Correct me if I am wrong, but I don't think the megacomboburrito filter can't really do on a DS since the DS chips already have their own pre-determined filters. I mean, are there any DS or hybrid chips out there with no built in filter that are a) still in production, b) sound worthy enough for such things? Makes me even wonder if Mike has attempted such things at one point or another. Anyway, fun to think about. Another way to think about modular is choice. What if someone wants multiple USB inputs? or multiple SPDIF inputs. Why does a DAC have to only have one of each? There are multiple sources these days. Plus, isn't a transport to be named later going to have USB out. Now, I don't want to have to swap USB cables around to listen to different sources. Besides, an AES/EBU would be mighty unused if I ever had a DAC with one like a Bifrost 2. Isn't variety the spice of life?