I doubt there are many DIY guys who built their own dacs on AA. You would need to peruse the more DIY oriented sites.
For those interested in trying out R2R/Ladder DACs, there are at least a few out there. One is obviously the fantastic US made Schiit DACs and another that seems to relatively popular is Audio-GD of China. The Audio-GD has been reviewed by some magazines and seems to be a decent product.
Here is a brief review of Audio-GD R2R 7 DAC.
https://www.youtube.com/watch?v=AhYXKKabZgc