This is a review of FiiO Portable USB (OTG) DAC and Headphone Amp for Android Phones. FiiO Getting my Galaxy Note 2 almost a year ago played a significant role in how I changed my home entertainment system. It became my go-to music player, my preferred movie player, my game console, and just in general my pocket entertainment system. Delivery of sound is the key element of such system, and that's how my journey begin to find decent headphones. I'm still on that journey and have found a lot of great choices in different price categories. But this journey took a slightly different direction when I started to visit audiophile communities to learn more about proper setup to achieve a great sound. One thing I found mentioned over and over again - to complete the equation of sound perfection you need audio source + quality DAC / headphone amplifier + headphones. Considering I wanted to stick with my Note 2 as audio source and already have a selection of preferred IEM, at first I got a little discouraged looking at different DAC and headphone amp bricks because I didn't want to loose my portability. But at the end I found the best solution with the most flexible setup - FiiO E18. As someone who hasn't been previously exposed to the audiophile world, I couldn't even believe my eyes that something like this even existed. That is why I'm very excited to share with you my Note 2 best new companion - E18. I always start with a packaging of the product since it sets the tone before the review. The product was packaged in a very sturdy hard carton box with a modest design. It's actually very environmentally conscious without any unnecessary plastic. But once you open it up and start taking E18 out along with all the accessories, it becomes almost like a magic trick how much they packed inside of this little box. In my pictures below the only extra thing was a second set of usb/micro-usb cable included inside of packing envelope while the product box only had one of these cables. E18 itself was inside of a form fitting soft storage pouch, intended for DAC/amp only, no extra room for cables. Once you take E18 you can't help but notice how light weight it is. With dimensions of only 130mm x 66.2mm and thickness of 14.6mm and a weight of 162g, it's super compact and fits nicely in the palm of your hand. The brushed metal finish of the case takes it to the next level of quality and appeal. Every element, every port, and every control on E18 screams high quality. All 3.5mm ports are gold plated and precisely aligned with the edge of the enclosure. Micro-usb ports are also aligned and slightly recessed so that mating cable doesn't stick out too much. Gain, Bass, and DAC/CHG switches have a precise click action, and Playback (next, prev, play/pause) Controls have a nice tactile response. Speaking of playback controls, the left/right arrows actually point to next/prev instead of typical prev/next like everywhere else, but you get used to it really quickly especially since play/pause button is not in the middle. Of course, the big star of the controls is Volume analog knob, ALPS potentiometer with a symmetrical placement for easy access and very precise smooth rotation movement. The volume knob also works as power on switch when you turn it from "0" position where you get red led power indicator. The feel of turning analog knob to control your volume is priceless, puts you in full control, and makes you feel like you are dealing with a real audiophile equipment. In addition, you also get a large selection of high quality accessories. You get usb/micro-usb charging cable which can also be used to connect to your laptop/computer, a short right angle 3.5mm male to male adapter for headphone amp connection between smartphone headphone jack and E18 line in, you get a very rare pair of micro-usb to micro-usb OTG cables to connect DAC to your smartphone/host for external audio processing, you also get 3.5mm to S/PDIF adapter for coaxial output to give you an option of outboard connection, you get 2 sets of rubber bands in standard and large sizes to attach E18 to your smartphone or music player, you get a set of stick-on rubber feet if you choose to attach it to a device like a smartphone without a case and want to prevent scratching, you get a very nice Quick Guide with explanation of every port and control, and a warranty card with step by step explanation how to check authenticity of your product. As you have seen from description of accessories, this little portable device is a swiss army knife of multiple functionality. First of all, it has it's own built in battery with 3500 mAh capacity to power up internal components AND also to work as external battery charger. Believe it or not but you can actually juice up your smartphone or wireless headphones/speakers/accessories using E18. With a battery full charged, confirmed by 3 leds indicators corresponding to low/medium/high capacity, you get 25hr of continuous AMP use or 12hr of continuous USB DAC use. Keep in mind, when used as USB DAC through OTG cable where your smartphone becomes a Host - E18 will not drain your phones battery because it uses it's own built in power supply. This USB DAC functionality is the most useful and sound rewarding in my opinion. Also, in that configuration you no longer need to rely on transport control of your audio player and instead can use remote Playback controls on E18 to play/pause and skip next/prev. Of course, your smartphone need to support USB OTG. If it doesn't, no worries since you can use E18 as headphone amp by connecting 3.5mm output from headphone jack of your smart device or tablet to E18 input and plugging your headphones of choice to headphone output of E18. And if you want more, just connect E18 to your laptop as an external USB sound card where in addition to higher quality sound output you can use the same remote Playback buttons to control your Windows Media player. It's great to know how well E18 operates in different modes and it's compatibility with smart devices through OTG USB, but without rewarding sound performance all this will be negligible. I'm not going to pretend to be an experienced audiophile, and for a more detailed analysis of this USB DAC/AMP I would suggest taking a look at this review on head-fi by one of their highly reputable reviewers: [Preview] FiiO E18 Kunlun . But I still would like to add my impression from a perspective of audiophile in training. For my test I used Logitech UE900 and Etymotic HF2 headphones, and did a number of a/b comparison using both through headphone amp only path and USB DAC path. Using 3.5mm audio jumper between my Note 2 headphone output and E18 input with headphones connected to E18, I found the sound to be relative transparent to my ears, exactly what headphone amp supposed to do - to amplify the sound without coloring with distortion or it's own built in EQ. USB DAC config is my main use for this device. Note 2 recognized E18 as peripheral device attached to a host without any problems. I also found that while playing music both Note 2 headphone output and E18 headphone outputs were active which helped with a/b comparison. Basically Note 2 recognized E18 being connected to the phone so sound wasn't playing through speaker of my smartphone. Even with a Gain set to low and Bass boost turned off, you can hear right away a significant difference in sound delivery where everything sounded tighter, with more headroom and improved dynamics especially as you raise the volume, and the sound itself felt a bit smoother and warmer. Gain switch added a significant boost in volume (supposed to be a little over 6dB) and Bass boost was a pure delight especially with UE900 which have a more balanced sound. That Bass boost added a nice warm low frequency punch and made sound more "fun". I was very pleasantly surprised how clean that boost was applied, not like a low frequency shelf EQ boost but rather a precisely tuned parametric EQ boost of sub bass frequencies. Btw for my test I was using stock Android audio player since my favorite Neutron MP turned out to have some incompatibility issue with E18 processing (added distortion and roll off of high frequencies). UPDATE: seems after the latest v1.7.53 update of Neutron everything works great and developer (Neutron) mentioned it could have been due to my own setting of auto-gain which needed a reset. Overall, I know this is the first time I used USB DAC/AMP but in my opinion FiiO E18 set a VERY HIGH bar for any future comparison. I think the combination of portable size, the build quality with all the precision controls, the enhanced sound quality and well executed Bass boost, and other bonuses such as playback control and external battery functionality - ALL make this portable device as a must have item for anybody who appreciates the high-fidelity sound and wants to enhance their listening experience with a smartphone, a tablet, or a laptop/PC. Since I received this E18 model as a review unit, I've been told that price will be set closer to $160, and we will find out very soon once it gets listed on amazon. In my opinion - this is one fantastic value!!! Here are the pictures in order of unboxing, walkthrough, and setup and use with my Note 2.