Studer a730 professional cd player

Need to know if any members try using the dac of the studer a730 or a727. That is to say having and external transport digital output then feeding the the signal to the studer a730, so the studer acts as a dac. I don't know if this is possible? I try using the unit as a transport with an external dac and it sounded pretty decent. But I was curious and would think that it should work as a dac since my unit has the philips tda 1541a s2 chipset, hoping the dac section of the unit can outperform many standalone unit dac out there. Also If any members experience using an external clock feeding it to the studer unit, i would be interest in hearing your experiences as well. Your advise is much appreciated.