Yes, i agree playing with EQ will degrade the sound quality a little.  I have the E18.  But i think it can't work with X5III, at least when i tested it with earlier firmware. 

Thanks a million!!!!! Yes, it works finally!!! 

is there anyway to EQ Spotify?  The EQ in Spotify does not have any effect.  Need EQ to tune down the treble on my Sony EX1000.  Viper Effect is usable in Fiio default music app and Poweramp EQ works too.  Just can't EQ Spotify. 

  I have this same problem on FW 1.1.0.  After installed with FW1.1.1., did a full factory reset, reinstall Spotify by Playstore (btw, no different if you install Spotify from Fiio market or Playstore), the problem seems gone.  The Spotify Premium downloaded songs will stay after power off...

opps... should be Sandisk 128GB Ultra Class 10.       Yes, by right it the downloaded songs should be still there after the app is updated, i have Spotify installed in my Note 3 too and never encounter this problem.    Yes, tried both - reinstalling the app and reset the Fiio to factory...

Yes, I suppose.. using version 1.1.0 (build number).  What microSD card you are using?  You Spotify will keep the downloaded songs after you update the app via Play Store?   I am very confirm mine will auto log out every time the app is updated.

Anyone using Spotify premium on Fiio X5 III?  I have some issues with it:   1.  After every app update, Spotify will auto log out and all downloaded songs are gone.  So i disable auto update in Play Store. 2.  After shut down and turn on again, Spotify seems like cannot link to the Sandisk...