I'm guessing Doug's mod is a "simple" hack to put an op-amp in front of the a/d section. Probably not unlike a warm/transparent mod ua5, etc. It'd be interesting to know the signal level that goes into the normal a/d section. I wonder how much gain Doug's mod adds, and whether it is subsequently attenuated?
As I understand the challenges, a lot of a great a/d is a great power supply. I don't know where or why the v3 a/d comes up short compared to the 7xx. Is it the chip? Is it the power supply? Something else? I mean, the a/d sounds very good, just not as good as the 722 as an a/d. The v3 a/d always sounded really clean. And it even came up subjectively short in a few comps against the r09. We really need to revisit that comp with the m10.
In many ways the a/d aspect of the v3 is really impressive. I mean, it has spdif, optical, wordclock, and double AES outputs. All from a little board (I recall that it's all done on that sub-board, but could be mistaken), and without additional external bulk or power. I wonder what it would take to entirely upgrade that board, and what quality could result? I've always assumed the mytek was a goal in terms of a/d units, but I have never owned one or even heard comps that confirmed that.
That new Tascam recorder presents some new opportunities because it appears to be a good, low-cost bit-bucket. Maybe that will spur some a/d experimentation.