We take great pride in our products, and go through great lengths to ensure consistency and quality. For that reason, this item was randomly selected for an additional step of Quality Assurance.
Try removing all other USB devices temporarily, and try each USB port on your computer one at a time to see which one works best in your setup. USB audio needs quite a bit of bandwidth, so for best results ensure your D3 is on a "High-Speed" bus and not a "Full-Speed" bus.
Your D3 will sound great out of the box and will get better over time. We do generally recommend playing music for 40 to 50 hours before doing any critical listening, though.
Although D3 may work just fine when connected to most USB hubs, this is not recommended as the data rate may not be fast enough for higher-resolution music. We therefore suggest you select a high-speed USB bus all by itself and don't use a USB port on your keyboard, for example.
The D3 is essentially a very high end external sound card. Its components and implementation make it more capable than what might be built in to a computer, not to mention the benefit of moving those sensitive components external to the potentially noisy interior of your computer. All of this means the signal your speakers receive will be clearer, with a lower noise-floor, and with a more pronounced dynamic range over your internal sound card.
It is normal for the D3 to be warm/hot to the touch as the outer case was designed to work as a heat-sink.
When connected via USB with a computer, the D3 acts like a USB sound-card. Because of this, once it's set as your default playback device, it should work with any application on your computer playing audio, and with any file format the software supports.
In the Foobar control panel, under Preferences->Output, set the buffer length to minimum. A few customers have mentioned that WASAPI mode is more stable when used under WinAmp, so try that as well.
If using a Mac, open the Audio MIDI Setup utility in Applications->Utilities, choose "Audioengine D3" under audio devices and check that the format is set to 96 and the bit depth is set to 24bit. Also a quick check is to simply observe the HD indicator on the D3 while music is playing. If the data rate of the digital signal being sent to the D3 is above 48K, then the HD indicator will be lit.
Yes, however, note that 24/96 HD digital audio pushes the limits of USB 1.1 speeds. Due to this it's highly recommended that you connect to a higher-speed USB 2.0 port.
The D3 is asynchronous, using dual clocking circuits to provide the greatest possible isolation between the system clock and the D3 DAC clock.
The primary volume adjustment for D3 is the system volume. This interacts directly with circuitry in the D3 to control volume at the output. You can also use the volume control of your media player, but this (if implemented incorrectly) can potentially affect the digital signal out from your computer, so is considered less desirable.