Hooking up a tube pre-amp to a processor

I'm not good at hooking up this stuff and here's what I want to do. I have a Proceed AVP that does not have an analog bypass. I have tried both digital and analog connections from the CD player and have settled sonically on the digital connection. But, will adding a good pre-amp, and I'm thinking tubes, do me any good? In other words, if I add one won't the signal still be converted by the processor's DAC, though it might be a more musical signal than the one coming directly from the CD player now. Will it be worth adding a pre-amp alone or do I replace the processor with one that has an analog by-pass and then also add a pre-amp. I use a Meridian CDP, Dreadnaught amp, Aerial 10-T speaks.

I appreciate all explanations and suggestions. Thanks.