For years now we have had a lot of hype over portable gear, much of it not living up to any expectations in comparison to dedicated home components. There is even a whole thread
dedicated to why. However, with the popularity of custom fit IEMs and vast improvements in digital technology, with portable DACs able to use an iDevice as a source, the possibility of having a truly hi-fidelity portable system is becoming all the more possible.
iBasso surprised everyone by coming out with an Android-running DAP (Digital Audio Player) using the famed Sabre ES9018 DA chip. Unlike iDevice-based solutions, this can play high-res music files up to 192/24 in most formats. While it is still very buggy in implementation, the hardware consists of a headphone amp that works remarkably well with all types of headphones -- orthodynamics through to high-impedance German models -- and even has a full-sized headphone socket.
Add to that a volume-controlled line out and both optical and S/PDIF digital outputs and the DX100 is incredibly versatile, being able to act as a good headphone amp, pre-amp, DAC and digital transport.
Comparing it as a DAC compared to my main DAC and as an amp compared to other amps, it isn't going to compete with them, but they cost 2-4x as much as the DX100. Though even the king of the (non-balanced) portables, the Triad Audio L3, is a better amp, that doubles the cost of the rig and makes it annoyingly bulky. I'll take the L3 along with me when I'm travelling overseas, but around town, being able to get a VERY satisfactory and enjoyable listen with the DX100, whether I'm using IEMs or full-sized headphones is incredibly handy.
I plugged the DX100 as a source and pre-amp into a Linn Klimax Twin power amp and surprised the dealer that was selling it with the results. While the limitations in the sound were apparent to me using my own music, such as the soundstage not being as wide and the instruments lacking that last bit of detail I get with my home DACs, that you can get something so capable in such a small package now is remarkable.
The amp side of things too is much the same story. Music sounds good with the LCD-3s plugged in, but my bigger, dedicated amps deliver more punch and detail. HIgh-impedance headphones such as the classic Sennheiser HD600s and 650s don't have as wide a soundstage with the DX100 as you get with a dedicated amp either, but even using sensitive IEMs and headphones with weird impedance issues (such as the new Sony XBA series), the result is consistently good.
Having both coax and digital optical outputs was a great bonus when testing digital equipment from other manufacturers, as having a couple of digital cables handy allowed me to listen to my own music using the DX100 as a transport when I was in Tokyo recently.
The main downsides to the device is the buggy software. One afternoon it started distorting, even when being used as a transport, requiring a reboot. The Android-based OS also requires third party software if you want to improve battery life and shut down unnecessary programs, such as those that would normally run phone features that don't exist on the device. Despite this, the battery will still drain down to zero within a full day even if the device is left idle.
Start-up is also slow, with the software taking some time to read the list of music if you've filled up the 64 GB of internal memory. Expansion in this case is limited to another 64 GB via an expensive micro-SD card, which needs to be formatted as FAT32.
If you want to play high-res files then you're limited to using the default music player, which, handily, recognises just about everything, though may not be able to read every type of file tag. When I tried last, it would read the tags on my FLAC files but not on my ALAC ones, reading the file name instead.
The music player itself comes with a standard set of options -- listing by artist, album, genre and the like and includes settings for up-sampling, random play (which isn't always so random) and a basic EQ.
Overall, it's a bit of a mixed bag: Excellent sound but annoying software, especially if you're used to using an iDevice from Apple. The firmware is being upgraded and the bugs fixed from time-to-time, so I wouldn't be surprised in a year if things were considerably better. Still, if you have some with patience for the software it makes for a very good one-box portable solution.