Madrigal says that their Levinson M37 transport will not (or may not?) play CD-Rs, but mine does. In fact I've never had a CD-R that didn't play in the M37. Like Swampwalker, I use "Audio" CD-Rs mostly, but others have sent me computer burned CD-Rs that also play in the M37. I would think that the Proceed uses the same transport and laser reading system as the 37, but maybe not? Or is your Proceed an earlier model? Good Luck. Craig