I no longer own a DAS but when I was shooting mine the Mountain Muffler string was the ticket.
Limbsavers at the fadeouts will help as well.
I've shot a bunch of different types of limbs on various risers and they all behave differently. I found that the Tradtech ExtremeBF limbs were a lot quieter than any other limb I have ever shot. Other limbs (W&W Focus, Winex, Samick Agulla, Sky Conquest) could be made to be as quiet with a variety of trick but those BF limbs just seem to be inherently quiet. Don't ask me why but they are.
I've had a few bows that seemed to really quiet down noticably (mostly Quinns) using an 8 strand 450+ string. Again, I don't know why but it was very noticable.
Lately I've just gone to making my strings with D97 (since I have a lot of it). I make them 12 strand and pad them with an 6 strands (10") of D97 or Dacron. They are pretty quiet as well.
You'll get that DAS whisper quiet with a little experimentation.