The reason for no sound could be as simple as not having set your ADAT to receive the bit and bite rate of the digital signal coming to it from the Sony. For example, if the Sony is delivering a 24/96 signal and your ADAT does not process that signal you will need to set the bit and bite rate going to the Sony from the source component to a bit and bite rate the ADAT will accept. This is what I have experienced, recording from my TA-E9000ES to a Sony PCM-7010F DAT Recorder. My scenario is just a little bit different than yours in that the 7010 does not have an optical input, requiring me to convert the optical output from 9000ES to IEC 958. At any rate, my 7010 will only receive/play 16/44, 16/48, and 16/32 information. Now, if you are trying to play ADAT material from the 9000ES you may need to confirm from the manual that the optical input you have plugged the ADAT's output to will process the bit and bite rate. I think the Sony's optical inputs will only process up to 24/96. The optical tape input, I'm not sure, however I do know that the tape input and output is all in digital realm, not capable of analog to digital conversion.