Need Help with Dacs.

Hi
I am new to the forum. Need some info on dacs , as of now my sytem has Meridian 263 delta sigma dac,it has a 16 bit chip and it runs on a 44 KHz. My transport is a
Meridian as well model 208. For some time now I have been debating if a different DAC would make my system sound smoother? I run regular cd's nothing in HDCD or DVD CD's, just your regular type. My system consists of the following.
1. Meridian 208 transport.
2. Meridian 263 delta sigma DAC.
3. Classe audio model Thirty preamp.
4. Krell KSA 100 s amp.
5. Linn Keilidh Speakers.
6. wire world interconnects.
7. Ixos 604 ofc biwire speaker cables.

Don't get me wrong ths system sounds fantastic, but you know I have had the upgrade itch for many years,
I am thinking of maybe getting a Mark Levinson 36 dac
someone is selling it, it runs on 4 Burr Brown 20 bit chips. At the same time I also own a Pioneer Elite DV-09 and it has twin 24 bit Burr Brown dacs and runs at 96KHz.
I am not sure on what to do? I really don't know what the dac does other than change a digital signal to analog,
and why some are crazy expensive and others are not.

Please Help.

Thanks
Slate.