Yes, I use FLAC to rip all my CDs. However, I probably wasn't clear. My Aurender unit does not play CDs, it only rips to the internal hard drive, or to an external NAS, and plays from it or streams. My CD Transport unit is a very nice Pioneer Elite BDP-09FD unit. Which I use as a transport only into my Audio Research DAC 9 via optical.
The Aurender goes to the DAC 9 via USB.
The Aurender is suppose to rip bit perfect. But, people say digital is digital or amps are amps, but.... not really.
Also, by-the-way, Pioneer Elite BDP-09 and DV-09 units are built like tanks. Seriously overbuilt and I've compared them to many, many other transports, most extremely high end and well known and the BDP-09 and also the DV-09 are right up there as transports go.
People replaced them because they were using them as DVD players or Blue Ray players and although quite nice, they loaded a little slowly and upgrading their home theater units with the latest and greatest. But, for music only and as a transport only, wow!
enjoy