Not sure if there is anything to set to get sound (any sound, even 2ch) over the decoder's SPDIF port. Sorry also don't have a 1110.
If you're still not coming right, I would try the following;
1. Call up HDcabling and ask (a) whether the have ppl successfully using the converter with the DSD1110 and (b) any troubleshooting tips they can advise.
2. In the mean time try some of your own process of elimination by using (borrowing) an older DVD player (many have both coax & optical). Try simple optical to the Samsung HTB until you get audio playing, then switch to coax via converter without changing anything on the HTB. If the DVD player works, then the issue is with decoder, otherwise its the converter which will have to be sorted out with HDcabling.