AudioQuest's DragonFly USB stick ($249) is a smart and simple solution that the company says makes great computer sound available to everyone.
Measuring 19mm x 12mm x 46mm (60mm including the USB connector), DragonFly is a portable and easy to use Digital-Audio Converter ("DAC") that plugs into a USB jack on a Mac or Windows PC, allowing the computer to improve sound through headphones, powered speakers, or a full-on audio rig.
DragonFly's full 2-volt output drives headphones and ear buds directly, with ease and clarity. DragonFly's versatility also means that it can drive powered desktop speakers or a power amplifier directly using its 64-position (computer-controlled) analog volume control. In 'fixed' output mode, DragonFly behaves like a traditional DAC or disc player, sending a line-level signal to a preamp or AV receiver. All that's required is a low-distortion cable with a 3.5mm plug on the DragonFly end, and a 3.5mm plug or stereo RCAs at the receiving end.
DragonFly employs an asynchronous USB audio data transfer protocol that dramatically reduces digital timing errors. DragonFly's dual clocks enable native resolution up to 24-bit/96kHz, and ensure that DragonFly doesn't rely on imperfect mathematical approximations in the process of reconstructing the signal, resulting in better "tracking" and better sound.
DragonFly plays all music files, from reconstructed MP3s and CD-standard 16-bit/44.1kHz, all the way up to 24-bit/192kHz: 24-bit/176.4kHz and 24-bit/192kHz high-resolution files are neatly halved by the source computer and processed as appropriate by DragonFly at 24-bits/88.2kHz or 24-bit/96kHz. A smart 5-color LED behind the translucent DragonFly logo indicates the resolution of the incoming signal, and which of the internal clocks is being used.