Sadhu

Will External Sound Card Improve Playback From Itunes And Other Online Music?

See very little on sound cards for the iMac. While I know that many users purchase sound cards for MacPro desktops, I am wondering if an external sound peripheral will improve the playback sound off my iMac Intel unit ... for sound OTHER THAN the tracks that I record or input INTO such a peripheral. In other words will I hear any improved audio quality if I purchase a good quality external sound card when listing back through my computer ... say through iTunes or through a high quality stream? I'm not concerned about the "value" of $ spent to the amount to improvement. I am simply interested to know if there will be an improvement in over all quality (say more defined bass, or tighther bass, or a more natural sounding midrange and high end?

Anyone have any comments on external sound cards and whether they improve the sound? If so, anyone have any suggestions on what products to look at? I eventually plan to buy a Mac Pro, so I don't mind spending more on good external card if they can be had as an external device for the mac.

Would appreciate any and all comments. Thanks in advance.

- Sadhu