I have the F-D4 and just bought a PHILLIPS CDR785 recorder.Your F-D8 should have an optical out in the back,its a little black plastic plug.Thats what I use.It plugs into the optical in on the recorder.Very easy.Twelve foot optical cord at RADIO SHACK is $44.00.The F-D4 manual says to go to the setup menu(or something)for DIGITAL OUT,but that only allows you two chanels to be recorded.That may be the right way to do it but I just set my 4 INPUT SELECT buttons down to TRACK,set the SELECTOR to (LR),preview the mix to my liking,start the recorder and hit play on the F-D4.I also compress the music once,sometimes twice with my Alesis 3630(which by the way works just fine)for all you 3630 haters.Compressing involves mixing down to two tracks and playing it out of channels 3 and 4.Good luck. DS