I've heard many Audio-gd DACs and have owned three myself over the years and I hold them in high regard. The best of my collection was the Reference 7.1 which is the predecessor to the Master 7. I've listened to many many DACs and find generally speaking I prefer the ladder or R-2R type DAC to the Delta-Sigmas. R-2R DACs seem to be making a come back these days and the Master 7 is an excellent choice in my opinion. I'm currently using a Schiit Yggrasil which is also R-2R... very different and I think I'm liking it a little better, seems more precise. I think the Lampizator is also a ladder dac. I found the Reference 7.1 to produce a huge soundstage which was very seductive.