Getting good audio results on dvd

I am not getting good sounding audio on my dvds. I’m making promo dvds that contains videos plus slideshows with audio from my cds. I rip from cd then import the audio. However it’s ripped at 44-16 and by the time it gets upsampled and encoded it doesn’t sound good, it sounds “edgy” and almost distorted…crunchy. I’m using TMPGEnc. Dolby Digital processed the file also looses data. I choose PCM which sounds a bit better but it’s still not as good as the track sounds on a CD. The audio on my video tracks sounds fine…it’s just tracks I’ve ripped from cds that sound bad.
Any help or tips on getting good audio results from ripped cd tracks…and what format to output to.

Maybe you can encode with a 3rd party tool (even in TMPGEnc) and then import this audio to authorize your dvd.