Would an external DAC improve the sound of my SONY

Agree with Bigkidz & Rbstehno, esp. a Cal Alpha.

Even new sonys have their own distinct sound. Personally, I think they make great transports but will only use one with an external DAC. I like warmer, less analytical sound.

Hi! I have Sony NS 999ES SACD/CD and have been doing extensive A/B testing, trying to compare my Sony with Musical Fidelity A3 24 upsampling DAC, that I have on loan in my system for the last few days. Mind you, the MF DAC MSRP is the same, as Sony ($1200), and it's been highly acclaimed by Sam Tellig of Stereofile not so long ago.
My conclusion so far is: no matter how hard I tried to like MF DAC ( and I can get a real good price on it), I could only hear very marginal difference b/w the two. Possibly a little bit more refinement in the HF region, and maybe, just maybe, slightly better articulated mids.
But again, the difference is so insignificant, that I cannot justify paying for such marginal improvement yet. I really tried to like it.

Medium to high-cost Sonys make great transports once they are modded properly, particularly the DVP-S7700. My personal DAC favorites are modded Perpetual P-3A and modded Birdland Odeon-lite.

Thanks for the response guys. I think I will keep the changer "as is" and look into a transport/DAC combo for more critical listening. If you have any ideas fire away
Bob.