  and a keeper.  I went computer audio from my YBA Design CDP  in 2016 and have auditioned a number of DACs. ARES is around $850 from Singapore.  Lots of reviews on it.

The Ares II is a fantastic DAC but I quickly uograded to the Pontus !!. Superb. Both tacks seem to handle treble naturally and the bass is much tighter and better defined.

@garypick - one more thought - if it were me, I would not introduce tubes into the equation at the DAC itself. Seems more logical to implement tubes at the preamp or amp - in any event, let us know what you decide to do!