5.1 channels sound AWFUL when being ripped. Any fixes?

I picked up the 2009 Deluxe edition of Black Sabbath's Paranoid, which includes a DVD containing quadraphonic mixes of the album material. I'm currently trying to rip those songs in 5.1 channel format so I can share them with you, but the 5.1 mix ends up sounding AWFUL in comparison to the album mix. I've tried a number of different programs, all with a less than optimal result:

Acrok Video Converter (trial version): sounds too grainy
Aiseesoft Video Converter (trial version): sounds too grainy
VideoProc Converter (FULL version): sounds too grainy!
HandBrake: this one I've had the best sound quality with... BUT it stutters every second!

I've had my patience with this rip wane every hour or so. I desperately need your advice on how to get the optimal result. Thanks.

DVD Audio Extractor is the best. It allows you to losslessly rip the sound in its original format, or even convert it to any other format you wish.

If you can rip directly to an ISO then someone here could likely convert / rip the audio from that for you.