Source recommendation

Get a Bel Canto DAC3. Sounds wonderful with Jazz, or any type of music.

You can always look at a unit like the esoteric sa50 that performs well as both a stand alone dac and a cd player.

I'm hooked on Bel Canto. The DAC 3 is spectacular sounding! If I were in your shoes, I'd sell the Pre2 and replace it with a DAC 2.5 or 3.5 depending on what you can afford. Along with dac functionality both of these units have analog input and remote volume control. There's no need for a separate preamp. You can use your Marantz CC4001 as a transport. You should hear a stunning improvement with this upgrade.

Audio aero or Metronome.Will match the Bel Canto well,methink...

Alternatively,EAR Acute or Acoustic Art..

Those players above are known for giveing the feel of'intimacy' which is important for Jazz

Thanks to everyone for their input