What format is your music stored in on your PC? It could also be the settings on your PC depending on the operating system you are using (Windows XP, Vista, 7, etc...). I would suggest going to Computer Audiophile (www.computeraudiophile.com) and check out many of the articles written on the correct PC settings you need to output but perfect resolution from your PC. Also make sure you are using one of the lossless resolution formats for any CDs you have ripped to your PC. If you are using mp3 or any other lossy format, it will not sound as good obviously versus your CDs.