It's been a few weeks since my last attempt to do this with my Roland M-5000 at church, but as I recall, you need to go into the patchbay on your M480 board and "build" the mix, by putting the channels you want in the correct order on REAC A. Then when you bring up the record meters in SAWStudio, you should be able to click on their "Input" window, choose (perhaps) Mono, then pick which record device to use. Please keep us posted on your progress!
John Francis
Rolla, MO
Connect With Us