As there are so many repeat questions in the DX100 thread, yet the thread is growing at an amazing rate, burying the answers, this F.A.Q. on the DX100 has been created.
The latest firmware is available from here  v1.4.2 (ZIP compressed file).
Previous firmware here -- v1.3.7 (ZIP compressed file).
Alternatively, since tends to be down from time to time, member dhobsd keeps a directory containing all release versions here (TX, US). You can also find v.1.2.7 from member Sorensiim, (compressed zip hereuncompressed image file here, EU).
Download the file, uncompress it (if you downloaded the RAR or ZIP) and copy it to the internal storage on the DX100. The file must be placed in the root of the onboard storage, next to the folders, like here (Windows 7):
Once the file has been transferred, disconnect the DX100 following the usual precautions: First "eject" it from the computer, then turn off USB storage on the DX100. Once it has disconnected, a media scan is automatically initiated and the DX100 will report that it has found a new firmware file and ask you if you want to update the firmware. Make sure you have connected the power supply while doing this. From here, the DX100 will take care of the rest and it will take some time - just let it do its thing. Interrupting the update (or the DX100 running out of battery) will brick your player, turning it into an $829 paperweight. After the update it will shut down and display the usual "Charging" symbol, the blue lightning. At this point you can power up your DX100 and enjoy your new firmware. 

A note about the 1.1.6 firmware:
Originally Posted by Currawong
For some people, after updating, the music player stops listing any of the music. Downgrading and upgrading the firmware again fixes this. Thanks to turokrocks for discovering this.

Updating to at least firmware v.1.1.7  is also a good idea since it is considered a much more stable release.
Main functions:
The volume controls only work when the screen is un-locked.
The line out level is controlled by the volume, but not affected by the gain switch.
Due to its powerful headphone amp and low impedance headphone output, the DX100 is capable of accommodating from low impedance & very sensitive IEM's to high impedance full-size headphones while maintaining a linear frequency response.
Originally Posted by Currawong
The headphone output works well even with LCD-2s and LCD-3s, though not as well as a good dedicated amp will with those headphones.

iBasso mentions that it only supports up to 32GB µSDHC cards, but it also supports 64GB µSDXC's after formatting those to FAT32.
Originally Posted by Omphalopsychite
While Windows 7 doesn't provide an option to format to FAT32, this freeware does.

Originally Posted by dsalomon
Supports 128GB SDXC (after being formatted to FAT32) using a µSDXC to SDXC extender/converter (see this post for details).

Originally Posted by turokrocks
External USB drives mount perfectly on the DX100; they will just suck the power of the DX100 quickly.

The DX100 has two headphone outputs, one 1/8" (3.5mm) and one 1/4" (6.3mm). A 1/8" (3.5mm) analog lineout is also present, as are two digital outputs (Coax + Mini-toslink) for use with an external DAC. All outputs are active at the same time, so the DX100 can be used as a source for no less than 5 components at the same time. 
Please take note, power requirement of your Headphones and IEM's are very different. If you plug your IEM's while listening to a Headphone, esp. with high ohms/power requirement, you will probably destroy your IEM's due to exceeding their power handling threshold.
General advices:
As you get hold of your DX100, and after having loaded it and maybe also one or more µSD's full of your favourite music, being impatient in wanting to listen to said favourite music straight off is not a good plan: the player needs to index the database of the loaded musical library, and this process takes a certain amount of time. Wanting to hit play immediately will result in much frustration, and it might even be a good idea to do a factory reset before anything else. Checking in Running Services under Settings that the scanning of the external Media is finished (said app Media disappears from the list) if a µSD is inserted can also give some useful indication.
For those who are using sensitive IEM's & CIEM's with their DX100 and keep unplugging and plugging them back in on start-up or on wake-up after standby to avoid the loud popping sound that can be hurtful to both their ears and their sensitive IEM's, it can be a good idea to use a ø1/4" to ø1/8" (ø6.3mm to ø3.5mm) adapter like this one in the ø1/4" (ø6.3mm) headphone output and save wear & tear on the DAP's ø1/8" (ø3.5mm) headphone output.
Pertinent impressions and reported issues with older firmware versions:
Alright, I've had my DX100 for 5 days now; some observations I made from my experience using it during that period of time; I'd like to see if others can confirm if they experience the same.
1.   Only MP3 tags can be read, FLAC/ALAC etc can be played but the tags are ignored and it uses folder name for the album name and the filename for the track name etc.
2.   Clicks/pops etc when you turn on the player, turn on/off the screen are normal.
3.   Clicks/pops when you play songs are not normal and I only get these after I have installed any apps that access the memory for whatever reason even if I close them eg. Go Launcher Ex or Super Manager etc.  The pops/clicks disappear once I uninstall them and reboot the DX100.  Right now, I turn off WiFi, syncing, Bluetooth, etc. and only have 2 apps installed, APK to be able to kill any processes and the album cover app to put covers for my FLAC/ALAC files.
      I have seen mention of using Launcher Ex and locking all apps but this never worked to prevent cracks/pops and any 3rd party apps that access the file system will cause these cracks/pops as I play my songs so I resorted to just not installing them in the 1st place.
4.   With no music playing and the screen turned off, I can hear cracks/pops every min or so as it sounds like the audio output is tuned on/off every now and then.  I see the same thing when using my Sony WM-Z1070 android player so maybe is an Android thing.
5.   Tracks will be played randomly no matter how I play them from albums etc. After a reboot of the DX100, it works normally if I go back in and select an album again.

