While the market is packed with add-in cards offering gaming and "multimedia" experiences, there have been very few that aspire to offer "audiophile" quality. There are very good reasons for this: the amount of rogue radio frequency present in a typical PC makes it quite difficult to turn out a hi-fi product. In an industry dedicated to making things faster and more powerful, not many companies are focused on making the computing experience "better".
But sound cards are sound cards, right? You wouldn't expect much difference between one and the other. It just works. Well, Creative would like to disagree with that.
Creative's E-mu division has a lot of experience in the pro audio field, and a lot of the technology produced there trickles down into Creative's high-end consumer audio cards, including this: the X-Fi Titanium HD.
While Auzentech and Asus have had "audiophile" cards on the market for some time, it's taken Creative quite a while to catch up. Like cards from those two manufacturers, the Titanium HD also caters to tweakers, with features like swappable op-amps enabling users to experiment with different sounds, but this isn't the most interesting thing about the card.
The Titanium HD is a high-end PCI Express x1 card, and includes features friendly to home cinemas and home recordists. Creative boasts that the Titanium has an audiophile DAC — a Burr-Brown PCM1794 according to Wikipedia — and is the first to include the THX TruStudio PC standard designed to "bring the same great audio experience found in live performances, films and recording studios to the PC". If you're looking to use this soundcard as part of a home theatre PC or as the basis for a home recording studio, then you'll be interested to know the card has two sets of dedicated stereo RCA inputs — one in and one out. The card also features an optical digital input and output, which are shared with RCA inputs. In addition, the card comes with a dedicated 3.5mm headphone jack and microphone.