Well, I was not sure should I post this in "computer audio", "portable sources" or "portable headphone amps" sections ... as this new breed of devices most certainly belongs to all categories. Maybe it's time for a new forum sub-section?!
Anyway, I was visiting my parents in the USA for the holiday season and just for fun ordered Audioengine D3. It was on special $165 offer on Amazon (roughly 100£). Cost of the D3 in the UK was £165 so it was quite substantial saving. I was pretty much reserved what to expect as I already have Audioquest DragonFly 1.0 and FiiO E17. Let alone my Meier Audio Corda Jazz desktop amp. I was keen to have another "DF like" (and usb cable free) portable dac/amp as I was not quite happy with the DF 1.0. Also, I was drawn to the D3 AKM4396 DAC because of hugely positive experience with all devices where this DAC was integrated (namely Gigaport HD+ and Auzentech Meridian V2 audio interfaces).
Oh boy. I was completely unprepared for this device, and that was a good thing! Simply put, D3 is amazing (as per post title) and it's quote astonishing how they achieved this in such small package. Speaking of technology advances ... huh?! I may queue DF 1.0 and FiiO E17 on eBay for sale as they will be rarely used from now. What is evident during the very fist listen (even before break-in) is that D3 gives more body, more bass, more structure and more "air" to the music. Things are rarely congested. It doesn't add or take away anything. It's very neutral and subjectively maybe a bit on the dark side. If you have bright headphones (as in my case) it's really fantastic pairing. What's even more intriguing is that I may be free to say that sound signature does have that analog feel. Crazy it is. Stereo field is noticeably wide, lower end of the audio spectrum is really deep and not muddy/congested. Trebles are very enjoyable and smooth (hence my comment about the bright headphones pairing). Last couple of days I found myself reaching for D3 instead of Coda Jazz desktop amp for a quick high quality session and that's saying something!
D3 draws 5V/200mA from the USB port and what's interesting is that it doesn't lack any power ... even when driving my HD600. On the other hand, my low impedance "bass-reference-electronic-music" choice Ultrasone Pro 900 headphones are easily best portable pairing I've heard. Pro 900 are rated at only 40ohm but you really need quality amp to explore all that bass, mid bass, sub bass and not end up with bland, rumbled, distorted and not overly exciting, toe tapping bass. D3 did really fantastic job here and auditioning Pro 900 was really exciting adventure. I'm still sceptically looking and D3 and thinking how device of this size can produce such fully bodied bass. Things were looking spot-on on the IEM front too. My Sennheiser IE8 were superb and quite probably at their best with the D3. There was no hissing or distortion at all. D3 does have really black background and quite passages are really enjoyable. AKM4396 by itself is very low noise, low distortion D/A converter but D3 as a "platform" is completely noise free.
Metal injection molded (MIM) aluminum case does get hot and aluminum is really a good choice here, acting as one huge heat-sink. Speaking of aluminum, D3 design is fantastic. It does have that industrial, cold looking but professional look. It's very easy on the eye. No bling, flashy, unnecessary details and that's a good thing. I believe that Mac owners will be quite pleased with D3 design as it's quite "compatible". There is noticeable "click" when the device is powered on, probably from the relay controlled outputs?! It's first time I've heard this on the device of such form factor. It was a bit unnerving at first, as I thought that something is not right. If someone is interested to use D3 as super portable, high fidelity Android platform ... I can confirm that D3 is working with the USB Audio Player, (UAPR) straight from the USB OTG port (on my HTC One) and without the need for any additional power (banks). With D3 paired with UAPR sound quality is exceptional. I couldn't use it outside of the UAPR domain, but that's probably because of the 24bit output requirements, so not exactly sure if Android OS is to blame. All in all, it's really super portable set-up. Take a look:
It would be interesting to see how D3 is behaving when used as pre-amp or pure DAC source. That's still in the queue.
I believe that I already wrote a lot of words and you attention may drift away. Seriously, I'm more keen to hear from other users experiences. Goor or bad. It would be interesting to hear how D3 fairs against the HRT Microstreamer and Centrance DACport (as I was deciding between them and D3). There are not many discussions (or reviews) about D3 around, so I do feel a bit lonely here ... :-)