oh sorry :) , "Every rockbox newbie should see the information about .. " and so on.     Any stock original firmware doesn't have an implementation for the DF on DX50 platform. SU is based on the original firmware. So..   We already could see this through reading  MangoPlayer code...

Sorry, but an original firmware has "fake" DF option :) It doesn't work. It works only on DX90 platform. (MangoPlayer is "shared" between platforms)

See the information about pre-installed theme - http://themes.rockbox.org/index.php?themeid=2172&target=cowond2 For a start you only need return to the main menu, so you can touch the top of the screen OR use long-press PLAY button.     yep

so 1.1.0 and 1.2.0 have two differences: 1. rockbox PCM initialization params are same as Mango(it provides more sound details, the difference is subtle, same as iir_bandwidth for example. so I don't wanna discuss this with "direct-DAC" guys. it's annoying :) ). 2. rolloff_speed set to "slow"...

You shouldn't install anything if you have no idea how to install it correctly. Use RKBatchTool to restore an original firmware.

RSU 1.2.0 - https://mega.co.nz/#!GQ1gTZ5Q!VIBLPMAAM1Bbed3L12Us817muJZpMYqcSpWomlXQ3fY

latest rockbox build for RSU -> https://mega.co.nz/#!GMNUSTDR!AE5NhJqnqt_FoXGNWhLeFzizxfhZbRI-ttvc9dFNSYA applied most of patches described in this post (modern UI, battery level improvements, governor fix) + changes from rockbox "master" branch  added "IIR bandwidth" settings to "Sound...

RSU 1.1.0  - based on old 1.2.2 platform  - no problems with uninstalling   to update RSU: - you should extract update.img from the archive to the root of your SD card - update using recovery   don't forget to change the governor to "powersave" mode, as I mentioned before.

We can try to run rockbox with higher process/IO priorities(the stockk firmware applies them for MangoPlayer).

This is good, but guys from the rockbox thread do not hear the difference. So cholero is just trolling me.

I have a question for you, do you hear difference of the sound signature using different scaling governors?(pretty sure it's smth that related to hardware but it doesn't matter here)

as cholero mentioned here, the ArgelErx's cleanup ps4 + Cholero modern_ui rockbox build contains a little bug so I recommend, change governover to "powersave" if you use RSU. (Setting -> General Settings -> System -> Freq Scaling ..)   and some tip for a "rockbox newbie":  if you are...

totally agree :) for me, they are defined much better than with my DX50.

For me, it changes a sound signature in way like a fast/slow rolloff filter changes it or smth similar. Hidizs on => slow(details become more smoothed, so vocal is pushed forward little bit), off => fast

I'm not sure, but it sounds less interesting than version based on the old platform(I prefer use it for my own). I can PM you the latest version based on 1.2.2 but it has  problem with uninstalling.