Some years ago I purchased a TotalDAC DAC and was taken by its R2R sound. I had by that time cycled through a series of the top-grade DACs but found the sound in all of them ultimately canned and processed, which I found decidedly lacking the TotalDAC. In purchasing a TotalDAC unit, and not being able to let well enough alone, I asked if the designer/manufacturer, Vincent Brient, would make a model for me with resistors I would specify. He agreed, the resistors being naked Vishays, which are the most transparent resistors available, beating the Vishay types Vincent was then using in his DACs. Vincent evidently investigated the issue, and subsequently started using these resistors in his gear, which was a good move on his part. At that time, I thought his technology would be awesomely suited to use in a portable unit using surface-mount Vishays, but I couldn’t convince him to manufacture such a unit. I then attempted, on my own, and with the aid of a well-known audio electronics designer, to create a portable R2R device with surface-mount Vishays. This project lasted a year before it terminated for various reasons, though I continued to believe an R2R, Vishays or not, would be the cat's meow of DAPs, if not more broadly in the DAC competition world.
I then heard of the LP6 R2R and immediately read some reviews I felt were competent, and purchased a unit on the faith it would be a ringer. I have received that unit and wish to report some of my experiences with it. My basic opinion of this DAP is that it shines above others in the field. I also own a few Astell&Kern models, the better being the SP1000M Gold, where in my comparison with these and other sufficiently portable DACs, like the Chord Hugo 2, I find the LP6 hands-down preferable. Its sound is the truer sound of R2R, which lacks the imprecision and noise ~~ basically a processed character ~~ of chip-based IV converters. I haven't yet directly compared its sound with my TotalDAC DAC, which I will some day soon and will report.