dac/transport/preamp connection problem..Help

To start-

I have had everything bench tested and everything is in perfect working order...however, when I try to connect a McCormack Digital Drive SST-1 transport through a California Audio Lab Sigma DAC along to an Anstgrom 200 Home Entertainment Director Pre-amp- I get no sound out of the speakers. When I connect a regular CD Player or DVD player or DirecTV signal through the pre-amp/amp, I have no problems. I am running a coax cable from the Digital transport into the DAC and regular RCA left/right cables out of the DAC into the Pre-amp, yet no signal. What gives? Any suggestions?

I appreciate any help. Thank you in advance.

James Hughes