The standard EDID for the J+P2g+ is PCM. I usually use the AVP piece, because of this issue. I have also found that the Roku will output 2ch PCM, even on the Toslink when connected to a 2g transmitter. I have one in a system where we took the HDMI to the J+P System, then Toslink to an AVR. There are no settings in the roku to change it....all done by EDID. If we disconnect the J+P, the ROku outputs DD through toslink. I assume you are having the same problem. Might want to try the AVP piece. Also, may need to change the EDID settings in the Tx. To do this you will need to setup a static route in the Araknis.