Originally Posted by Currawong
I found that with 1000 tracks loaded, on start-up, the music app would freeze for a long time. If I first click on the "lightning" button on one of the Go Launcher widgets, which nukes unnecessary background processes, the issue is fixed. As well, the unit no longer gets warm. The Go Launcher Ex reports on a full charge 44 minutes remaining, but I've left the unit on all day without a huge amount of battery drain.

More on the loud pop when the unit is turned on or waking-up from stand-by:
Originally Posted by Mimouille 

The answer I got from iBasso a long time ago to a query of mine on the topic was:
Originally Posted by iBasso
The DX100 has lot of large capacitors, therefore it has the pop noise. It is the sound of the current impulse flowing through the capacitors. If we removed all of those large capacitors, then the DX100 wouldn't have the pop noise, but would it still be a Hi-Fi player without those large capacitors?

Android Apps
As the DX100 is powered by Android 2.3 (Gingerbread) with full access to the Android Market (Now called "Google Play"), you are able to install a host of applications on it.
PowerAmp is a highly recommended app for music playback. Looks nicer than the stock player, but does not support high-resolution files.
No Lock does exactly what the name implies - disables the screen lock for faster access to the controls; this app is redundant since the latest DX100 firmware updates, v.1.1.0 to v.1.4.2: pressing the volume or power-on/off physical buttons re-activates the touch-screen
Go Launcher Ex provides an excellent user interface, others prefer ADW Launcher for a more minimalist approach.
Cover Art Grabber or Cover Art Downloader help add album art if it's missing, you'll need a WiFi connection if you want the apps to get art from the net.
Copying music to the DX100:
When you connect the DX100 to your computer via a USB cable it will appear as a drive in (My) Computer on Windows or on the Desktop in Mac OS X. Create a folder/directory named "Music" in there and copy your music folders/directories into that.
Nota Bene:
Originally Posted by Currawong
Be careful NOT to copy any music into the "sdcard" directory, as that is the mount point for the SD card in the Android file system and any music in there wont appear if an SD card is inserted.

Mac OS X iTunes syncing:
Originally Posted by Currawong
Missing Sync for Android 2.0: Works, but you must tell it that the device allows playback of ALAC and AIF files so it will copy them. To do this, double-click on the Music plug-in and then on Advanced Options (bottom left). Add the file extensions required, eg: M4A, FLAC, WAV, AIF, AIFF. Since the latest firmware for the DX100 supports tagged Apple Lossless and presumably AIFF files, you can sync it all straight without issues. Not sure if they've fixed this, but it might be worth checking that track numbers start with a leading zero to ensure the playback order is correct, eg: 01, 02 etc. instead of 1, 2... You don't need to set up the Missing Sync software on the DX100 unless you want to sync via wireless or Bluetooth (both of which have crappy reception and will drain you battery) as The Missing Sync will copy files fine to either the DX100 or a Micro SD card mounted over USB.
Software not working last I checked:
Songbird: Doesn't recognise the DX100's USB Storage mode.
Clementine: Renames the files when it copies them, so, despite the fact that it can import playlists exported from iTunes, those playlists can't be used, even after changing the file paths in the file. Artist and track name are also reversed in the software.
TunesSync: Skips ALAC files (even though they can be played). 
Winamp: Errors on trying to read the iTunes library. Hasn't been updated in a while, which might be the reason why.

