Massdrop RDAC https://www.massdrop.com/buy/massdrop-x-airist-audio-r-2r-dac Going to pull off a Julia Child's cookbook thing here with no photos and only text. Decided against photos because Massdrop is better at photos and I don't have time for it. I'm going to keep this short and sweet. At $350, the closest competition will be the Modi Multibit. Overall, I feel this is a step up from the Modi Multibit. The RDAC definitely reminds me of the old school R2R DACs of the 90s. First things first: those who really want deeply placed stage and stage depth with layering might want to reconsider. The RDAC has NOS qualities. The stage is wide, however, the location of the stage is close. As @Hands says, there is a bit of dimensionality around the instruments with NOS with less of a paper cutout effect, despite the close stage with lack of depth. Now I am not totally convinced this is NOS. It almost sounds like it's somewhere in between, but much toward NOS. Personally, I don't give a crap about headstage with headphones; but I do know that many of you do. Those using Audeze, Grado, or Focal, it doesn't really matter since those headphones don't stage worth shit anyway, no matter what you throw at them. The RDAC does have an open sounding quality to it though - it doesn't sound closed or congested. Now let's get to the good part: very good clarity, excellent microdynamics (makes the most of it), nuanced - a very involving listen. This is why I really like it. The tonal balance is even, perhaps just slightly tilted down. The Modi Multibit in comparison is bassier and warmer, and with some congestion, and less bass extension. Plankon, ambient cues, trailing decays are just a touch behind Modi Multibit using USB. Transients are crisper and grip is better on the RDAC. However, SPDIF is where the RDAC really shines. The Modi Multibit is known to scale quite a bit with good SPDIF sources. The RDAC scales even more than Modi Multibit. Everything gets better across the board, with resolution equaling, maybe even nudging ahead of Modi Multibit using SPDIF, and microdynamics being knocked out of the park. Despite being SE out, a great match with Massdrop x THX AAA BTW. Makes sense if you think about it. The RDAC chassis is the exact same style and height and width as the THX AAA and MCTH. BTW, I did get a chance to hear a prototype version of this using a battery for the power supply. It was even better than the stock switcher. So there is plenty of potential. Sure an uber external LPS and USB to SPDIF add to the cost; but what we have is upgradeable to something better than a Metrum Amethyst, at two-thirds the cost when everything is added together.