@tomcy6 The S-280 does have a built-in DAC which is actually quite good. I will put it up against any DAC in the ~$2-3K range. However, the DAC in the U-280 is substantially better. I preferred it, by a substantial margin, over Denafrips Terminator II and T+A 200. The DAC in U-280 easily competes with anything up to $5-7K based on my experience. Besides the U-280 (which is what I have), they also have an I-280 which is basically the same as the U-280 sans the DAC.
I have owned Luxman 590AXII, Naim Supernait 3, Audio Research GSi75, VAC 160i, VTL I-85, and few more integrated amps. I recently took my Aavik to a friend’s house who has a Pass Labs INT-250. We compared the Aavik and Pass in his system. He was quite shocked to hear how much the SQ resembled -- same level of heft, warmth, imaging, etc. The Pass had a little more bloom (for SS standards) and the Aavik had more transparency and much lower noise floor. Of course, the Aavik is much much lighter in weight and doesn’t put out as much heat.
I know it is class D and does not have the same brand name recognition in these forums, but at least for me, it is one of the best integrated amps I have owned.