Audioengine D1 DAC. It’s a pretty simple and minimal DAC with good sound quality.
It’s got a USB input on the rear, which also supplies data and power to the unit. There’s also an optical input as well as a pair of gold-plated stereo RCA plugs for output. If you’re using the optical input, then you need a USB power adapter to provide power to the unit, however if you’re using USB to connect to your computer, then it uses the power supplied over the USB bus. It doesn’t need drivers on OS X (confirmed) or Windows (not tested by me) – immediately after plugging it in, a new audio output source is available called Audioengine D1.
On the front of the unit is a rotary volume dial (with smooth rotation, no clicks or indentations), the power button with a white LED power indicator and a 3.5mm headphone jack.
With no headphones plugged in, audio is output to the stereo RCAs on the rear. Plugging in headphones mutes the RCA output and directs the audio to the headphones.
How does it sound?
It seems that it will be able to drive difficult headphones with no problems – my Sennheiser Momentums (which are a low-impedance headphone) only need a small amount of volume on the dial to achieve a comfortable listening volume. Sending the RCA output to my Audioengine A2‘s delivers clear sound and, at least through these speakers, I can’t hear anything negative about the sound it delivers.
Sound quality is very good – I’m of the opinion that a well-made amplifier should be a straight wire with gain, and this amp seems to do the job. There are no bass or treble controls, the sound seems to be a nice flat frequency response and the DAC adds no colouration to the sound.
The D1 comes with a nice microfibre bag for transporting the unit as well as short, a gold-plated USB cable (for what it’s worth). The cable wasn’t long enough for me to have the DAC where I wanted it to live, so I’m running it through a cable that came with a printer or a hard drive a while back. If you’re of the type who claims they can hear a difference between different USB cables, then this DAC is nowhere near expensive enough for your self-satisfaction.
Whilst I think my Mac Pro has a good DAC in it, the D1 definitely can play louder and will handle higher impedance headphones a lot better than the onboard sound. This DAC can possibly handle higher sample rates as well, I think the onboard DAC “only” does up to 96kHz whereas this one can do 192kHz. The D1 can also handle 16-bit and 24-bit audio which I believe the Mac Pro can do natively too.
The alternatives I was looking at before settling on this one were the Schitt Magni/Modi combo gear as well as an O2+ODAC combo. In the end, this one was good because it’s all in one compact box, and with the Massdrop discount, I got it for $150 including shipping to Australia.
TL;DR version. Good DAC. Sounds clean. Easy to use. Plays loud.