Last year we tested Fiio’s X3 Mark III DAP, a dedicated music player which was affordable and competent, but a little slow and clunky to use. This week, we have the privilege of trying Fiio’s top-of-the-line X7 Mark II, an Android-based DAP with swappable amp modules, 64 GB of onboard storage, two microSD slots, and the best audio hardware Fiio has to offer. It can’t compete with modern smartphone processors and displays, but we think the X7MkII is an awesome no-compromises portable audio device even at its relatively steep price.

The X7MkII is a beefy aluminum rectangle — it looks like a smartphone from an alternate timeline where we weren’t collectively obsessed with ‘thinness.’ It’s heavier than the iPhone X by 38 grams, but lighter than it looks. It appears to be designed for use in the left hand, with all the hardware controls located along an angled surface on one side of the device. Though a clear TPU case and red-stitched faux leather case are in the box (along with other accessories), the X7MkII really should be experienced directly in the hand — its sandblasted aluminum chassis, punctuated with polished chamfering, feels solid and substantial. There’s a ton of functionality just in the hardware — next to the X7MkII’s recessed power button is triple-function 3.5mm coaxial/optical/line out jack. On the right side are two microSD slots which allow for expansion of the onboard 64 GB of memory to an additional 512 GB. When connected to a Mac or PC, the X7MkII can use its microUSB port to function as a USB DAC (driver required for PC). The X7MkII’s dedicated buttons for track play/pause, forward/back, and volume have nice tactile feel, activate with positive clicks, and can be individually disabled if desired. In a market full of thin, rounded slabs of tech, we find the X7MkII’s hardware design distinct and refreshing; clearly Fiio has put significant thought into its design language. In our testing, we found that the X7MkII’s hardware buttons are sometimes more responsive than the touchscreen and, though not necessarily a problem, the volume wheel can feel a little ineffectual when scrolling through the X7MkII’s 120 volume steps.
The X7MkII features 2 GB of RAM and a Rockchip RK3188, 1.4 Ghz quad-core CPU running on highly-customized build of Android 5.1.1. Don’t expect current-generation smartphone performance from the X7MkII — in Android mode, this device is not as snappy as iOS 11 and Android O, and we did experience occasional unresponsiveness and stuttering. Still, we found the experience acceptable and certainly faster than other DAPs we’ve tried. The Google Play Store is included, and many apps run just fine on the X7MkII. Crucially, Spotify, Tidal, and Apple Music work with the X7MkII, though the latter had to be side-loaded and ran with frequent hiccups. The 3.97-inch, 800×480 touch display is a far cry from the OLED retina LCDs we stare at most of the day and has comparatively limited viewing angles and brightness. The X7MkII was clearly not designed to compete with modern smartphones in productivity or video but, as a DAP, it’s screen is more than adequate — text and album art look sharp, and we had no problems watching YouTube when we needed a break from music. Depending how you plan to use it, the X7MkII’s Android Mode may either be pure bonus functionality, or absolutely necessary for streaming; the good news is that it performs well in either case. Though Apple Music runs a little choppier than we would have liked, if you’re looking at a device with this much expandable storage, you probably own a large music library and, if you’re an iTunes user, there are apps like iSyncr on the Google Play store that will mostly replicate the iTunes sync experience.
Though its Android functionality is nice, the X7MkII performs best in its “Pure Music” mode. Activated through Android’s drop-down menu, Pure Music mode bypasses Android’s software decoders (which limit the sampling rate to 48 khz) to use only Fiio’s software and hardware, unlocking the X7MkII’s bit-perfect decoding abilities. Only the Fiio Music app is usable in this mode, but that’s okay — Fiio’s custom music player is very good. It’s packed with functionality, including a long list of “VIPER” EQ and DSP effects, and easy enough to navigate. Playlist creation from within the Fiio Music is better than that of the X3MkIII — at least now we have a touch screen — but still too manual and slow compared to modern alternatives. We found it best to organize our music in old-school album folders; we think most people in this device’s target market will do the same. We found the Fiio Music interface to be a bit cluttered at times, since folder and song titles don’t scroll, but generally it makes good use of the X7MkII’s limited screen real estate. In our testing, album art was sometimes slow to load, and lyrics were rarely downloaded as they were supposed to. In general, however, we like the Fiio Music player, even compared to our old Android favorite PowerAmp. For a company whose better known for its hardware than its software, Fiio Music is surprisingly good.
The X7MkII’s Pure Music Mode would mean nothing if it wasn’t talking to good hardware. Inside the X7MkII is the ESS Sabre ES9028 Pro, a high-end DAC chip usually found in desktop devices that will decode PCM up to 64bit/384kHz, DSD up to 256, DXD, ALAC, FLAC, and more. Fiio went with the desktop version of the ES9028 for some extra performance. This comes at a cost to battery life, however, as we got only about eight hours of life out of the X7MkII’s substantial 3800 mAh battery, and noticed that it can drain faster than expected on standby. Wi-Fi and Bluetooth 4.2 AptX are included in the X7MkII; luckily, Fiio seems to have eliminated EMI with generous use of internal shielding; we heard no noise even with sensitive IEMs.
Like Fiio’s Q5 DAC we recently reviewed, the X7MkII uses swappable amplifier modules, secured into the bottom of the device with T5 screws. Currently bundled with the unit is Fiio’s A3MA unit, which includes a 3.5mm single-ended jack capable of outputting 150 mW into 32 ohms and 2.5mm balanced jack rated for 400 mW into 32 ohms. After listening to the X7MkII for a few weeks, we found it to be exceedingly resolving and transparent — it sounds as good as a flagship device should. We might prefer the AM3B module, but the AM3A performed well with a variety of headphones, though we had to use high gain for cans like the Sony Z1R and Focal Elear. Of course, using high gain or the higher-output balanced connector will drain the X7MkII’s battery faster.
What does it mean for a device to be a “flagship?” Aside from big price tags, flagship devices should include the best technology and design that a manufacturer can offer — the finest expression of their engineering and design talent. The Fiio X7MkII doesn’t feature a 4K OLED display, the latest version of Android, or a Qualcomm 835, but we don’t think that matters. Even if it was practical for Fiio to add those to the X7MkII, it would most certainly have launched the price into the stratosphere. After living with this device for a few weeks, we think there are some improvements that could be made to its interface, but the X7MkII supports OTA updates and Fiio releases software updates all the time. Still, we think X7MkII justifies its price tag with the best audio hardware and software design that Fiio can offer. If you’re the type of audiophile who has a large library of hi-res tracks but also that is looking for a versatile DAP that makes no compromises on sound, we think the Fiio X7 Mark II is worth checking out.
Our Rating
Company and Price
Company: Fiio
Model: X7 Mark II
Price: $650