General perception of the new firmware is sad. In two words - looks like you came towards consumer sound from clarity and density.
Separation is "better"... to tell the true I just got lost in some track that was listening before where is who playing around me. "Sounds" are all around me from all the sides. But not instruments any more. "Hotel California" by Eagles is now some kind of guess what sound depicts what instrument. Here is something like a guitar... there is something like
Sound is bassy but without that previous linearity in the middle. Middle sounds (for example guitar in "Hotel California" by Eagles) are lost and like couldn't decide either go to L channel or R. And splitting feeling makes instrument sound unnatural, dirty. You can't read the main tune. Just peak notes.
The same thing with vocal. Now vocal is lost somewhere between L and R channels. Looks like you have two stereo speakers playing and then singer standing behind them crying as background. So me and listener is trying to find and chase him out of the massive noise.
Accordion - lost density and part of its timbre.
Violins - the same.
Piano - sounds like something likely piano. Hard to split is it natural or electronic.
For now it sounds more like mp3 sound on tracks even with material like " trondheim solistene divertimenti (24bit.192khz) ".
It may be just a first perception, so I will try now to go down to previous firmware and compare sound again.
But if that would be the same then - I ask you to add in the player possibility to choose between that "all around but nothing specific" sound and that "dense and clear" one of the last firmware. Maybe 10% of users percive new sound as not acceptable.
2. Brightness problem - in the menu "brightness" in settings it is going lower till the middle of the marker, then just goes up again with marker going to "minimal". Then when you use player brightness jumps up and down when it wish.
3. While changing tracks first half of the second of the sound may contain any king of ****: either twice the beging of the present track, either first sounds of the last track or some other's from the album or played before.
4. I don't know why people say that menu started to work faster. Mine for sure (i double checked with downgrade to 1.2.7 and upgrade to 1.3.5 again) is working faster on 1.2.7. Especially when I scroll down list of track in the album or folders list.
.....SO. I have just downgraded to 1.2.7 (without factory reset yet) and listened to the first track. That was again Hotel California. And need to say that device sounded again with dense and colorful sound. Voice of the singer is in the center before the instruments and you are not painfully trying to identify him from the all the bassy-bumping noise around you. Yes... separation of instruments and back vocal voices is not that "good". But once again what do I need that 5.1 kind separation if all those separated voices became mp3 stile thin, dirty and unnatural. Just try yourself... maybe you also believed that crowd saying "wow! it is better... bass is better"... Just try yourself what is worth to be.
Made factory reset to double check any changes... No. Sound is the same as after downgrade to 1.2.7.
OK. Some subjected s..t about sound:
Eagles, Unplugged Hotel California 16.44 = new sound just makes be uncomfortable with guitar 100% in left ear in the beginign of the track. Bass present and booming but not that attacking clear. Sound of the guitars are kind of mp3 sharp but without definitions. Feeling of 5.1 listening with instruments falling on you from unexpected sides.
Vaya Cod Dios, Sunny Days 24.96 = with new sound her voice lost velvet but sharp timbro. Maybe overal picture of sound became smooth. But for me boring... cause I personally listen to her voice. Plus compare that "..sunny days are over..." refrain with 2 men voices on 1.2.7 and 1.3.5 sound. In first case they make me smile.. in second - just make background.
Yo Yo Ma, Libertango (track 1) and Sur Regresso Al Amor (track 4) 16.44 = they became just funny background. Accordeon is not touching. Hard to split mood of upper and lower notes. On 4th track sound of scratching the string is not touching at all on 1.3.5.
Brian Bromberg Wood II, track 1, Caravan = that wish to split chanels and extra bass on 1.3.5 just make ground beef of the melody. You just sitting and trying to glue it all together of that noise falling on you...
Brian Bromberg Wood, track 4, Goodbye to my father = over bassy.. I can't enjoy the sharpness of the upper bass, just unpleasant vibration in my headphones. Piano sounds cheap and somewhere behind that overbassy cacophony.
Trondheim solistene divertimenti (24bit.192khz) = that one I liked the most on 1.3.5. But still like more compressed sound of 1.2.7 when the whole orchestra is infront of me sounding on me with dense front and not that funny felling like two close violins playing completely in two different ears. Like they are sitting in different sides from me and me in the middle. IMHO...
Jethro Tull, Stand Up, B2 Fat Man, 24.96 = funny feelingg. :) With 1.3.5 surround effect that track sounded funny like I listen to 5.1 soundtrack to LionKing. :)))) WIth accent on dialog of instruments talking to each other directly through me sitting in the center of them. Funny feeling. May be pleased with... On 1.2.7 there is no such "fun". But more texturized voice of the singer in front of me. Everyone should choose what he likes.
Norah Jones, A5 Come Away With Me, 24.96 = The voice became softer. Lost some sandy taste [but I am not sure it should be there]. Electric guitar sounds like "something like electric guitar" as to me.
AC DC, 2LPs rip 2008, track B1 Decibel and B7 Black Ice = on 1.2.7 sound has some velvet (I don't know why... maybe guitar tube amplifiers makes such a sound). On 1.3.5 I don't hear it any more. Sound is more dirty and mp3-dirty.
Okey. Enough this subjective delirium. I think I am too emotional with my disappointment with new sound. :(
Will go on for second upgrade and downgrade listening and post the comment if my feelingы would not change.
No.. it din't. So I hope iBasso would at least hear my ask to leave possibility to have this "more mono style sound as in 1.2.7" and still have possibility to have bugs fixed.
PS. I was listening in Beyerdynamic DT 990 Pro headphones (250 Ohm) and Grado 80i headphones. Grado with 1.3.5 just stopped sound at all. So track to track comparison I made with DT 990 Pro after having some feeling that something happened wrong with Grado.
PPS. And sorry for my English. :))))