Help needed with Tube Audio Design (TADAC)

I have 2009 TADAC with HT bypass.  Have been using RCA outputs on the TADAC for years and wanted to try balanced cables.   Are the Balanced ports on the TADAC for output or input (they are not labeled on the back of the TADAC and it came with no manual). I just bought some XLR cables, attached to the TADAC then to a Hegel amp and am getting no sound. I am lost but I am assuming that the ports and only for input???  Really could use some help from anyone who is familiar with this issue. Much appreciated.