Rotel RCD-1570 cd player + RC-1572 Preamp

Hi all,

I am seeking for an advice on how to connect Rotel RCD-1570 cd player and RC-1572 Preamp.
The CD player has an analog balanced output and digital output port, and the preamp has a balanced in and digital in port. 
Should I use balanced output port to balanced input port or digital output port to digital input port? 
Is one better than the other? 

I found some pictures of both devices from google search for your reference. 
CD player:http://www.aussieaudiomart.com/details/649292680-rotel-rcd1570-cd-player/images/1298343/
Preamp: https://www.westcoasthifi.com.au/product/rotel-rc-1572-stereo-preamplifier/


Thanks!