Thank you all for your great answers.
After reviewing everyone's answer and doing additional research, I've found that there are not many USB 2.0 DACs that support all of the available sampling rates. However, I think I'll have more options to choose if I get an S/PDIF connection. So I was searching for an affordable PCI sound card that supports various sampling rates and found ESI Maya44. Has anyone used ESI Maya44 sound card for S/PDIF connection? What's the major difference between USB to S/PDIF converter and PCI sound card with S/PDIF connector?
After reviewing everyone's answer and doing additional research, I've found that there are not many USB 2.0 DACs that support all of the available sampling rates. However, I think I'll have more options to choose if I get an S/PDIF connection. So I was searching for an affordable PCI sound card that supports various sampling rates and found ESI Maya44. Has anyone used ESI Maya44 sound card for S/PDIF connection? What's the major difference between USB to S/PDIF converter and PCI sound card with S/PDIF connector?