Now using the Zenfone 3 with the 10 driver Heir Audio 10.0 (also the 8 driver InEar Prophile-8 was used here), I realize that this DAC and implementation are excellent. The Zenfone 3 has such a big soundstage compared for example with the Galaxy S3's Wolfson DAC and an high level of fidelity, detail, separation and bass. The bass response is fantastic and still you can hear the lowermost details. I also like the timbre, electric guitars sound realistic and true-to-life. I will have a FiiO X5-III soon just for the sake of comparison, since it's not accurate to give impressions without a comparison point and I also need a DAP with superior amplification to drive 300 Ohm headphones. But by memory and comparing to all the DACs I've had (Cowon Plenue 1, Chord Mojo, etc), I think this is a pretty good DAC for a phone. Hope I'm not wrong, the X5-III will prove me wrong or right soon. I know it will be superior, I just want to know how much. But one thing is for sure, the zenfone 3 does not embarass with 1000€+ IEMs