Connecting the Audioengine D3 cannot get easier. Just plug it into any USB port, and you are done! No cables/drivers/additional power supply required. Plug and play simplicity at its best.
The output is only via its 3.5mm socket. You can connect a pair of active speakers or even big headphones having a 6.3mm connector via the bundled 6.3mm – 3.5mm converter.
There is no support for 5.1 or any other input/output but the USP of the Audioengine D3 is its size and simplicity. It is far smaller than any of the DACs I have ever used in the past.
There are no buttons or switches on the body. There are 2 tiny led lights that inform you if the device is connected to a USB 2.0 port and above which allows it to play 24-bit files or to an older port where it can only play 16-bit files.
Audioengine claims the D3 can drive any headphone out there and while I was skeptical that such a small device had the juice to do that, the D3 proved me wrong. It could drive even my high impedance low sensitivity Yamaha Yh-100 with gusto. An amazing feat for such a small compact device!
Other than that the D3 is a well-made device. Build quality, fit and finish are all at a very high level. However, the device does get a bit hot after some use.