Rail- Certainly, an improvement in your transport will be beneficial. However, the transport system needs to be consider in total: this includes the platform/isolation equipment, the transport itself, power cord/conditioning, and the interconnecting cable. You might find that a better platform (perfectly leveled) can give you the extra improvement you're looking for. However, for audio, a dedicated CD player is probably your best approach. I've found that few DVD players are really up to the task, and those that are, aren't inexpensive. Check out a used Cary 303, or better yet, a used Electrocompaniet EMC-1 or Audio Aero CDP if the budget fits. If you were still inclined to use the DACs in the Krell, then look into a used Sony XA7ES. I've tried the Sony 7000 and the 7700 as a CD transport, and they weren't even close to the Sony XA7ES as a CD transport. Just MHO. Good luck.