Hey guys,
I have the OP3 A3003 for a few weeks now, coming from a samsung s4 i9505. Let me share my two cents, I use them with the RHA 750's.
Long story short, I am absolutely blown away by the sound quality of this device. At the beginning I thought there was something wrong with the thing, because everything sounded horrible. Turned out it was showing the crippled nature of bad mp3's. I have never had a device that was so damn precise and I never noticed that some of my files were so bad. I would even say the s4 was an big upgrade from my ipod touch 4G, but this thing is in a league of its own.
With good quality mp3's (or FLAC's of course) the OP3 absolutely rocks. All the detail is right there, as if there wasnt a single analog component that touched the signal. Some particular sounds seemed to have 'cleaned up' coming from the s4. They have gotten a whole new feel and atmosphere to them, and there is new micro detail to be found in them. I listen to songs on the OP3 and I find myself thinking "aaah, that is the way this sound was supposed to be". Every kick drum and every high hat sounds different with device.
The soundstaging on this thing is pretty good too, great focus and depth. The bass is kind of heavy but very nimble at the same time, the mids are very clear and have a lot of attack (might be a bit too much for some), the highs are quite airy but also very fast. Overall its a very clear and dynamic sound, with lots of attack but lacking a bit in punch. The s4 sounds muddy in comparison.
To me it is solid performer, it delivers the sound with bit precision without any polishing, which is a rare characteristic that I really appreciate. Use it with bad files you will have a very bad time, with good files and recordings its a pleasure to listen to.
I might put it against me dad's iphone 6 when I get the chance. I expect the iphone to sound much more polished and warm, but that is what I recollect from a long ago memory. Probably it works better with poor quality audio also. I really liked the headphone output of the iphone back then.
After the review from gsmarena I was really suprised by the sound quality of this phone. The people from pocketnow found different results, but they dont really talk a lot about them (https://www.youtube.com/watch?v=RkbH0QtssU4). Anyway, to me it is possible that the output of the OP3 was crippled due to the high playback volume. Also, I dont really care about most of those numbers; which phone has the most not-audible stereo crosstalk should not really be a big consideration IMO. What those numbers do not tell you is transient wave response, which is about 10x more important then what those numbers show because nobody ever listens to monotone frequency sweeps (I hope
). My s4 measures way better, but I prefer the SQ of the OP3 by a large extend.
On the practical side, the amp goes incredibly loud, I bet you can drive some pretty serious cans with the OP3. The downside to this, is that the volume steps are very big for easy-to-drive buds like mine. I often feel that the sound is either to soft or loud, that's a pretty big con for me. What I find really handy are the gesture controls. Which means you can go to the next song by writing ">" on the screen whilst the device is locked etc.
