Audioengine is one of those rare companies that gets it right every time. Its desktop speakers excel in a very crowded, highly competitive field, and its digital converters are also strong performers.
Audioengine's latest release, the tiny USB-powered D3 digital converter, continues that tradition. The aluminum body feels nice and solid, and its digital converter can accept 24-bit/192KHz audio. The headphone amplifier works with low- and high-impedance headphones. Alternatively, you can run a set of powered desktop speakers, such as Audioengine A2+s or A5+s, directly from the D3's headphone jack.
The D3 was designed to work with Mac and PC computers, not phones. Included accessories are limited to a small padded carrying case and a 3.5mm-to-6.3mm headphone plug adaptor. Volume control is handled on your computer.
The very first pair of headphones I plugged into the D3, the Audeze LCD X, told me all I needed to know about the little guy's sound in a New York minute. The D3 is refined, dynamic, and highly transparent, and bass prowess is impressive. My old Sennheiser HD 580 headphones were next, and again the D3 didn't miss a beat. To put the D3's accomplishments in perspective I plugged the HD 580 directly into my Mac Mini's headphone jack. Detail and resolution took a hike, dynamic contrasts fell flat, and bass oomph slackened. Once you hear the difference you'll never want to plug headphones directly into a computer again.
I next compared the D3 with AudioQuest's DragonFly USB digital converter/headphone amp. The DragonFly is certainly decent, but the D3 sounds more transparent and effortless. After spending time with the D3, the DragonFly's sound seemed coarser and more opaque.
I really like the D3, but a better AC-powered and much larger headphone amp such as the $249 Schiit Asgard 2 is even more detailed, plays louder, and sounds more dynamically alive. It's not really a fair comparison; the D3 is seriously tiny, just 0.5 inch by 1.8 inches by 2.6 inches, so it's very portable, and it includes a digital converter. The Asgard 2 is a lot bigger and doesn't have a converter, it's just an amp. As always, better isn't the first consideration; get the one that best suits your needs. In a few weeks I'll be looking at another Mini-USB converter, the Cambridge Audio DAC Magic XS.
The Audioengine D3 sells for $189 direct from the company's Web site with a 30-day home trial, free ground shipping, and no sales tax. The D3 is also available from Audioengine's authorized dealers, including Amazon.