I got one of these, not off of Drop though.
I use them with a pair of Micca RB42 for my PC, works fine for me. The AD18 is connected via USB and I got it set to 96kHz, don't got a sub hooked up to it and the speakers are connected through some 12 AWG banana plug cables which may have been more than needed.
Only real issue I have is that if I accidentally leave the AD18 on during a cold startup of my PC it makes this horrific beeping noise. I haven't observed any noise or hissing or anything for my particular unit.