My biggest question at this time though is; with running the DS direct to the Amp my volume setting on the DS is about 60-65. Could I be truncated bits?My guess is Yes and losing resolution so I suggest running through your pre at full volume.
I know PS says it shouldn't, but, I don't know...
I've tried many DACs and always prefer going through a pre. Had a Lamp L5 with analog volume control and still much prefer going through pre. Sometimes theory <> practice.