Mac sound quality


I'm using the new IMac , burning my CDs in AIFF . Its hooked up to an audio grade power conditioner , power cord and run to a Levinson #360S dac from the digital out through a audio grade digital cable . The sound quality is not nearly as good as my mid fi CD player . Iv'e read many posts saying this type of hard drive is far better than good quality CD players , too many posts to disregard . What am I doing wrong , the other posters were down loading , but can there be that much difference ?
tmsorosk
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4est . Settings were as you recommended , except error correction was off , does this mean all imported CDs will have to be reburnt ? I could not find the audio midi set . This is the newest Imac , could it be different ?

Thanks
I'm running MacMini, apple lossless with error correction ripping, usb connection to my amp and PURE MUSIC software....I couldn't be happier, I've got better than cd sound with the convenience of my my Itouch as a remote.
TOSlink out to the DAC is not the best way to go, but it should be at least decent. What are you using for a TOSlink cable?