A quick search on Marantz website reveals your ND8006 does not have XLR / Balanced outputs! It’s a Single Ended design (RCA outputs only).
https://www.marantz.com/-/media/files/documentmaster/marantzna/us/nd8006_product_info_sheet_en01.pdf
https://www.marantz.com/-/media/files/documentmaster/marantzna/us/nd8006_product_info_sheet_en01.pdf