Caveat: this is not a review and I don’t claim to be an audiophile. Just giving my impressions to help out others who might considering a device like this.
I got this dac in order to connect my Android device to my NAD home amp via RCA, as output straight from the headphone jack sounded terrible.
The model I am referring to is the android specific version with the micro usb plug– not the U2 ASYNCHRONOUS USB DAC as is more common in these forums.
Got to say I wasn’t expecting much but was pleasantly surprised. Sound quality is quite smooth. It only takes CD quality files (up to 48Khz/16bit) but that’s good enough for me not being a highly discerning listener. It can certainly hold its own compared to my standalone home CD player (Yamaha) listening through the same NAD amp.(listening on some budget audio technica closed headphones)
Overall this an excellent little dac. . Works with my cheapo Chinese tablet using usb audio player pro. Sound quality is good for something that's so small and cheap. Probably best appreciated with phones/tablets with average sound quality you want to improve, as I don't think it would make a whole lot of difference to phones with a decent audio chip in them (e.g the samsungs).
I would recommend this when:
(1) You have a phone/tablet with poor sound and are on a tight budget
(2) Want a Line out from your phone/tablet other than the headphone jack.