The M17 is the flagship DAP from FiiO. But the M17 is not just any DAP, it is a true power monster! Legendary 2x 3W@32Ohm of the currently strongest DAP on the market drive any headphones, no matter how hard they are to drive. Whether this is really so I will try at the end of the review with my Susvara and Abyss 1266 TC.
It is delivered in two packages, one for the DAP including accessories and one for the docking station. The M17 comes pre-assembled with a screen protector. A replacement screen protector is included. Also a power supply for using the „Extended Over Ear mode“ and a USB-C cable. To protect the player, you can use the brown leather case, which is a perfect fit and has a clasp to prevent the DAP from sliding out. The back is equipped with metal air inlets through which the fan can do its work effortlessly in docking mode. The notches of the control buttons on the leather case are about 1mm apart, so you have to press with enough pressure to activate the desired function. With the included rubber pads, this distance is shortened and you have to exert much less pressure.
After opening, the brute size of the DAP initially blew me away a bit. I already know this from the iBasso DX320 Max Ti, but the M17 is still a bit longer and about as wide and thick as the iBasso. In terms of weight, both take nothing, about 600 grams. The workmanship of the CNC-milled aluminum housing is as the price tag suggests absolute top class. I also like the feel very much. Especially the large very handy volume control. Very good that FiiO has thought of a "Hold" switch that locks the buttons. Because if I put such a large DAP in my pocket, then inevitably sometimes accidentally pressed buttons. I would have liked to have this switch for my DX320 MAX Ti. The exterior lighting in the form of arrows in different colors also pleases me visually very well. Depending on the state (on, charging), these are permanently on or flashing. The color signals the bit rate of the played track. In terms of connections, everything is really on board here. Headphones and IEMs can be connected via 3.5mm, 2.5mm, 4.4mm and even 6.35mm. Dust protection sleeves are available for less needed connections like the 6.35mm output. The unbalanced 3.5mm connector as well as the 4.4mm balanced connector can function as headphone output as well as lineout. And of course, a "real" lineout is installed here, which does not pass through the amplifier section, but outputs the completely pure sound of the DAC. In addition to USB-C for charging/PC connection and a digital coax output, the M17 also has a 12V input for power supply operation where you can use the “Extended Over Ear mode“ and then up to 2x 3W@32Ohm with 27.7 Vp-P peak output voltage instead of 19.7 Vp-P are available. Since this also produces a lot of waste heat, the M17 can be operated on the docking station, which has an integrated fan that can be switched on with 2 speeds.
On the technical side, two ESS9038 DACs for digital-to-analog conversion and two THX AAA-788+ amplifiers work together to deliver the concentrated power in watts to the outputs. Of course, this requires a large battery, so FiiO gives the M17 a brute 9200mAh battery. Using USB-C and the QC 3.0/4.0 + PD 2.0/3.0 fast charging protocols, the battery charges in about 4.5 hours and then runs for an average of 9 hours. It can also be charged via the included 12V power adapter. The 5.99-inch display delivers a very bright and fantastic image.
In terms of software, FiiO uses Android 10. The whole thing can be operated very smoothly via a Snapdragon 660 with 4 GB of RAM. Internally, 64 GB of RAM are available, which can be expanded via a micro SD card. I would have liked a bit more internal storage here. FiiO's music player is very sophisticated and offers all necessary functionalities including EQ. Even a PEQ can be used, although it can only be added experimentally for now, since it is still in development. Other Android apps like the Neutron Player can of course also be installed and used.
A total of 5 gain levels are available. You can effortlessly fine tune very easy to drive IEMs (low gain) up to a Susvara in the last mode (Extended Over Ear Mode) via 12V power supply.
I tested the M17 with my two IEMs U4s as well as Foure Blanc from 64 Audio. In addition a Focal Utopia 2022 and of course the two hard to drive bolides, the Hifiman Susvara and Abyss 1266 TC. I tested the Lineout on my Niimbus US4 and compared it with the Topping D90SE, which, as you know, uses the same DAC from ESS.
The M17 sounds simply fantastic. It is totally balanced and here everything fits from bass to treble. This is another device where you don't have to crystallize individual components in the sound, but the whole thing is so coherent that you don't have to worry during playback whether the bass is very pronounced and detailed and the resolution is only average. No, every link in the chain fits together perfectly.
The power with which my IEMs and headphones are driven, you can just hear. Total control down to the lowest registers and really loud, if you like it, without losing control. The first time I used the M17 with the Utopia 2022, the planned minutes turned into 2 hours of listening.
Tonally, we have to do here with a neutral tuning that covers up absolutely nothing in the mids and treble and makes real steam in the lower range. Here, the M17 plays together with the DX320 MAX Ti in a league of its own. One, M17 with more focus on the low bass, the other MAX with more focus on detail from sub to midbass. Switching back and forth I can't decide who the winner is. It's different as so often, but not better or worse. The Impact in bass with the Utopia 2022 and Fourte Blanc is really amazing with rock and metal.
The ESS DACs are always said to have a very bright presentation. That is not the case here at all. The M17 sounds very clean and illuminates the treble range very widely, but at no time sounds harsh or obtrusive. To test this, I like to use my U4s, which can sometimes sound a bit sibilant with sources that are too bright. But this is not the case here. Absolutely brilliant treble reproduction and resolution.
Since the M17 plays sonically in places far above many other DAPs I compared it only with the DX320 MAX Ti. Both play as I have described very neutral and balanced. The differences are due to the DAC used and you can hear that most in the midrange. Neither discolors, each plays for itself an interpretation that leaves nothing to be desired. The MAX with a bit more fullness in the mids, the M17 a bit more stripped down and detached. The instrument separation succeeds both fulminant with the larger stage representation on the part of the MAX.
Excited I connected the lineout of the M17 with my Niimbus and then compared against the Topping D90SE and here both are tonally very close. The development of DAPs is currently so far advanced that these are now absolutely recommendable as source for stationary amps. Provided that they also have a "real" lineout like the M17 or MAX.
Even more exciting was my test in docking mode with connected power supply and “Extended Over Ear Mode“. Incredibly, I can enjoy my Hifiman Susvara and Abyss 1266 TC from now on on the terrace where a power outlet is available in a quality that seemed almost impossible before. No DAP that I know of can drive these two headphones as well as the M17. The distance to my stationary amp, the Niimbus US4 is of course still there in direct comparison, but nowhere near as great as before.
In conclusion, I can say that the M17 is a true powerhouse at the highest technical level. For those who not only own IEMs and easily driven headphones and would like to drive everything with only one device, which you can operate portable and stationary (for full power), I can recommend the M17.