DX100 Streaming capability

If you install a UPnP/DLNA streaming app (for example BubbleUPnP) you can stream music from your PC to the DX100. Once installed you point the DX100 to your media server of choice:
Foobar (using foo_upnp)
Logitech Media Server
Windows Media server

You can then play media from that server - either on the DX100 itself or to various other renderers you may have connected to your network. The Playback Stream Capture option allows you to use your PC to control playback on the DX100 - there is a slight delay - for example after hitting pause in Foobar it takes a second for the music on the DX100 to stop playing. Because it's Android based it's currently limited to 44/16 (it seems to stream 192/24 but it doesn't play).
Rooting and Optimizing the DX100
Rooting and optimizing the DX100
First I'll have to warn you: If you root the DX100 you'll be able to turn your excellent DAP into an $829 paperweight. Yes, this could happen with one wrong push of a button.
You need to install the Gingerbreak APK. Install the app, open it, read the instructions carefully and let it do its thing. When mine was finished, the DX100 shut down and I had to use the reset button (tricky to hit, that thing is!) to bring it back to life. After that, I had root access on my DX100. Once you have that, update SuperUser from the Play store and install the full (=Paid) version of Titanium Backup. This will allow you to "freeze" apps, so that they disappear completely, as far as the OS is concerned, but can be easily re-enabled from within Titanium Backup. But here's the tricky bit: Freeze the wrong service and you might not be able to access TB again to unfreeze. This is where you might brick your DAP if you're not careful ONLY to freeze apps that you are absolutely certain about. Make sure you install another launcher - I prefer ADW Launcher to Go Launcher as I find Go to be a little bloated with stuff and gadgets I don't need on my DAP. The launcher is your entire user interface, it's the steering wheel, pedals and gear knob. You'll want to have one.
I assume no responsibility for this. If you break your DX100, it's not my fault. 
Right, you have been warned: The apk is here
First: Do a full backup in Titanium Backup
Stuff I have frozen and/or uninstalled using TB:
Search 1.1 (does not disable searching in the Music app)
Search Application Provider
Animated backgrounds
Bluetooth sharing
Email 2.3
Ethernet Settings (Not needed since the DX100 doesn't have a RJ45 connector...)
Google Calendar Sync (I use my phone for calendar stuff)
Calendar 2.3.1
Calendar Storage
Pico TTS (Text To Speak service. Useful for GPS navigation. If the device had GPS)
Start screen tips
TTS Service 2.3.1 
Animated background chooser
VPN Services
...something labeled in Chinese. The chinese keyboard I assume.
ES File Explorer (Only because I prefer Root Explorer, you might want to keep ES)
That shoddy calendar app Ibasso for some unknown reason saw fit to include.
Two things I just want to add:
1) If the above instructions are not detailed enough for you, you might want to get a friend to help you or avoid rooting your DX100 entirely. I mean no disrespect and I'm sorry if I offend anyone, but if you can't swim then keep your ass out of the pool.
2) A head-fi'er actually asked me if a cracked version of Titanium Backup would work. That's just low. $829 DAP and you couldn't find $5 to support the developer of one of the best Android apps ever made? $cumb@g. Go read this:


Getting the best from the battery
Keep wifi and bluetooth switched off unless you need them
Disable "Background data" option - this can be found in the "Accounts & sync settings" section from the Settings page.
The Energizer XP8000 backup battery will happily charge the DX100, a full charge takes 3-4 hours.
The DX100 uses 2pcs 2000mah battery in series, to reach 8.4V
Links to reviews
Setting up DX100 to use Playlists Via MediaMonkey:
Originally Posted by lee730 

Connect your DX100 to the machine and start up MediaMonkey. You wanna configure the settings in MediaMonkey first. Configure both internal and external storage. It may take a little while to scan if you got a crap load of music like I do.

Click on the "ibasso DX100 Internal" listed on the left hand side of MediaMonkey. Select "Options." Under "Destination" copy and paste: \Music\\ under "Sync Music files." I also did the same thing under "Classical music files" just in case. Make sure to click "Apply" or it won't save. Do the same for the below directions or you'll end up kicking yourself

If you are syncing FLAC files I recommend you set up a custom preset under "Auto conversion". Its also listed in the Options tab I had mentioned earlier. Under You'll find a list of options. Next to "When the format is:" Change it to "FLAC." Now under "If any of the following conditions are true:", "For Audio bitrate" change it to "Above" and change "input" to "128 kbps." Further below change "To the following format:" to "FLAC." Customize the compressions if you wish. I recommend 6 at the most. So that would be the third to the last line then select OK.

Now under "auto sync" select the playlists that you imported. If you haven't added the playlists you can manually do it from "File/Add /Rescan Folders" and point it to where you have your playlists stored. It will add them to "Imported playlists" in MediaMonkey. Whichever playlists you select will sync once you press the auto sync button. Just check-mark the desired playlists you want to be synced and apply. Then hit the Auto-Sync button. That should be it. Happy listening. (One more thing guys). Under Option/Playlists be sure to check-mark Sync Playlists, Library Playlists, Artists, Albums, Location. Also checkmark Use Unicode (UTF-8 Encoding) for M3u playlists. The 4th picture in my below posts will show you exactly what I mean.

