In the world of digital audio, the Digital to Analog Converter, or DAC, is your interpreter. It takes gibberish, in this case 0s and 1s, and turns them into the analog waves that your brain identifies as “Paradise City.” Every computer with a sound card includes one of these little wonders but there is good reason to look at outboard units.
Sound cards are seldom designed with great audio in mind yet they are a required stop on the way to your speakers. Since every audio system is only as good as its weakest link, this is where music goes to get lobotomized.
Enter the external DAC. These miniature components are designed to accurately reproduce every nuance of the original recording. If you hook one up to your computer through a USB connection, and reset your computer to output audio though that USB port, you bypass that nasty old sound card and take a giant step toward high fidelity.
DACs used to be just for esoteric stereo systems but companies like Cambridge Audio are rolling out new units at reasonable prices. The DacMagic is their latest gadget and Computer Audiophile offers a quick review. One aspect targeted is upsampling, a process where the DAC looks at what it is being fed and tries to add some educated guesses at what may be missing. Digital recordings are like digital pictures; the images are created by dots, and the more there are the clearer the image. There are differing opinions about the value of this process, but when done right, I have heard upsampling give digitally recorded music a more realistic and fluid sound.
If you have gone through the trouble of recording your music in a lossless compression scheme, your next step is getting the translation right, and that means adding DAC to your vocabulary.