FYI, my Audio-GD DAC-19 (10th Anniversary Edition) arrived today. It's a SE DAC with 2x PCM1704 chips. This is one of the last brand new Burr-Brown R2R DAC's on the market and it comes in at just over $800 after shipping. This new version has the same filters as the Master 7, their flagship DAC with 8x 1704 chips (also one of the top units on Purrin's list).
Some advantages over vintage R2R DACS: It's brand new, it's fully supported/warrantied, it has a USB input (no additional transport needed), it will actually play up to 32bit/192k files over USB, oh and the USB input is modular/upgradable.
I have it hooked up to my amp through the Schiit SYS (along with the Theta) so I can A/B with the Theta by pushing one button. I synch up my two players and I can easily just swap back and forth.
So, it's only been on for about 5 hours and I've only listened for about 2, but already I can say that it is very comparable to my Basic II in SE mode. I think the DAC-19's bass is a bit bloomier (but not in a muddy way, just a bit more quantity) and it's a bit more mid-forward. They're very close at first glance and I'm going to need a lot more time to really tease out the subtle differences.
And of course what that means to me is that the DAC-19 makes a fantastic alternative to a vintage R2R for those who want R2R without all the compromises inherent in a 20 year old unit. For the price (almost 1/3 of the Yggy), I'd say it's worth looking into for those like me who like the idea of the Yggy but can't swing the price.
I'll be posting more impressions over in the DAC-19 thread if anyone is interested. Just thought you folks might find it interesting.