Once you have synced everything try and have a look at both your playlists and music folder on your DX100. You'll notice they are all named the same thing. This makes it very easy to edit and add onto your DX100 and keep everything organized. When you want to add on you just update the playlist in MediaMonkey and apply the changes to the playlist (overwrite it). At which point I recommend you clear the playlists from MediaMonkey library and rescan them. This should take about 10 secs to do and will reflect the changes you made. If you intend to not add a lot you can just copy and past the new music over to the intended folder and then delete the old playlist from your DX100 and copy the updated playlist over to the DX100 Playlist folder (should be the same playlist but with the new music you added to it as well). Once you disconnect your DX100 it will reflect the same playlists but with your new music files added and in the order you put them in. Happy listening.


The following illustrations below will guide you in setting up MediaMonkey to use playlists on your DX100. A picture is worth a thousand words and may be even easier to follow than my above directions.

Using mp3 tag to properly clean and edit your tags for both DX100 and Hisound Products:
The directions below are in large part dealing with the Hisound products but you can use them as well to get your DX100 to properly show tags and music in general. I do not recommend having more than 1 type of tag embedded into the file. I do use ID3V2 though on mp3 files on the DX100 where I want the album art to show up. So you can change things accordingly regarding that. However if you are using FLAC files I recommend removing all tags besides the (FLAC) tag. You can embed your album art as well to have the art show up on the DX100. If you want all this album art to show up without having to download album art grabber for 1.1.7 you can revert to 1.2.3. Do a factory reset. Select play all albums. Put the device on shuffle and let it sit for a while. Once you see all the album art has showed up via the album art view (small album art view) you know it has all been cashed in memory. You can then revert back to 1.1.7 and this time don't do a factory reset. All your album art will show up an you have the great sound of 1.1.7.
Use mp3 tag to tag your files
Step 1: Download Mp3tag
Step 2: Go into Tool/Options. Under Tags you have Mpeg and Ape, Mpc... You want to make sure Read is check marked for both Mpeg and Ape. For "Write" make sure only ID3v1 is checked (for both Mpeg and Ape). Under "Remove" check ID3v2 and APE. If you have APE files it is recommended not to use them as those files work slow on the Studio V. Convert them over to FLAC instead. Then select Ok to apply changes in options.
Step 3: Drag and drop your files you wish to apply this to. I recommend doing this from your Hard drive if you wanna save time as the changes can be applied much faster this way. Then again reloading your Studio V and SD card could take the same amount of time. It's really only a 1 time process thing so it's not a big deal. Anyways once you've dragged and dropped the files you wish to apply these changes to, highlight all the files or click on the "Filename" area and then press Ctrl + A. Now Select Remove tags or that big X just below "Edit" (top left corner area of Mp3tag). Once all tags have been removed simply click "undo Changes" located next to "Remove tags". This will restore all your tags on the fly except for v3.2 tags. To be on the safe side you can also select "Save" to ensure these changes stay. This is located to the left of "Remove tags".
Step 4: I also recommend cleaning up your tags. If you have junk such as "Comment", "Composer", "Disc number", and "embedded album art" this will all contribute to slowing down your device. I'll tell you how to remove all this on the fly. Again press Ctrl + A to hilight all your files. Then under Comment/Composer/Disc number select <blank> for them all. Once you've completed this now right click on the album art area (located below disc number). Select "Remove Cover". Now all you have to do now is Select "Save" and it will apply all these changes for you (just make sure all your files are constantly hilighted when doing all the above directions in order to apply them).
Problem should be solved and your player should be rather responsive on start up. Mine takes roughly 16 seconds (correction) to load from the SD card and on-board. I did a countdown myself and it's 16 seconds for my unit (20 seconds if you start the countdown from when you first power the unit on).
You can also configure mp3 tags buttons to do auto changes on the fly for you.
Under the "Tools" tab you'll notice 4 buttons with an arrow pointing to the right.
For the first one click it and copy and paste this: %track% %title%
Second one: % track% %title%
Now look further to the right and you'll notice one of these buttons marked as 1 2 on a page (red numbers). Click that and input this:
Begin at tracknumber: 1
Check-mark: Leading zeros for tracknumbers (01,02). This will allow your tracks to be automatically numbered from 01, 02, 03, 04 etc. Just make sure they are in the correct order starting from 1,2,3,4 and it will automatically rename them correctly to 01, 02, 03, 04. I've noticed issues if you don't have it done this way. Basically when changing your tracks be sure to do this part first. Then you can refer to those other buttons I had mentioned earlier. As long as your Titles of your tags are correct it will combine that along with the 01, 02, 03 and rename your Filename according to that format. Basically saving you a lot of time and making this process quite easy.

Enjoy folks! :)