Krell SACD Standard redbook playback improvement

Has anyone experimented with improving the regular CD playback sound ( not the SACD, which I think is excellent) ? Specifically, has anyone tried hooking up an outboard DAC for this purpose? If so, what DAC has worked well? I am currently looking for an excellent DAC for my SACD Standard. I am very satisfied with the SACD playback........I just want to improve the redbook sound only. Thanks for your input.
What's the matter.......doesn't anyone own a Krell SACD Standard player?????
If so, is everyone satisfied with the Redbook playback?????????
The red book play back thru balanced cables are not bad at all. You need to get a dac that is much better than the PS Audio Ultralink Two. I am using hi-end balanced cables, power cord, BDR cone, puck and shelf for the Ultralink Two already.

You have to include the cost of the digital cable, power cord, vibtation control stuff into the final cost to see if it is worth while to go that route. Just my 2 cents.
I've had my Krell SACD Standard since 2004. I run pure-silver balanced interconnects into a Krell KAV-400xi and out to a pair of B&W 803s. I bought this player primarily for Redbook CDs, I own only 10 SACDs. As far as CD playback is concerned, this is a very, very good player, it's among the best that I have heard south of the Classe Top-Loader @ $12K. In my opinion Krell should rename it the "CD Standard" since this is what most owners use it for. I haven't heard of any owners modifying this Player-it's near perfect as is.