I have a very clean Dac 19 that has 2 rca outputs instead of one ACSS connection. It's sounds really good with the NFB 1 and C2 amplifiers I used it with. Has a very smooth somewhat laid back sound. With other amps like the Jotunheim and Gustard H10 it just sounded ok but with the Audio gd C2 it had very good instrument separation very open sound with bass that hit really low. I do not have the original box but paper work the previous owner used and showed his preference for the jumpers you can change inside. I have it set to what Kingwa recommended. I also have the adapter for changing the firmware I will throw in and there is a newer version if you want to update it. I will make sure its boxed real good and that price is shipped. Thanks for looking.