Any product can fail, so negative reviews are always statistically suspect. However... I have bought SIX of these (including two of the RCA-less uDAC2HP model), over a period of a couple of years, and TWO were DOA. Also, two of the supplied USB cables were shorted, in one case apparently damaging a PC. (Sensed that the audio problem might be in the wiring when the USB cable got hot to touch.)
When it works: a good entry-level USB DAC, also unusually portable for frequent flyers. Sound quality (to my ears) not quite up to standard of other brands not that much more, so I'd recommend the step up where feasible. And very reasonably priced now, with prices way down in just a couple of years. [Oops - must have been a momentary blip on Amazon.]
One of my first Icon uDACs had terrible sound; company apparently was familiar with the problem, and replaced it fairly quickly. (I still had to deal with the return; recommend buying through Amazon or someplace else that covers returns.) They also knew about the bad cables, which weren't worth the effort/postage of returning; I'm a little surprised that Nuforce wouldn't just send replacements on trust.
I bought some of the Icons for "inventory" as future gifts. I've been buying hifi equipment since the days of Mac tube amps, AR3 speakers and the Thorens TD-124. Never had a defective new product (maybe just lucky?), so it didn't occurred to me to break the package seal on a relatively simple device for an on-arrival test. One of these was opened recently, an HP model, and didn't work at all. (Bad cable, too.) Nuforce took a while to decide that this model was too ancient to be supported. They suggested that I might separately contact their sales dep't., who might make some accommodation on another product.
Decided I just couldn't be bothered to plea for a small discount on another uncertain product. So the Icon is a desk ornament until it gets recycled to scrap. Nice micro-project box, but I'm not building electronics these days.
It is pretty apparent from my experience and other reviews that Nuforce QC leaves a lot to be desired. The two failed units clearly hadn't had even a minimal plug-in test. And support afterwards was uninspiring.
I hate to put down a company that makes useful little products at moderately reasonable prices. But recent promotional material suggests that they are heading toward the fashion-conscious yuppie gadget market, rather than boring black boxes that merely sound great. I am unlikely to do business with them again. For those who do, I suggest putting each purchase through its paces immediately, and be very wary of defects as early as possible.
Disappointed, but life happens. HRT Music Streamers are still working just fine. And the Nuforce earbuds are holding up well for me. I rate the Icon uDACs that actually work at about 4 stars; it's adding 50% to the price for the bad ones, plus a fried USB system, plus the hassle of dealing (or failing to deal with) the defective ones that forces down my rating.