I also own the Amber II. It is tube rectified. I am currently having the super-clocks installed. Hope to have it back this week. This is a very nice DAC, no complaints. I have own the Exogal Comet, PWDII, Auralic Vega and the Amber is my favorite. Much more musical. I also am going to try the SR Blue fuse once I do some listening for a few weeks.
