GoodOutcomeI'm not sure which soundcard you have, but the ZuperDAC is a huge upgrade to the soundcard in my Thinkpad x220 laptop. All of my headphones sound great off of it, including Ultrasone HFI-680. In fact, I like the ZuperDAC so much that I bought another one to pair up with my Galaxy S5. Very happy.
GoodOutcomeHow much that dac affect the battery?
I want to buy it to pair up with the lg g2 (its sound quality sucks even with cm13 plus viper 4 android), but I'm afraid of battery draining considering that I'm going to use it on the go!
Is it necessary to use a specific app or it works with Spotify too?
ogpaulLG G2 (Pro) is listed among supported devices, every app should work with USB Audio. Huge upgrade of audio indeed. But battery drain is significant, expect 6-8 hours of battery life (a bit more than screen on, but not by much).
http://www.zorloo.com/faq