Ok I tried with my Fitear 335SR. I tested with Spotify. Test with Thai Rock Song.
I think the sound is neither impressive nor bad. It is quite medium.
Sound signature is Mid Range oriented. I don't see the "breathtaking impact" that I expected to see in Rock Genre.
Detail Retrieval is ok from mid to mid bass. But I don't think I get enough deep bass and high frequency from this phone.
headstage (soundstage) is mediocre compared to I received from vivo,lg, meizu.
I think this phone is not good for audiophiles but already good for common pop-rock listeners and I would say it can't distract you when you are working like when you are using DAP or External Dac-Amp.
Oh another thing, volume scale is only common rough 15 volume steps so I don't think I can volume matching with other phones. So I'd rather not comparing with other phone that I own.